IEEE https://store.theartofservice.com/itil-2011-foundation-complete-certification-kit-fourth-edition-study-guide-ebook-and-online-course.html.

C99 IEEE 754 floating point support
A major feature of C99 is its numerics support, and in particular its support for access to the features of IEEE (also known as IEC 60559) floating point hardware present in the vast majority of modern processors (defined in "Annex F IEC floating-point arithmetic"). Platforms without IEEE 754 hardware can also implement it in software.

float is defined as IEEE 754 single precision, double is defined as double precision, and long double is defined as IEEE 754 extended precision or some form of quad precision where available (e.g., Intel 80 bit double extended precision on x86 or x86-64 platforms), else double precision. Previously, all C90 floating operations were defined to occur in double-precision, with subsequent rounding to single precision, to store results, where necessary.

arithmetic operations and functions are correctly rounded as defined by IEEE 754.

expression evaluation is defined to be performed in one of three well-defined methods, indicating whether floating point variables are first promoted to a more precise format in expressions: FLT_EVAL_METHOD == 2 indicates that all internal intermediate computations are performed by default at high precision (long double) where available (e.g., 80 bit double extended); FLT_EVAL_METHOD == 1 performs all internal intermediate expressions in double precision (unless an operand is long double); FLT_EVAL_METHOD == 0 specifies each operation is evaluated only at the precision of the widest operand of each operator

FLT_EVAL_METHOD == 2 is the safest default as it limits the risk of rounding errors affecting numerically unstable expressions (see IEEE 754 design rationale) and is the designed default method for x87 hardware; FLT_EVAL_METHOD == 1 was the default evaluation method originally used in K&R C, which promoted all floats to double in expressions; and FLT_EVAL_METHOD == 0 is also commonly used and specifies a strict "evaluate to type" of the operands

4G IEEE 802.16m or WirelessMAN-Advanced
The IEEE m or WirelessMAN-Advanced evolution of e is under development, with the objective to fulfill the IMT-Advanced criteria of 1 Gbit/s for stationary reception and 100 Mbit/s for mobile reception.

4G Mobile WiMAX (IEEE e) The Mobile WiMAX (IEEE e-2005) mobile wireless broadband access (MWBA) standard (also known as WiBro in South Korea) is sometimes branded 4G, and offers peak data rates of 128 Mbit/s downlink and 56 Mbit/s uplink over 20 MHz wide channels.

4G Mobile WiMAX (IEEE e) In June 2006, the world's first commercial mobile WiMAX service was opened by KT in Seoul, South Korea.

4G Mobile WiMAX (IEEE e) Sprint has begun using Mobile WiMAX, as of 29 September 2008, branding it as a "4G" network even though the current version does not fulfil the IMT Advanced requirements on 4G systems.

4G Mobile WiMAX (IEEE e) In Russia, Belarus and Nicaragua WiMax broadband internet access is offered by a Russian company Scartel, and is also branded 4G, Yota.

Peak upload 56 Mbit/s 4G Mobile WiMAX (IEEE 802.16e)

4G iBurst and MBWA (IEEE 802.20) systems
The iBurst system (or HC-SDMA, High Capacity Spatial Division Multiple Access) was at an early stage considered to be a 4G predecessor. It was later further developed into the Mobile Broadband Wireless Access (MBWA) system, also known as IEEE

Cable modem IEEE 802.3b (10BROAD36)
(In real-world systems, higher-order signal components become indistinguishable from background noise.) In the market 10BROAD36 equipment was not developed by many vendors nor deployed in many user networks as compared to equipment for IEEE 802.3/Ethernet baseband standards such as 10BASE5 (1983), 10BASE2 (1985), 10BASE-T (1990), etc.

Cable modem IEEE 802.7 The IEEE 802 Committee also specified a broadband CATV digital networking standard in 1989 with However, like 10BROAD36, saw little commercial success.

Cable modem IEEE Azzam was Secretary of the IEEE Working Group, and his book, High-Speed Cable Modems, describes many of the proposals submitted to

Bluetooth Bluetooth vs. Wi-Fi (IEEE 802.11)
Bluetooth and Wi-Fi (the brand name for products using IEEE standards) have some similar applications: setting up networks, printing, or transferring files

Bluetooth Bluetooth vs. Wi-Fi (IEEE 802.11)
Wi-Fi is a wireless version of a common wired Ethernet network, and requires configuration to set up shared resources, transmit files, and to set up audio links (for example, headsets and hands-free )

Ken Thompson - IEEE Richard W. Hamming Medal
In 1990, both Thompson and Dennis Ritchie received the IEEE Richard W. Hamming Medal from the Institute of Electrical and Electronics Engineers (IEEE), "for the origination of the UNIX Operating System and the C programming language".

Passive optical network - IEEE
The upstream channel can support simultaneous operation of IEEE 802.3av and 1 Gbit/s 802.3ah simultaneously on a single shared (1,310 nm) channel.

Passive optical network - IEEE
There are currently over 40 million installed EPON ports making it the most widely deployed PON technology globally. EPON is also the foundation for cable operators’ business services as part of the DOCSIS Provisioning of EPON (DPoE) specifications.

RuBee - The IEEE 1902.1 protocol details
However, IEEE will be used in many sensor network applications, requiring this physical layer standard in order to establish interoperability between manufacturers

ISO/IEEE 11073 CEN ISO/IEEE Health informatics - Medical / health device communication standards enable communication between medical, health care and wellness devices and with external computer systems. They provide automatic and detailed electronic data capture of client-related and vital signs information, and of device operational data.

ISO/IEEE Goals Real-time plug-and-play interoperability for citizen-related medical, healthcare and wellness devices;

ISO/IEEE Goals Efficient exchange of care device data, acquired at the point-of-care, in all care environments.

ISO/IEEE Goals “Real-time” means that data from multiple devices can be retrieved, time correlated, and displayed or processed in fractions of a second.

ISO/IEEE Goals “Plug-and-play” means that all a user has to do is make the connection – the systems automatically detect, configure, and communicate without any other human interaction

ISO/IEEE Goals “Efficient exchange of care device data” means that information that is captured at the point-of-care (e.g., personal vital signs data) can be archived, retrieved, and processed by many different types of applications without extensive software and equipment support, and without needless loss of information.

ISO/IEEE Goals The standards are targeted at personal health and fitness devices (such as glucose monitors, pulse oximeters, weighing scales, medication dispensers and activity monitors) and at continuing and acute care devices (such as pulse oximeters, ventilators and infusion pumps). They comprise a family of standards that can be layered together to provide connectivity optimized for the specific devices being interfaced. There are four main partitions to the standards:

ISO/IEEE Goals Device data, including a nomenclature, or terminology, optimized for vital signs information representation based on an object-oriented data model, and device specialisations;

ISO/IEEE Problems In the absence of standards for these devices, (a) data is captured either manually or at considerable expense (using specialized equipment), or (b) it is not captured at all, which is most often the case.

ISO/IEEE Problems Manually captured data is labour intensive, recorded infrequently (e.g., written down hourly by a nurse clinician), and prone to human error.

ISO/IEEE Problems Use of expensive custom connectivity equipment (a) drives up the cost of care delivery; (b) is only used for patients with the highest acuity; and (c) tends to lock care providers into single companies or partnerships that provide “complete” information system solutions, making it difficult to choose best-of-breed technologies to meet client needs, or the most cost effective systems.

ISO/IEEE Problems Development and deployment of advanced care delivery systems are hindered. For example, systems that collect real-time data from multiple devices and use the information to detect safety problems (e.g., adverse drug events), or to quickly determine a client's condition and automatically, or with minimal carer involvement, optimally adjust a device’s operation (e.g., for insulin delivery based on glucose level information) cannot operate without these standards.

ISO/IEEE Problems With no standardisation in this area, even when similar devices do provide communications, there is no consistency in the information and services that are provided, thus inhibiting the development of advanced care delivery systems or even consistent health records.

ISO/IEEE Problems In short: appropriate use of device communication standards can help deliver better health, fitness and care, more quickly, safely, and at a lower cost.

ISO/IEEE Motivation They provide a complete solution for medical device connectivity, starting at the physical cable or wireless connection up through the abstract representation of information and the services used for its management and exchange.

ISO/IEEE Motivation They can enable full disclosure of device-mediated information. So measurement modalities be declared in detail and the associated metrics & alerts communicated, together with any user-made changes to settings. In addition, the device can communicate its manufacturer, model, serial number, configuration, operating status and network location – all in real time if required.

ISO/IEEE Motivation They have been, and continue to be, adopted as International Standards Organisation (ISO) standards through ISO TC215 Health Informatics and as European standards through the Committee for European Normalisation (CEN) TC251 Health Informatics, specifically as the CEN ISO/IEEE series

ISO/IEEE Motivation These CEN ISO/IEEE standards have been developed in close coordination with other standards development organisations, including IEEE 802, IHTSDO, IrDA, HL7, DICOM, and CLSI.

ISO/IEEE Motivation Memoranda of Understanding with IHE, IHTSDO, and HL7; and (through ISO) close liaison with Continua Health Alliance assist still wider integration.

ISO/IEEE Motivation The CEN ISO/IEEE nomenclature is now being used to populate, and to establish equivalence, within SNOMED CT - the most widely used clinical terminology.

ISO/IEEE Motivation A liaison between the IEEE standards group and the USA Food and Drug Administration (FDA) Center for Devices and Radiological Health (CDRH) in the USA helps ensure that patient safety and efficacy concerns are fully addressed in the standards.

ISO/IEEE Motivation The Continua Health Alliance and the English NHS National Programme for Information Technology (NPfIT) both specify use of the standards for device communication.

ISO/IEEE Motivation The standards have been included in the USA National Committee on Vital and Health Statistics recommendations to the Department of Health and Human Services related to patient medical record information message formats supporting Health Insurance Portability and Accountability Act (HIPAA) compliant implementations.

ISO/IEEE Motivation The cost of integrating innovative technologies into established product lines is reduced — and a barrier to new companies is lowered.

ISO/IEEE 11073 - Availability
11073 standards are available freely to those actively involved in their development, others may purchase them. For published and draft standards search for '11073' at: IEEE, ISO or CEN. Standards may be purchased from your national standards organisation or bookstore (e.g. AFNOR, BSI, DIN, JIS, UNI, etc.).

ISO/IEEE Overview The ISO/IEEE Medical / Health Device Communication Standards are a family of ISO, IEEE, and CEN joint standards addressing the interoperability of medical devices. The ISO/IEEE standard family defines parts of a system, with which it is possible, to exchange and evaluate vital signs data between different medical devices, as well as remote control these devices.

ISO/IEEE 11073 - Point-of-care medical device
Health informatics - PoC medical device communication - Part 00101: Guide—Guidelines for the use of RF wireless technology

:2004(E) Health informatics - Point-of-care medical device communication - Part 10101: Nomenclature

:2012(E) Health informatics - Point-of-care medical device communication Part 10103: Nomenclature - Implantable device, cardiac

:2004(E) Health informatics - Point-of-care medical device communication - Part 10201: Domain information model

:2004(E) Health informatics - Point-of-care medical device communication - Part 20101: Application profile - Base standard

a:2011 (E) Health informatics - Point-of-care medical device communication - Part 30200: Transport profile - Cable connected (amended)

:2004(E) Health informatics - Point-of-care medical device communication - Part 30300: Transport profile - Infrared wireless

:2012(E) Health informatics - Point-of-care medical device communication - Part 30400: Transport profile - Cabled Ethernet

ISO/IEEE 11073 - Personal health device
ISO/IEEE personal health device (PHD) standards are a group of standards addressing the interoperability of personal health devices (PHDs) such as weighing scales, blood pressure monitors, blood glucose monitors and the like. The standards draw upon earlier IEEE11073 standards work, but differ from this earlier work due to an emphasis on devices for personal use (rather than hospital use) and a simpler communications model.

ISO/IEEE 11073 - Nomenclature
Within this standard nomenclature codes are defined, these give the possibility to clearly identify objects and attributes in relation to the so-called OID-Code (). The nomenclature is divided in partitions, to demarcate codes with regards to content and functional. Programmatically these codes are defined as constants, those can be used by a pseudonym.

ISO/IEEE 11073 - Nomenclature
/* Definition für die Partition Object Infrastructure */

ISO/IEEE 11073 - Domain information model
This standard is the "heart" of VITAL. Within this, objects and their arrangement in a Domain Information Model for vital signs data transmission are defined. Beyond this the standard defines a service model for the standardized communication.

ISO/IEEE 11073 - Base standard
The common background for assembly and transmission of objects and their attributes are defined in this standard. It's subdivided in a communication model and an information model. The communication model describes the layers 5 to 7 of the OSI 7-layer model. The information model defines the modeling, formatting and the syntax for transmission coding of the objects.

ISO/IEEE 11073 - Agent/manager principle
All defined parts of this standard family are designed to allow communication according to this principle. The arrangement of two or more medical devices as a system, so that the components are possible to understand and to interact, are the basic idea of this principle.

ISO/IEEE 11073 - Agent/manager principle
The agent is the part of the principle that is connected to the medical devices

ISO/IEEE 11073 - Agent application process(es)
This module is the interface between a proprietary (eventually native) protocol and the ISO/IEEE (VITAL) object world. It is not defined within the standard and as a result it can be implemented free.

ISO/IEEE 11073 - Medical data information base
MMOs (Managed Medical Objects) are stored hierarchically within a tree structure in a form named Domain Information Model (DIM). This MMOs and their arrangement in the DIM are defined within this standard. The implementation of the MDIB (Medical Device Information Base) and their functionallity is out of the scope of the standard.

ISO/IEEE 11073 - Association service control element
This module is subject to the standards ISO/IEC and ISO/IEC It has services available, that controlling the association assembly and disassembly. A possible association and their condition is negotiated here, no MMOs are transmitted over this module.

ISO/IEEE 11073 - Common medical device information service element
Services for the data exchange of MMOs (Managed Medical Objects) between Agent-Manager systems, are defined in this module. This data exchange is highly dynamic. Objects are created, changed or deleted by services named CREATE, UPDATE, DELETE. Through reports, which can be defined detailed down to the single object attribute, it is possible to trigger complex operations in Agent or Manager, through this services.

ISO/IEEE 11073 - Presentation layer
This layer contains the encoding of object data. Objects, groups of objects attributes or single attributes are encoded by ASN.1 representations, respectively the spezialization MDER (Medical Device encoding Rules).

ISO/IEEE 11073 - Domain information model
The central core of the standard is the so-called Domain Information Model. Objects containing vital-sign data representations and their relationships are defined in this model. Objects for additional services around vital signs data objects, are defined also here.

ISO/IEEE 11073 - Alert package
This small package is related within the medical package. It is used for setting and administrating alert parameters to objects from the medical package.

ISO/IEEE 11073 - System package
A representation of a medical device can be achieved with objects of this package. It contains concrete derivations of the abstract MDS (MedicalDevice System) object. One of these concrete derivations are ever the root object of a DIM tree. The Battery object and the Clock object are further objects in this package. The last one can be used for time synchronization of medical device data.

ISO/IEEE 11073 - Control package
Inside the control package, objects for the remote control of a medical device are defined. There are objects used for influenceing the modality of measuring (for example the SetRangeOperation object) and objects for direct remote control of medical devices (for example the ActivateOperation object).

ISO/IEEE 11073 - Extended services package
Other than the name supposes, in this package essential and ever used objects are defined

ISO/IEEE 11073 - Communication package
The objects in these package contain information, which are responsible for basic communication profiles. These packages are developed very open, so that different communication profiles and interfaces to proprietary device interfaces can be built. Annotation by the author: From a historic view, the standard was developed for the first time in the early 90s, this package has to be reconstructed.

ISO/IEEE 11073 - Patient package
The patient package contains only one object, the Patient Demographics object. This object contains patient related data and can be set in relationship to an MDS object or one of the objects from the archive package, to give anonymous data the reference to patient data.

ISO/IEEE 11073 - Communication model
The complete communication sequence can be very complex. This article should provide basic information, that can be more detailed at a later time in a separate article.

ISO/IEEE 11073 - Finite state machine
The finite state machine regulates the synchronization of an Agent Manager system over different conditions. A complete session roundtrip starts up with the disconnected state, is transferred by multiple stages to the initialized state, in what the actual data transfer shall be done, and ends with the disconnected state.

ISO/IEEE 11073 - Initializing MDIB
During the association phase, the configuring state will be reached

ISO/IEEE 11073 - Data exchange through services
The Common Medical Device Information Service Element (CMDISE) provides a GET service, to deliver data requested by the Manager. The Agent GET service retrieves a list of attribute ids. These ids identify explicit values within Agents MDIB. Now the Agent creates a report, containing the requested values. This report is sent back to the Manager.

ISO/IEEE 11073 - Data exchange through scanner objects
In an MDIB, additional objects shall be created through the CREATE service of CMDISE

IEEE 802.2 IEEE is the name given to a subsection of the IEEE 802 standard that describes a software component of a computer network

IEEE 802.2 The Subnetwork Access Protocol (SNAP) allows EtherType values to be used to specify the protocol being transported atop IEEE 802.2, and also allows vendors to define their own protocol value spaces.

IEEE 802.2 - Operational modes
Type 1 is an unacknowledged connectionless mode for a datagram service. It allows for sending frames

to a single destination (point-to-point or unicast transfer),

to multiple destinations on the same network (multicast),

The use of multicasts and broadcasts reduce network traffic when the same information needs to be propagated to all stations of the network. However the Type 1 service provides no guarantees regarding the order of the received frames compared to the order in which they have been sent; the sender does not even get an acknowledgment that the frames have been received.

Type 2 is a connection-oriented operational mode. Sequence numbering ensures that the frames received are guaranteed to be in the order they have been sent, and no frames are lost.

Type 3 is an acknowledged connectionless service. It supports point-to-point communication only .

IEEE LLC header The header includes two eight-bit address fields, called service access points or SAPs in OSI terminology; they are the destination SAP (DSAP), and the source SAP (SSAP)

IEEE LLC header Some protocols, or families of protocols, have one or more SAPs assigned to them; for example, IPv4 has a SAP value of hex 06. Those protocols operate directly on top of LLC, which provides both datagram and connection-oriented network services.

IEEE LLC header The Subnetwork Access Protocol (SNAP) can be used with IEEE 802.2; it allows EtherType values to be used with all IEEE 802 protocols, as well as supporting private protocol ID spaces. When both the DSAP and the SSAP are set to the hexadecimal value 0xAA (or 0xAB, if the low-order bit of the field is set), the SNAP service is requested.

IEEE LLC header In IEEE 802.3x-1997, the IEEE Ethernet standard was changed to explicitly allow the use of the 16-bit field after the MAC addresses to be used as a length field or a type field.

IEEE LLC header There exists an Internet standard, RFC 1042, for encapsulating IP version 4 traffic in IEEE frames with LLC/SNAP headers. It is almost never implemented on Ethernet, although it is used on FDDI and on token ring, IEEE , and other IEEE 802 networks.

IEEE LLC header IP traffic can not be encapsulated in IEEE LLC frames without SNAP because, although there is an LLC protocol type for IP, there is no LLC protocol type for ARP. IP Version 6 can also be transmitted over Ethernet using IEEE with LLC/SNAP, but, again, that's almost never used (although LLC/SNAP encapsulation of IPv6 is used on IEEE 802 networks).

IEEE LLC header Following the destination and source SAP fields is a control field. IEEE was conceptually derived from HDLC, and has the same three types of PDUs:

IEEE LLC header Unnumbered format PDUs, or U-format PDUs, with an 8-bit control field, which are intended for connectionless applications;

IEEE LLC header Information transfer format PDUs, or I-format PDUs, with a 16-bit control and sequence numbering field, which are intended to be used in connection-oriented applications;

IEEE LLC header Supervisory format PDUs, or S-format PDUs, with a 16-bit control field, which are intended to be used for supervisory functions at the LLC (Logical Link Control) layer.

IEEE LLC header Of these three formats, only the U-format is commonly used. The format of a PDU frame is identified by the lower two bits of the first byte of the control field.

ISO/IEC 42010 - Conformance to ISO/IEC/IEEE 42010
ISO/IEC/IEEE defines four cases of conformance to the standard:

ISO/IEC 42010 - History of ISO/IEC/IEEE 42010
The origin of the standard was the fast track international standardization of IEEE 1471:2000. The standard was originally balloted as ISO/IEC DIS It was subsequently adopted and published as ISO/IEC 42010:2007 which was identical with IEEE 1471:2000.

In 2006, ISO/IEC JTC1/SC7 WG 42 and IEEE Computer Society launched a coordinated revision of this standard to address: harmonization with ISO/IEC and ISO/IEC 15288; alignment with other ISO architecture standards (e.g. ISO/IEC Reference Model Open Distributed Processing); the specification of architecture frameworks and architecture description languages; architecture decision capture; and correspondences for model and view consistency.

In July 2011, the Final Draft International Standard was balloted and approved (21-0) by ISO member bodies. The corresponding IEEE version, P42010/D9, was approved as a revised standard by the IEEE-SA Standards Board on 31 October ISO/IEC/IEEE 42010:2011 was published by ISO on 24 November 2011.

IEEE 1901 The IEEE Std is a standard for high speed (up to 500 Mbit/s at the physical layer) communication devices via electric power lines, often called broadband over power lines (BPL)

IEEE 1901 The IEEE Std standard replaced a dozen previous powerline specifications. It includes a mandatory coexistence Inter-System Protocol (ISP). The IEEE 1901 ISP prevents interference when the different BPL implementations are operated within close proximity of one another.

IEEE 1901 The 1901 standard is mandatory to initiate SAE J1772 electric vehicle charging and the sole powerline protocol for IEEE heterogeneous networking. It was highly recommended in the IEEE P smart grid standards because those are primarily for control of AC devices, which by definition always have AC power connections - thus no additional connections are required.

IEEE Status The IEEE P1901 Working Group started in June More than 90 organizations contributed to the standard. Half of the organizations were from US, a quarter from Japan and the last quarter from Europe.

IEEE Status IEEE 1901 completed a formal standard IEEE Std published in December The working group which maintains and extends the standards is sponsored by the IEEE Power Line Communication Standard Committee (PLCSC).

IEEE ITU-T G.9972 The IEEE 1901 ISP coexistence protocol has been extended to support the International Telecommunication Union's family of home networking standards ITU-G.hn, and adopted by the ITU-T as Recommendation ITU-T G.9972.

IEEE SGIP The Smart Grid Interoperability Panel (SGIP) initiated by the U.S. National Institute of Standards and Technology (NIST) mandates the implementation of the IEEE 1901 ISP coexistence mechanism (or ITU-T G.9972) in all technologies operating over power lines. NISTIR 7862: Guideline for the Implementation of Coexistence for Broadband Power Line Communication Standards The IEEE 1901 standard is included in the SGIP Catalog of Standards

IEEE SAE and IEC 62196 The SAE J1772 and IEC standards for electric vehicle charging include IEEE 1901 as the standard for power line communication between the vehicle, off-board charging station, and the smart grid, without requiring an additional pin; SAE International and the IEEE Standards Association are sharing their draft standards related to the smart grid and vehicle electrification.

IEEE IEEE IEEE 1901 is the PLC standard supported by the IEEE Standard for a Convergent Digital Home Network

IEEE Description The 1901 standards include two different physical layers, one based on FFT orthogonal frequency-division multiplexing (OFDM) modulation and another based on wavelet OFDM modulation. Each PHY is optional, and implementers of the specification may, but are not required to include both. The FFT PHY is derived from HomePlug AV technology and is deployed in HomePlug-based products. The Wavelet PHY is derived from HD-PLC technology and is deployed in HD-PLC-based products.

IEEE Description The fast Fourier transform (FFT) PHY includes a forward error correction (FEC) scheme based on convolutional turbo code (CTC). The second option "Wavelet PHY" includes a mandatory FEC based on concatenated Reed-Solomon (RS) and Convolutional code, and an option to use Low-Density Parity-Check (LDPC) code.

IEEE Description On top of these two physical layers, two different MAC layers were defined; one for In-home networking and the other for Internet access. Two MACs were needed because each application has different requirements.

IEEE Description To manage coexistence between PHYs and MACs the Inter-System Protocol (ISP) was developed

IEEE 1901 - Related PLC standards
Another trade group called the HomeGrid Forum was formed in 2008 to promote the ITU-T home networking standards known as G.hn. Recommendation ITU-T G approved in June 2010, specifies a coexistence mechanism for home networking transceivers capable of operating over powerline wiring. This recommendation is based on IEEE 1901 ISP.

"IEEE 1675". is another IEEE standard related to Broadband over Power Line. P1675 provides testing and verification standards for the hardware commonly used for Broadband over Power Line (BPL) installations (primarily couplers and enclosures) and provides standard installation methods to ensure compliance with applicable codes and standards.

"IEEE 1775".: Power Line Communication EMC Working Group.

"IEEE ".: Standard for a Convergent Digital Home Network for Heterogeneous Technologies

"IEEE P1901.2".: Standard for Low Frequency (less than 500 kHz) Narrow Band Power Line Communications for Smart Grid Applications

"IEEE P1909.1".: Recommended Practice for Smart Grid Communication Equipment -Test methods and installation requirements

IEEE projects are named by prefixing a P to the name of the intended standard. A project that has not produced a standard yet, or a draft protocol that is not yet approved as a standard but is being tracked by vendors, is often referred to with the P in its name to indicate that the standard is still a draft.

IEEE Availability The HD-PLC Alliance provides certification. Panasonic is a member of the HD-PLC Alliance, and licenses its patents and technologies that support IEEE K-Micro (also a member) announced a product in The Qualcomm Hy-Fi networking marketing program combines IEEE 1901 (on AC outlets in every room) with IEEE ad branded as Wi-Fi (which does not penetrate walls).

Management information base - IEEE maintained
The IETF and IEEE have agreed to move MIBs relating to IEEE work (for example Ethernet and bridging) to their respective IEEE workgroup. This is in process and a few items are complete.

IEEE 1394 IEEE 1394 replaced parallel SCSI in many applications, because of lower implementation costs and a simplified, more adaptable cabling system

IEEE 1394 IEEE 1394 is the High-Definition Audio-Video Network Alliance (HANA) standard connection interface for A/V (audio/visual) component communication and control. FireWire is also available in wireless, fiber optic, and coaxial versions using the isochronous protocols.

IEEE 1394 - History and development
FireWire is Apple's name for the IEEE 1394 High Speed Serial Bus. It was initiated by Apple (in 1986) and developed by the IEEE P1394 Working Group, largely driven by contributions from Apple, although major contributions were also made by engineers from Texas Instruments, Sony, Digital Equipment Corporation, IBM, and INMOS/SGS Thomson (now STMicroelectronics).

IEEE 1394 is a serial bus architecture for high-speed data transfer. FireWire is a serial bus, meaning that information is transferred one bit at a time. Parallel buses utilize a number of different physical connections, and as such are usually more costly and typically heavier. IEEE 1394 fully supports both isochronous and asynchronous applications.

On June 12, 2008, all these amendments as well as errata and some technical updates were incorporated into a superseding standard, IEEE Std

Sony's implementation of the system, i.LINK, used a smaller connector with only four signal conductors, omitting the two conductors that provide power for devices in favor of a separate power connector. This style was later added into the 1394a amendment. This port is sometimes labeled S100 or S400 to indicate speed in Mbit/s.

The system is commonly used to connect data storage devices and DV (digital video) cameras, but is also popular in industrial systems for machine vision and professional audio systems

IEEE 1394 - Intellectual property considerations
MPEG LA sublicenses these patents to providers of equipment implementing IEEE 1394

In total, over 1770 patents issued in the 20 years (the WIPO minimum) preceding 2011 contain "IEEE 1394" in their titles alone, placing 1500 unavailable from MPEG LA.

The 1394 High Performance Serial Bus Trade Association (the "1394 TA") was formed to aid marketing of IEEE Its bylaws prohibit dealing with intellectual property issues.

IEEE 1394 - Technical specifications
FireWire can connect up to 63 peripherals in a tree or daisy-chain topology (as opposed to Parallel SCSI's electrical bus topology)

FireWire devices implement the ISO/IEC "configuration ROM" model for device configuration and identification, to provide plug-and-play capability. All FireWire devices are identified by an IEEE EUI-64 unique identifier in addition to well-known codes indicating the type of device and the protocols it supports.

FireWire devices are organized at the bus in a tree topology. Each device has a unique self-id. One of the nodes is elected root node and always has the highest id. The self-ids are assigned during the self-id process, which happens after each bus resets. The order in which the self-ids are assigned is equivalent to traversing the tree depth-first, post-order.

In IEEE % of the bus is reserved for isochronous cycles, leaving asynchronous data with a minimum of 20% of the bus.

IEEE Encoding scheme FireWire uses Data strobe encoding (D/S encoding). In D/S encoding, two non-return-to-zero (NRZ) signals are used to transmit the data with high reliability. The NRZ signal sent is fed with the clock signal through an XOR gate, creating a strobe signal. This strobe is then put through another XOR gate along with the data signal to reconstruct the clock. This in turn acts as the bus's Phase-locked loop for synchronization purposes.

IEEE Arbitration The process of the bus deciding which node gets to transmit data at what time is known as arbitration

IEEE 1394 - Standards and versions
The previous standards and its three published amendments are now incorporated into a superseding standard, IEEE The features individually added give a good history on the development path.

IEEE 1394 - FireWire 400 (IEEE 1394-1995)
The original release of IEEE specified what is now known as FireWire 400. It can transfer data between devices at 100, 200, or 400 Mbit/s full-duplex data rates (the actual transfer rates are , , and Mbit/s, i.e., , and megabytes per second respectively). These different transfer modes are commonly referred to as S100, S200, and S400.

Cable length is limited to 4.5 metres (14.8 ft), although up to 16 cables can be daisy chained using active repeaters; external hubs, or internal hubs are often present in FireWire equipment. The S400 standard limits any configuration's maximum cable length to 72 metres (236 ft). The 6-conductor connector is commonly found on desktop computers, and can supply the connected device with power.

The 6-conductor powered connector, now referred to as an alpha connector, adds power output to support external devices. Typically a device can pull about 7 to 8 watts from the port; however, the voltage varies significantly from different devices. Voltage is specified as unregulated and should nominally be about 25 volts (range 24 to 30). Apple's implementation on laptops is typically related to battery power and can be as low as 9 V.

IEEE 1394 - Improvements (IEEE 1394a-2000)
An amendment, IEEE 1394a, was released in 2000, which clarified and improved the original specification. It added support for asynchronous streaming, quicker bus reconfiguration, packet concatenation, and a power-saving suspend mode.

IEEE 1394a offers a couple of advantages over IEEE a is capable of arbitration accelerations, allowing the bus to accelerate arbitration cycles to improve efficiency. It also allows for arbitrated short bus reset, in which a node can be added or dropped without causing a big drop in isochronous transmission.

1394a also standardized the 4-conductor alpha connector developed by Sony and trademarked as "i.LINK", already widely in use on consumer devices such as camcorders, most PC laptops, a number of PC desktops, and other small FireWire devices. The 4-conductor connector is fully data-compatible with 6-conductor alpha interfaces but lacks power connectors.

IEEE 1394 - FireWire 800 (IEEE 1394b-2002)
However, while the IEEE 1394a and IEEE 1394b standards are compatible, FireWire 800's connector, referred to as a beta connector, is different from FireWire 400's alpha connectors, making legacy cables incompatible

The full IEEE 1394b specification supports data rates up to 3200 Mbit/s (i.e., 400 megabytes/s) over beta-mode or optical connections up to 100 metres (330 ft) in length. Standard Category 5e unshielded twisted pair supports 100 metres (330 ft) at S100. The original 1394 and 1394a standards used data/strobe (D/S) encoding (renamed to alpha mode) with the cables, while 1394b added a data encoding scheme called 8B10B referred to as beta mode.

Beta mode is based on 8B/10B (Gigabit Ethernet & Fibre Channel)

IEEE FireWire S1600 and S3200 In December 2007, the 1394 Trade Association announced that products would be available before the end of 2008 using the S1600 and S3200 modes that, for the most part, had already been defined in 1394b and were further clarified in IEEE Std The 1.6 Gbit/s and 3.2 Gbit/s devices use the same 9-conductor beta connectors as the existing FireWire 800 and are fully compatible with existing S400 and S800 devices. It competes with USB 3.0.

IEEE FireWire S1600 and S3200 S1600 (Symwave) and S3200 (Dap Technology) development units have been made, however because of FPGA technology DapTechnology targeted S1600 implementations first with S3200 not becoming commercially available until 2012.

IEEE 1394 - FireWire S800T (IEEE 1394c-2006)
IEEE 1394c-2006 was published on June 8, 2007.

It provided a major technical improvement, namely new port specification that provides 800 Mbit/s over the same 8P8C (Ethernet) connectors with Category 5e cable, which is specified in IEEE clause 40 (gigabit Ethernet over copper twisted pair) along with a corresponding automatic negotiation that allows the same port to connect to either IEEE Std 1394 or IEEE (Ethernet) devices.

Though the potential for a combined Ethernet and FireWire 8P8C port is intriguing, as of November 2008, no products or chipsets include this capability.

IEEE 1394 - Future enhancements (including P1394d)
A project named IEEE P1394d was formed by the IEEE on March 9, 2009 to add single mode fiber as an additional transport medium to FireWire.

IEEE 1394 - Future enhancements (including P1394d)
Other future iterations of FireWire are expected to increase speed to 6.4 Gbit/s and additional connectors such as the small multimedia interface.

IEEE 1394 - Operating system support
Full support for IEEE 1394a and 1394b is available for Microsoft Windows, FreeBSD, Linux, Apple Mac OS 8.6 through Mac OS 9, Mac OS X, NetBSD, and Haiku.

In Windows XP, a degradation in performance of 1394 devices may have occurred with installation of Service Pack 2

In Linux, support was originally provided by libraw1394 making direct communication between user space and IEEE 1394 buses. Subsequently a new kernel driver stack, nicknamed JuJu, has been implemented.

IEEE 1394 - Cable TV system support
Cable TV providers (in the US, with digital systems) must, upon request of a customer, provide a high-definition capable cable box with a functional FireWire interface. This applies only to customers leasing high-definition capable cable boxes from their cable provider after April 1, The relevant regulation is 47 CFR Section 4 Subsections i and ii. The interface can be used to display or record Cable TV, including HDTV programming.

IEEE 1394 - Comparison with USB
While both technologies provide similar end results, there are fundamental differences between USB and FireWire

The FireWire host interface supports DMA and memory-mapped devices, allowing data transfers to happen without loading the host CPU with interrupts and buffer-copy operations

While USB 2.0 expanded into the fully backwards-compatible USB 3.0 and 3.1 (using the same main connector type), FireWire used a different connector between 400 and 800 implementations.

IEEE Automobiles IDB-1394 Customer Convenience Port (CCP) is the automotive version of the 1394 standard.

IEEE 1394 - Wind power turbines
Audio monitoring for vibrations in the power transmission in wind driven electrical turbines uses a 1394 network for data gathering.

IEEE 1394 - Networking over FireWire
FireWire can be used for ad-hoc (terminals only, no routers except where a FireWire hub is used) computer networks. Specifically, RFC 2734 specifies how to run IPv4 over the FireWire interface, and RFC 3146 specifies how to run IPv6.

Windows 95, Windows 98, Windows Me, Windows XP and Windows Server 2003 include native support for IEEE 1394 networking

On December 4, 2004, Microsoft announced that it would discontinue support for IP networking over the FireWire interface in all future versions of Microsoft Windows. Consequently, support for this feature is absent from Windows Vista and later Windows releases. Microsoft rewrote their 1394 driver in Windows 7 but networking support for FireWire is not present. Unibrain offers free FireWire networking drivers for Windows called ubCore, which support Windows Vista and later versions.

The PlayStation 2 console had an i.LINK-branded 1394 connector. This was used for networking until the release of an Ethernet adapter late in the console's lifespan, but very few software titles supported the feature.

IEEE IIDC IIDC (Instrumentation & Industrial Digital Camera) is the FireWire data format standard for live video, and is used by Apple's iSight A/V camera. The system was designed for machine vision systems but is also used for other computer vision applications and for some webcams. Although they are easily confused since they both run over FireWire, IIDC is different from, and incompatible with, the ubiquitous AV/C (Audio Video Control) used to control camcorders and other consumer video devices.

IEEE DV Digital Video (DV) is a standard protocol used by some digital camcorders. All DV cameras that recorded to tape media had a FireWire interface (usually a 4-conductor). All DV ports on camcorders only operate at the slower 100 Mbit/s speed of FireWire. This presents operational issues if the camcorder is daisy chained from a faster S400 device or via a common hub because any segment of a firewire network cannot support multiple speed communication.

IEEE DV Labelling of the port varies by manufacturer, with Sony using either its i.LINK trademark or the letters 'DV'. Many digital video recorders have a "DV-input" FireWire connector (usually an alpha connector) that can be used to record video directly from a DV camcorder ("computer-free"). The protocol also accommodates remote control (play, rewind, etc.) of connected devices, and can stream time code from a camera.

IEEE DV USB is unsuitable for transfer of the video data from tape because tape by its very nature does not support variable data rates. USB relies heavily on processor support and this was not guaranteed to service the USB port in time. The recent move away from tape towards solid state memory or disc media (e.g. SD Cards, optical disks or Hard Drives) has facilitated moving to USB transfer because file based data can be moved in segments as required.

IEEE Frame grabbers IEEE 1394 interface is commonly found in frame grabbers, devices that capture and digitize an analog video signal; however, IEEE 1394 is facing competition from the Gigabit Ethernet interface (citing speed and availability issues).

IEEE iPod and iPhone iPods released prior iPod with Dock Connector used IEEE 1394a ports for syncing music and charging, but in 2003, the FireWire port was no longer used in iPod and it's succeeded by Dock connector, since then, IEEE 1394 to 30-pin connector cables was made. Apple Inc. dropped support for FireWire cables in iPod nano (4th Generation), iPod touch (2nd Generation), and iPhone 3G in favor of USB cables.

IEEE Security issues Devices on a FireWire bus can communicate by direct memory access (DMA), where a device can use hardware to map internal memory to FireWire's "Physical Memory Space"

IEEE Security issues On many implementations, particularly those like PCs and Macs using the popular OHCI, the mapping between the FireWire "Physical Memory Space" and device physical memory is done in hardware, without Operating System intervention

IEEE Security issues An unsecured FireWire interface can be used to debug a machine whose Operating System has crashed, and in some systems for remote-console operations. Windows natively supports this scenario of kernel debugging. On FreeBSD, the dcons driver provides both, using gdb as debugger. Under Linux, firescope and fireproxy exist.

IEEE They are created and maintained by the IEEE LAN/MAN Standards Committee (IEEE 802)

IEEE 802.11 - General description
The family consist of a series of half-duplex over-the-air modulation techniques that use the same basic protocol

802.11b and g use the 2.4 GHz ISM band, operating in the United States under Part 15 of the U.S

The segment of the radio frequency spectrum used by varies between countries

IEEE History technology has its origins in a 1985 ruling by the U.S. Federal Communications Commission that released the ISM band for unlicensed use.

IEEE History In 1991 NCR Corporation/AT&T (now Alcatel-Lucent and LSI Corporation) invented the precursor to in Nieuwegein, The Netherlands. The inventors initially intended to use the technology for cashier systems. The first wireless products were brought to the market under the name WaveLAN with raw data rates of 1 Mbit/s and 2 Mbit/s.

IEEE History In 1999, the Wi-Fi Alliance was formed as a trade association to hold the Wi-Fi trademark under which most products are sold.

IEEE Protocol MIMO streams Modulation Approximate indoor range Approximate outdoor range

IEEE Protocol A1 A2 IEEE y-2008 extended operation of a to the licensed 3.7 GHz band. Increased power limits allow a range up to 5,000 m. As of 2009, it is only being licensed in the United States by the FCC.

IEEE Protocol B1 B2 Assumes short guard interval (SGI) enabled, otherwise reduce each data rate by 10%.

IEEE ( legacy) The original version of the standard IEEE was released in 1997 and clarified in 1999, but is today obsolete

IEEE ( legacy) Legacy with direct-sequence spread spectrum was rapidly supplanted and popularized by b.

IEEE a OFDM Waveform Originally described as clause 17 of the 1999 specification, the OFDM waveform at 5.8GHz is now defined in clause 18 of the 2012 specification and provides protocols that allow transmission and reception of data at rates of 1.5 to 54Mbit/s

IEEE a OFDM Waveform The a standard uses the same data link layer protocol and frame format as the original standard, but an OFDM based air interface (physical layer). It operates in the 5 GHz band with a maximum net data rate of 54 Mbit/s, plus error correction code, which yields realistic net achievable throughput in the mid-20 Mbit/s.

IEEE a OFDM Waveform Since the 2.4 GHz band is heavily used to the point of being crowded, using the relatively unused 5 GHz band gives a a significant advantage

IEEE b 802.11b has a maximum raw data rate of 11 Mbit/s and uses the same media access method defined in the original standard b products appeared on the market in early 2000, since b is a direct extension of the modulation technique defined in the original standard. The dramatic increase in throughput of b (compared to the original standard) along with simultaneous substantial price reductions led to the rapid acceptance of b as the definitive wireless LAN technology.

IEEE b 802.11b devices experience interference from other products operating in the 2.4 GHz band. Devices operating in the 2.4 GHz range include microwave ovens, Bluetooth devices, baby monitors, cordless telephones and some amateur radio equipment.

IEEE g In June 2003, a third modulation standard was ratified: g. This works in the 2.4 GHz band (like b), but uses the same OFDM based transmission scheme as a. It operates at a maximum physical layer bit rate of 54 Mbit/s exclusive of forward error correction codes, or about 22 Mbit/s average throughput g hardware is fully backward compatible with b hardware and therefore is encumbered with legacy issues that reduce throughput when compared to a by ~21%.

IEEE g The then-proposed g standard was rapidly adopted by consumers starting in January 2003, well before ratification, due to the desire for higher data rates as well as to reductions in manufacturing costs

IEEE g Like b, g devices suffer interference from other products operating in the 2.4 GHz band, for example wireless keyboards.

IEEE In 2003, task group TGma was authorized to "roll up" many of the amendments to the 1999 version of the standard. REVma or ma, as it was called, created a single document that merged 8 amendments (802.11a, b, d, e, g, h, i, j) with the base standard. Upon approval on March 8, 2007, REVma was renamed to the then-current base standard IEEE

IEEE n The IEEE has approved the amendment and it was published in October 2009

IEEE In 2007, task group TGmb was authorized to "roll up" many of the amendments to the 2007 version of the standard. REVmb or mb, as it was called, created a single document that merged ten amendments (802.11k, r, y, n, w, p, z, v, u, s) with the 2007 base standard. In addition much cleanup was done, including a reordering of many of the clauses. Upon publication on March 29, 2012, the new standard was referred to as IEEE

IEEE ac IEEE ac is a standard under development which will provide throughput in the 5 GHz band. This specification will enable higher multi-station WLAN throughput of at least 1 gigabit per second and a maximum single link throughput of at least 500 megabits per second, by using wider RF bandwidth (80 or 160 MHz), more streams (up to 8), and high-density modulation (up to 256 QAM).

IEEE ad IEEE ad "WiGig" is a published standard that is already seeing a major push from hardware manufacturers. On 24 July 2012 Marvell and Wilocity announced a new partnership to bring a new tri-band Wi-Fi solution to market. Using 60 GHz, the new standard can achieve a theoretical maximum throughput of up to 7 Gbit/s. This standard is expected to reach the market sometime in early 2014.

IEEE 802.11 - Channels and frequencies
802.11b, g, and n-2.4 utilize the – GHz spectrum, one of the ISM bands a and n use the more heavily regulated – GHz band. These are commonly referred to as the "2.4 GHz and 5 GHz bands" in most sales literature. Each spectrum is sub-divided into channels with a center frequency and bandwidth, analogous to the way radio and TV broadcast bands are sub-divided.

The 2.4 GHz band is divided into 14 channels spaced 5 MHz apart, beginning with channel 1 which is centered on GHz. The latter channels have additional restrictions or are unavailable for use in some regulatory domains.

The channel numbering of the – GHz spectrum is less intuitive due to the differences in regulations between countries. These are discussed in greater detail on the list of WLAN channels.

IEEE 802.11 - Channel spacing within the 2.4 GHz band
In addition to specifying the channel centre frequency, also specifies (in Clause 17) a spectral mask defining the permitted power distribution across each channel. The mask requires the signal be attenuated a minimum of 20 dB from its peak amplitude at ±11 MHz from the centre frequency, the point at which a channel is effectively 22 MHz wide. One consequence is that stations can only use every fourth or fifth channel without overlap.

Availability of channels is regulated by country, constrained in part by how each country allocates radio spectrum to various services. At one extreme, Japan permits the use of all 14 channels for b, and 1–13 for g/n-2.4. Other countries such as Spain initially allowed only channels 10 and 11, and France only allowed 10, 11, 12 and 13. They now allow channels 1 through 13. North America and some Central and South American countries allow only 1 through 11.

Since the spectral mask only defines power output restrictions up to ±11 MHz from the center frequency to be attenuated by −50 dBr, it is often assumed that the energy of the channel extends no further than these limits

Confusion often arises over the amount of channel separation required between transmitting devices b was based on DSSS modulation and utilized a channel bandwidth of 22 MHz, resulting in three "non-overlapping" channels (1, 6, and 11) g was based on OFDM modulation and utilized a channel bandwidth of 20 MHz. This occasionally leads to the belief that four "non-overlapping" channels (1, 5, 9 and 13) exist under g, although this is not the case.

Although the statement that channels 1, 5, 9, and 13 are "non-overlapping" is limited to spacing or product density, the concept has some merit in limited circumstances. Special care must be taken to adequately space AP cells since overlap between the channels may cause unacceptable degradation of signal quality and throughput. If more advanced equipment such as spectral analyzers are available, overlapping channels may be used under certain circumstances. This way, more channels are available.

IEEE 802.11 - Regulatory domains and legal compliance
IEEE uses the phrase regdomain to refer to a legal regulatory region. Different countries define different levels of allowable transmitter power, time that a channel can be occupied, and different available channels. Domain codes are specified for the United States, Canada, ETSI (Europe), Spain, France, Japan, and China.

Most Wi-Fi certified devices default to regdomain 0, which means least common denominator settings, i.e. the device will not transmit at a power above the allowable power in any nation, nor will it use frequencies that are not permitted in any nation.

The regdomain setting is often made difficult or impossible to change so that the end users do not conflict with local regulatory agencies such as the USA's Federal Communications Commission.

IEEE 802.11 - Layer 2 – Datagrams
The datagrams are called "frames". Current standards define "frame" types for use in transmission of data as well as management and control of wireless links.

Frames are divided into very specific and standardized sections. Each frame consists of a MAC header, payload and frame check sequence (FCS). Some frames may not have the payload. The first two bytes of the MAC header form a frame control field specifying the form and function of the frame. The frame control field is further subdivided into the following sub-fields:

Protocol Version: two bits representing the protocol version. Currently used protocol version is zero. Other values are reserved for future use.

Type: two bits identifying the type of WLAN frame. Control, Data and Management are various frame types defined in IEEE

Sub Type: Four bits providing additional discrimination between frames. Type and Sub type together to identify the exact frame.

ToDS and FromDS: Each is one bit in size. They indicate whether a data frame is headed for a distribution system. Control and management frames set these values to zero. All the data frames will have one of these bits set. However communication within an IBSS network always set these bits to zero.

More Fragments: The More Fragments bit is set when a packet is divided into multiple frames for transmission. Every frame except the last frame of a packet will have this bit set.

Retry: Sometimes frames require retransmission, and for this there is a Retry bit which is set to one when a frame is resent. This aids in the elimination of duplicate frames.

Power Management: This bit indicates the power management state of the sender after the completion of a frame exchange. Access points are required to manage the connection and will never set the power saver bit.

More Data: The More Data bit is used to buffer frames received in a distributed system. The access point uses this bit to facilitate stations in power saver mode. It indicates that at least one frame is available and addresses all stations connected.

Order: This bit is only set when the "strict ordering" delivery method is employed. Frames and fragments are not always sent in order as it causes a transmission performance penalty.

The next two bytes are reserved for the Duration ID field. This field can take one of three forms: Duration, Contention-Free Period (CFP), and Association ID (AID).

An frame can have up to four address fields. Each field can carry a MAC address. Address 1 is the receiver, Address 2 is the transmitter, Address 3 is used for filtering purposes by the receiver.

The Sequence Control field is a two-byte section used for identifying message order as well as eliminating duplicate frames. The first 4 bits are used for the fragmentation number and the last 12 bits are the sequence number.

An optional two-byte Quality of Service control field which was added with e.

The Frame Body field is variable in size, from 0 to 2304 bytes plus any overhead from security encapsulation and contains information from higher layers.

The Frame Check Sequence (FCS) is the last four bytes in the standard frame. Often referred to as the Cyclic Redundancy Check (CRC), it allows for integrity check of retrieved frames. As frames are about to be sent the FCS is calculated and appended. When a station receives a frame it can calculate the FCS of the frame and compare it to the one received. If they match, it is assumed that the frame was not distorted during transmission.

IEEE 802.11 - Management Frames
Management Frames allow for the maintenance of communication. Some common subtypes include:

Authentication frame: authentication begins with the WNIC sending an authentication frame to the access point containing its identity

Association request frame: sent from a station it enables the access point to allocate resources and synchronize. The frame carries information about the WNIC including supported data rates and the SSID of the network the station wishes to associate with. If the request is accepted, the access point reserves memory and establishes an association ID for the WNIC.

Association response frame: sent from an access point to a station containing the acceptance or rejection to an association request. If it is an acceptance, the frame will contain information such an association ID and supported data rates.

Beacon frame: Sent periodically from an access point to announce its presence and provide the SSID, and other parameters for WNICs within range.

Deauthentication frame: Sent from a station wishing to terminate connection from another station.

Disassociation frame: Sent from a station wishing to terminate connection. It's an elegant way to allow the access point to relinquish memory allocation and remove the WNIC from the association table.

Probe request frame: Sent from a station when it requires information from another station.

Probe response frame: Sent from an access point containing capability information, supported data rates, etc., after receiving a probe request frame.

Reassociation request frame: A WNIC sends a reassociation request when it drops from range of the currently associated access point and finds another access point with a stronger signal. The new access point coordinates the forwarding of any information that may still be contained in the buffer of the previous access point.

Reassociation response frame: Sent from an access point containing the acceptance or rejection to a WNIC reassociation request frame. The frame includes information required for association such as the association ID and supported data rates.

IEEE 802.11 - Information Elements
2. In terms of ICT, an Information Element (IE) is a part of management frames in the IEEE wireless LAN protocol. IEs are a device's way to transfer descriptive information about itself inside management frames. There are usually several IEs inside each such frame, and each is built of TLVs mostly defined outside the basic IEEE specification.

The common structure of an IE is as follows:

Whereas the OUI (organizationally unique identifier) is only used when necessary to the protocol being used, and the data field holds the TLVs relevant to that IE.

IEEE Control Frames Control frames facilitate in the exchange of data frames between stations. Some common control frames include:

IEEE Control Frames Acknowledgement (ACK) frame: After receiving a data frame, the receiving station will send an ACK frame to the sending station if no errors are found. If the sending station doesn't receive an ACK frame within a predetermined period of time, the sending station will resend the frame.

IEEE Control Frames Request to Send (RTS) frame: The RTS and CTS frames provide an optional collision reduction scheme for access points with hidden stations. A station sends a RTS frame to as the first step in a two-way handshake required before sending data frames.

IEEE Control Frames Clear to Send (CTS) frame: A station responds to an RTS frame with a CTS frame. It provides clearance for the requesting station to send a data frame. The CTS provides collision control management by including a time value for which all other stations are to hold off transmission while the requesting station transmits.

IEEE Control Frames Data frames carry packets from web pages, files, etc. within the body, using RFC 1042 encapsulation and EtherType numbers for protocol identification.

IEEE 802.11 - Standard and amendments
Within the IEEE Working Group, the following IEEE Standards Association Standard and Amendments exist:

IEEE a: 54 Mbit/s, 5 GHz standard (1999, shipping products in 2001)

IEEE b: Enhancements to to support 5.5 and 11 Mbit/s (1999)

IEEE c: Bridge operation procedures; included in the IEEE 802.1D standard (2001)

IEEE d: International (country-to-country) roaming extensions (2001)

IEEE e: Enhancements: QoS, including packet bursting (2005)

IEEE F: Inter-Access Point Protocol (2003) Withdrawn February 2006

IEEE h: Spectrum Managed a (5 GHz) for European compatibility (2004)

IEEE : A new release of the standard that includes amendments a, b, d, e, g, h, i and j. (July 2007)

IEEE k: Radio resource measurement enhancements (2008)

IEEE n: Higher throughput improvements using MIMO (multiple input, multiple output antennas)

IEEE p: WAVE—Wireless Access for the Vehicular Environment (such as ambulances and passenger cars)

IEEE u: Improvements related to HotSpots and 3rd party authorization of clients, e.g. cellular network offload

IEEE y: 3650–3700 MHz Operation in the U.S. (2008)

IEEE : A new release of the standard that includes amendments k, n, p, r, s, u, v, w, y and z

IEEE aa: Robust streaming of Audio Video Transport Streams

IEEE ad: Very High Throughput 60 GHz - see WiGig

IEEE In process IEEE ac: Very High Throughput <6 GHz; potential improvements over n: better modulation scheme (expected ~10% throughput increase), wider channels (estimate in future time 80 to 160 MHz), multi user MIMO; (~ February 2014)

IEEE In process IEEE ah: Sub 1 GHz sensor network, smart metering. (~ January 2016)

IEEE In process To reduce confusion, no standard or task group was named l, o, q, x, ab, or ag.

IEEE In process 802.11F and T are recommended practices rather than standards, and are capitalized as such.

IEEE In process 802.11m is used for standard maintenance ma was completed for and mb was completed for

IEEE 802.11 - Standard vs. amendment
Both the terms "standard" and "amendment" are used when referring to the different variants of IEEE standards.

New versions of the IEEE were published in 1999, 2007 and 2012.

The working title of was REVma. This denotes a third type of document, a "revision". The complexity of combining with 8 amendments made it necessary to revise already agreed upon text. As a result, additional guidelines associated with a revision had to be followed.

IEEE Nomenclature Various terms in are used to specify aspects of wireless local-area networking operation, and may be unfamiliar to some readers.

IEEE Nomenclature For example, Time Unit (usually abbreviated TU) is used to indicate a unit of time equal to 1024 microseconds. Numerous time constants are defined in terms of TU (rather than the nearly equal millisecond).

IEEE Nomenclature Also the term "Portal" is used to describe an entity that is similar to an 802.1H bridge. A Portal provides access to the WLAN by non LAN STAs.

IEEE 802.11 - Community networks
Many hotspot or free networks frequently allow anyone within range, including passersby outside, to connect to the Internet. There are also efforts by volunteer groups to establish wireless community networks to provide free wireless connectivity to the public.

IEEE Security In 2001, a group from the University of California, Berkeley presented a paper describing weaknesses in the Wired Equivalent Privacy (WEP) security mechanism defined in the original standard; they were followed by Fluhrer, Mantin, and Shamir's paper titled "Weaknesses in the Key Scheduling Algorithm of RC4"

IEEE Security IEEE i (also known as WPA2) itself was ratified in June 2004, and uses the Advanced Encryption Standard AES, instead of RC4, which was used in WEP

IEEE Security In January 2005, the IEEE set up yet another task group "w" to protect management and broadcast frames, which previously were sent unsecured. Its standard was published in 2009.

IEEE Security In December 2011, a security flaw was revealed that affects wireless routers with the optional Wi-Fi Protected Setup (WPS) feature. While WPS is not a part of , the flaw allows a remote attacker to recover the WPS PIN and, with it, the router's i password in a few hours.

IEEE 802.11 - Non-standard 802.11 extensions and equipment
Many companies implement wireless networking equipment with non-IEEE standard extensions either by implementing proprietary or draft features. These changes may lead to incompatibilities between these extensions.

IEEE IEEE is a series of Wireless Broadband standards written by the Institute of Electrical and Electronics Engineers (IEEE). The IEEE Standards Board established a working group in 1999 to develop standards for broadband for Wireless Metropolitan Area Networks. The Workgroup is a unit of the IEEE 802 local area network and metropolitan area network standards committee.

IEEE Although the family of standards is officially called WirelessMAN in IEEE, it has been commercialized under the name "WiMAX" (from "Worldwide Interoperability for Microwave Access") by the WiMAX Forum industry alliance. The Forum promotes and certifies compatibility and interoperability of products based on the IEEE standards.

IEEE The e-2005 amendment version was announced as being deployed around the world in The version IEEE was amended by IEEE j-2009.

IEEE Standards Projects publish draft and proposed standards with the letter "P" prefixed, which gets dropped and replaced by a dash and year when the standards are ratified and published.

Standard Description Status
IEEE Projects Standard Description Status

802.16-2001 Fixed Broadband Wireless Access (10–66 GHz) Superseded
IEEE Projects Fixed Broadband Wireless Access (10–66 GHz) Superseded

802.16.2-2001 Recommended practice for coexistence Superseded
IEEE Projects Recommended practice for coexistence Superseded

IEEE Projects 802.16a-2003 Physical layer and MAC definitions for 2–11 GHz Superseded

(Maintenance and rollup of 802.16.2–2001 and P802.16.2a) Current
IEEE Projects (Maintenance and rollup of –2001 and P a) Current

IEEE Projects 802.16f-2005 Management Information Base (MIB) for Superseded

802.16e-2005 Mobile Broadband Wireless Access System Superseded
IEEE Projects 802.16e-2005 Mobile Broadband Wireless Access System Superseded

(an amendment to IEEE 802.1D) Current
IEEE Projects (an amendment to IEEE 802.1D) Current

802.16g-2007 Management Plane Procedures and Services Superseded
IEEE Projects 802.16g-2007 Management Plane Procedures and Services Superseded

IEEE Projects (rollup of –2004, /Cor 1, e, f, g and P802.16i) Current

802.16j-2009 Multihop relay Current
IEEE Projects 802.16j-2009 Multihop relay Current

IEEE Projects 802.16h-2010 Improved Coexistence Mechanisms for License-Exempt Operation Current

IEEE Projects Aiming at fulfilling the ITU-R IMT-Advanced requirements on 4G systems. Current

IEEE Projects P802.16p Enhancements to Support Machine-to-Machine Applications In Progress

IEEE PHY 802.16e uses Scalable OFDMA to carry data, supporting channel bandwidths of between 1.25 MHz and 20 MHz, with up to 2048 sub-carriers

IEEE PHY Although the standards allow operation in any band from 2 to 66 GHz, mobile operation is best in the lower bands which are also the most crowded, and therefore most expensive.

IEEE MAC The MAC describes a number of Convergence Sublayers which describe how wireline technologies such as Ethernet, Asynchronous Transfer Mode (ATM) and Internet Protocol (IP) are encapsulated on the air interface, and how data is classified, etc

IEEE MAC A key feature of is that it is a connection oriented technology. The subscriber station (SS) cannot transmit data until it has been allocated a channel by the Base Station (BS). This allows e to provide strong support for Quality of Service (QoS).

IEEE QoS Quality of service (QoS) in e is supported by allocating each connection between the SS and the BS (called a service flow in terminology) to a specific QoS class. In e, there are 5 QoS classes:

IEEE QoS Unsolicited Grant Service UGS Real-time data streams comprising fixed-size data packets issued at periodic intervals T1/E1 transport

IEEE QoS Real-time Polling Service rtPS Real-time data streams comprising variable-sized data packets that are issued at periodic intervals MPEG Video

IEEE QoS Non-real-time Polling Service nrtPS Delay-tolerant data streams comprising variable-sized data packets for which a minimum data rate is required FTP with guaranteed minimum throughput

IEEE QoS Best Effort BE Data streams for which no minimum service level is required and therefore may be handled on a space-available basis HTTP

IEEE QoS The BS and the SS use a service flow with an appropriate QoS class (plus other parameters, such as bandwidth and delay) to ensure that application data receives QoS treatment appropriate to the application.

IEEE Certification Because the IEEE only sets specifications but does not test equipment for compliance with them, the WiMAX Forum runs a certification program wherein members pay for certification. WiMAX certification by this group is intended to guarantee compliance with the standard and interoperability with equipment from other manufacturers. The mission of the Forum is to promote and certify compatibility and interoperability of broadband wireless products.

IEEE IEEE is a working group of the Institute of Electrical and Electronics Engineers (IEEE) IEEE 802 standards committee which specifies Wireless Personal Area Network (WPAN) standards. It includes seven task groups.

IEEE 802.15 - Task Group 1: WPAN / Bluetooth
Task group one is based on Bluetooth technology. It defines physical layer (PHY) and Media Access Control (MAC) specification for wireless connectivity with fixed, portable and moving devices within or entering personal operating space. Standards were issued in 2002 and 2005.

IEEE 802.15 - Task Group 2: Coexistence
Task group two addresses the coexistence of wireless personal area networks (WPAN) with other wireless devices operating in unlicensed frequency bands such as wireless local area networks (WLAN). The IEEE standard was published in 2003 and task group two went into "hibernation".

IEEE 802.15 - Task Group 3: High Rate WPAN
IEEE a was an attempt to provide a higher speed UWB PHY enhancement amendment to IEEE for applications which involve imaging and multimedia. The members of the task group were not able to come to an agreement choosing between two technology proposals, Multi-band Orthogonal Frequency Division Multiplexing (MB-OFDM) and Direct Sequence UWB (DS-UWB), on the table backed by two different industry alliances and was withdrawn in January 2006.

IEEE b-2005 amendment was released on May 5, It enhanced to improve implementation and interoperability of the MAC. This will include minor optimizations while preserving backward compatibility. In addition, this amendment corrected errors, clarified ambiguities, and added editorial clarifications.

The IEEE Task Group 3c (TG3c) was formed in March 2005

IEEE 802.15 - Task Group 4: Low Rate WPAN
IEEE (Low Rate WPAN) deals with low data rate but very long battery life (months or even years) and very low complexity. The standard defines both the physical (Layer 1) and data-link (Layer 2) layers of the OSI model. The first edition of the standard was released in May Several standardized and proprietary networks (or mesh) layer protocols run over based networks, including IEEE , ZigBee, 6LoWPAN, WirelessHART, and ISA100.11a.

IEEE 802.15 - WPAN Low Rate Alternative PHY (4a)
IEEE a (formally called IEEE a-2007) is an amendment to IEEE specifying additional physical layers (PHYs) to the original standard

IEEE 802.15 - Revision and Enhancement (4b)
IEEE b was approved in June 2006 and was published in September 2006 as IEEE The IEEE task group 4b was chartered to create a project for specific enhancements and clarifications to the IEEE standard, such as resolving ambiguities, reducing unnecessary complexity, increasing flexibility in security key usage, considerations for newly available frequency allocations, and others.

IEEE 802.15 - PHY Amendment for China (4c)
IEEE c was approved in 2008 and was published in January This defines a PHY amendment adds new rf spectrum specifications to address the Chinese regulatory changes which have opened the MHz, MHz, and MHz bands for Wireless PAN use within China.

IEEE 802.15 - PHY and MAC Amendment for Japan (4d)
The IEEE Task Group 4d was chartered to define an amendment to the existing standard The amendment defines a new PHY and such changes to the MAC as are necessary to support a new frequency allocation (950 MHz -956 MHz) in Japan while coexisting with passive tag systems in the band.

IEEE 802.15 - MAC Amendment for Industrial Applications (4e)
The IEEE Task Group 4e is chartered to define a MAC amendment to the existing standard The intent of this amendment is to enhance and add functionality to the MAC to a) better support the industrial markets and b) permit compatibility with modifications being proposed within the Chinese WPAN. Specific enhancements were made to add channel hopping and a variable time slot option compatible with ISA100.11a. These changes were approved in 2011.

IEEE 802.15 - PHY and MAC Amendment for Active RFID (4f)
The IEEE f Active RFID System Task Group is chartered to define new wireless Physical (PHY) layer(s) and enhancements to the standard MAC layer which are required to support new PHY(s) for Active RFID System bi-directional and location determination applications.

IEEE 802.15 - PHY Amendment for Smart Utility Network (4g)
IEEE g Smart Utility Networks (SUN) Task Group is chartered to create a PHY amendment to to provide a global standard that facilitates very large scale process control applications such as the utility smart-grid network capable of supporting large, geographically diverse networks with minimal infrastructure, with potentially millions of fixed endpoints. Recently news came up they released the g radio standard.

IEEE 802.15 - Task Group 5: mesh networking
The low-rate mesh is built on IEEE MAC, while the high rate mesh utilizes IEEE /3b MAC

IEEE 802.15 - Task Group 6: Body Area Networks
As of December 2011, the IEEE task group has approved a draft of a standard for Body Area Network (BAN) technologies

IEEE 802.15 - Task Group 7: visible light communication
As of December 2011, The IEEE Visible Light Communication Task Group has completed draft 5c of a PHY and MAC standard for Visible Light Communications (VLC). The inaugural meeting for Task Group 7 was held during January 2009, where it was chartered to write standards for free-space optical communication using visible light.

IEEE 802.15 - Wireless Next Generation Standing Committee
The IEEE P Wireless Next Generation Standing Committee (SCwng) is chartered to facilitate and stimulate presentations and discussions on new Wireless related Technologies that may be subject for new standardization projects or to address the whole work group with issues or concerns with current techniques or technologies.

IEEE 802.1Q IEEE 802.1Q is the networking standard that supports Virtual LANs (VLANs) on an Ethernet network. The standard defines a system of VLAN tagging for Ethernet frames and the accompanying procedures to be used by bridges and switches in handling such frames. The standard also contains provisions for a quality of service prioritization scheme commonly known as IEEE 802.1p and defines the Generic Attribute Registration Protocol.

IEEE 802.1Q Traffic on a VLAN-unaware (i.e., IEEE 802.1D conformant) portion of the network will not contain VLAN tags

IEEE 802.1Q The standard was developed by IEEE 802.1, a working group of the IEEE 802 standards committee and continues to be actively revised with notable revisions including IEEE 802.1ak, IEEE 802.1Qat and IEEE 802.1Qay.

IEEE 802.3-2005 Clause 3.5) IEEE 802.1Q - Frame format

IEEE 802.1Q - Frame format Tag Protocol Identifier (TPID): a 16-bit field set to a value of 0x8100 in order to identify the frame as an IEEE 802.1Q-tagged frame. This field is located at the same position as the EtherType/Length field in untagged frames, and is thus used to distinguish the frame from untagged frames.

IEEE 802.1Q - Frame format Priority Code Point (PCP): a 3-bit field which refers to the IEEE 802.1p priority. It indicates the frame priority level. Values are from 0 (best effort) to 7 (highest); 1 represents the lowest priority. These values can be used to prioritize different classes of traffic (voice, video, data, etc.). See also Class of Service or CoS.

IEEE 802.1Q - Frame format Drop Eligible Indicator (DEI): a 1-bit field. (formerly CFI[note 1]) May be used separately or in conjunction with PCP to indicate frames eligible to be dropped in the presence of congestion.

IEEE 802.1Q - Frame format VLAN Identifier (VID): a 12-bit field specifying the VLAN to which the frame belongs. The hexadecimal values of 0x000 and 0xFFF are reserved. All other values may be used as VLAN identifiers, allowing up to 4,094 VLANs. The reserved value 0x000 indicates that the frame does not belong to any VLAN; in this case, the 802.1Q tag specifies only a priority and is referred to as a priority tag. On bridges, VLAN 1 (the default VLAN ID) is often reserved for a management VLAN; this is vendor-specific.

IEEE 802.1Q - Frame format For frames using IEEE 802.2/SNAP encapsulation with an OUI field of (so that the protocol ID field in the SNAP header is an EtherType), as would be the case on LANs other than Ethernet, the EtherType value in the SNAP header is set to 0x8100 and the aforementioned extra 4 bytes are appended after the SNAP header.

IEEE 802.1Q - Frame format Because inserting the VLAN tag changes the frame, 802.1Q encapsulation forces a recalculation of the original FCS field in the Ethernet trailer.

IEEE 802.1Q - Frame format The IEEE 802.3ac standard increased the maximum Ethernet frame size from 1518 bytes to 1522 bytes to accommodate the four-byte VLAN tag. Some network devices that do not support the larger frame size will process the frame successfully but may report them as a "baby giant" anomalies.

IEEE 802.1Q - Double tagging With the IEEE standard 802.1ad, double-tagging can be useful for Internet service providers, allowing them to use VLANs internally while mixing traffic from clients that are already VLAN-tagged. The outer (next to source MAC and representing ISP VLAN) S-TAG (service tag) comes first, followed by the inner C-TAG (customer tag). In such cases, 802.1ad specifies a TPID of 0x88a8 for service-provider outer S-TAG.

Non-standard triple-tagging is also possible
IEEE 802.1Q - Double tagging Non-standard triple-tagging is also possible

IEEE 802.1Q - Double tagging The contents of TPID0+TPID1+TPID2 contain the 48-bit MAC Address of the Source Device.

IEEE 802.1Q - Trunk ports and the native VLAN
The terminology of trunk ports and native VLANs is non-standard. Annex D to the Q standard uses the concept of trunk links, but the current (IEEE Std 802.1Q-2011) standard does not use the terms "trunk" or "native."

Some vendors (most notably Cisco) use the concepts of a) trunk ports and b) native VLAN. The proprietary term native VLAN is similar to the 802.1Q PVID (port VLAN Identifier), which is used "to associate a VID with untagged and priority-tagged received frames." A trunk port can refer a port that sends and receives tagged frames on all VLANs, except the native VLAN, if one is configured. The term trunk may also be used to refer to a connection using link aggregation.

Frames belonging to the native VLAN do NOT carry VLAN tags when sent over the trunk. Conversely, if an untagged frame is received on a trunk port, the frame is associated with the native VLAN configured on that port.

For example, if an 802.1Q port has VLANs 2, 3 and 4 assigned to it, with VLAN 2 being the native VLAN, frames on VLAN 2 that are sent from the aforementioned port are not given an 802.1Q header (i.e

Note that unexpected results may occur if the native VLAN configuration is not the same on all sending and receiving ports on a link

IEEE 802.1Q - Multiple VLAN Registration Protocol
In addition, IEEE 802.1Q defines the Multiple VLAN Registration Protocol (MVRP), an application of the Multiple Registration Protocol, allowing bridges to negotiate the set of VLANs to be used over a specific link.

IEEE 802.1Q - Multiple Spanning Tree Protocol
The 2003 revision of the standard included the Multiple Spanning Tree Protocol (MSTP) which was originally defined in IEEE 802.1s.

IEEE 802.3 - Communication Standards
Ethernet Mbit/s (367 kB/s) over coaxial cable (coax) bus

(DIX v2.0) Mbit/s (1.25 MB/s) over thick coax. Frames have a Type field. This frame format is used on all forms of Ethernet by protocols in the Internet protocol suite.

802.3u BASE-TX, 100BASE-T4, 100BASE-FX Fast Ethernet at 100 Mbit/s (12.5 MB/s) w/autonegotiation

802.3x 1997 Full Duplex and flow control; also incorporates DIX framing, so there's no longer a DIX/802.3 split

802.3y BASE-T2 100 Mbit/s (12.5 MB/s) over low quality twisted pair

802.3ac 1998 Max frame size extended to 1522 bytes (to allow "Q-tag") The Q-tag includes 802.1Q VLAN information and 802.1p priority information.

A revision of base standard incorporating the four prior amendments and errata.

802.3an GBASE-T 10 Gbit/s (1,250 MB/s) Ethernet over unshielded twisted pair (UTP)

802.3ap 2007 Backplane Ethernet (1 and 10 Gbit/s (125 and 1,250 MB/s) over printed Circuit Boards)

802.3aq GBASE-LRM 10 Gbit/s (1,250 MB/s) Ethernet over multimode fiber

802.3au 2006 Isolation requirements for Power over Ethernet ( /Cor 1)

802.3aw 2007 Fixed an equation in the publication of 10GBASE-T (released as /Cor 2)

802.3ba Gbit/s and 100 Gbit/s Ethernet. 40 Gbit/s over 1m backplane, 10 m Cu cable assembly (4x25 Gbit or 10x10 Gbit lanes) and 100 m of MMF and 100 Gbit/s up to 10 m of Cu cable assembly, 100 m of MMF or 40 km of SMF respectively

/Cor Increase Pause Reaction Delay timings which are insufficient for 10 Gbit/s (workgroup name was 802.3bb)

802.3bc 2009 Move and update Ethernet related TLVs (type, length, values), previously specified in Annex F of IEEE 802.1AB (LLDP) to

802.3bd 2010 Priority-based Flow Control. An amendment by the IEEE Data Center Bridging Task Group (802.1Qbb) to develop an amendment to IEEE Std to add a MAC Control Frame to support IEEE 802.1Qbb Priority-based Flow Control.

MIB definitions for Ethernet. It consolidates the Ethernet related MIBs present in Annex 30A&B, various IETF RFCs, and 802.1AB annex F into one master document with a machine readable extract. (workgroup name was P802.3be)

802.3bf 2011 Provide an accurate indication of the transmission and reception initiation times of certain packets as required to support IEEE P802.1AS.

802.3bg 2011 Provide a 40 Gbit/s PMD which is optically compatible with existing carrier SMF 40 Gbit/s client interfaces (OTU3/STM-256/OC-768/40G POS).

802.3bj ~Mar 2014 Define a 4-lane 100 Gbit/s backplane PHY for operation over links consistent with copper traces on “improved FR-4” (as defined by IEEE P802.3ap or better materials to be defined by the Task Force) with lengths up to at least 1m and a 4-lane 100 Gbit/s PHY for operation over links consistent with copper twin-axial cables with lengths up to at least 5m.

MediaTek - IEEE As a result of the merger with Ralink, MediaTek has added wireless network interface controllers for IEEE standards, and SoCs with MIPS CPUs to its product portfolio.

RT3883 includes a MIPS 74KEc CPU and a IEEE 802.11n-conformant WNIC
MediaTek - IEEE RT3883 includes a MIPS 74KEc CPU and a IEEE n-conformant WNIC

RT6856 includes a MIPS 34KEc CPU and a IEEE 802.11ac-conformant WNIC
MediaTek - IEEE RT6856 includes a MIPS 34KEc CPU and a IEEE ac-conformant WNIC

IEEE Computer Society IEEE Computer Society (sometimes abbreviated Computer Society or CS) is a professional society of IEEE. Its purpose and scope is “to advance the theory, practice, and application of computer and information processing science and technology” and the “professional standing of its members.” The CS is the largest of 38 technical societies organized under the IEEE Technical Activities Board.

IEEE Computer Society The Computer Society sponsors workshops and conferences, publishes a variety of peer-reviewed literature, operates technical committees, and develops IEEE computing standards. It supports more than 200 chapters worldwide and participates in educational activities at all levels of the profession, including distance learning, accreditation of higher education programs in computer science, and professional certification in software engineering.

IEEE Computer Society The IEEE Computer Society is also a member organization of the Federation of Enterprise Architecture Professional Organizations (FEAPO), a worldwide association of professional organizations which have come together to provide a forum to standardize, professionalize, and otherwise advance the discipline of Enterprise Architecture.

IEEE Computer Society - History
The group established its own constitution and bylaws in 1971 to become the IEEE Computer Society.

IEEE Computer Society - History
The CS maintains its headquarters in Washington, D.C. and additional offices in California and Japan.

IEEE Computer Society - Main activities
The Computer Society maintains volunteer boards in six program areas: education, membership, professional activities, publications, standards, and technical and conference activities. In addition, 12 standing committees administer activities such as the CS elections and its awards programs to recognize professional excellence.

IEEE Computer Society - Education and professional development
The Computer Society participates in ongoing development of college computing curricula, jointly with the Association for Computing Machinery (ACM). Other educational activities include software development certification programs and online access to e-learning courseware and books.

IEEE Computer Society - Publications
The Computer Society is a leading publisher of technical material in computing. Its publications include 13 peer-reviewed technical magazines and 20 scholarly journals called Transactions as well as conference proceedings, books, and a variety of digital products.

IEEE Computer Society - Publications
The Computer Society Digital Library (CSDL) provides subscriber access to all CS publications. In 2008, the Computer Society launched Computing Now, a Web portal featuring free access to a rotation of CSDL articles, along with technical news, CS blogs, and multimedia content.

IEEE Computer Society - Technical conferences and activities
The Computer Society sponsors more than 170 technical conferences each year and coordinates the operation of about 30 committees (e.g., the Technical Committee on Multimedia Computing), councils (e.g., the Technical Council on Software Engineering), and task forces.

The CS also maintains 12 standards committees to develop IEEE standards in various areas of Computer and software engineering (e.g., the Design Automation Standards Committee and the IEEE 802 LAN/MAN Standards Committee).

In 2010 the CS introduced Special Technical Communities (STCs) as a new way for members to develop communities focusing on selected technical areas, integrating with contemporary technology in a way that breaks down silos and fosters growth in a dynamic environment

IEEE Computer Society - Awards
The IEEE Computer Society recognizes outstanding work by computer professionals who advance the field in three areas of achievement: Technical Awards (e.g., the Seymour Cray Computer Engineering Award or the IEEE Computer Pioneer Award), Education Awards (e.g., Taylor L. Booth Education Award), and Service Awards (e.g., Richard E. Merwin Distinguished Service Award).

Test plan - IEEE 829 test plan structure
IEEE , also known as the 829 Standard for Software Test Documentation, is an IEEE standard that specifies the form of a set of documents for use in defined stages of software testing, each stage potentially producing its own separate type of document.

Suspension criteria and resumption requirements

The IEEE documents that suggest what should be contained in a test plan are:

IEEE Standard for Software and System Test Documentation

IEEE Standard for Software Test Documentation (superseded by )

IEEE Standard for Software Unit Testing

IEEE Standard for Software Verification and Validation (superseded by )

IEEE Standard for Software Verification and Validation Plans (superseded by )

IEEE Guide for Software Verification & Validation Plans (withdrawn)

Exception handling - Hardware exception handling/traps: IEEE 754 floating point
Exception handling in the IEEE 754 floating point hardware standard refers in general to exceptional conditions and defines an exception as "an event that occurs when an operation on some particular operands has no outcome suitable for every reasonable application. That operation might signal one or more exceptions by invoking the default or, if explicitly requested, a language-defined alternate handling."

infinity for a divide by zero exception, and providing status flags for later checking of whether the exception occurred (see C99 programming language for a typical example of handling of IEEE 754 exceptions)

The IEEE 754 standard uses the term "trapping" to refer to the calling of a user-supplied exception-handling routine on exceptional conditions, and is an optional feature of the standard. The standard recommends several usage scenarios for this, including the implementation of non-default pre-substitution of a value followed by resumption, to concisely handle removable singularities (see for an example of this approach). Other examples are given in the following references:.

The default IEEE 754 exception handling behaviour of resumption following pre-substitution of a default value avoids the risks inherent in changing flow of program control on numerical exceptions: for example, in 1996 the Ariane V rocket exploded due in part to the Ada programming language exception handling policy of aborting computation on arithmetic error - a floating point to integer conversion overflow - which would not have occurred if the IEEE 754 exception-handling policy of default substitution had been used.

From the processing point of view, hardware interrupts are similar to resumeable exceptions, though they are typically unrelated to the user program's control flow.

IEEE 829 IEEE , also known as the 829 Standard for Software and System Test Documentation, is an IEEE standard that specifies the form of a set of documents for use in eight defined stages of software testing, each stage potentially producing its own separate type of document

IEEE 829 Master Test Plan (MTP): The purpose of the Master Test Plan (MTP) is to provide an overall test planning and test management document for multiple levels of test (either within one project or across multiple projects).

IEEE 829 Level Test Plan (LTP): For each LTP the scope, approach, resources, and schedule of the testing activities for its specified level of testing need to be described. The items being tested, the features to be tested, the testing tasks to be performed, the personnel responsible for each task, and the associated risk(s) need to be identified.

IEEE 829 Level Test Case (LTC): Specifying the test data for use in running the test cases identified in the Level Test Design.

IEEE 829 Level Test Procedure (LTPr): Detailing how to run each test, including any set-up preconditions and the steps that need to be followed.

IEEE 829 Level Test Log (LTL): To provide a chronological record of relevant details about the execution of tests, e.g. recording which tests cases were run, who ran them, in what order, and whether each test passed or failed.

IEEE 829 Anomaly Report (AR): To document any event that occurs during the testing process that requires investigation

IEEE 829 Level Interim Test Status Report (LITSR): To summarize the interim results of the designated testing activities and optionally to provide evaluations and recommendations based on the results for the specific test level.

IEEE 829 Level Test Report (LTR): To summarize the results of the designated testing activities and to provide evaluations and recommendations based on the results after test execution has finished for the specific test level.

IEEE 829 Master Test Report (MTR): To summarize the results of the levels of the designated testing activities and to provide evaluations based on these results

IEEE Use of IEEE 829 The standard forms part of the training syllabus of the ISEB Foundation and Practitioner Certificates in Software Testing promoted by the British Computer Society. ISTQB, following the formation of its own syllabus based on ISEB's and Germany's ASQF syllabi, also adopted IEEE 829 as the reference standard for software and system test documentation.

IEEE n-2009 It is an amendment to the IEEE wireless networking standard

IEEE n-2009 Proposed enhancements to n are under development as part of IEEE ac.

IEEE n Description IEEE n is an amendment to IEEE as amended by IEEE k-2008, IEEE r-2008, IEEE y-2008, and IEEE w-2009, and builds on previous standards by adding multiple-input multiple-output (MIMO) and 40MHz channels to the physical layer|PHY (physical layer), and frame aggregation to the MAC layer.

IEEE n Description MIMO is a technology that uses multiple antennas to coherently resolve more information than possible using a single antenna

IEEE n Description It can be enabled in the 5GHz mode, or within the 2.4GHz mode if there is knowledge that it will not interfere with any other or non (such as Bluetooth) system using the same frequencies. The MIMO architecture, together with wider-bandwidth channels, offers increased physical transfer rate over a (5GHz) and IEEE g-2003|802.11g (2.4GHz).

IEEE n Data encoding The transmitter and receiver use precoding and postcoding techniques, respectively, to achieve the capacity of a MIMO link. Precoding includes beamforming|spatial beamforming and spatial coding, where spatial beamforming improves the received signal quality at the decoding stage. Spatial coding can increase data throughput via spatial multiplexing and increase range by exploiting the spatial diversity, through techniques such as Space–time block code|Alamouti coding.

IEEE 802.11n-2009 - Number of antennas
The number of simultaneous data streams is limited by the minimum number of antennas in use on both sides of the link

IEEE 802.11n-2009 - Number of antennas
The n draft allows up to 4 x 4 : 4. Common configurations of 11n devices are 2 x 2 : 2; 2 x 3 : 2; and 3 x 2 : 2. All three configurations have the same maximum throughputs and features, and differ only in the amount of diversity the antenna systems provide. In addition, a fourth configuration, 3 x 3 : 3 is becoming common, which has a higher throughput, due to the additional data stream. (PDF)

IEEE n Data rates Data rates up to 600Mbit/s are achieved only with the maximum of four spatial streams using one 40MHz-wide channel. Various modulation schemes and coding rates are defined by the standard and are represented by a Modulation and Coding Scheme (MCS) index value. The table below shows the relationships between the variables that allow for the maximum data rate. GI (Guard Interval) : Timing between symbols.

IEEE 802.11n-2009 - Frame aggregation
PHY level data rate improvements do not increase user level throughput beyond a point because of protocol overheads, like the contention process, interframe spacing, PHY level headers (Preamble + PLCP) and acknowledgment frames. The main media access control (MAC) feature that provides a performance improvement is aggregation. Two types of aggregation are defined:

# Aggregation of MAC service data units (MSDUs) at the top of the MAC (referred to as MSDU aggregation or A-MSDU)

# Aggregation of MAC protocol data units (MPDUs) at the bottom of the MAC (referred to as MPDU aggregation or A-MPDU)

Frame aggregation is a process of packing multiple MSDUs or MPDUs together to reduce the overheads and average them over multiple frames, thereby increasing the user level data rate. A-MPDU aggregation requires the use of block acknowledgement or BlockAck, which was introduced in e and has been optimized in n.

IEEE 802.11n-2009 - Backward compatibility
When g was released to share the band with existing b devices, it provided ways of ensuring coexistence between legacy and successor devices n extends the coexistence management to protect its transmissions from legacy devices, which include IEEE g-2003|802.11g, IEEE b-1999|802.11b and IEEE a-1999|802.11a. There are MAC and PHY level protection mechanisms as listed below:

# PHY level protection: Transmissions using a 40MHz channel in the presence of a or g clients require using IEEE RTS/CTS|CTS protection on both 20MHz halves of the 40MHz channel, to prevent interference with legacy devices.

# MAC level protection: An RTS/CTS frame exchange or CTS frame transmission at legacy rates can be used to protect subsequent 11n transmission.

Even with protection, large discrepancies can exist between the throughput an n device can achieve in a greenfield project|greenfield network, compared to a mixed-mode network, when legacy devices are present. This is an extension of the b/802.11g coexistence problem.

IEEE 802.11n-2009 - Deployment strategies
To achieve maximum output, a pure n 5GHz network is recommended

IEEE n MHz in 2.4GHz The 2.4GHzISM band is fairly congested. With n, there is the option to double the bandwidth per channel to 40MHz which results in slightly more than double the data rate. However, when in 2.4GHz, enabling this option takes up to 82%Example: Channel 3 SCA (secondary channel above) also known as 3+7 reserves the first 9 out of the 11 channels available in North America. of the unlicensed band, which in many areas may prove to be infeasible.

IEEE n MHz in 2.4GHz The specification calls for requiring one primary 20MHz channel as well as a secondary adjacent channel spaced ±20MHz away. The primary channel is used for communications with clients incapable of 40MHz mode. When in 40MHz mode, the center frequency is actually the arithmetic mean|mean of the primary and secondary channels.

IEEE n MHz in 2.4GHz Local regulations may restrict certain channels from operation. For example, Channels 12 and 13 are normally unavailable for use as either a primary or secondary channel in North America. For further information, see List of WLAN channels.

IEEE 802.11n-2009 - Wi-Fi Alliance
As of mid-2007, the Wi-Fi Alliance started certifying products based on IEEE n draft 2.0.

IEEE n Timeline ;September 11, 2002: The first meeting of the High-Throughput Study Group (HTSG) was held. Earlier in the year, in the Wireless Next Generation standing committee (WNG SC), presentations were heard on why they need change and what the target throughput would be required to justify the amendments. Compromise was reached in May 2002 to delay the start of the Study Group until September to allow 11g to complete major work during the July 2002 session.

IEEE n Timeline The TGn amendment is based on IEEE Std , as amended by IEEE Std k-2008, IEEE Std r-2008, IEEE Std y-2008 and IEEE P802.11w

IEEE n Timeline ;September 15, 2003: The first meeting of the new Task Group (TGn).

;May 17, 2004: Call for Proposals was issued.
IEEE n Timeline ;May 17, 2004: Call for Proposals was issued.

;September 13, 2004: 32 first round of proposals were heard.
IEEE n Timeline ;September 13, 2004: 32 first round of proposals were heard.

IEEE n Timeline ;March 2005: Proposals were downselected to a single proposal, but there is not a 75% consensus on the one proposal. Further efforts were expended over the next 3 sessions without being able to agree on one proposal.

IEEE n Timeline ;July 2005: Previous competitors TGn Sync, WWiSE, and a third group, MITMOT, said that they would merge their respective proposals as a draft. The standardization process was expected to be completed by the second quarter of 2009.

IEEE n Timeline ; January 19, 2006: The IEEE n Task Group approved the Joint Proposal's specification, enhanced by EWC's draft specification.

IEEE n Timeline ;March 2006: IEEE Working Group sent the n draft to its first letter ballot, allowing the voters to review the document and suggest bug fixes, changes, and improvements.

IEEE n Timeline ; May 2, 2006: The IEEE Working Group voted not to forward draft 1.0 of the proposed n standard. Only 46.6% voted to approve the ballot. To proceed to the next step in the IEEE standards process, a majority vote of 75% is required. This letter ballot also generated approximately 12,000 comments—many more than anticipated.

IEEE n Timeline ;November 2006: TGn voted to accept draft version 1.06, incorporating all accepted technical and editorial comment resolutions prior to this meeting. An additional 800 comment resolutions were approved during the November session which will be incorporated into the next revision of the draft. As of this meeting, three of the 18 comment topic Ad Hoc groups chartered in May had completed their work, and 88% of the technical comments had been resolved, with approximately 370 remaining.

IEEE n Timeline ;January 19, 2007: The IEEE Working Group unanimously (100 yes, 0 no, 5 abstaining) approved a request by the n Task Group to issue a new draft 2.0 of the proposed standard. Draft 2.0 was based on the Task Group's working draft version Draft 2.0 was at this point in time the cumulative result of thousands of changes to the 11n document as based on all previous comments.

IEEE n Timeline ;February 7, 2007: The results of Letter Ballot 95, a 15-day Procedural vote, passed with 97.99% approval and 2.01% disapproval. On the same day, Working Group announced the opening of Letter Ballot 97. It invited detailed technical comments to closed on 9 March 2007.

IEEE n Timeline ;March 9, 2007: Letter Ballot 97, the 30-day Technical vote to approve draft 2.0, closed. They were announced by IEEE 802 leadership during the Orlando Plenary on 12 March The ballot passed with an 83.4% approval, above the 75% minimum approval threshold. There were still approximately 3,076 unique comments, which were to be individually examined for incorporation into the next revision of draft 2.

IEEE n Timeline ;June 25, 2007: The Wi-Fi Alliance announced its official certification program for devices based on draft 2.0.

IEEE n Timeline ;September 7, 2007: Task Group agreed on all outstanding issues for draft Draft 3.0 is authorized, with the expectation that it go to a sponsor ballot in November 2007.

IEEE n Timeline ;November 2007: Draft 3.0 approved (240 voted affirmative, 43 negative, and 27 abstained). The editor was authorized to produce draft 3.01.

IEEE n Timeline ;January 2008:Draft 3.02 approved. This version incorporates previously approved technical and editorial comments. There remain 127 unresolved technical comments. It was expected that all remaining comments will be resolved and that TGn and WG11 would subsequently release draft 4.0 for working group recirculation ballot following the March meeting.

IEEE n Timeline ;July 2008:Draft 5.0 approved and anticipated publication timeline modified.

IEEE n Timeline ;January 2009:Draft 7.0 forwarded to sponsor ballot; the sponsor ballot was approved (158 for, 45 against, 21 abstaining); 241 comments were received.

IEEE n Timeline ;March 2009: Draft 8.0 proceeded to sponsor ballot recirculation; the ballot passed by an 80.1% majority (75% required) (228 votes received, 169 approve, 42 not approve); 277 members are in the sponsor ballot pool; The comment resolution committee resolved the 77 comments received, and authorized the editor to create a draft 9.0 for further balloting.

IEEE n Timeline ;April 4, 2009: Draft 9.0 passed sponsor ballot recirculation; the ballot passed by an 80.7% majority (75% required) (233 votes received, 171 approve, 41 not approve); 277 members are in the sponsor ballot pool; The comment resolution committee is resolving the 23 new comments received, and will authorize the editor to create a new draft for further balloting.

;May 15, 2009: Draft 10.0 passed sponsor ballot recirculation.
IEEE n Timeline ;May 15, 2009: Draft 10.0 passed sponsor ballot recirculation.

;June 23, 2009: Draft 11.0 passed sponsor ballot recirculation.
IEEE n Timeline ;June 23, 2009: Draft 11.0 passed sponsor ballot recirculation.

IEEE n Timeline ;July 17, 2009: Final WG Approval passed with 53 approve, 1 against, 6 abstain. Powerpoint Slide 10 Unanimous approval to send Final WG draft 11.0 to RevCom.

Common External Power Supply - IEEE P1823, Universal Power Adapter for Mobile Devices (UPAMD)
Institute of Electrical and Electronics Engineers|IEEE P1823 is a proposed global standard for a Universal Power Adapter for Mobile Devices (UPAMD) that require between 10Watt|W and 240W. e.g. Laptop|Laptop PCs, larger Tablet computer|tablets and other mobile devices that can require much more power than the current USB battery charging specification limit of 7.5W at 5V.

Double-precision floating-point format - IEEE 754 double-precision binary floating-point format: binary64 Double-precision binary floating-point is a commonly used format on PCs, due to its wider range over single-precision floating point, in spite of its performance and bandwidth cost. As with single-precision floating-point format, it lacks precision on integer numbers when compared with an integer format of the same size. It is commonly known simply as double. The IEEE 754 standard specifies a 'binary64' as having:

Double-precision floating-point format - IEEE 754 double-precision binary floating-point format: binary64 This gives from 15–17 significant decimal digits precision. If a decimal string with at most 15 significant digits is converted to IEEE 754 double precision representation and then converted back to a string with the same number of significant digits, then the final string should match the original; and if an IEEE 754 double precision is converted to a decimal string with at least 17 significant digits and then converted back to double, then the final number must match the original.

Double-precision floating-point format - IEEE 754 double-precision binary floating-point format: binary64 The format is written with the significand having an implicit integer bit of value 1 (except for special datums, see the exponent encoding below). With the 52 bits of the fraction significand appearing in the memory format, the total precision is therefore 53 bits (approximately 16 decimal digits, 53 log10(2) = ). The bits are laid out as follows:

Double-precision floating-point format - IEEE 754 double-precision binary floating-point format: binary64 The real value assumed by a given 64-bit double-precision datum with a given biased exponent 'e'

Double-precision floating-point format - IEEE 754 double-precision binary floating-point format: binary64 Between 252=4,503,599,627,370,496 and 253=9,007,199,254,740,992 the representable numbers are exactly the integers. For the next range, from 253 to 254, everything is multiplied by 2, so the representable numbers are the even ones, etc. Conversely, for the previous range from 251 to 252, the spacing is 0.5, etc.

Double-precision floating-point format - IEEE 754 double-precision binary floating-point format: binary64 The spacing as a fraction of the numbers in the range from 2n to 2n+1 is 2n−52.

Double-precision floating-point format - IEEE 754 double-precision binary floating-point format: binary64 The maximum relative rounding error when rounding a number to the nearest representable one (the machine epsilon) is therefore 2−53.

IEEE g-2003 'IEEE g-2003' or '802.11g' is an amendment to the IEEE specification that extended throughput to up to 54 Mbit/s using the same 2.4 GHz band as b. This specification under the marketing name of Wi-Fi has been implemented all over the world. The g protocol is now Clause 19 of the published IEEE # |IEEE standard, and Clause 19 of the published IEEE # |IEEE standard.

802.11g is the third modulation standard for wireless LANs
IEEE g Descriptions 802.11g is the third modulation standard for wireless LANs

IEEE g Descriptions The modulation scheme used in g is orthogonal frequency-division multiplexing (OFDM) copied from a with data rates of 6, 9, 12, 18, 24, 36, 48, and 54 Mbit/s, and reverts to Complementary code keying|CCK (like the b standard) for 5.5 and 11 Mbit/s and Phase-shift keying|DBPSK/Phase-shift keying|DQPSK+DSSS for 1 and 2 Mbit/s. Even though g operates in the same frequency band as b, it can achieve higher data rates because of its heritage to a.

IEEE g Adoption The then-proposed g standard was rapidly adopted by consumers starting in January 2003, well before ratification, due to the desire for higher speeds and reductions in manufacturing costs. By summer 2003, most dual-band a/b products became dual-band/tri-mode, supporting a and b/g in a single mobile adapter card or access point.

IEEE g Adoption Despite its major acceptance, g suffers from the same interference as b in the already crowded 2.4 GHz range

IEEE 802.11g-2003 - Channels and frequencies
:Note: Not all channels are legal to use in all countries.

IEEE The 'Institute of Electrical and Electronics Engineers' ('IEEE', read I-Triple-E) is a professional association headquartered in New York City that is dedicated to advancing technological innovation and excellence. It has about 425,000 members in about 160 countries, slightly less than half of whom reside in the United States.

IEEE Spectrum 'IEEE Spectrum' is a magazine edited by the Institute of Electrical and Electronics Engineers. The IEEE's description of it is:

IEEE Spectrum : IEEE Spectrum Magazine, the flagship publication of the IEEE, explores the development, applications and implications of new technologies. It anticipates trends in engineering, science, and technology, and provides a forum for understanding, discussion and leadership in these areas.

IEEE Spectrum IEEE Spectrum began publishing in January 1964 as a successor to Electrical Engineering. It contains peer-reviewed articles pertaining to technology and science

IEEE Spectrum trends affecting business and society, with a scope that covers information pertaining

IEEE Spectrum to electrical and electronics engineering, mechanical and civil engineering, computer

IEEE Spectrum science, biology, physics and mathematics. Additional content is gleaned from several hundred

annual international conferences.
IEEE Spectrum annual international conferences.

IEEE Spectrum As a general magazine, the articles attempt to be accessible to non-specialists, though an engineering background is assumed.

IEEE Spectrum Twelve issues are published annually, and IEEE Spectrum has a circulation of over 380,000 engineers worldwide, making it one of the leading science and engineering magazines.

IEEE Spectrum Article submission to IEEE Spectrum is open access. Individuals and corporations have the right to post their

IEEE Spectrum IEEE-copyrighted materials on their own servers without express permission.

IEEE Spectrum In 2010, IEEE Spectrum was the recipient of Utne Reader magazine's Utne Independent Press Award for Science/Technology Coverage.

IEEE 'IEEE ' is a standard which specifies the physical layer and Media Access Control|media access control for low-rate wireless personal area networks (LR-WPANs). It is maintained by the IEEE working group.

IEEE ISA100.11a, WirelessHART, and MiWi specifications, each of which further extends the standard by developing the upper Protocol stack|layers which are not defined in IEEE Alternatively, it can be used with 6LoWPAN and standard Internet protocols to build a wireless embedded Internet.

IEEE Overview IEEE standard intends to offer the fundamental lower network layers of a type of wireless personal area network (WPAN) which focuses on low-cost, low-speed ubiquitous communication between devices (in contrast with other, more end-user oriented approaches, such as Wi-Fi). The emphasis is on very low cost communication of nearby devices with little to no underlying infrastructure, intending to exploit this to lower power consumption even more.

IEEE Overview The basic framework conceives a 10-meter communications range with a transfer rate of 250 kbit/s. Tradeoffs are possible to favor more radically Embedded system|embedded devices with even lower power requirements, through the definition of not one, but several physical layers. Lower transfer rates of 20 and 40 kbit/s were initially defined, with the 100 kbit/s rate being added in the current revision.

IEEE Overview Even lower rates can be considered with the resulting effect on power consumption. As already mentioned, the main identifying feature of IEEE among WPANs is the importance of achieving extremely low manufacturing and operation costs and technological simplicity, without sacrificing flexibility or generality.

IEEE Overview Important features include Real-time computing|real-time suitability by reservation of guaranteed time slots, collision avoidance through CSMA/CA and integrated support for secure communications. Devices also include power management functions such as link quality and energy detection.

IEEE Overview IEEE conformant devices may use one of three possible frequency bands for operation.

IEEE 802.15.4 - The physical layer
Physical layer is the initial layer in the OSI reference model used worldwide.

The physical layer (PHY) ultimately provides the data transmission service, as well as the interface to the physical layer management entity, which offers access to every layer management function and maintains a database of information on related personal area networks. Thus, the PHY manages the physical Radio frequency|RF transceiver and performs channel selection and energy and signal management functions. It operates on one of three possible unlicensed frequency bands:

* MHz: Europe, allows one communication channel (2003), extended to three (2006)

* MHz: North America, up to ten channels (2003), extended to thirty (2006)

* MHz: worldwide use, up to sixteen channels (2003, 2006)

The original 2003 version of the standard specifies two physical layers based on direct sequence spread spectrum (DSSS) techniques: one working in the 868/915MHz bands with transfer rates of 20 and 40 kbit/s, and one in the 2450MHz band with a rate of 250 kbit/s.

The 2006 revision improves the maximum data rates of the 868/915MHz bands, bringing them up to support 100 and 250 kbit/s as well

Beyond these three bands, the IEEE c study group considered the newly opened MHz, MHz, and MHz bands in China, while the IEEE Task Group 4d defined an amendment to to support the new 950MHz-956MHz band in Japan. First standard amendments by these groups were released in April 2009.

In August 2007, IEEE a was released expanding the four PHYs available in the earlier 2006 version to six, including one PHY using Direct Sequence ultra-wideband (UWB) and another using Chirp Spread Spectrum|chirp spread spectrum (CSS). The UWB PHY is allocated frequencies in three ranges: below 1GHz, between 3 and 5GHz, and between 6 and 10GHz. The CSS PHY is allocated spectrum in the 2450MHz ISM band.IEEE Computer Society, (August 31, 2007). IEEE Standard a-2007

In April, 2009 IEEE c and IEEE d were released expanding the available PHYs with several additional PHYs: one for 780MHz band using Phase-shift keying#Offset QPSK (OQPSK)|O-QPSK or MPSK,IEEE Computer Society, (April 17, 2009). IEEE Standard c-2009 another for 950MHz using Gaussian frequency-shift keying|GFSK or Phase-shift keying#Binary phase-shift keying (BPSK)|BPSK.IEEE Computer Society, (April 17, 2009). IEEE Standard d-2009

IEEE e was chartered to define a MAC amendment to the existing standard which adopts channel hopping strategy to improve support for the industrial markets increases, robustness against external interference and persistent multi-path fading. On February 6, 2012 the IEEE Standards Association Board approved the IEEE e which concluded all Task Group 4e efforts.

IEEE The MAC layer The medium access control (MAC) enables the transmission of MAC frames through the use of the physical channel. Besides the data service, it offers a management interface and itself manages access to the physical channel and network Beacon (networking)|beaconing. It also controls frame validation, guarantees Time-division multiplexing|time slots and handles node associations. Finally, it offers hook points for secure services.

IEEE The MAC layer Note that the IEEE standard does not use 802.1D or 802.1Q, i.e., it does not exchange standard Ethernet frames. The physical frame-format is specified in IEEE in section It is tailored to the fact that most IEEE PHYs only support frames of up to 127 bytes (adaptation layer protocols such as 6LoWPAN provide fragmentation schemes to support larger network layer packets).

IEEE Higher layers Other higher-level layers and interoperability sublayers are not defined in the standard. Specifications, such as 6LoWPAN and ZigBee specification|ZigBee, build on this standard. TinyOS, Unison RTOS, DSPnano RTOS and Contiki stacks also use a few items of IEEE hardware.

IEEE Node types The first one is the 'full-function device' (FFD). It can serve as the coordinator of a personal area network just as it may function as a common node. It implements a general model of communication which allows it to talk to any other device: it may also relay messages, in which case it is dubbed a coordinator (PAN coordinator when it is in charge of the whole network).

IEEE Node types On the other hand there are 'reduced-function devices' (RFD). These are meant to be extremely simple devices with very modest resource and communication requirements; due to this, they can only communicate with FFDs and can never act as coordinators.

IEEE Topologies Networks can be built as either peer-to-peer or Star network|star networks. However, every network needs at least one FFD to work as the coordinator of the network. Networks are thus formed by groups of devices separated by suitable distances. Each device has a unique 64-bit identifier, and if some conditions are met short 16-bit identifiers can be used within a restricted environment. Namely, within each PAN domain, communications will probably use short identifiers.

IEEE Topologies 'Peer-to-peer (or point-to-point)' networks can form arbitrary patterns of connections, and their extension is only limited by the distance between each pair of nodes

IEEE Topologies A more structured 'star' pattern is also supported, where the coordinator of the network will necessarily be the central node. Such a network can originate when an FFD decides to create its own PAN and declare itself its coordinator, after choosing a unique PAN identifier. After that, other devices can join the network, which is fully independent from all other star networks.

IEEE 802.15.4 - Data transport architecture
Data frame|Frames are the basic unit of data transport, of which there are four fundamental types (data, acknowledgment, beacon and MAC command frames), which provide a reasonable tradeoff between simplicity and robustness

Within superframes contention occurs between their limits, and is resolved by CSMA/CA

Data transfers to the coordinator require a beacon synchronization phase, if applicable, followed by CSMA/CA transmission (by means of slots if superframes are in use); Acknowledgement (data networks)|acknowledgment is optional

Point-to-point networks may either use unslotted CSMA/CA or synchronization mechanisms; in this case, communication between any two devices is possible, whereas in “structured” modes one of the devices must be the network coordinator.

In general, all implemented procedures follow a typical request-confirm/indication-response classification.

IEEE 802.15.4 - Reliability and security
The physical medium is accessed through a CSMA/CA protocol. Networks which are not using beaconing mechanisms utilize an unslotted variation which is based on the listening of the medium, leveraged by a Exponential backoff|random exponential backoff algorithm; acknowledgments do not adhere to this discipline. Common data transmission utilizes unallocated slots when beaconing is in use; again, confirmations do not follow the same process.

Confirmation messages may be optional under certain circumstances, in which case a success assumption is made. Whatever the case, if a device is unable to process a frame at a given time, it simply does not confirm its reception: Timeout (telecommunication)|timeout-based retransmission can be performed a number of times, following after that a decision of whether to abort or keep trying.

Because the predicted environment of these devices demands maximization of battery life, the protocols tend to favor the methods which lead to it, implementing periodic checks for pending messages, the frequency of which depends on application needs.

Regarding secure communications, the MAC sublayer offers facilities which can be harnessed by upper layers to achieve the desired level of security

In addition to this secure mode, there is another, insecure MAC mode, which allows access control lists merely as a means to decide on the acceptance of frames according to their (presumed) source.

Mobile broadband - IEEE 802.16 (WiMAX)
The IEEE working group IEEE , produces standards adopted in products using the WiMAX trademark. The original Fixed WiMAX standard was released in 2001 and Mobile WiMAX was added in The WiMAX Forum is a non-profit organization formed to promote the adoption of WiMAX compatible products and services.

Mobile broadband - IEEE 802.20
In 2002, the Institute of Electrical and Electronics Engineers (IEEE) established a Mobile Broadband Wireless Access (MBWA) working group. They developed the IEEE standard in 2008, with amendments in 2010.

IEEE b-1999 'IEEE b-1999' or '802.11b', is an amendment to the IEEE wireless networking specification that extends throughput up to 11 Mbit/s using the same 13-centimeter band|2.4GHz band. This specification is marketed as Wi-Fi and has been implemented all over the world. A related amendment was incorporated into the IEEE # |IEEE standard.

IEEE b Description 802.11b has a maximum raw data rate of 11 Mbit/s and uses the same Carrier sense multiple access with collision avoidance|CSMA/CA media access method defined in the original standard. Due to the CSMA/CA protocol overhead, in practice the maximum b throughput that an application can achieve is about 5.9 Mbit/s using Transmission Control Protocol|TCP and 7.1 Mbit/s using User Datagram Protocol|UDP.

IEEE b Description 802.11b products appeared on the market in mid-1999, since b is a direct extension of the Direct-sequence spread spectrum|DSSS (Direct-sequence spread spectrum) modulation technique defined in the original standard

IEEE b Description 802.11b devices suffer interference from other products operating in the 2.4 GHz band. Devices operating in the 2.4 GHz range include: microwave ovens, Bluetooth devices, baby monitors and cordless telephones. Interference issues and user density problems within the 2.4 GHz band have become a major concern and frustration for users.

IEEE b Range 802.11b is used in a point-to-multipoint configuration, wherein an Wireless access point|access point communicates via an omnidirectional antenna with mobile clients within the range of the access point

IEEE b Range Some b cards operate at 11 Mbit/s, but scale back to 5.5, then to 2, then to 1 Mbit/s (also known as Adaptive Rate Selection) in order to decrease the rate of re-broadcasts that result from errors.

IEEE 802.11b-1999 - Channels and Frequencies
:Note: Channel 14 is only allowed in Japan, Channels are allowed in most parts of the world, except the USA, where only Channels 1 to 11 are legal to use. More information can be found in the List of WLAN channels.

IEEE Communications Letters
The impact factor is 1.16 (2012), eigenfactor , and article influence score Communications Letters, IEEE[ IEEE Xplore digital library, Retrieved IEEE Communications Letters[ IEEE Communications Society, Retrieved

George Karagiannidis serves as the current Editor-in-Chief of the Communications Letters.

According to the publication's website, communications technology topics include, but are not limited to: Modulation and Signal Design; Speech, Image, and Video Communications; Coding Theory and Applications; Wireless Personal Communications, Spread Spectrum Communications, Synchronization and Channel Equalization; Detection and Estimation; Multiplexing and Carrier Techniques; Optical Communications, Communications Networking and Multimedia ATM Design.

Optical resolution - IEEE Std 208-1995 target
The 'IEEE ' resolution target is similar to the EIA target. Resolution is measured in horizontal and vertical TV lines.

IEEE floating-point standard
The international standard 'ISO/IEC/IEEE 60559:2011' (with identical content to IEEE 754) has been approved for adoption through ISO/IEC JTC1|JTC1/SC 25 under the ISO/IEEE PSDO Agreement[ FW: ISO/IEC/IEEE (IEEE Std )] and published.[ ISO/IEC/IEEE 60559: Information technology - Microprocessor Systems - Floating-Point arithmetic]

* arithmetic formats: sets of Binary code|binary and decimal floating-point data, which consist of finite numbers (including signed zeros and subnormal numbers), infinity|infinities, and special not a number values (NaNs)

* interchange formats: encodings (bit strings) that may be used to exchange floating-point data in an efficient and compact form

* rounding rules: properties to be satisfied when rounding numbers during arithmetic and conversions

* exception handling: indications of exceptional conditions (such as division by zero, overflow, etc.)

The standard also includes extensive recommendations for advanced exception handling, additional operations (such as trigonometric functions), expression evaluation, and for achieving reproducible results.

The standard is derived from and replaces IEEE , the previous version, following a seven-year IEEE 754 revision|revision process, chaired by Dan Zuras and edited by Mike Cowlishaw. The binary formats in the original standard are included in the new standard along with three new basic formats (one binary and two decimal). To conform to the current standard, an implementation must implement at least one of the basic formats as both an arithmetic format and an interchange format.

IEEE floating-point standard - Formats
An IEEE 754 format is a set of representations of numerical values and symbols. A format may also include how the set is encoded.

* Finite numbers, which may be either base 2 (binary) or base 10 (decimal). Each finite number is described by three integers: s= a sign (zero or one), c= a significand (or 'coefficient'), q= an exponent. The numerical value of a finite number is (−1)s × c × bq where b is the base (2 or 10). For example, if the sign is 1 (indicating negative), the significand is 12345, the exponent is −3, and the base is 10, then the value of the number is −

* Two kinds of NaN: a quiet NaN (qNaN) and a signaling NaN (sNaN). A NaN may carry a payload that is intended for diagnostic information indicating the source of the NaN. The sign of a NaN has no meaning, but it may be predictable in some circumstances.

The possible finite values that can be represented in a format are determined by the base (b), the number of digits in the significand (precision, p), and the exponent parameter emax:

* c must be an integer in the range zero through bp−1 (e.g., if b=10 and p=7 then c is 0 through )

* q must be an integer such that 1−emax ≤ q+p−1 ≤ emax (e.g., if p=7 and emax=96 then q is −101 through 90).

Hence (for the example parameters) the smallest non-zero positive number that can be represented is 1×10−101 and the largest is ×1090 ( ×1096), and the full range of numbers is − ×1096 through × The numbers −b1−emax and b1−emax (here, −1×10−95 and 1×10−95) are the smallest (in magnitude) normal numbers; non-zero numbers between these smallest numbers are called subnormal numbers.

Zero values are finite values with significand 0. These are signed zeros, the sign bit specifies if a zero is +0 (positive zero) or −0 (negative zero).

IEEE 1680 In computing 'IEEE 1680' refers to a standard by the IEEE for the environmental performance criteria for desktop computers, notebook computers and monitors.Code of Federal Regulations, Title 48, Federal Acquisition Regulations System, Chapter 1 (Pt. 1-51), Revised as of October 1, 2010 by Office of the Federal Register (U.S.) (Feb 25, 2011) ISBN page 516

IEEE 1680 IEEE 1680 is the defacto standard for green computing at the desktop level.Information Systems Theory: Explaining and Predicting Our Digital Society, Vol. 1 by Yogesh K. Dwivedi, Michael R. Wade and Scott L. Schneberger 2011 ISBN page 395

At the moment (Aug 2013), the 1680 standards family consists of:
IEEE 1680 At the moment (Aug 2013), the 1680 standards family consists of:

IEEE 1680 # – Umbrella Standard, provides guidelines and implementation procedures for this IEEE 1680 Family of Standards.

IEEE Intelligent Transportation Systems Society - Field of Interest
The IEEE ITS Society's field of interest is in theoretical, experimental and operational aspects of Electrical engineering|electrical and electronics engineering and Information technology|information technologies as applied to Intelligent Transportation Systems (ITS), defined as those systems utilizing Synergistic technology|synergistic technologies and systems engineering concepts to develop and improve transportation systems of all kinds.[ IEEE ITSS Field of Interest Statement]

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