1. Lecture 2: Facts of network technologies developments Networking Trends

2. Introduction Computer networks: A computer network is a system of interconnected computers and peripheral devices. Communication: Communications is about the transfer of information from a sender, across a distance, to a receiver The older forms of communications technology, such as telephones and radios, use analog signals. Computers communicate with digital signals.

3. Top Networking Research Topics 1.Security 2.Mobile Computing 3.Network-based computing 1.Cloud Computing 2.Grid Computing 3.Internet-of-things (IoT) 4.Voice-over-IP (VoIP) 5.Large-scale wireless networks (Sensors, RFID) 6.High-speed wireless

4. Mobile Computing Mobile computing is a generic term describing one's ability to use technology while moving. Mobile computing involves: mobile communication, mobile hardware, and mobile software.  Mobile Hardware includes mobile devices or device components.  Mobile software deals with the characteristics and requirements of mobile applications.  Communication issues in mobile computing include ad hoc and infrastructure networks as well as communication properties, protocols, data formats and the existing technologies.

5. Mobile Computing: Items  There are at least three different classes of mobile computing items:  portable computers, compacted lightweight units including a full character set keyboard and primarily intended as hosts for software that may be parametrized, as laptops, notebooks, notepads, etc.  mobile phones including a restricted key set primarily intended but not restricted to for vocal communications, as cell phones, smart phones, phonepads, etc.  wearable computers, mostly limited to functional keys and primarily intended as incorporation of software agents, as watches, wristbands, necklaces, keyless implants, etc.  The existence of these classes is expected to be long lasting, and complementary in personal usage, none replacing one the other in all features of convenience..

6. Mobile Computing: Devices and Limitations  Devices  Many types of mobile computers have been introduced since the 1990s including the:  Personal digital assistant/enterprise digital assistant  Smartphone  Tablet computer  Ultra-Mobile PC  Wearable computer  Limitations  Range & Bandwidth  Security standards  Power consumption  Transmission interferences  Potential health hazards  Human interface with device

7. Internet-based technologies and services: VoIP  VoIP  Voice over Internet Protocol (VoIP) is a general term for a family of transmission technologies for delivery of voice communications over IP networks such as the Internet or other packet-switched networks.  Other terms frequently encountered and synonymous with VoIP are IP telephony, Internet telephony, voice over broadband (VoBB), broadband telephony, and broadband phone.

8. VoIP  Internet telephony refers to communications services including: voice, fax, and voice-messaging applications-that are transported via the Internet, rather than the public switched telephone network (PSTN).  The basic steps involved in originating an Internet telephone call are:  conversion of the analog voice signal to digital format, and  compression/translation of the signal into Internet protocol(IP) packets for transmission over the Internet;  the process is reversed at the receiving end.

9. VoIP  VoIP systems employ session control protocols to control the set-up and tear-down of calls as well as audio codes which encode speech allowing transmission over an IP network as digital audio via an audio stream.  Codec use is varied between different implementations of VoIP  some implementations rely on narrowband and compressed speech, while others support high fidelity stereocodes

10. Cloud Computing  Cloud computing is the delivery of computing as a service rather than a product, whereby shared resources, software, and information are provided to computers and other devices as a utility (like the electricity grid) over a network (typically the Internet). Clouds can be classified as public, private or hybrid.

11. Cloud Computing  Cloud computing relies on sharing of resources to achieve coherence and economies of scale, similar to a utility (like the electricity grid) over a network.  At the foundation of cloud computing is the broader concept of converged infrastructure and shared services.  Cloud computing, or in simpler shorthand just "the cloud", also focuses on maximizing the effectiveness of the shared resources.  Cloud resources are usually not only shared by multiple users but are also dynamically reallocated per demand. This can work for allocating resources to users.

12. The Internet of Things  The Internet of Things (IoT) refers to the interconnection of uniquely identifiable embedded computing-like devices within the existing Internet infrastructure.

13. The Internet of things  We have passed the threshold where more things are connected to the Internet than people.  The transition to IPv6 also supports seemingly limitless connectivity.  Cisco IBSG predicts the number of Internet-connected things will reach 50 billion by 2020, which equates to more than six devices for every person on Earth.  Many of us in the developed world already have three or more full-time devices connected to the Internet when factoring in PCs, smartphones, tablets, television devices and the like.

14. The Internet of Things  Things, in the IoT, can refer to a wide variety of devices such as heart monitoring implants, biochip transponders on farm animals, automobiles with built-in sensors, or field operation devices that assist fire-fighters in search and rescue.  Future IoT? IoT of sensor networks, using low-power sensors that "collect, transmit, analyze and distribute data on a massive scale," says Evans.

15. The Internet of Things  Typically, IoT is expected to offer advanced connectivity of devices, systems, and services that goes beyond machine-to-machine communications (M2M) and covers a variety of protocols, domains, and applications.  IoT Applications :  Environmental Monitoring, Infrastructure Management, Industrial Applications, Energy Management, Medical and Healthcare Systems, Building and Home Automation, Transport Systems, Large Scale Deployments  IoT Trends:  Intelligence, Architecture, Complex system

16. Wireless Sensor Networks (WSNs) 16  A sensor network is a wireless network that consists of thousands of very small nodes called sensors. Base station Figure 1: Architecture of wireless sensor networks

17. Wireless Sensor Networks (cont.)  WSN Sensors are equipped with sensing, limited computation, and wireless communication capabilities. 17 Typical hardware components of a sensor node in wireless sensor networks

18. WSNs Applications 18 WSNs Applications

19. WSNs Challenges  Limited Sensor Resources  Battery power, computation capability, memory, etc.  Networking Challenges  Limited bandwidth, routing, multi-hop communication, mobility, topology control, large no. of sensors, frequent node on/off, etc.  Environment/Application-Driven Challenges  Requirements, extreme conditions, interference, etc.  Other Challenges  Security, synchronization, localization, deployment.. 19

20. Next Lecture!  Quiz: Lectures 1 & 2