Presentation on theme: "A Wireless Local Area Network (WLAN) is a network that interconnects devices using radio waves. Wireless networking technologies allow devices to communicate."— Presentation transcript:
A Wireless Local Area Network (WLAN) is a network that interconnects devices using radio waves. Wireless networking technologies allow devices to communicate to each other without using cables or wires.
The most common wireless technologies are:
Bluetooth Infrared Direct Access (IrDA) Shared Wireless Access Protocol (SWAP) Wireless Ethernet Compatibility Alliance (WECA)
Bluetooth allows low bandwidth, short-range (up to 10 m) wireless communication using the 2.4GHz unlicensed ISM (Industrial, Scientific and Medicine) band. This technology is used to connect two or more devices in a home network and can support data rate up to 1Mbps. An example of a Bluetooth iapplication is a laptop making call over a cellular phone. Another example is cordless keyboard, mouse and speaker connected to a Personal Computer.
This technology allows devices to communicate using infrared light at a speed up to 4Mbps. Infrared light cannot pass through the walls or obstacles. So, devices can only communicate with each other, if they are in direct line of sight. A simple example of IrDA application is a laptop sending print documents to a printer using infrared port. Most of the new mobile phones and laptops have infrared port. You can also transfer data (like address book and calendar) between a mobile phone and a laptop through infrared port, if both devices have infrared port.
. Shared Wireless Access Protocol (SWAP) is a standard developed by an alliance of businesses called HomeRF Working Group. The HomeRF Working Group allows data and voice transmission using 2.4GHz ISM band. It supports data rate up to 1.6Mbps within the range of 30m.
The IEEE specifications of the standard for wireless LANs have provided a big boost to the WLAN industry. These specifications allowed the creation of large scale commercial WLANs, but they do notcertify WLANs equipments The IEEE b was the commonly used standard before It uses the 2.4 GHz radio spectrum and supports data rate up to11 Mbps. The new IEEE a standard operates in the 5.2 GHz- 5.8GHz spectrum and supports up to 54 Mbps rates. This technology allows a radio transmitter (Wireless Network Card) to spread data packets over a fixed range of the frequency band. Another device carrying a radio receiver (WirelessNetwork Card) These WLANs can transmit data within a radius of 300 feet indoors and 1000 feet outdoors.
It is a point-to-point network and is also called Ad hoc network. A basic peer-to-peer WLAN comprises two computers or/and laptops equipped with wireless adapter cards within range of one another These networks are easy to install, manage and require no administration. There is no need of central device and each client would directly access resources of the other client.
It is a Client-Server network and is commonly called Infrastructure network. In these networks, there is a need of a central device called Access Point. Each client on the network will communicate with other clients through this Access Point. It can provide services to clients and extends the range of a peer-to-peer (ad hoc) network. An Access Point also connects wired and wireless networks together in a building. It enables the transfer of data between the clients of a wireless network and of a wired network
Wireless transmission via optical carriers opens doors of opportunity in areas as yet largely unexplored. Offering significant technical and operational advantages, optical wireless communication (OWC) can be, in some applications, a powerful alternative to and, in others, complementary to existing radio frequency (RF) wireless systems. Variations of OWC can be employed in a diverse range of communication applications ranging from very short- range (on the order of millimetres) optical interconnects within integrated circuits through outdoor inter-building links (on the order of kilometres) to satellite links (larger than 10,000 kilometres).
Access networks consume a significant portion of overall Internet energy consumption. With the increase of bit-rate requirements in access networks, future-proof access technologies should be energy efficient. In this paper, we show how we can build a very high-throughput hybrid wireless- optical broadband access network (WOBAN). We devise novel energy-saving techniques for WOBAN to improve its energy efficiency and network utilization. We present a mixed integer linear program (MILP) model, which acts as a benchmark for evaluating our techniques. We analyze the impact of energy- aware design and protocols on the performance of WOBAN over dynamic traffic profiles. Illustrative numerical examples show that, with suitable design parameters, we can efficiently reduce energy consumption in WOBAN without significantly impacting the network performance.