The information age has been revolutionized not just by the power of computers to process data, but also by the power of communication amongst computers. This communication is responsible for the proliferation of computer networks. Sharing of information, sharing of resources (both software and hardware) and sharing of processing load are some of the major objectives of a computer network. One of the recent trends in the computer and communication industries is wireless communication. A wireless network does not use cables, but instead uses radio waves. Such networks enhance the functionality of computing devices by freeing them from the location constraints of a wired network. Although wireless networking is of great use to the laptop users who move from one location to the other throughout the day, there are benefits for fixed users as well. Many schools and businesses have an architecture that is unsuited for a wired network. Wired networking is very cost effective in such environments.
Wireless networks can be broadly classified as fixed wireless systems and mobile wireless systems. A fixed wireless system supports a little or no mobility of the equipment related to the wireless network. For example, a local area network can be set up using wireless network to get rid of the hassles of laying cables. The mobile wireless systems support mobility of the equipment, enabling the user to access information from anywhere and at any time. The equipments used in the mobile wireless systems include personal digital assistants (PDAs), smart phones and pager with Internet access.
Wireless networks communicate by modulating radio waves or pulsing infrared light. A wireless networking router is linked to the wired network infrastructure by stationary transceivers. Wireless communication technologies used in wireless networks include analog cellular, digital cellular, Cellular Digital Packet Data (CDPD), mobile radio networks, personal communication services (PCS), satellite, microwave systems and local multipoint distribution systems (LMDS). Although the data rates supported by analog cellular technology are low, it is the most popular methods for wireless data communications due to the wide availability of modems and analog cellular services. The commonly used wireless technologies include 2G and 3G technologies, wireless LANs, Wireless Local Loops (WLLs), radio-router technology, Multihop wireless network and Wireless Application Protocol (WAP).