We have already defined Wireless communication as transfer of information from the origin to destination without the use of a physical connection. In general, the complexity of the wireless communication system increases as the distance between the communicating devices increase. In the light of this statement let us have a look at some wireless systems that we encounter in our everyday lives:
Wireless Personal Area Networks (WPAN)
Wireless personal area networks are systems that connect two personal or short ranged devices that are located very close together, usually in the same room. They generally have a coverage area of less than 30 feet. The two technologies that are predominant in this sector are:
Bluetooth is a two way wireless communication system between devices placed very close to each other. It has proved to be very effective in reducing the clutter of wires. It can connect a mouse to the computer, headphone to an mp3 player etc.
- Infrared (IR) wireless communication
In Infrared wireless communication systems, data or information is carried over Infrared waves between two points. The Infrared frequencies lie between the microwave and the visible light ranges in the electromagnetic spectrum. Infrared waves are electromagnetic waves and have wavelength that is longer the wavelength of red light. This technology has a limitation that it can operate only within the line of sight, which means that the straight line path between the transmitter and receiver should be clear of obstructions. These systems are generally used for very small range of distance like TV remote control.
Wireless Local Area Networks (WLAN)
Wireless local area network or WLAN connects two or more transceivers using a wireless distribution technique like OFDM. The devices connected with a WLAN are rendered mobile within the local area, say a home or small office covered under the WLAN network. The most common WLAN is:
This is a system that is basically related to computer networking. It generally consists of a wired internet connection that is guided to a router. The router is the transceiver that communicates wirelessly with other devices such as computers, tablets or phones. The distance range is generally one home or small office. For larger campuses such as schools, signal amplifiers or range extenders can be placed at strategic positions to cover the entire area under the network.
Wireless Metropolitan Area Network (WMAN)
WMANs are a connection of multiple networks in a metropolitan area. Several smaller networks existing within a metro are connected wirelessly rather than laying copper or fiber cables. For e.g. wirelessly connecting individual WLANS of a single firm’s various office buildings which are spread across a city.
WiMax is a wireless broadband system which can deliver data at more than 30 megabits per second. WiMAX is a 4G wireless technology.
Wireless Wide Area Network (WWAN)
WWANs are communication networks that have to be maintained over very large areas, such as states or countries, sometimes using satellite systems or transmission towers generally taken care of by a service provider. All Cellular communication systems would fall under this category.