Wireless Networking Technologies
How would today’s communications take place if it had not been for the work of scientists like Marconi and Hertz, perhaps the two most recognizable names in communications? The early research into wireless communications has resulted in radio, infrared, satellite, and microwave communications. Each form of wireless communication has an ideal use, and this is mainly attributed to the properties of electromagnetic waves at the various frequencies in which these communications methods reside.
Radio Systems
Wireless communications based on radio waves use frequencies between 10KHz and 1GHz, a range of frequencies that is especially susceptible to electrical interference. The lower frequencies in this spectrum are capable of penetrating solid object without much loss of signal strength, but the lower frequencies are also incapable of carrying as much data as a higher frequency (Regan, 2004).
An appropriate use for radio systems is a home network where high bandwidth can be achieved and the limitation on transmission distance is rarely an important consideration.
Infrared Systems
Infrared systems use the range of frequencies between 100 GHz and 1,000 THz, which is just below the range of visible light. LEDs, ILDs, and photodiodes work in conjunction to send and receive infrared signals at a maximum of 1Mbps in omnidirectional (all directions, or “dispersed” IR) mode and a maximum of 16Mbps in directional, or focused, mode (Regan, 2004).
The Essay on Wireless radio signals
Coverage area: The space in which the wireless radio signals in one wireless LAN can effectively reach and be used to send and receive data between the WLAN’s APs and its clients. Shared bandwidth: A term referring to how some networks must share the right to send data by taking turns, which limits the total number of bits sent by all devices (the network’s total capacity). Wi-Fi: A term created ...
Because light cannot pierce solid objects, a line of sight between the sender and receiver is required, and the distance between them cannot exceed 50 feet in directional mode (Cannon, 2006).
Infrared communications can be used for close-range peer-to-peer networks or even for a television remote control.
Satellite Systems
Satellite systems have the capability to span the globe, a distinction unique among wireless communications methods. Electromagnetic frequencies in the satellite communications range are above 1GHz, meaning they are above the 100MHz threshold where waves begin to travel in only a straight line (Regan, 2004); this is where the parabolic dish comes in handy. Parabolic dishes are used to focus the signal, thereby increasing the distance the signal can travel. As with IR networks, line of sight is required between two devices transmitting via satellite. An ideal use for satellite communications is to send television programming from one side of the world to the other.
Microwave Systems
Microwave communications systems use the same band of frequencies as satellite communications. The increased frequency over radio communications means microwaves are capable of much higher bandwidth, and microwaves are capable of traveling large distances. Microwaves are prone to electromagnetic interference, and even rain and fog can cause loss of signal strength. The cost of implementing a microwave network is prohibitive because a repeater is needed every 80 kilometers and such communications require an unobstructed line of sight. Today’s mobile phones use microwave radiation frequencies, a source of much debate over the safety of their use (Naish, 2011).
Conclusion
Different wireless technologies are suited for different purposes. From moving data from a television remote to a television to sending large files halfway around the world, there is a technology that can accomplish the task more efficiently than any other. Figure one below presents a chart that outlines the similarities and differences between wireless technologies. Prior to installing a wireless network, the proper technology should be selected according to the figure.
The Term Paper on 4G Wireless System
ABSTRACT: Believe it or not, 4G is coming. Before many of us even have 3G cellular service, the outlook for 4G—although still Although the new, third generation (3G) wireless technology has not yet been implemented, leading companies in the industry are already laying the groundwork for what some are calling fourth generation (4G) technology. For this purpose 4G will be as considered those ...
