Talk:The Computer Revolution/Networks/Four Types of Wireless Communications

There are 4 types of wireless communication.

1) Radio transmission:(Ex- AM, FM)   + It is easy to generate.   + It is omnidirectional, so travels long distance.   + It has high penetration power.   - It is frequency dependent, so distance covered changes with frequency.   - It has low bandwidth for data communication.   - It is highly licence by governments. 2) Micro wave transmission:(Ex- TV Broadcast, DTH) + Used for long distance communication, It has high attenuation power. + Having high S/N ratio. + It is relatively inexpensive. - It has low penetration power, so cant penetrate building well. - frequency dependent. - Due to low penetration power, requires Line Of Sight communication. 3) Infrared and millimeter wave transmission:(Ex- Remote)  + Short range communication.   + Can't penetrate objects, so benefit is they do not interfere if operated in different rooms.   - Small Bandwidth. 4) Light wave transmission:(Ex- Communication using LASER on two building) + Achieved using unguided optical signal like LASER. + Easy to install, Unidirectional. + Require no license. - No penetration power (rain and fog can't be penetrate), - Diverted by turbulent air.