Ans. The wireless communication is an efficient way of transmitting signals through space without guidance. We do not need any ‘medium’ for the transport of electromagnetic energy from the transmitter to the outside world and in reverse from the outside world to the receiver. [...]
Ans. The small – scale fading is less predictable and more potentially destructive than large –scale fading, most of the discussion is based on small-scale fading. Delay spread and Doppler effect are the two main effects observed on the signal due to small- scale [...]
Ans. Multipath waves in the radio channel combine at the receiver to give a resultant signal that can vary widely in amplitude and phase over a short period of time or over a small travel distance. This short- term rapid fluctuation of signal strength [...]
Ans. Since the antenna height of the mobile unit is lower than its typical surrounding, and the carrier frequency wavelength is much less than the sizes of the surrounding structure multipath waves are generated. At the mobile unit, the sun of the multipath waves [...]
Ans a signal radiated from an antenna travels along one of three routes- ground wave, sky wave, or line of sight (LOS). Generally we are concerned with LOS communication, a short overview of propagation modes are given below- (i) Ground wave propagation – ground wave [...]
Ans. Antenna gain is a measure of the directionality of an antenna. Antenna gain is defined as the power output, in a particular direction, compared to that produced in any direction by a perfect omnidirectional antenna (isotropic antenna). For example, if an antenna has [...]
Ans. In wireless environment the main parameters to achieve the wireless environment is the transmission and reception of an antenna, the antenna radiates electromagnetic energy into the medium (usually air), and for reception, the antenna picks up electromagnetic waves from the surrounding medium. There [...]
Ans. Wireless transmission has the following impairments- (i) Lower security, simple to attack- not only can portable devices be stolen more easily, but the radio interface is also prone to the dangers of eavesdropping. Wireless access must always include encryption, authentication and other security mechanisms [...]
Ans. The main reason of developing a wireless system and deploying it in several cities is the operational limitation of conventional mobile telephone systems, such as poor service performance, limited service capability and inefficient frequency utilization. Poor service performance – in the past, a [...]
Ans. Wireless networks find their applications in the following application environments- Vehicles- today’s car already comprise some, but tomorrow’s car will comprise several wireless communication systems and mobility aware application. Road conditions, weather reports, music, news, and other broadcast information are received via digital audio [...]
Ans. The term wireless refers to connection by ratio. The wireless communication is independent of physical connection. The wireless networks differ mainly in their physical layer from their fixed counterpart. The transmission of data takes place using electromagnetic waves which propagate through space, reflected, [...]
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