Basic Computer Science

Radio transmission can take place using many different frequency bands. Each frequency band exhibits certain advantages and disadvantages. Figure gives a rough overview of the frequency spectrum that can be…

The number dialed to reach a mobile subscriber (MSISDN) contains no information at all about the current location of the subscriber. In order to establish a complete connection to a…

GSM architecture is a layered model that is designed to allow communications between two different systems. The lower layers assure the services of the upper-layer protocols. Each layer passes suitable…

If you are in Europe or Asia and using a mobile phone, then most probably you are using GSM technology in your mobile phone. ·        GSM stands for Global System for Mobile Communication. It…

Spread spectrum multiple access (SSMA) uses signals which have a transmission bandwidth whose magnitude is greater than the minimum required RF bandwidth. There are two main types of spread spectrum…

FDMA is the basic technology for advanced mobile phone services. The features of FDMA are as follows. FDMA allots a different sub-band of frequency to each different user to access…

In the cases where continuous transmission is not required, there TDMA is used instead of FDMA. The features of TDMA include the following. TDMA shares a single carrier frequency with…

Code division multiple access technique is an example of multiple access where several transmitters use a single channel to send information simultaneously. Its features are as follows. In CDMA every…

Space division multiple access or spatial division multiple access is a technique which is MIMO (multiple-input multiple-output) architecture and used mostly in wireless and satellite communication. It has the following…