GSM technologies

Explain the following techniques in GSM: a.) Sectorization of a cell b.) Frequency Re-use c.) Transmitted Power Control d.) Discontinuous Transmission

a.) Sectorization of a cell

- Sectorization is a process to cut down equipment costs in a cellular network. It influences in traffic load and cell size
- Sectorization reduces co-channel interference, when applied to clusters of cells
- The maximum traffic capacity of sectored antennas is more than omnidirectional antennas.

b.) Frequency Re-use

- Frequency re-use is the key factor of cellular network ability for increasing both coverage and capacity.
- Different frequencies are utilized by adjacent cells; however problem does not arise to determine the cell sufficiently far apart using the same frequency.
- Reuse distance and the reuse factor are the two elements that influence frequency reusability
- The frequency is 1/K, where K is the number of cells that cannot use the same frequencies for transmission.

c.) Transmitted Power Control

- Transmitted power control is one of the technical mechanism used within some networking devices
- TPC is used for preventing too much unwanted interference among wireless networks
- The central idea is to automatically reduce the transmission output power used, when other networks are within the same range.
- TPC reduces interference problems and increases the battery capacity
- The power levels of a single mobile device can be reduced by 6dB

d.) Discontinuous Transmission

- Discontinuous Transmission, also known as DTX in short is a method of momentarily powering down a mobile set when there is no voice input to the set.
- The overall efficiency of a wireless voice communication system is optimized by DTX.
- Each speaker in a two way conversation speaks slightly less than half of the time.
- The workload of the components in the transmitter amplifiers are made easy and reduces interference.