el. There are again two types of frequency diversity technique: random FH and sequential FH. Sequential FH is used more in practical network planning as it gives more improvement to the network quality. If the number of frequency channels increases in the radio network, the number of frequencies used increases in the network, SO reducing the interference effect at the mobile station. This leads to an increase in signal level, and an improvement in the power budget. 2.4.3 Equipment Enhancements Receiver Diversity Diversity is the most common way to improve the reception power of the receiving an- tenna. Major diversity techniques are space diversity, frequency diversity, and polarisation diversity. Frequency diversity is also known as frequency hopping. Space diversity involves installing another antenna at the base station. This means that there are two antennas receiving the signal at the base station instead of one and are sep- arated in space by some distance. There is no fixed distance of separation between the antennas, which depends upon the propagation environment. Depending on the environ- mental conditions, the distance between the main and the diversity antenna can vary from 1 to 15 wavelengths. Polarisation diversity means that the signals are received using two polarisations that are orthogonal to each other. It can be either vertical-horizontal polarisation or it can be +45-degree slated polarisation. Low-noise Amplifiers (LNA) Where the received power is limited by the use of long cables, low-noise amplifiers can be used to boost the link budget results. As the name suggest, a LNA has a low noise value RADIO NETWORK PLANNING AND OPTIMISATION and can amplify a signal. The LNA is placed at the receiving end. When space diversity is being used, the LNAs should be used on both the main and the diversity antennas, thereby improving the diversity reception. As stated above, this is used for improvement of the uplink power budget. Power Boosters Power in the downlink direction can be increased by the use o