ERP,EIRP,dB and dBm calculation are Most important thing to take care in RF Planning of any site. Isotropic RF Source A point source that radiates RF energy uniformly in all directions (I.e.: in the shape of a sphere) Theoretical only: does not physically exist. Has a power gain of unity I.e. 0dBi. Effective Radiated Power … Read more
Which step to make clear before select any site at any location like equipment type, construction and link balance calculation which describe detail as below. Select Equipment Type For Site Select equipment for the cell depending on channel requirements Selection of antenna type and accessories. Locate Equipment On Site For Construction Drawing Plan of the … Read more
Here I write about selection of new site in rf planning, how step by step any new site planned is as per below. Prepare Initial Search Ring Note the latitude and longitude from planning tool. Get the address of the area from mapping software. Release the search ring with details like radius of search ring, … Read more
DTX has some effect on the RXQual distribution. Normally the BER is averaged over the duration of one SACCH frame lasting 0.48 seconds and consisting of 104 TDMA frames. However, four of these TDMA frames are used for measurements, so that only 100 bursts are actually transmitted and received. When DTX is in use and … Read more
Both the power control and the DTX are standard GSM features, which are designed to minimize the interfering transmission when possible. They are both mandatory features in the mobile terminals, but it is up to the network operator to decide whether to use them or not. DTX prevents unnecessary transmissions when there is no need … Read more
In a conventional non-hopping network, each call is transmitted on a single fixed frequency. This means that the interference situation in a network is also quite stable. Some calls may experience very little interference and the other calls may be interfered severely. Severe interference can be avoided by a handover, but the probability of finding … Read more
Effect in Cell Coverage Area In coverage limited cells the frequency hopping may increase the cell coverage area because of the frequency diversity gain, but since the BCCH time slot doesn’t hop, the increased coverage area is relevant only for the ongoing calls that have been successfully established and are allocated a hopping TCH. According … Read more
Cyclic vs. Random Hopping Sequences Both cyclic and random hopping modes are available in GSM. In the cyclic mode the frequencies are changed sequentially from the lowest frequency to the highest as defined in the MA-list. In random mode the frequency to be used for each burst is selected from the MA-list by a predefined … Read more
Effect of Interleaving In GSM the speech frame is transmitted over eight consecutive bursts. The fast fading causes bursty bit errors that degrade the efficiency of the convolutional coding. The interleaving is designed to spread these errors over longer time. However, the decoding performance is not significantly improved if consecutive bursts are exposed to the … Read more
Work of MA, HSN and MAIO in GSM Mobile Allocation The MA is a list of hopping frequencies transmitted to a mobile every time it is assigned to a hopping physical channel. The MA-list is a subset of the CA list. The MA-list is automatically generated if the baseband hopping is used. If the network … Read more