MSC 'pages' the requested subscriber information to all the BSCs within a location area. The BSC in turn sends this information to the BTS to find the subscriber through the paging and access grant channel (PAGCH). The tasks assigned to the BSC and BTS may vary from network to network. The subscriber should be able to connect to the network irrespective of his or her location. The subscriber movement can be intra-region or inter-region (including inter-country). For this kind of flexibility, the subscription has to be associated with the concept of a 'public land mobile network' (PLMN). Any operational network can be said to be a PLMN. There can be one or more than one PLMN in one country. To give users the immense flexibility to be connected even when changing between PLMNs (in the same or a different country) means that communication has to take place between these PLMNs. The mobile, when entering a different PLMN, searches for its own home/serving cells. When no service is detected, then it can search in automatic mode or the desired PLMN can be selected manually. Neighbour Cells While in operation, a mobile is required to make evaluations regarding the quality and level of the neighbour cells. It has to decide which cells are better in terms of coverage and capacity. This is done by taking advantage of the TDMA scheme, whereby the measurements are made during the uplink transmissions and downlink reception bursts. The evaluation is done with the help of algorithms resident in the BSS. These algorithms make a decision and convey it to the mobile station. One important thing to remember here is that every cell has its own identity code, known as the base station identity code (BSIC). Neighbour cells can have the same BSIC, SO in those cases the mobile identifies the neighbour cell by a 'colour code'. Recall that SCH and FCCH play an important role in logging the mobile to the network, and these channels transmit their information on a frequency known as the beacon frequency. Neighbour cells may have the same be