Network for mobile users to check the legitimacy of the entity. Mobile users call in the beginning, being called, the implementation of location updates to the user authentication, and frequently updated authentication data, to safeguard the legitimate rights and interests. 4.1.4 Operation and Maintenance Center (OMC). Public land mobile communication network with all levels of operation and maintenance center to the operation of the equipment and network management. 4.2 Mobile communications network in the area defined. (1) cell: a base station by using omni-directional antenna coverage area, or a wireless base station using a directional fan-shaped coverage area. (2) base station area: a base station of the area covered by all cells. (3) location area: MS can move without the need for location update area. In existing networks is generally controlled by a BSC area is defined as a location area. To call this position of a region MS, all in the same location area radio base station simultaneously launched the MS paging. The education department will need more and more Cell Phone Jammer Legal .
(4) Mobile Switching Area (Business District MSC): a MSC / VLR area under the control of the business, can cover a number of location area. (5) mobile local network: in principle, with a long-distance area code corresponding to a mobile local area network can be established, within the network can be set to one or more MSC. (6) Public Land Mobile Network (PLMN): a mobile operator (for example: China Mobile, China Unicom) established by the mobile communication network. Net with a uniform numbering system and a unified routing scheme. (7) service area: for registered mobile users in a PLMN service area available, that is, different communication network (PLMN, PSTN, ISDN, etc.) users do not know the actual location of the MS can communicate with the area (including international roaming area). The mutual inspection of cell phone jammer should also be performed.
China GSM PLMN using three-tier structure, from a mobile service tandem Center (TMSC1), two tandem mobile services center (TMSC2) and the Bureau of MSC composition of the mobile terminal. Original TMSC1 are located in eight large district, the provinces were set TMSC2. TMSC1 connection between the mesh, and their respective TMSC2 the TMSC1 set between the low-loss direct way. China GSM PLMN network and the PSTN is shown in Figure 10. With the rapid development of GSM network, since 1998 in the provincial capital city of the new, expanded 28 pairs TMSC1, between the old and new TMSC1 mesh connection, to allow a large area centered TMSC1 role of slowly fading. With the large number of laying fiber, it is possible to TMSC1 with TMSC2 gradually merged into TMSC, then China will evolve into two GSM PLMN network. cell phone jammer will turn on during class.