LocationUpdate汇总.docx

LA 2 LA 1 VLR MSC Location Update Types of Location Update ? Location Registration (power on) ? Generic ? Periodic Location registration takes place when a mobile station is turned on. This is also known as IMSI Attach because as soon as the mobile station is switched on it informs the Visitor Location Register (VLR) that it isnow back in service and is able to receive calls. As a result ofa essful registration, work sends the mobile station two numbers that are stored in the SIM (Subscriber Identity Module) card of the mobile station : Location Area Identity (LAI) + Temporary Mobile Subscriber Identity (TMSI). work, via the control channels of the air interface, sends the LAI. The TMSI is used for security purposes, so that the IMSI ofa subscriber does not have tobe transmitted over the air interface. The TMSI isa temporary identity, which regularly gets changed. A Location Area Identity (LAI) 位置区识别码 isa globally unique number. LAI 用于移动用户的位置更新。 LAI = MCC + MNC + LAC MCC =移动国家号,与 IMSI 中的 MCC 一样具有 3 个数字,用于识别一个国家,中国为 460 。 MNC =移动网号,识别国内 GSM 网,与 IMSI 中的 MNC 的值是一样的。 LAC =位置区号码,识别一个 GSM 网中的位置区。 LAC 最大长度为 16Bit ,理论上可以在一个 GSM/VLR 内定义 65536 个位置区。 A Location Area Code (LAC) is only unique ina work. location update timer values. Therefore, when the set time isup, the mobile station initiates a registration process by sending a location update request signal. The VLR receives the request