What is the use and function of HLR in mobile communication? Please introduce it to us. . .

HLR: Home Location Register, Chinese: Home Location Register, which belongs to the communication core network element. In the core network, HLR is responsible for storing the service information of mobile users. Such as: mobile phone voice service, short message service, low-speed data service, videophone, caller ID, call waiting, call holding, conference call, color ring back tone, call forwarding, call barring, mobile secretary, GPRS service, shutdown, group service, prepayment, risk control, etc. Control the opening and closing of these services. HLR also integrates AUC (Authentication Center), which mainly authenticates users and provides security functions. In the process of connecting the phone, HLR is responsible for finding the called location. HLR stores the user's location information and keeps real-time update with the VLR where the user is currently located. HLR is also responsible for maintaining resources related to subscriber numbers, such as roaming restrictions (actually registration restrictions, which only allow registration to some VLRs), call forwarding restrictions, and call forwarding number modification (the area code is not entered on the mobile phone, but is automatically added by HLR). Settings related to new services, such as parsing, such as USSD(** 139 service) and so on.

In a word, the core equipment of HLR mobile communication mainly stores the service information of users. Cooperate with other core network elements to realize various mobile services of mobile users.