HLR is a central database that serves as a reference point for storing and retrieving essential subscriber parameters. It holds critical information associated with mobile subscribers, including their unique subscriber IDs, current locations, authentication keys, and other relevant data. The HLR, HSS, and Unified Database Server fulfill the critical function of storing and organizing subscriber-related information to ensure secure and authorized access to IoT services offered by the respective mobile network operator.
Subscriber data management
Location Tracking of mobile subscribers
Authentication checks
Retrieval and routing of calls and messages
Each time a mobile device initiates a connection to a cellular network for making calls, a message switching center (MSC) performs a check on the Home Location Register (HLR) within the network. This verification process serves several purposes, including determining the caller's network access permissions, billing arrangements (such as roaming charges), and establishing appropriate call routing for incoming and outgoing connections. It is important to note that emergency numbers are typically exempted from this verification process. If the user’s contractual agreement with their carrier expires, the carrier eventually removes the caller's details, including their number and identification information, from the HLR. This prohibits the user from utilizing the carrier's network for making calls.
