How do you integrate HLR with other core network components, such as MSC, VLR, or HSS?

1 MSC and VLR

MSC, or Mobile Switching Center, is a node that handles the call routing and switching functions in the mobile network. It communicates with the base stations and the external networks, such as PSTN or ISDN. VLR, or Visitor Location Register, is a database that stores temporary information about the subscribers that are roaming in the MSC's area. It reduces the need for frequent queries to the HLR and speeds up the call setup process. To integrate HLR with MSC and VLR, you need to establish a signaling link between them using protocols such as SS7 or SIGTRAN. The HLR sends updates to the VLR whenever a subscriber's location or service profile changes, and the VLR sends requests to the HLR whenever a subscriber initiates or receives a call or service.

2 HSS and IMS

HSS, or Home Subscriber Server, is a database that stores information about the subscribers of the IMS, or IP Multimedia Subsystem, which is a framework for delivering multimedia services over IP networks. It combines the functions of the HLR and the AuC, or Authentication Center, and supports both circuit-switched and packet-switched domains. IMS is a part of the core network that enables convergence and interoperability between different networks and devices. To integrate HLR with HSS and IMS, you need to use protocols such as CAMEL or Diameter. The HLR sends updates to the HSS whenever a subscriber's service profile changes, and the HSS sends requests to the HLR whenever a subscriber accesses an IMS service or registers with an IMS network.

3 Benefits and challenges

Integrating HLR with other core network components offers several advantages, such as reducing latency and congestion, improving security and privacy, and enabling value-added services like VoLTE, VoWiFi, or RCS. It also facilitates the coexistence of different generations and technologies of mobile networks. However, integrating HLR with other core network components can also be challenging. It increases the complexity and cost of the network architecture, requires compliance and interoperability of standards and protocols, exposes the network to potential vulnerabilities and attacks, and demands more resources from the HLR.

4 Here’s what else to consider

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