HLR (Home Location Register)

What is the Home Location Register (HLR)?

An HLR (Home Location Register) is a database used to manage subscribers on 2G and 3G networks. This database helps in ensuring that only authenticated and permitted users and devices can use a comapny’s services for IoT purposes.

Each operator of a 2G or 3G network maintains its own Home Location Register, a network database that includes specific information about each user or subscriber. This function is carried out by a Home Subscriber Service (HSS), a master database on 4G networks. For 5G, this is controlled by a Unified Database Server.

How does HLR work?

Every time a mobile phone attempts to connect to a cellular network (make a call), a message switching center (MSC) checks the network's HLR to determine whether the caller is permitted to use the network, how to bill the caller (i.e., whether they are using roaming or not), and how to route connections to and from that phone. The only exception to this is emergency numbers.

When a caller's contract with a carrier expires, the carrier will eventually delete the caller, their number, and their identification information from the HLR, essentially barring that user from using their network to make calls. 

In short, for both telecoms and non-telco enterprises, an HLR gathers extremely valuable data related to phone whereabouts and roaming.

Is the Home Location Register secure?

Although HLR contains sensitive information, such as subscribers’ most recent location, rest assured that the database is not accessible to the general public and is secured with the same protection that mobile operators employ for their own confidential information.

It should be noted that in most territories, law enforcement organizations can ask the HLR for information as part of an inquiry after a crime has been committed.

What information does the HLR contain?

A user's preferences, features they have subscribed to, account information, account status, current location, and other information are all contained in an HLR. 

The benefits of HLR

Security and time and money savings are the two main benefits of HLR lookups. Here are some ways businesses can benefit from an HLR:

1. Location tracking
   The network can verify a device's most recent location by periodically delivering Tracking Area Updates (TAUs). The HLR then stores this information.

2. Mobile subscriber management:
   The HLR can differentiate between various levels of subscriptions and enable or disable user access in order to optimize your business operations.