What is HLR and its function in GSM

HLR.
               HLR means Home Location Register.

Home Location Register (HLR)

The HLR is the reference database for subscriber parameters. Actually HLR Having all the detail like customer ID, customer number, billing detail and for prepaid with IN intelligent network its has detail of current recharge of prepaid user so far its is very complex but i just make it in simple word for you.

Various identification numbers and addresses are stored, as well as authentication parameters. This information is entered into the database by the network provider when a new subscriber is added to the system. The HLR database contains the master database of all the subscribers to a GSM PLMN.

The data it contains is remotely accessed by all the MSCs and the VLRs in the network and, although the network may contain more than one HLR, there is only one database record per subscriber – each HLR is therefore handling a portion of the total subscriber database.

The subscriber data may be accessed by either the IMSI or the MSISDN number. The data can also be accessed by an MSC or a VLR in a different PLMN, to allow inter-system and inter-country roaming.

The Basic Parameters stored in the HLR are listed below:

• Subscriber ID (IMSI and MSISDN)
• Current Subscriber VLR (Current Location)
• Supplementary Services Subscriber to (Caller Tone, Missed Call Alert, Any Other Services etc.)
• Subscriber Status (Registered or Deregistered)
• Authentication Key and AUC Functionality
• Mobile Subscriber Roaming Number.

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