The function is to update IMEISV information of the MS to the HLR in time. When the MS originates location update upon power-on, ordinary location update and periodic location update, the MSC can determine whether to update the IMEISV information of the MS to the HLR according to whether the local and home HLRs support the ADD function. When the local and corresponding HLRs support the ADD function, the changes to the IMEISV information of the MS can be updated to the HLR in time during location update.

 

Implemented node : VMSC/VLR

 

Served network: GSM and UMTS

 

Service benefits:

 

For carriers: Provide a capability of getting subscriber IMEISV information in time, and realize flexible control over the MS.

For subscribers: The network can know changes of subscriber equipment in time. This helps to implement new services.

 

Requirements for peripheral network entities: The HLR needs to support the ADD function.

 

The IMEISV is the software version of the IMEI (international Mobile equipment Identity).

From Wiki: The International Mobile Station Equipment Identity or IMEI is a number, usually unique, to identify 3GPP (i.e., GSM, UMTS and LTE) and iDEN mobile phones, as well as some satellite phones. It is usually found printed inside the battery compartment of the phone, but can also be displayed on-screen on most phones by entering *#06# on the dialpad, or alongside other system information in the settings menu on smartphone operating systems.

The IMEI number is used by a GSM network to identify valid devices and therefore can be used for stopping a stolen phone from accessing that network. For example, if a mobile phone is stolen, the owner can call his or her network provider and instruct them to "blacklist" the phone using its IMEI number. This renders the phone useless on that network and sometimes other networks too, whether or not the phones SIM is changed.

The IMEI is only used for identifying the device and has no permanent or semi-permanent relation to the subscriber. Instead, the subscriber is identified by transmission of an IMSI number, which is stored on a SIM card that can (in theory) be transferred to any handset. However, many network and security features are enabled by knowing the current device being used by a subscriber.

The challenge with the use of IMEI in blacklisting phones is that this is only tied to a single operator unless there is a central database for all operators, in this way a blacklisted mobile on one carrier automatically becomes blacklisted across many carriers.

This document is very well done

What is  IMEISV ?

HLR Dependency: The HLR needs to support the ADD function.

Its a totally new concept, thanks for sharing.