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IMSI

 

International Mobile Subscriber Identity (IMSI)

An IMSI is used in any mobile network that interconnects with other networks. This unique, 15-digit international identifier, which is included in a mobile device, allows for roaming on mobile service provider networks. 

An IMSI includes three components:

  1. Three-digit Mobile Country Code (MCC)
  2. Three-digit Mobile Network Code (MNC)
  3. Nine-digit Mobile Station Identification Number (MSIN)

 

The Home Network Identity (HNI)

The Home Network Identity (HNI) identifies a mobile subscriber’s home network and is assignable to mobile network operators with international roaming capabilities.  

 

IMSI Block Number for Citizens Broadband Radio Service (CBRS)

Within the United States, a Shared HNI is used to identify a Citizens Broadband Radio Service (CBRS) operation. The overall IMSI format remains the same; however; for the purposes of defining an HNI for the CBRS range, the MSIN is divided into two components:

  • The first four digits are used as the IMSI Block Number (IBN).
  • The last five digits are used for the User Identification Number (UIN). 

 

Visit the HNI assignments or CBRS assignments page to view a list of current HNI assignments.

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Requests and Changes

To apply, deploy, modify or return a code, fill out the appropriate form. Visit the HNI or CBRS form page for more information.


 
More information can be found in the IMSI Assignment Guidelines and Procedures on the atis.org website, which are maintained by the ATIS - IMSI Oversight Council (IOC).

Oversight

The IMSI Oversight Council (IOC), a committee of the Alliance for Telecommunications Industry Solutions (ATIS), that oversees the performance of the IMSI administration. Revisions to the guidelines are effective upon approval by the IOC.

iconectiv is the United States IMSI Administrator which administers the HNI and IBN on behalf of the Department of State.

The Mobile Station Identification Number (MSIN) is administered by the network operator to which the HNI is assigned.

More information can be found in the IMSI Assignment Guidelines and Procedures on the atis.org website, which are maintained by the ATIS - IMSI Oversight Council (IOC).