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Access Classes and Emergency Calls - Optimization for Checking Access Classes

IP.com Disclosure Number: IPCOM000131881D
Publication Date: 2005-Nov-21
Document File: 2 page(s) / 9K

Publishing Venue

The IP.com Prior Art Database

Abstract

GPP TS25.304 v3.12.0 5.3.1.3 and TS22.011 v3.8.0 4.4 describe details of how to determine if emergency calls are allowed in cells using the IE "Access class barred list" which is broadcast in System Information Blocks 3 and 4 (SIB3 and SIB4).

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ACCESS CLASSES AND EMERGENCY CALLS

Access Classes and Emergency Calls - Optimization for Checking Access Classes

Disclosed Anonymously

GPP TS25.304 v3.12.0 5.3.1.3 and TS22.011 v3.8.0 4.4 describe details of how to determine if emergency calls are allowed in cells using the IE "Access class barred list" which is broadcast in System Information Blocks 3 and 4 (SIB3 and SIB4).

Network access for emergency calls is controlled by Access class 10. A normal UMTS user equipment (UE) is assigned an access class randomly from 0 to 9; this is stored in the Universal Subscriber Identity Module (USIM). A special UE may also be assigned an access class from 11 to 15, these would typically used by emergency services, network staff, etc (see 22.011 4.2 for details).

When determining if a typical UE (access class 0 to 9) is allowed to make a normal non-emergency call in a cell, the entry in the "Access class barred list" which corresponds to the access class of the UE is examined. If this indicates the access class is barred, the UE is not allowed to make the call.

When determining if a typical UE is allowed to make an emergency call in a cell, access class 10 needs to be checked.

In the case where emergency calls are barred in a cell, is there a need to check access classes 0 to 9 to determine if normal calls are allowed? It would seem reasonable that if emergency calls cannot be connected then all other calls would be barred too.

The 3GPP standards allow the case where emergency calls are...