3GPP Work Item description

This page contains informal descriptive text only.  See master WID page for further details.

Feature: Access Class Barring and Overload Protection

SA2 has received requirement from SA1 (S2-040529 = S1-040129) to investigate any mechanisms necessary for Domain Specific Access Control within the UTRAN, and was asked for investigation related to an issue where overload in the CS transit network caused a restriction in the packet switched traffic while radio capacity was available.
It was considered valuable to investigate impacts and study issues that go beyond CS congestion issues on the UTRAN.
In addition, S2-040842 indicates that the Access Class Control and Overload Protection functions of the 3GPP system have not been enhanced to cope with architectural changes made in R’97, R’99 and R’5.
SA2 believes that these aspects should be studied urgently. 

Objective:

This work item is intended to study possible enhancements to the 3GPP system needed to cope with R’97 (GPRS), R’99 (UMTS) and R’5 (“Iu-flex”) architectural changes.

It is anticipated that the following types of overload situation will be studied: 

    §         cell level congestion (eg traffic jam on country road served by one cell)

    §         wide area radio interface congestion (eg traffic jam in a large town served by many cells)

    §         RNC/BSC overload

    §         MSC overload/failure

    §         Voice transit network (and/or MGW?) overload/failure

    §         SS7 signalling network overload/failure (eg impact on MM, GMM and SMS)

    §         SGSN overload/failure

    §          “packet backbone” (GTP-U or Gi) overload/failure

    §         GGSN overload/failure (eg how to prevent all mobiles re-establishing PDP contexts when one GGSN fails.)

Based on the requirement given from S2-040529, the solution of domain specific access control in case of CS domain overload in R’6 is given the higher priority of this study.

Other aspects that may need consideration include:

    §         the impact of the URA-PCH and Cell-PCH states

    §         how to avoid automatic re-establishment attempts by PS domain applications (cf the auto-redialling restrictions in 02.07 Annex A)

Under this Work item, appropriate CRs will also be generated.