METHOD FOR PREVENTING OVERLOAD IN MOBILE TELEPHONE NETWORKS USING 'ALWAYS-ON' IN THE CASE OF INCOMING CALLS

摘要

The invention concerns a method for preventing overload in IMS telecommunications networks using 'always-on' for a call received by a user; - if the GGSN is about to deactivate a user PDP Context because it has been inactive, the association [user IP, GGSN IP, SGSN IP] is not eliminated from an AAA server in which said association was previously saved, and in addition the P-CSCF wherein said user is held adds an indicator that said user is registered in IMS but without an active PDP context; and, when an incoming call is received: - the P-CSCF verifies the state of the PDP Context of the user by means of said indicator, and if it is not active, said PDP context is reactivated for which purpose the P-CSCF informs the GGSN of the IP address to be assigned to said user, and - if said IP address has not been assigned to another user, an attempt is made to reactivate the PDP context by using the address given by the P-CSCF for which - the GGSN uses the Network-Requested PDP context activation method, where it is necessary to consult the AAA server using that IP address as the principal consultation parameter; - the AAA server with that IP address as index responds to the GGSN with the IP address of the SGSN under which the user is located; - and if said IP address has already been assigned, it is reinitiated after the failure of the call.