Patent ID: 7145997
Filing Date: 2006-12-05
Classification: H04M,H04W

Abstract:
1. A method for enabling a call-back from an entity to an user equipment initiating a session comprising: when the user equipment initiates a session, the user equipment sends a session setup message for initiating the session to a first node, wherein the first node stores a first record for the user equipment for a predetermined time, the first record including an address and an identity of the user equipment and the first node forwards the session setup message to a second node; the second node stores a second record for the user equipment for a predetermined time which second record includes the address of the first node and the identity of the user equipment and the second node forwards the session setup message to a third node or an emergency center; the third node or the emergency center stores a third record for the user equipment for a predetermined time which third record includes the address of the second node and the identity of the user equipment; in case of a call-back, the entity comprises the third node or the emergency center and uses the stored identity of the user equipment to find and in the third record the address of the second node and the third node or the emergency center sends to the second node a message related to the call-back which includes the identity of the user equipment; the second node uses the user equipment identity included in the message, received from the third node related to the call-back to find in the second record the address of the first node and the second node sends to the first node a message related to the call-back includes the identity of the user equipment; and the first node uses the user equipment identity included in the message received from the second node related to the call-back to find in the first record an address of the user equipment and the first node sends to the user equipment a session initiation message.