Voice call continuity in hybrid networks

摘要

Voice call continuity is provided for calls that are carried over a hybrid network infrastructure in which access connections are distributed over loosely coupled network portions including a backend network such as a core VoIP (Voice over Internet Protocol) service network, one or more cellular mobile networks, and a public switched telephone network (“PSTN”). The calls are routed through the core VoIP network regardless of their points of origination or termination in other network portions so that signaling and call context are anchored in the core VoIP network. The conditions under which user equipment operate are continuously monitored so that when a connection is determined to have been unacceptably degraded or is likely to be interrupted, and/or a more optimal connection is available, a handover of the call to another connection is initiated so that call continuity is maintained using the lowest cost connection that provides acceptable call quality.

主权项

1. A method for providing voice call continuity in a hybrid network comprising loosely coupled network portions, the network portions including at least a mobile operator network and a VoIP (Voice over Internet Protocol) network, the method comprising the steps of:
receiving a call from a mobile user equipment that accesses the hybrid network over a connection to one of the network portions; anchoring both a media path and a signal path for the call in the VoIP network irrespective of the call's point of origin or point of termination in the hybrid network, the anchored call including an original call leg; generating a voice call continuity identifier for the call, the voice call continuity identifier being unique for each call on the mobile user equipment; upon initiation of a decision to perform a handover, implementing a new connection to one of the network portions; creating a new call leg over the new connection; and associating the voice call continuity identifier with each of the original call leg and new call leg so that the legs are connectable at a common port in the VoIP network.