Patent ID: 8369292

Claim:
A communication network for use in mobile communications, comprising: at least one mobile device configured to communicate with a corresponding host through a first wireless local area network of the communication network; a packet data gateway configured to detect an attachment of a mobile device of the at least one mobile device to a second wireless local area network controlled by the packet data gateway when the mobile device roams into the second wireless local area network from the first wireless local area network, and to allocate an 1 P address to the mobile device; and a mobility server for establishing a call session between the mobile device and the corresponding host when the mobile device roams into the second wireless local area network from the first wireless local area network, wherein the mobility server manages the mobility for the mobile device and initiates the call session between the mobile device and the corresponding host, and wherein the packet data gateway is further configured to: monitor a state of a tunnel associated with the mobile device; determine the attachment by detecting a change of the monitored state of the tunnel associated with the mobile device; and notify the attachment to the mobility server.