Hard handoff from a wireless local area network to a cellular telephone network

The invention claims for supporting a wireless (wireless) is cellular telephone call network hard side zone switching control system and method. The method comprise: A ring and user terminal (UT) and service WLAN, and via the WLAN ring is calling; Of cellular network telephone for monitoring service; A are connected to the cellular network to the information transmission of UT to powering to the service, WLANThe response is connected with the service WLAN the ring, the performing propped to the cellular network the upper side zone; switchAnd via the cellular network to casing of calls. Generally talk-back; and WLAN is connected to the transmission state of UT to the cellular telephone, and capable performing of the upper side zone switch, wherein the cellular network is in the confirm to the position UT. With the UT to receiving resource allocation the performing to the upper side zone switch the common control channel message, wherein the common control channel message for example is a short message service (sending) or a paging message.