Method and system for interworking of cellular networks and wireless local area networks
A method and system for interworking between cellular networks and wireless local area networks (WLANs) are disclosed. At least one cellular network, at least one WLAN, and an IP network may be deployed. A wireless transmit/receive unit (WTRU) may establish a connection to a WLAN and a tunnel between an access point (AP) and a packet data gateway (PDG) may be established. The PDG may establish a tunnel to an IP network. The WTRU may invoke a service which is delivered through the WLAN. As signal quality from the AP degrades below a predetermined threshold, a handover from the WLAN to the cellular network may be performed. A new connection to the cellular network may be established either before or after breaking the current connection to the WLAN or the two connections may be maintained simultaneously.
1. A wireless transmit/receive unit (WTRU) comprising:
a cellular transceiver configured to communicate using a cellular protocol, the cellular transceiver configured to provide a cellular connection;
a wireless local area network (WLAN) transceiver configured to communicate using a WLAN protocol, the WLAN transceiver configured to provide a WLAN connection, the WLAN transceiver configured to obtain an address of a packet data gateway (PDG) using Domain Name Service (DNS) via the WLAN connection and establish a tunnel between the WTRU and the PDG wherein the WLAN transceiver is configured to receive the service from an Internet Protocol (IP) multimedia subsystem (IMS) via the WLAN and the tunnel between the WTRU and the PDG; and
a controller configured to direct services between the cellular transceiver and the WLAN transceiver based on monitored services, while the cellular connection and the WLAN connection are maintained simultaneously by the WTRU.
2. The WTRU of claim 1 wherein the controller is further configured to switch radio access bearers (RABs) between the WLAN communication and cellular communication.
3. The WTRU of claim 1 wherein the WLAN transceiver is further configured to register with the IMS via the WLAN using Session Initiation Protocol (SIP).
4. The WTRU of claim 1 , wherein the service is a voice call service.
5. A method for use in wireless transmit/receive unit (WTRU) comprising:
communicating via a cellular connection using a cellular transceiver using a cellular protocol;
communicating via a wireless local area network (WLAN) connection using a WLAN transceiver using a WLAN protocol;
obtaining via the WLAN transceiver an address of a packet data gateway (PDG) using Domain Name Service (DNS) via the WLAN;
establishing via the WLAN transceiver a tunnel between the WTRU and the PDG:
receiving, via the WLAN transceiver, the service from an Internet Protocol (IP) multimedia subsystem (IMS)via the WLAN and the tunnel between the WTRU and the PDG; and
directing services via a controller between the cellular transceiver and the WLAN transceiver based on monitored services, while the cellular connection and the WLAN connection are maintained simultaneously by the WTRU.
6. The method of claim 5 further comprising switching, via the controller, radio access bearers (RABs) between the WLAN communication and cellular communication.
7. The method of claim 5 further comprising registering, via the WLAN transceiver, with the IMS via the WLAN using Session Initiation Protocol (SIP).
8. The method of claim 5 , wherein the service is a voice call service.
9. The WTRU of claim 1 , wherein the monitoring monitors signal quality.
10. The WTRU of claim 1 , wherein based on the monitoring includes a determination that the signal quality has degraded below a predetermined threshold.