Patent ID: 7586878

Claim:
A vertical handoff method between a first communication network and a second communication network for reducing handoff latency, the method comprising: establishing a first tunnel by assigning a first parameter and a second parameter when a user equipment is located in the second communication network; translating the first parameter and the second parameter into a first packet filter and a second packet filter; establishing a second tunnel and a first table based on the first packet filter and the second packet filter for the user equipment to access services from the first communication network; generating the first packet filter and the second packet filter by the user equipment when the user equipment roams into the first communication network; establishing a third tunnel and a fourth tunnel based on the first packet filter and the second packet filter; and searching for the first table based on the second parameter in the second packet filter for reusing the first table, for the user equipment to continue to access the services from the first communication network.