Handoff method and system for mobile terminal

摘要

Disclosed in the present invention are a handover method and system for a mobile terminal (MT) based on a wireless local area network. The method includes: sending a data frame to a second AP when an MT needs to hand over from a cell covered by a first AP service to a cell covered by a second AP service, with the data frame including an associated number between the MT and the first AP and an MAC access of the first AP; and the second AP looking up locally stored mobile terminal certification and association information about the cell covered by the first AP service and rapidly determining whether to allow the access of the MT according to the stored information.

主权项

1. A handover method for a mobile terminal, comprising:
a second access point (AP) storing mobile terminal certification and association information about a cell which overlaps with a cell covered by the second AP service, wherein the mobile terminal certification and association information comprises an associated number between a mobile terminal (MT) and a first AP of the cell which overlaps with the cell covered by the second AP service, associated AP information, MT certification information, and a media access control (MAC) address of the first AP; the mobile terminal (MT) sending a data frame to the second access point (AP) when the mobile terminal (MT) needs to hand over from a cell covered by a first wireless AP service to a cell covered by the second AP service, wherein the data frame contains the associated number between the MT and the first AP and the media access control (MAC) address of the first AP; after having received the data frame, the second AP comparing the associated number between the MT and the first AP and the media access control (MAC) address of the first AP in the data frame with corresponding contents in the mobile terminal certification and association information stored by the second AP, when the comparison result presents to be consistent, the second AP encrypting a new key using a shared key of the first AP and sending information obtained from the encryption to the MT, and the MT relieving the association with the first AP and obtaining a number associated with the second AP; the MT adding an association with the second AP according to the obtained number associated with the second AP, decrypting the obtained new key, and carrying out a data transmission with the second AP using the new key; the second AP sending MT and the second AP certification and association information to APs of cells which overlaps with a cell covered by the second AP service; after APs of cells which overlap with cells covered by the second AP service and do not overlap with cells covered by the first AP service have received the MT and the second AP certification and association information, said APs looking up the locally stored mobile terminal certification and association information respectively, determining that the MT and the second AP certification and association information is not previously stored, then storing the MT and the second AP certification and association information; and after APs of cells which overlap with cells covered by both the first AP service and the second AP service, and the first AP have received the MT and the second AP certification and association information, said APs and the first AP looking up the locally stored mobile terminal certification and association information respectively, determining that the MT and the first AP certification and association information is previously stored, then deleting the MT and the first AP certification and association information and storing the MT and the second AP certification and association information.