Method for realizing seamless switching in 802.11 wireless local area network and access points thereof

Abstract

The invention relates to a method for realizing seamless switching in an 802.11 wireless local area network and access points thereof. The method comprises the following steps: when a new station enters the 802.11 wireless local area network, the new station sends out an authentication request to access points firstly; every access point uses a stochastic confirmation function to judge whether the authentication request is returned for confirmation or not; all the access points report that the authentication request is received to an access controller; the access controller selects a service access point for the new station; and the service access point updates a service list so as to store the information of the new station. The access points comprise a service list device used for storing the information of stations serviced by the access points and inquiring about the source addresses of received frames when receiving the frames, and a stochastic confirmation device used for judging whether the received frames are returned for confirmation or not on the basis of a confirmation strategy. Therefore, by using the method, seamless switching can also be realized without modifying stations or protocols.

Description

technical field [0001] The present invention generally relates to a method for a station to roam in an 802.11 wireless local area network (such as WiFi), and in particular to a method for realizing seamless handover in an 802.11 wireless local area network and an access point (AP) used in the method : Access Point). Background technique [0002] In recent years, IEEE 802.11 wireless networks have developed rapidly and become more and more popular. Wireless networks provide access to the Internet for delivering various services such as VoIP (Voice over IP), multimedia or data transmission. Therefore, supporting user and device mobility is a key issue since continuous network connectivity is highly desirable for most services. However, IEEE 802.11 adopts a hard handover method, which means that, before a station (STA: station) connects to a new access point, the station must disconnect itself from the currently associated access point. This can lead to long handover latency...

AI Technical Summary

Problems solved by technology

However, this raises the following question: If a new station enters the network and sends an authentication request frame, which access point will answer with an ACK? Authentication Request (Frames of type "Authentication" and Authentication Transaction Sequence Number 1

Therefore, this mode cannot use a unified backend authentication server

But for the 802.11 WLAN that is not only open to various sites but also to the unified ISP authentication server, this solution is not feasible

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