A method for realizing cross-channel roaming switching of wireless terminal in wlan

Abstract

The present invention requests protection of a method for realizing cross-channel roaming switching of wireless terminals in a WLAN. The WLAN network consists of at least one SDN controller and multiple programmable APs. Adjacent APs work on different channels. Each AP There are two wireless network cards with the same frequency. When the wireless terminal is far away from the original AP, the controller first adjusts the auxiliary wireless network card channel of its neighbor AP to the working channel of the wireless terminal to obtain the signal strength value of the wireless terminal; The AP transfers to the target AP; finally, the original AP is ordered to issue a channel switching notification. After receiving the channel switching notification, the wireless terminal switches the channel to the target AP channel. After the channel is switched, the wireless terminal can directly transmit user data with the new AP. In the whole switching process, the wireless terminal only needs to switch channels, and the time is within a few milliseconds, which realizes the purpose of fast cross-channel roaming switching of the wireless terminal in the WLAN.

Description

technical field [0001] The invention belongs to the technical field of communication, and in particular relates to a method for realizing roaming switching of a wireless terminal in a WLAN. Background technique [0002] According to the IEEE 802.11 specification, a terminal (STA) working in the infrastructure mode and its associated access point (Access Point, AP) together form a basic service set (BSS). In the basic service set, the wireless terminal must establish an Only after being associated can it communicate with other nodes, that is, the data transmission between the wireless terminal and other nodes must be forwarded by the AP. Because in a basic service set, the network coverage of AP is very limited, usually within 200 meters. Such a small transmission distance limits the mobile range of the wireless terminal. [0003] In this regard, the coverage of the network is generally extended by increasing the number of APs in the network. Connect multiple APs together ...

AI Technical Summary

Problems solved by technology

[0005] However, there are several main problems in the current standard: one is that the two APs for fast switching need to be on the same channel. Terminals are constantly switched between APs, which not only affects terminal services, but also seriously consumes AP performance

The second problem is that the fastest switching time based on the 802.11r standard modification is limited to a theoretical 50ms, which is not enough for some real-time multimedia services

The third problem is that these handover decisions are made by wireless terminals, but due to the diversity of wireless terminals, some terminals do not support related 802.11 handover protocols, which makes it difficult for WLAN networks to provide unified services for all wireless terminals. more complicated

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