Access Point Channel Switching for Seamless Terminal Roaming
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Solution Overview
Problem
In wireless local area networks (WLANs), terminals without wireless network management support experience prolonged service interruptions during roaming, as they need to re-authenticate after disassociating from the original access point (AP), leading to inefficient roaming processes.
Innovation Solution
The method involves sending a unicast channel switching message from the first AP to a terminal associated with it, instructing the terminal to switch to a different channel while the AP remains on its original channel, allowing the terminal to associate smoothly with a new AP, and optionally using simulation beacon frames to facilitate seamless handover and reduce service interruption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If an AP sends a disassociation frame or deauthentication frame to trigger terminal roaming, then the terminal can be forced to roam to a new AP, but the terminal becomes unassociated and requires re-authentication, resulting in long service interruption time
Solution Approach 1:
The patent applies preliminary action by having the terminal perform authentication with the target AP before actually disassociating from the current AP. The terminal receives authentication information from the current AP, pre-authenticates with the target AP, and only then disassociates. This ensures the terminal is already authenticated before the handover, eliminating service interruption time while simplifying the roaming process.
2Ease of operation
If an AP instructs terminal to switch channel using unicast channel switching message, then terminal can be guided to new channel, but terminal cannot find AP on new channel and must re-associate
Solution Approach 1:
The patent applies preliminary action by having the terminal pre-authenticate with the target AP before channel switching occurs. The current AP provides authentication information to the terminal, which then uses this information to authenticate with the target AP on the new channel beforehand. This ensures seamless channel transition without re-association delays.
Solution Approach 2:
The patent uses authentication information as an intermediary element that bridges the current AP and target AP. The current AP generates and transmits authentication information to the terminal, which then uses this intermediary credential to authenticate with the target AP, enabling smooth channel transition without full re-association procedures.
3Adaptability or versatility
If terminal switches to new operating channel, then terminal can access new AP, but terminal cannot find the associated AP and must re-authenticate
Solution Approach 1:
The patent applies preliminary action by having the terminal pre-authenticate with the target AP before actually switching channels. The authentication process is completed in advance using authentication information provided by the current AP, so when the terminal switches to the new channel, it is already authenticated and can immediately access the target AP without re-authentication delays.
Data Source
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AI summary
The present invention relates to the communications field, and in particular, to a method for triggering terminal roaming by an access point (AP) and an access point. In the method, a first AP sends, by using a first channel, a unicast channel switching message to a first terminal associated with the first AP, where the unicast channel switching message is used to instruct the first terminal to switch from the first channel to a second channel, a receiver address of the unicast channel switching message is an address of the first terminal, the first channel is an operating channel of the first AP, and the second channel and the first channel are different; and retains the first channel as the operating channel of the first AP after the unicast channel switching message is sent. According to the method, a process of associating with a new AP can be simplified, an AP can trigger smooth roaming of a terminal, and a service interruption time of the terminal can be reduced.