In the 802.11 association process an STA will send an Association Request to the AP which it has discovered to have the highest RSSI (Received Signal Strength Indicator). If the AP responds with an Association Response , then the STA-AP association is complete. But what if the selected AP rejects the request? Would the STA move on to try to associate with the AP with the next highest RSSI ? Or else would it simple retry to connect to the initial AP (which has the highest RSSI )?
The STA should only send association requests to APs with the same SSID. In that case, the AP has no reason to reject the request. I don't think the standard either says "STA must associate with AP with highest RSSI first", nor does it describe what happens if the AP (wrongfully) denies a request, so my guess is it's implementation dependent. But that's easy to find out by reading the standard .
Commented Nov 21, 2017 at 17:11@Tyson actually this is for a research project I'm doing. The success of a particular approach that I'm considering will depend on what exactly happens here.
Commented Nov 22, 2017 at 17:59@dirkt I tried to find an answer in the standard but couldn't find a decisive one. It just says that the STA should wait x number of seconds before retrying, but doesn't mention to which AP the retry request should be sent. Also, I'm not talking about an everyday network here - an AP might purposefully reject a request to force the STA to associate with another AP for some reason.
Commented Nov 22, 2017 at 18:08Then the success of your particular approach probably depends on the implementations, so look at the implementations. there's not that many to check.
Commented Nov 22, 2017 at 18:40The IEEE 802.11 standard does not specify the STA behavior here, so it is up to the implementers to decide what to do.
The implementations I’m familiar with will look at the reason / result code to determine whether to retry with the same AP or move on to another one.
answered Nov 21, 2017 at 20:12 107k 17 17 gold badges 189 189 silver badges 248 248 bronze badgesThe first packet that is sent from a station is a Probe Request. There are two different Probe Requests, a directed one and a broadcast one. The directed one requests specifically for a specific BSSID and the broadcast one is sent out into the air and waits for all the APs with the same SSID in the are to respond. Based on the Probe Responses, the Station algorithm then makes a decision as to where to send its Association Request. With that said, if an Association fails, typically the Station algorithm will retry the association process x times and then it will halt for x seconds and try again. If there is overlap on the signal for two APs with the same SSID, once a Probe Request is sent out, the Station may attempt an association to the AP that responds first, if the "bad" AP responds first every time, the station will fail every time. Anyway, wireless adapter firmware all behave differently - There is no standard for wait times and retries. If the association fails, the user should figure out why the association is failing. Is it a station issue or an AP issue? If it turns out to be an AP issue and the AP is not fixed, this may create a hole in the wireless deployment.
answered Nov 21, 2017 at 19:21 1,051 5 5 silver badges 14 14 bronze badgesTo subscribe to this RSS feed, copy and paste this URL into your RSS reader.
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