Craig, Changing the data rate will only affect how YOU interfere with them, but not in reverse. When an AP (well, any Wi-Fi device) hears a Wi-Fi signal of any data rate it will defer (not transmit).
I don’t know your Wi-Fi vendor but a trick to try is to reduce your AP receive sensitivity. SOME vendors allow this, sometimes only in CLI. This is a very advanced and rare feature because it can be messed up in a hurry. But, it has some awesome advantages in the right environment. To completely understand this, there is one component that isn’t always understood. A Wi-Fi device CAN hear multiple Wi-Fi signals and still get the data without a failure. Let’s say there are two Wi-Fi APs even of different SSIDs. They both transmit at the same time and a single client device hears both. Its commonly understood that this would result in a failed transmission because the resulting signals to the client would interfere with each other. BUT, if the signals have enough delta in signal strength, the client will still get the stronger data. As an example, the client receives a signal at –80dBm and another at the same time at –60dBm that’s still a 20dB SNR and the client won’t have a problem at all discerning the two. It will receive and process the stronger signal with no errors. The problem is, your AP isn’t transmitting as often as it could because it hears too much. But, you can configure SOME APs to not defer until a certain signal strength. This allows the AP to transmit more often and could provide more downstream data to your client devices. Sorry that’s such a long explanation but hope it helps. GT From: The EDUCAUSE Wireless Issues Constituent Group Listserv <[email protected]> on behalf of Craig Simons <[email protected]> Reply-To: The EDUCAUSE Wireless Issues Constituent Group Listserv <[email protected]> Date: Friday, May 27, 2016 at 2:44 PM To: <[email protected]> Subject: Re: [WIRELESS-LAN] Beacon Intervals Jason, Thanks for the reply. Actually the link you mention is what got me going on this in the first place. Our downtown campus is situated in a very busy urban environment - hotels, coffee shops, apartments, you name it. Several places in the building can see 25+ SSIDs, of which only 3 are ours. I’ve done as much tuning as I can to limit co-channel interference on 2.4, the minimum data rate is 12 (I could boost to 24 I suppose), so I’m just looking for more tricks to try. - Craig On May 26, 2016, at 6:38 PM, Jason Cook <[email protected]> wrote: My understanding is you really don’t want to be playing with this, perhaps if all other avenues have been exhausted it can be investigated…. Reduce your SSID’s, disable lower data rates, reduce co-channel AP’s (your own and neighbours) If you haven’t seen it play with this tool (Changing the beacon Rate shows the variations) http://www.revolutionwifi.net/revolutionwifi/p/ssid-overhead-calculator.html -- Jason Cook Technology Services The University of Adelaide, AUSTRALIA 5005 Ph : +61 8 8313 4800 From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:[email protected]] On Behalf Of Britton Anderson Sent: Friday, 27 May 2016 10:10 AM To: [email protected] Subject: Re: [WIRELESS-LAN] Beacon Intervals Hey Craig, It really depends on how dense your environment is. Keep in mind, the longer your beacon interval, the slower the roaming time clients take between APs. In my mind, the overhead that beacons introduce is far less of an issue than mobile clients dropping connections when they're roaming through the network. Especially considering the vast majority of cell carriers using WiFi calling now. --Britton Britton Anderson | Senior Network Communications Specialist | University of Alaska | 907.450.8250 On Thu, May 26, 2016 at 4:16 PM, Craig Simons <[email protected]> wrote: Hello Group, On most vendor products that I’ve seen, the beacon intervals for SSIDs by default are set to ~100ms. Has anyone gone to the lengths of increasing this default in an effort to combat overhead? - Craig SFU SIMON FRASER UNIVERSITY Network Services Craig Simons Network Operations Manager Phone: 778-782-8036 Cell: 604-649-7977 Email: [email protected] Twitter: simonscraig ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
