I seem to recall that with the M series, at least, a 30 mhz channel works 'better' than a 40 because the 40 is really two 20 mhz channels bonded together, where a 30 mhz channel is a 30 mhz channel.
-----Original Message----- From: Af [mailto:[email protected]] On Behalf Of Rory Conaway Sent: Saturday, June 6, 2015 8:32 PM To: [email protected] Subject: Re: [AFMUG] EPMP 10 mhz vs 20mhz I'm not that familiar with the ePMP's yet but I can tell you some things that we saw with Ubiquiti. One is that channel width does not scale with bandwidth that that Atheros chipset. For example, 40MHz channels rarely hit their theoretical maximum due to a variety of factors, noise, lower s/n, processor limitations, etc... Second, 20MHz channels seem to be the sweet spot but even with GPS sync, you have to deal with reflections. Third, 10MHz channels have more overhead as a percentage of total capacity and don't handle a lot of users well (above 40 for example with the older 400MHz chipsets. I'm starting to deploy XW radios with the 520MHz processors but everything is 20MHz now so I don't have a comparison). We did see peaks of 32Mbps with some customers on 10MHz channels but that's non-peak times. In peak times, we were seeing 8Mbps when more users were online. Rory -----Original Message----- From: Af [mailto:[email protected]] On Behalf Of Craig House Sent: Saturday, June 06, 2015 5:20 PM To: [email protected] Subject: [AFMUG] EPMP 10 mhz vs 20mhz We have deployed 6 towers to begin our new EPMP network and 4 of those towers have a full cluster of 2.4 90 degree EPMP sectors. They are configured with ACS turned off now because in several cases they all ended up on the same or very close to the same channel. I have Front back designations and non overlapping channels set up on all towers. I have tried 40 mhz 20 mhz and now 10mhz channels and while the customer stability has gotten better the more I play with settings I have kind of hit a point I dont know what else to try. I have some that the uplink quality will vary wildly from 100% to 0%. Most have gotten better since I went to a 10mhz channel. Most of the customers get 12MB -30mb down in the wireless link test but the uplinks are as bad as .17. What is the cause of this poor uplink quality? Is it interfernece? My one 5ghz AP does not have this problem but even with noise many of these customers have -50 signals and oddly enough the ones with the great signals seem to be the ones that have the poorest link tests on the up link side. I also have customes with -65 or -72 signals that get 5MB up on the same sectors? Im scratching my head a bit on what the fix is for this? Should I leave ACS on and change everything to 10mhz channels? Will a full cluster with ACS on work all on the same channel? I'm used to FSK where you pick your channel and any channels that are adjacent will cause problems with connected SM's. So am I just applying old knowledge to a technology that it doesn't apply to? Craig
