Might check this out: http://revolutionwifi.blogspot.com/2014/08/80211ac-adjacent-channel-interference.html?m=1
There's and image there you should find similar. Sent from my iPhone > On Mar 8, 2017, at 4:58 PM, Chuck Enfield <chu...@psu.edu> wrote: > > Cool images. I’ve never tried this. I would have this afternoon, but our > operations guys have the spectrum analyzer in another building. I’m a little > surprised to see as nice a plot as you got in the second trace. Between near > field effects and the potential to push the Rx amplifiers into a non-linear > region I would have expected something more messy. > > Do you know what the max signal strength was in the two traces? Also, do you > know how to account for the increased duty cycle in the second one? I’m > wondering if this is due to different iperf behavior or if it’s weirdness > caused by proximity. I’ve been doing Wi-Fi for 15 years and still find > myself guessing on a regular basis. > > From: The EDUCAUSE Wireless Issues Constituent Group Listserv > [mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jason Cook > Sent: Wednesday, March 08, 2017 6:08 PM > To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU > Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference > > Still learning my way through signatures but I have been caught out before > with the anaylzer being too close to a wifi source > Below shows this on channel 132, using iperf for a data burst in the first > image the anaylzer is 1m away from a Mac Air, > In the second it’s a few centimetres away from it. You can really see the > impact on neighbouring channels at that distance (I think there’s even a bit > in the 36-40 area) > > I now keep the anaylzer away from wifi devices as much as possible J > > <image003.jpg> > > <image005.jpg> > > -- > Jason Cook > Technology Services > The University of Adelaide, AUSTRALIA 5005 > Ph : +61 8 8313 4800 > > From: The EDUCAUSE Wireless Issues Constituent Group Listserv > [mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Gray, Sean > Sent: Thursday, 9 March 2017 7:26 AM > To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU > Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference > > Nope, the spectrum analyzer is going directly into a Surface Pro 2. > > > From: The EDUCAUSE Wireless Issues Constituent Group Listserv > [mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jake Snyder > Sent: March-08-17 1:30 PM > To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU > Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference > > Are you using a USB 3.0 hub? > > > On Mar 8, 2017, at 1:23 PM, Jason Heffner <jdh...@psu.edu> wrote: > > I’ve seen something similar when running some of the older Cisco controllers. > If you ruled out everything else and are starting to look for devices causing > interference I'd check out some of your wireless mic systems. We had some > 800Mhz that we had to salvage that were causing harmonic distortion on 2.4GHZ > similar to this on the lower channels. > > On Mar 8, 2017, at 2:32 PM, Gray, Sean <sean.gr...@uleth.ca> wrote: > > Hi Everyone, > > I’ve been doing a little spectrum analysis around campus and I keep seeing > the same interference signature in different buildings. I was wondering if > anyone had seen anything like this before. It is typically visible for well > over 10 minutes at a time and then it completely disappears. > > Thanks > > Sean > > > Sean Gray | B.Sc (Hons) > Voice, Collaboration & Wireless Network Analyst > ITS, University of Lethbridge > > > ********** Participation and subscription information for this EDUCAUSE > Constituent Group discussion list can be found at > http://www.educause.edu/discuss. > <Unknown Interference Source.PNG> > > ********** Participation and subscription information for this EDUCAUSE > Constituent Group discussion list can be found at > http://www.educause.edu/discuss. > > > ********** Participation and subscription information for this EDUCAUSE > Constituent Group discussion list can be found at > http://www.educause.edu/discuss. > ********** Participation and subscription information for this EDUCAUSE > Constituent Group discussion list can be found at > http://www.educause.edu/discuss. > ********** Participation and subscription information for this EDUCAUSE > Constituent Group discussion list can be found at > http://www.educause.edu/discuss. > ********** Participation and subscription information for this EDUCAUSE > Constituent Group discussion list can be found at > http://www.educause.edu/discuss. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/discuss.
