On Sep 10, 2015, at 1:47 PM, Michael Englehorn <michael@englehorn.com> wrote:
My issue with the "free" wifi that comcast is forcing into our homes and businesses is that it's also interfering with our own access points in the same building!
[resending due to hitting limit on file size to nanog list] This is the biggest problem I’ve seen regarding this. If you care about 5ghz please provide feedback about the LTE-U stuff and encourage the cablewifi, wayport, etc to do a proper listen-before-use similar to what is required with DFS to avoid interference. Here’s a sample of what a spectrum might look like: http://puck.nether.net/~jared/airview_20150910_210354.png and http://puck.nether.net/~jared/airview_20150910_211313.png You can clearly see things at the various frequencies but without looking at the waveform you may not see the 40mhz user and where their center frequency is. If they are just sending beacons it may look different. A “site survey” isn’t a spectrum view as your receiver may not understand what is going on. This is the UBNT 5ghz AC radio which is quite handy, but it as it’s an 802.11 device it may not see other things that use the ISM band and aren’t 802.11 based. These do exist, eg: mimosa b5, af-5/af-5x. These may use different frequencies for TX vs RX as well. Either way, I figure this is interesting enough to share if you aren’t doing WISP stuff or looking at spectrum often. - Jared