WiFI on utility poles

Thu Sep 10 17:15:29 UTC 2015

The tower-deployed AP can see the cable wireless APs for miles and can see a few dozen of them at any one time. Given the goal of full modulation at all times for optimal use of spectrum and dollars, the ever increasing noise from the cable APs makes this a challenge. You need 25 to 30 dB to maintain full modulation and that's increasingly difficult when you hear cable APs everywhere at -70. 

The APs can't have narrow radiation patterns given that they need to cover a roughly 90* area of where the customers are. An 18 to 20 dB gain sector antenna will pick up those cable radios from pretty far away. 

----- 
Mike Hammett 
Intelligent Computing Solutions 
http://www.ics-il.com 

Midwest Internet Exchange 
http://www.midwest-ix.com 

----- Original Message -----

From: "Scott Helms" <khelms at zcorum.com> 
To: "Jared Mauch" <jared at puck.nether.net> 
Cc: "Mike Hammett" <nanog at ics-il.net>, "Corey Petrulich" <Corey_Petrulich at cable.comcast.com>, "Kenneth Falkenstein" <Ken_Falkenstein at cable.comcast.com>, "NANOG mailing list" <nanog at nanog.org> 
Sent: Thursday, September 10, 2015 10:00:41 AM 
Subject: Re: WiFI on utility poles 

This sounds like a hypothetical complaint, AFAIK none of the members of the CableWiFi consortium are deploying APs outside of their footprint. Since most of the APs use a cable modem for their backhaul it's not really feasible to be without at least one broadband option (the cable MSO) and be impaired by the CableWiFi APs. 

Now, there is one potential exception to this I'm aware of which is Comcast's Xfinity on Campus service, but I'd expect the number of colleges they're servicing that aren't already getting cable broadband service to approach zero. 

http://www.philly.com/philly/business/20150909_Comcast_streams_onto_college_campuses.html 

https://xfinityoncampus.com/login 

Having said all of that, I'd agree that a good radio resource management approach would benefit all of us, including the CableWiFi guys. 

http://www.cablelabs.com/wi-fi-radio-resource-management-rrm/ 

Scott Helms 
Vice President of Technology 
ZCorum 
(678) 507-5000 
-------------------------------- 
http://twitter.com/kscotthelms 
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On Thu, Sep 10, 2015 at 10:52 AM, Jared Mauch < jared at puck.nether.net > wrote: 

> On Sep 10, 2015, at 9:00 AM, Mike Hammett < nanog at ics-il.net > wrote: 
> 
> 5 GHz noise levels affecting people whose primary means of Internet access is via fixed wireless . 
> 

This is a huge deal for those people like myself that depend on fixed wireless for access at home because there is no broadband available despite incentives given by cities and states and the federal government. 

The local WISPs are good at coordinating access in these ISM bands amongst themselves but when someone appears with a SSID without doing a peek at the spectrum (note: not a site survey, but actual spectrum view w/ waterfall, as site survey only checks for the channel width that the client radio is configured for, not al the 10, 15, 8, 30mhz wide variants). 

It’s just poor practice to show up and break something else because you can’t be bothered to notice the interference or noise floor you created. I suspect the hardware that Comcast is using doesn’t notice this interference or adjacent channel issues. With the FCC aiming to let cell carriers also clog the 5ghz ISM band it’s only going to get worse. 

- Jared 