nanog mailing list archives

Re: Marriott wifi blocking


From: Clay Fiske <clay () bloomcounty org>
Date: Mon, 6 Oct 2014 11:53:40 -0700


On Oct 6, 2014, at 8:41 AM, Owen DeLong <owen () delong com> wrote:


Actually, in multiple situations, the FCC has stated that you are responsible
when deploying a new unlicensed transmitter to insure that it is deployed in
such a way that it will not cause harmful interference to existing operations.

I recognize that you were making this statement in the context of colliding SSIDs, but to me this could be an 
interesting point in another way.

Suppose from Marriott’s perspective that your personal wifi network is interfering with the throughput of their 
existing network. After all, if you fire up your personal AP, with a non-colliding SSID, and start downloading multi-GB 
files, that’s bound to impact[1] anything else using that channel. While there are at least a few non-overlapping 
channels on most wifi networks, if Marriott(’s third party network operators) had any sense they likely would have 
situated their APs and channels to provide the most range with the least amount of frequency overlap. Now here your 
personal AP on one of those channels consuming enough of its bandwidth to significantly degrade performance for anyone 
else, and they may not have access to (or usable signal strength or bandwidth on) another channel from their hotel room.

During a big convention for example, the hotel network is probably at its busiest while the number of guests using 
personal APs is likely also at its peak. This may be a stickier case, as no one user is causing the issue but one could 
make the case that, in aggregate, they are very much interfering with existing operations.

There are probably a couple of different angles to consider, but I’m thinking in terms of the “first come, first 
served” concept. At what point is the extra bandwidth consumed by your personal wifi network considered to be harmfully 
interfering with an existing network?

FWIW I am not defending Marriott’s actions, nor even positing that this was the reason for them. I just want to gain 
understanding.

-c

[1] This is of course assuming you’re getting decent throughput from your 3G/4G provider’s network. But even though 
it’s almost certainly slower than wifi it’s probably generating enough packets in a collision-based medium to impact 
other flows.


Current thread: