Wireless mesh network question
HI guys, I am planning to setup a wireless mesh network at a ham radio event in June. Each mesh node will consist of two Linksys WRT54GLs, much like the demo I showed at a recent WLUG meeting. One of the WRT54GLs will be on channel 6 and carry mesh network traffic. The other one will be on channel 1 and allow generic wifi devices access to the mesh network. It seems like there would be an interference problem if every node allowed wifi access on channel 1. Should this be 4 different wifi channels? It is possible for a user to be within radio range of multiple of them simultaneously. Thoughts? I've never setup a wireless network before and could use your advice. These mesh nodes will be placed outside in weatherproof enclosures with battery power. Thanks! Andy -- Andy Stewart (KB1OIQ) Founder: Worcester Linux Users' Group Founder: Chelmsford Linux Meetup Group President: PART of Westford, MA (WB1GOF)
HI gang, I setup an experiment with all of the wifi access on one channel. WiCD saw both access points with the same SSID and wifi channel. Connecting to either of them seems to have no ill effects. Andy -- Andy Stewart (KB1OIQ) Founder: Worcester Linux Users' Group Founder: Chelmsford Linux Meetup Group President: PART of Westford, MA (WB1GOF)
75 degrees! On 2/16/2015 11:59 AM, Andy Stewart wrote:
HI gang,
I setup an experiment with all of the wifi access on one channel. WiCD saw both access points with the same SSID and wifi channel. Connecting to either of them seems to have no ill effects.
Andy
Every access point on the same channel (as well as every client) shares bandwidth. If all of the networking is happening on channel one, with two clients, you would end up with 1/6 the bandwidth. The problem isn't interference, it's making a 6 lane highway a two lane road. If you use distinct, but overlapping channels, you end up with radio level interference, so not shared bandwidth, but lots of retransmits when both are active. The best case is using the non overlapping channels which allows you full bandwidth and very low interference. So I would have your backbone on some far channel from your clients, or your chatty mesh protocol will slow the normal clients to a crawl. You could even use the three distinct channels so that one is backbone and the other two are not overlapping where the two circles fall in the same territory. On Feb 16, 2015 7:00 PM, "Andy Stewart" <andystewart@comcast.net> wrote:
HI gang,
I setup an experiment with all of the wifi access on one channel. WiCD saw both access points with the same SSID and wifi channel. Connecting to either of them seems to have no ill effects.
Andy
-- Andy Stewart (KB1OIQ) Founder: Worcester Linux Users' Group Founder: Chelmsford Linux Meetup Group President: PART of Westford, MA (WB1GOF) _______________________________________________ Wlug mailing list Wlug@mail.wlug.org http://mail.wlug.org/mailman/listinfo/wlug
As long as all of the APs are on either matching or non-overlapping channels, you should be fine. In practice, this means you'll get the best overall throughput by evenly distributing them across channels 1, 6, and 11. You *might* be able to get away with channel 14 (this is outside of the normal part 15 regs, but you can probably legally get away with it since you're licensed), but you may have strange results if you're trying to have standard wifi clients connecting to them, as some of them are set up only for US options and won't look at that channel at all. Frank Sweetser fs at wpi.edu | For every problem, there is a solution that Manager of Network Operations | is simple, elegant, and wrong. Worcester Polytechnic Institute | - HL Mencken On 02/16/2015 11:39 AM, Andy Stewart wrote:
HI guys,
I am planning to setup a wireless mesh network at a ham radio event in June.
Each mesh node will consist of two Linksys WRT54GLs, much like the demo I showed at a recent WLUG meeting.
One of the WRT54GLs will be on channel 6 and carry mesh network traffic. The other one will be on channel 1 and allow generic wifi devices access to the mesh network.
It seems like there would be an interference problem if every node allowed wifi access on channel 1. Should this be 4 different wifi channels? It is possible for a user to be within radio range of multiple of them simultaneously.
Thoughts? I've never setup a wireless network before and could use your advice. These mesh nodes will be placed outside in weatherproof enclosures with battery power.
Thanks!
Andy
participants (4)
-
Andy Stewart -
Frank Sweetser -
Michael Limanni -
Randall Mason