Amateur Mesh Networks -Messing around in Hamilton
At the April general meeting, I gave a presentation on Ham Mesh networking. I was assisted by Anthony, VA3IDL, who made the drive in from Mississauga to talk about activities happening at his club. This article is presented as a follow-up to that discussion, to offer some suggestions on how to get involved in this relatively new branch of amateur radio.
Amateur mesh networking grew out of the work of the High Speed Multi-Media working group formed by the ARRL some 10 years ago. Since then, the term HSMM has become synonymous with amateur mesh networking. The most prevalent, and arguably most successful, mesh software is now called Broadband Hamnet. Much has been written about it, so rather than repeat all that work done by others, I’ll refer you to their website:-broadband-hamnet.
Getting started with mesh networking is one of the least expensive forms of radio tinkering I’ve done. All you really need is a compatible wifi device, and a computer. Most ham shacks these days are equipped with the computer. To date, certain versions of the popular Linksys WRT54 home wifi router, and several models of the Ubiquiti line of commercial wifi radios can be loaded with the BBHN firmware. Each have specific strengths.
The Linksys routers come with a Linux based computer. It’s greatest strength is the ability to run various Linux programs right on the router device, removing the need for an attached computer. The Linksys router is great if you want to experiment with Linux on a small scale. I’ve begun my Linux education using several of these devices.
The Ubiquiti radios are a little more purpose-built. Also based on Linux, they can also support small Linux applications right on the radio. Unlike the Linksys, they don’t have a built-in router or switch; they only have a single network connection. The biggest difference between Ubiquiti and Linksys is the quality of their radio. The Ubiquiti radio has higher power output, greater sensitivity, and deals with interference and noise much more effectively than the Linksys.
So what does it cost to get started? I’ve picked up Linksys routers at Value Village and the Salvation Army Thrift Shop for around $5. Be careful to check the model and version to be sure they’re compatible with BBHN. Refer to the ‘shopping list’ on their website. I’ve also picked up Linksys routers from Kijiji. EBay has lots, but the prices are usually higher than I’m willing to pay.
If you prefer new, Canada Computers sells the Cisco Linksys WRT54GL, which is compatible with BBHN, for about $70.
For just a bit more, you can order new Ubiquiti radios from http://www.ubntu.ca. I have two Nanostation M2’s, and can highly recommend them for simplicity of use and effectiveness. The M2 is self-contained, with an 11db cross-polarized antenna array and weatherproof housing. Simply stick it up a pole and go. I’ve currently got one strapped to the roof rack on my van as a mobile node.
I’d recommend starting out with two devices so that you can see how they interact in a mesh.
Once you’ve gotten a node or five working, it’s time to ask the inevitable question that all meshers ask: “what now?” A quote that I read about amateur mesh networking: “Broadband Hamnet is a solution in search of a problem”.
Many of the clubs around Hamilton are working towards building mesh infrastructures for linking repeaters, internet extension, and various other long range applications. If you’ve seen the latest issues of QST and CQ magazines, you may have seen some of the articles about the efforts in the American south-west to build a mountain-top to mountain-top mesh network. Locally, clubs in Barrie, York, Peel, Mississauga and Niagara have all begun work groups for infrastructure level networks.
I think a more practical avenue of investigation for Hamilton is to develop a protocol for rapid deployment of a large number of nodes. For example, if a group of 10 hams each built a kit with two nodes each, a large enough mesh could be deployed to provide data coverage in an area the size of Gage Park, or the Ancaster Fairgrounds. Once some network resources exist at a user level, plans for an infrastructure can be explored.
The mesh network’s greatest strength is it’s ability to pass around large amounts of data very quickly. Video feeds from race checkpoints, web services between operational sites, text messaging and information distribution between wifi devices within a large perimeter. All without internet or cell phone access and the resulting data charges.
The next step is human networking. I propose a meeting with those interested in pursuing this technology to exchange ideas, help build nodes and deployment kits, and plan future steps. If you already have an operational node you’d like to test, take it down to Sam Lawrence Park and point it at downtown. I have a test node installed and running on a roof near the corner of Mary and King William. You can see the antennas with a pair of binoculars. It’s name is VE3RTJ-CP1. Leave your call sign and signal report on the built-in hamchat server.
That link, Sam Lawrence Park to downtown, is about 2 km line-of-sight. I’ll be testing other paths during the spring, and probably taking the node down in June. (It’s a terrible site, I chose it for it’s convenience) If you can link to it from any other location, please let me know.
Please feel free to e-mail me with any questions or suggestions. Happy meshing.
Ron Pereira, VE3RTJ, firstname.lastname@example.org