Meshing Around in York Region
by Steve Brady VA3SRV

The York Region Amateur Radio Club (YRARC) was recently awarded a Trillium grant that allowed them to acquire a D-Star Repeater system.  One of the key things that sets a D-Star system aside from a regular digital repeater is having Internet access.

Radio Clubs benefit from the generousity of some of the Comm tower companies across the country, but getting a "good price" for the required Internet access is sometimes next to impossible to attain.  Our Club VP (Chris – VE3NRT) has a day job in the IT world and was responsible for setting up the D-Star gateway and, while looking for ways of getting Internet to a proposed D-Star site, he stumbled on to a Ham supported Mesh project that could potentially solve the Club‘s needs as well as open up many other possibilities.

High Speed Multi-Media MESH (www.hsmm-mesh.org) is a project that originated with the ARRL and took advantage of existing open software architecture on the WRT54Gx models of Linksys routers. 

These routers can be found for as little as $30 (there is a hardware compatability list that should be referenced) and the firmware installation is painless with an easy to follow tutorial that lives on the main site.

In short, the firmware is based on "open-WRT" and has had a "MESH" layer added to it that gives the "magic" that makes it work.  Except for changing the Node name to include your callsign, there is little else to be done  ...the moment any of these "modified" routers come within range, they will automatically connect to each other.

So, that doesn't sound much different than a regular wireless network  ....but it is!!

What sets a Mesh aside is the auto-traffic routing that it performs. The routers automatically take the most effective path to its destination and should any router fail, the mesh survives as it re-directs to the nodes still online.  So, in the end, the more stations in range the better!!

These same routers have removeable antennas with RP-TNC connections that allow for higher gain or directional antennas to be used!  So the creativity can pour forth into the metal wands we stick in to the air.

Sounds great  ...but, are there drawbacks? YES, the bugger is that, with 2.4 GHz signals, it is VERY important to have a direct line-of-site between nodes.  So, terrain plotting programs (i.e., Splat, Radio Mobile, etc.) were used to determine if paths existed between different QTHs.  This helped with determining where the terrain prevented a path and where directional antennas should be used, but it does NOT take into account foliage, condos, etc, so it is only used as a guide.

York Region, north of Toronto, is a large geographically diverse area of over 2,100 sq. Km., slightly larger than the country of Israel!  Our Club is centrally located in the Newmarket/Aurora area in an undulating bowl completely cut off from the Greater Toronto Area (GTA) due to the Oak Ridges Moraine (it would be great to put a site up on the top of the Moraine to help bridge the region).  My QTH is further removed, within the Holland Marsh, and I'm eagerly awaiting a viable link to point my Yagi's at!

MESH routers can be built into an enclosure and mounted up on your tower.  Power can be passed through an ethernet cable using Power-Over-Ethernet (POE) breakout cables  ...or power can be run directly from batteries or solar panels via a small charge controller. 

In true Amateur fashion, there are folks repurposing old digital satellite dishs for use on their systems.  It takes a bit more work to make sure the focal point is set, but there are lots of web references to assist.  As well, the DIY'er can play with Cantenna's and Pringle's cans to see what luck they have.

Image Courtesy of Brad (VE3HII)

The routers will only talk to each other, so don't expect to connect to them with your laptop/smartphone, though you can still see their SSID name. The easiest way to connect is to plug your LAN cable in to the router. This does offer some security from the conventional user.

At our recent Hamfest, I was able to cludge together a demo that consisted of a few updated routers and Raspberry Pi's running USB webcams. It's all eye-candy, but it demonstrated some of the basic functions to be explored. You can run a FTP server, which is a simple way to exchange/retrieve files during deployments (emergency or event based).  There's also the ability to have text based "IRC chatrooms" where everyone can share information ...and there's work underway on VOIP-type software as well.  Really, just about anything you can do on your home/Internet network can be done on the HSMM-MESH network. The routers allow port forwarding as well as "advertised services" assignment.  So a basic functioning webpage can be built on each router that could link to ftp servers, imagery, etc....

If you are in the region and have interest, please join the conversation on the club bulletin board or send me an email at This email address is being protected from spambots. You need JavaScript enabled to view it.

Cheers Steve Brady VA3SRV

Sites of interest: Main site - http://hsmm-mesh.org/ Google Map of HSMM nodes - http://www.hsmm-mesh.org/googlemapped-mesh-nodes.html General Info - http://www.n5oom.org/hsmm/ Facebook group - http://www.facebook.com/groups/105333036166026/ York Region ARC Info page - http://www.yrarc.org/index.php/interest-groups/hsmm-mesh

 

Plot of potential links within YRARC Mesh network Note the East/West ridgeline transmitting site 6; this would make for an excellent 'over the hill' linking stations.

Status as of December 13, 2012 – several stations on the air but no links achieved.

 

Image Courtesy of Matt (VA3MGN)

For community events, or emergency callouts, there can be occasions when you need to bridge geographic gaps between areas.  Sending an outfitted person can be a waste of resources, so why not deploy a standalone MESH Node!?

Matt (VA3MGN) surprised me at our Hamfest MESH Demo by bringing in his newly built transportable Node. It's similar to other ideas on the Internet, but I got to look at this one in person.

Matt made use of a directional antenna and an omni (the Yagi would link in to an active mesh node and the omni would provide local coverage), but this can be easily converted to two Yagis if the true intent was to link the gap between two distance nodes.

The enclosure was a re-purposed sprinkler timer control box that already had the waterproof gaskets and the bonus of a locking latch for security. Three holes were cut in to the bottom with PL259 bulkhead connectors for the antennas and one feedthrough connector for network/power.

There is plenty of room in this box without having to use a ratchet clamp to close the lid!

 

Image Courtesy of Matt (VA3MGN)

The tripod is a re-purposed camera tripod, which makes for a light base. An adjustable vertical leg extension can fit over a ground stake to help secure the station in a wind.  Another option for a stand could be a surveyors tripod.

Ultimately, this is a nice/clean way of building a transportable node where the item costs were just over $350.  There are ways to cut costs, but in the end the main costs will be your antennas and router.

Kitty Litter "Go" Box - http://www.hsmm-mesh.org/images/stories/KittyKontainerKitRev2.pdf PVC Electrical Enclosure "DropBox" - http://www.hsmm-mesh.org/documentation/121-drop­boxes.html

It could be an old cooler, storage tote, backpack....or a couple of pipes jammed in to the ground with wireties and duct-tape (think of it as art!), but in the end you have an effective way to bridge any service gaps for your event.

Reference link - http://www.w5adc.com/HSMM.htm More info – http://www.hsmm-mesh.org/ and – http://www.n5oom.org/hsmm/