Meshing at the 3/12/2016 Breakfast Deployment

Post date: Mar 13, 2016 3:57:37 AM

This morning, I deployed 3 routers (2 HSMM and 1 AREDN) for intra-station communications at this morning's Breakfast Deployment organized by Jim Montgomery, WB3KAS. We were deployed at the new Prince George's County Fire Department station in Brandywine, MD.

This drill was meant to simulate an impromptu, "unplanned" deployment--unlike the heavily organized Simulated Emergency Test and Field Day deployments.

Configuration

Charles, AA3WS, working the VHF/UHF RMS Packet station, and I were able to communicate via HamChat over the 3-node mesh. One of the HSMM nodes was connected to the fire station's Ethernet ports and provided shared Internet access throughout the mesh. The AREDN node (a Ubiquiti Networks bullet M2 connected to a 21dBi omni) was installed outside the fire house--to provide potential access to external nodes. No changes were made to the configurations of any router/node.

Lessons Learned

  • HamChat worked very well over the mesh. It's easier to copy and paste from chats if you uncheck the Auto-Refresh box. This prevents the screen from "jumping up and down" as you're attempting to highlight text
  • A "back door" router configured as an Access Point is needed in every deployment to provide wireless access for tablets, smart phones, and other devices not equipped with Ethernet ports.
  • Lynwood Leach, KB3VWG, a network engineer with Prince George's county, was a great help in gaining access to the Internet through the county's LAN. He noticed that the network has a web content filter that, for some unknown reason, blocks access to the bbhn.org website.
  • Apparently, recent upgrades to my laptop version of Xubuntu Linux prevent the olsr-topology-view PERL script from executing properly--so that I was not able to get a good "map" of the mesh network.
  • It would be an excellent "public service" to create a how-to guide or link to one about intra-station deployment mesh deployment. Norfolk ARES has a great site.
  • I was concerned about interference from the routers or their power supplies, so I selected wall-warts that I thought may be "linear" (the one's with heavy transformers) vice the lighter weight units that were obviously switching supplies. Neither AA3WS (working the digital on the VHF band) or Dick, WA3YTK (working digital HF) noticed any interference. However, my Yaesu FT-60R HT registered a loud hum in the 2 meter band near the router and Ethernet cables I was was using.
  • I need a telescoping mast for the bullet and omni configuration. I couldn't get it above the fire station roofline with my ~8 foot PVC pipe.
  • The bullet worked nicely from the stock 24VDC Power-over-Ethernet (PoE) through the 100' CAT-5 cable. Will there be enough voltage left at the bullet from a 13.8VDC supply? I'll need to test this because in a "real deployment" the unit may be connected to batteries.

This "exercise within the exercise" proved the ability to use the mesh as a means of communications between stations in a shelter. I look forward to future deployments taking into account the improvement mentioned.