This is the homepage for the

Research Triangle Park - Ham Radio Digital network

Created Sept 15, 2018
Last updated Sept 19, 2018

Goals

This page and our groups.io reflector will be used to provide helpful material and links about demonstration hardware, methods, and support, so hams can individually assemble their own stations both to tie into the infrastructure our group will create, and to create new infrastructure.

Rules of the org:

On our meeting of September 19th, we decided we want to focus on ham radio networks. While we want to be capable of tying our network into the Internet during an emergency, and we will practice for that, we're not planning on having Internet connections to our main network except in scheduled tests or emergencies. No Wormholes, tunnels, VPNs through the Internet will be tolerated into and out of our main network. We'll also not be bridging between our network and any network that does tollerate Internet linking in other than emergencies or emergency simulations.
Also on September 19th we decided we want to at least work toward supporting LinkSys equipment in some location(s) in the network. It was proposed that the LinkSys routers, being plentiful and on-hand, might be ideal for outfitting a demo at a hamfest, or a field-day site, or emergency operation encampment. We should make sure there is a way to get traffic to or from the LInkSys devices into our hub, when we have a hub.

Give us 24 hours to respond to your join request! Thanks!

BLOGS

Ken's Blog

Links and basic info

The discussion we're having so far is about using WIFI-type hardware to establish links which use 10megabit/second channels. There are at least 3 bands which are usable with WIFI-type hardware including 2.4Ghz, 3.4Ghz and 5.8Ghz. The 2.4Ghz band includes frequencies which are not-for-ham-radio, only-for-ham-radio, and mixed consumer and ham radio use. The 5.8Ghz band is the same way. The 3.3Ghz band, on the other hand, is not available for non-ham use but the equipment is made for export markets. We can get 3.3Ghz equipment for prices similar to the consumer WIFI gear but we get clear channels and we can buy it using our callsigns for credentials.

The channels available for each band are narrower than the bandwidth of the radio signals. A station on channel 1 can take interference from channels 2 and 3 but will not decode the channel 2 or 3 messages. I don't know how many channels a signal takes up. Does it vary by the configured bits per second?

Firmware exists for some off-the-shelf WIFI gear which gives it new peer to peer capability. It is possible to have a single device which runs data in and out at 5Megabits per second (faster rates also available) and which talks to several or dozens of other stations. Routing is automatically configured and can relay through a device between two different geographic spaces. Units can be daisy chained entirely over the radio to make a long network. There are performance penalties for using them this way but it does work. Dedicated point to point links can be arranged for long distance traffic up to 10s of miles. The range with off-the-shelf WIFI hardware is very dependent on line-of-site. Using some hardware we were shown that the range was about 1/4 of a mile in the Raleigh suburbs. Using slightly different hardware it was obvious that range is much much greater than that when demonstrated across a big field or between two high spots.

There is free or nearly free equipment for 2.4Ghz use and that equipment has been programmable for the firmware.

There are two big ham-radio-over-WIFI-hardware organizations. BBHN is original and AREDN is a spin-off.

Broadband-Hamnet   BBHN

Broadband Hamnet is pretty old. Possibly as old as 2000.

Broadband-Hamnet org web page.

This page talks about the LinkSys devices and what hardware works:
Broadband-Hamnet hardware-to-use

Amateur Radio Emergency Digital Network   AREDN

AREDN is much newer. Possibly as new as 2015. AREDN has a great big presence at Dayton

AREDN web page
Live map of registered stations. Note that these stations are not necessarily connected to each other via Ham Radio.
AREDN Forum Note the regional parts of the forum. There is a page for NC.

This document is interesting.
DCC2015-AREDN-Project-K6AH pdf

Suppliers

Flytec Computers

Radio Mobile path study tool.