Support Required for Mesh

We are looking for support in setting up a series of MESH nodes for use on events and training purposes both within the club and for use on RAYNET events.  Broadband-Hamnet™ (formerly called HSMM-Mesh™)  is a high speed, self discovering, self configuring, fault tolerant, wireless computer network that can run for days from a fully charged car battery, or indefinitely with the addition of a modest solar array or other supplemental power source. The focus is on emergency communications but can be implemented into many scenarios.

Yet another side to Amateur Radio that incorporates the use of IT and programming, hopefully gaining the interest of younger Amateurs to be.

A lot of data is available on the web including these websites Broadband Hamnet and Feednet

Linksys Router

Linksys Router

We have purchased some of the hardware required to get a small network up and running and have a few bits of hardware available from club members start experimenting with some setups including a Raspberry Pi which could be used as a server for the project.

If you already have tinkered with this kind of project or are interested in joining us for some experiments then please do get in touch and we can arrange a club meeting around the project.  There are a few clubs that are using this system and we may be able to arrange a joint training day with one of them.

 

7 Responses to “Support Required for Mesh”

  1. M0EPR 27 October, 2016 at 14:40 #

    Can’t wait for the hardware to arrive this weekend and start experimenting!

  2. Chris Hayes 28 October, 2016 at 10:55 #

    Hi All, I’m Sandiacre based and would be interested in joining in if I’m in range of another node. 73, Chris. 2e0xch.

  3. Angus 30 October, 2016 at 13:57 #

    I have ordered up a pair of WRT54GLs to have a play with. I will try to interface one to a Raspberry Pi that I have here that is not doing too much and the other to the laptop and see if a 2 node mesh magically appears. Configuration of the routers requires the node to be assigned a callsign specific name if I read the info correctly. I’ll use mine for one, can I use the Club callsign to configure the other, at least for test purposes? If I get anywhere I’ll bring the pair to the 27thNov operating day.

  4. Angus 1 November, 2016 at 10:54 #

    Some progress… The two 54GLs have been flashed with the Broadband Hamnet firmware and are happily in contact so that’s the low level transport working.
    I have Emailed the Feednet group for a link to their Pi image to get some server software for Email etc up and running on my Pi.
    I have also ordered a 2W booster module and a selection of antennas (a yagi and 2 Omni) and 54GL antenna connectors to play with.
    Now all I have to do is try to understand networking as I am rapidly reaching the limit of my understanding…….
    Anybody good at networking want to get involved???

  5. M0EPR 1 November, 2016 at 12:36 #

    Hi Angus, I am pretty good with networking and also a new member Ben will know a thing or two about it. He will be starting his Intermediate soon so when we start might be worth popping into the conference call for a chat.

  6. Angus 1 November, 2016 at 19:23 #

    Node Link Budget and range
    I have been having a look at the performance of the 54GL routers in my local environment. The local noise floor seems to be around -90dBm as reported by the status screen and the weakest local wifi signal that seems to be consistently readable is around -85dBm. The output power of the bare router seems to be 19dBm maximum or 80mW. The antenna fitted looks like a standard +5dB gain device. A quick internet search gives the free space loss of a 2.4GHz link as100+20log(d[km]).
    With this data I think the free space range of the bare router acting as a node should be around 5Km. ie
    alog[(19+5+85+5-100)/20]=5Km
    For a static link with 2 x 25dB yagis facing each other with say 3dB loss in extra connectors and feeds at each end
    alog[(19+25-3+85+25-3-100)/20] = 250Km
    and if you raise the tx power to 2W ie 33dBm the free space results getter even more optimistic etc etc.
    Now I am a complete novice at link budgets and real world performance of data links at these frequencies. I realise that these theoretical results, even if I have calculated correctly, are not likely to be achieved in practice with ground reflections and atmospheric absorbtions etc. etc.
    So is there anybody in the club who would like to comment on the above and suggest why these results seem so optimistic?

  7. Angus 16 November, 2016 at 13:22 #

    A little progress…..
    I have installed Teamtalk conferencing server on the Pi and am able to send voice, video, text and files + instant messaging across the mesh links between laptops. Any number (<1000) users can be linked together for conferencing using this freeware, so in the absence of response to emails to freenet for their software, might be worth a look. Client software is available for most platforms.
    I have knocked up a feed for the 75cm dish antenna and am conducting a few comparison tests in the garden between the dish, the yagi and the Omni antennas using a Wifi monitor app on the mobile phone. However, as I suppose is to be expected, the signal strength varies widely when moving the receiver a few inches, because of all the reflections around from houses etc and with such a short wavelength any measurements are prone to large errors because of this. Need to do an open site test at some time.

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