[HamWAN PSDR] 1.2GHz to Paine [was: 44.x.x.x HamWAN network at Paine]

[Bart Kus]

Wow that sucks.  :(  Is the signal level just too low?  Is it a matter 
of interference?

And yeah, I can confirm that the microwave stuff we use includes both 
FEC (at up to 1/2 rate) and an ARQ system (look at "hw-retries" 
setting).  These features are common to all WiFi systems too, and 
they're just carried over into our NV2 TDMA system.

--Bart


On 5/24/2014 10:19 AM, Dean Gibson AE7Q wrote:
> Scott Honaker and I have moved forward on this project:
>
>  1. We have installed a gateway (Linksys BEFSR41) between the ID-1 and
>     the internal ARES/RACES subnet (not 44.x.x.x) of the DEM.
>  2. We have installed a Digi "AnywhereUSB" box to give us remote
>     access to the ID-1's USB port, and thus remote control of the ID-1
>     radio.  This not only allows multiple use of the ID-1 (which has
>     useful 1.2GHz FM and digital voice modes as well as Ethernet
>     data), but provides for remote frequency agility and a diagnostic
>     capability.  This works beautifully (eg, to search for and use a
>     low-noise frequency)!
>
> Unfortunately, what does not work very well, is the RF portion of the 
> connection.  PINGs failed at a rate of over 99% when using the 1.2GHz 
> antenna at the 70 ft level on the tower, so we swapped the antenna 
> with the one used for the Icom 1.2GHz repeater (which wasn't seeing 
> any action anyway) at 100 ft. That made a "dramatic" improvement, as 
> PINGs now only fail at a 98% rate (depends upon the time of day, etc)!
>
> Antenna comparison between 1.2GHz and 5.9 GHz for the two sites:
>
>  1. On 1.2GHz, both antennas are omni-directional.
>  2. At the DEM, the 1.2GHz antenna is now at the 100' level, whereas
>     the 5.9GHz antenna is at 150'.
>  3. At my home, the 1.2GHz antenna is about 10' above the 5.9GHz
>     antenna, and it's on the same line-of-sight path.
>
> Note that voice communication between the two sites using the two ID-1 
> radios, is fine (there is a slight bit of noise on FM).
>
> The big difference, in my opinion?  I'll bet that the wireless 
> protocol used by the MikroTik radios includes an aggressive error 
> correction and retry protocol, whereas the ID-1 is like a piece of 
> Ethernet cable, and thus relies on the standard TCP/IP retry 
> mechanism.  The TCP/IP protocols, while "unreliable" in the technical 
> sense of the term, require a higher overall reliability than a typical 
> raw wireless connection.
>
> What this says (and I'm a bit surprised to note this), is that sites 
> considering using ID-1 radios for data communications, may find that 
> even with the tighter siting requirements of 5.9GHz, that the latter 
> may be more successful (whether or not part of HamWAN).  In addition 
> to being a lower-cost radio with a much higher data rate, the MikroTik 
> radios offer a built-in router, which can obviate the need for a 
> separate router.
>
> -- Dean
>
> ps: The callsign and digital code filtering features of D-Star that we 
> previously discussed, are not available (greyed out in the software) 
> for digital *data* mode.  Huh?  Another fine example of software of 
> the "seven last words" of poor program design: "Why would you want to 
> do that?"
>
>
>
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