[App_rpt-users] Digital Audio was: analog voting

Steve Wright info at meshnetworks.co.nz
Wed Mar 30 19:16:07 EDT 2016


On 31/03/16 09:53, KM4NRJ FLORIDA <km4nrj at gmail.com> wrote:
> Unless you are talking private links using microwave unlicensed spectrum
> technology, I think it may be a hair puller.

That's not too hard to do though.  The gear is off-the-shelf, effective, 
inexpensive, and uncomplicated.  2.4, 3.3, 5.8, and 10GHz radios are 
available.  The only issue with these radios and links, is they're not 
actually that solid, and if something gets wedged you need an admin who 
really knows which chain to flush, or your repeater is going to be down 
days or weeks.  It's nearly mandatory that hams know how to acquire some 
obsolete Ubiquiti, plug it in, and shoot a 100mbit link with it, and 
it's fun too.  Many many cool stunts can be done over a link like that.

Internet trunking between 'Repeaters' doesn't get anywhere near the 
workout that a local voted system would - where users really want to 
beat it to death in near-real-time.  As long as a courtesy tone tells 
users "we're connected somewhere - there may be delays" then that is 
fine.  It's not irlp, kerchunk kerchunk.. ;)

Interesting comments on the PTP sub-microsecond timing protocols.  I 
just installed the daemon with a flick of my admin finger, so deploying 
servers is a doddle.  XIPAR source can be googled trivially.  Sadly, I 
am not a coh-derrr, so others may comment.

I don't mind Digital Audio over Ham Radio, but it doesn't 'feel like 
radio'.  Maybe I'd get used to that, if it was nice warm 64kbit audio.  
I wouldn't mind the occasional blip in the voted audio - that doesn't 
sound anywhere near as bad as mister robota d-stir.

I spent some time looking at transverters for our 1.3GHz band.  The 
concept was to use a 5MHz wide channel with the Unifi zero-handoff 
5.8GHz radios as the IF.  25 watt mobiles and 100 watt base stations 
would be easy to deploy (no duplexing).  Testing at -70dbm shows a 
32MBit connect and an *actual* TCP throughput of 3.5mbit/sec full-duplex 
for a channel total of 7mbit/sec.   I stopped work on it because I 
wasn't really in a position to design and build the high-side LO and 
mixer board for it.

Just ideas.

Steve




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