[NLRS] Important matter for VHFers

[Dr. Gerald N. Johnson]

Seems like it was decades ago that broad band ham narrow shift FSK 
hardware was developed for packet at 56KB, in 120kHz or 150kHz 
bandwidth. A couple years later in a subsequent ARRL digital conference 
proceeding the developer was asking, "Where's the 56KB data?" as it 
hadn't been put to work. Even today much packet runs at 1200 baud on VHF 
and at 300 baud or slower on HF linking distant points. Much of that 
infrastructure has been destroyed by internet ties because RF forwarding 
has been organized by workable paths (nearby on VHF and UHF) while 
internet bypassing that has been totally indiscriminate about "local" 
routing and so has destroyed the local routing algorithms. To the user 
its the same bother to route internet traffic via Timbuktu as via the 
nearest big city.

In Texas, among other places, they are extending ordinary wireless 
routers with antennas and power and ham IDs. They also change the serial 
port crystals from 20 to 19 or 19.5 MHz and that makes them not copyable 
by standard routers and wireless interfaces. Changes their channel 
frequencies as well as the data rates to make them less than public. 
Megabit rates seem to be where it is now, though if we didn't have the 
microwave bands we'd be wishing for higher speed data on the bands with 
signal bandwidth limits. Though Spread Spectrum may not have such a data 
speed limit so long as after spreading or hopping it stays within the 2 
meter band. Which might be another option.

Patents would be a problem in making ham narrow band high speed. But if 
we could fool commercial chips into working without active equalization 
we get the rights to use the patented technology by paying for the 
chips. We get into trouble if we make or own chips or software emulation.

73, Jerry, K0CQ

On 4/25/2011 9:15 PM, tom ring wrote:
>
>
> On 25 Apr 2011 at 14:07, Dr. Gerald N. Johnson wrote:
>
> <snip some good comment>
>
>> If we worked at it we could get higher speeds than 9600 in 15 KHz
>> bandwidth. It would take multiple tones like land line modems that get
>> nearly 56 KB in less than 3 KHz bandwidth. It would take serious modem
>> modifications to accommodate varying pass bands without having to
>> negotiate phase and amplitude equalization for each transmission.
>> Probably would have to use complex forward error correction.
>
> And it's all been done if it's possible with present technology.  The only
> question is how much is patented, how much is already open source, and how much
> is secret.  The sets will overlap.
>
> tom
> K0TAR
>