[aprssig] HF APRS new ideas

[Bob Bruninga]

As lynn says below... it aint easy and there is no obvious algorithm that would let individual IGates know if they are in the best place to be the local IS=>RF IGate of a particular station...

Its almost as if ALL the HF igates have to talk to each other and VOTE on who has the best signal and so who should be the IS-to-RF igate for a particular packet.  Then we'd have to have all the HF Igates logged onto a special server maybe...

Each Igate would report its packets-per-hour heard from each HF mobile station over the last hour (after each packet heard).  The one with the highest score would be the reverse IGate for the next packet that needs to go back to RF.

So mobile HF users might need to register with the system so the system would know who out of the 40,000 APRS users these statistics are needed on.

In any case, I'm ready to declare the HF path of GATE,WIDE2-1 obsolete in light of the stability of the APRS-IS.  Can everyone agree with that?

Bob, WB4APR


---- Original message ----
>Date: Mon, 31 May 2010 17:37:21 -0400
>From: aprssig-bounces at tapr.org (on behalf of "Lynn W. Deffenbaugh (Mr)" <ldeffenb at homeside.to>)
>Subject: Re: [aprssig] HF APRS new ideas  
>To: TAPR APRS Mailing List <aprssig at tapr.org>
>
>Bob Bruninga wrote:
>> What we need are SMART HF 2-way IGates that will ONLY consider theseleves to be the "local" Igate for relaying that message if and only if IT heard the mobile in say ...the last say 10 minutes.  This would go a long way towards eliminating dupes from multiple two-way IGates.
>>
>> Only the one with immediate NOW propogation to the mobile would send the messge.
>>
>> Can someone comment on how well something like this can be managed with most existing IGate packages?  Can the statistics of their "HEARD LOCAL" list be used smartly?
>>   
>
>I'm designing ARPSISCE/32 to do exactly that, including much more 
>granular configuration of digipeating, both within and across individual 
>RF interfaces.  Configuration of the definitions of "recent" (time) and 
>"local" (hops) for gating messages to RF are in the plans, probably 
>sooner than later.
>
>However, the propagation of HF, at least the 30m that I've been 
>monitoring, is interesting and unpredictable to say the least.  I'm 
>fairly certain that coordination of which Igates are even configured to 
>gate messages from -IS to RF will be required to avoid just the 
>collisions you describe.  And even then, the "hidden transmitter" 
>becomes a major issue if a station in the center of the US transmits and 
>is heard by an east and west coast IGate and then a messages appears on 
>the -IS for that station.  Both of the gates will consider the station 
>local and will transmit, probably completely eliminating the ability for 
>the station in the center to receive it.
>
>I've been trying to think of a zoned approach for IGates, possibly 
>encouraging an east-to-west priority or vice-versa, to at least stagger 
>the gating of the packets since on HF it's unlikely that the gates can 
>hear each other and the FM capture effect isn't going to help the receiver.
>
>Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32
>Monitoring 30m APRS on both AX.25 and PSK63 and Receive-Only IGating as 
>KJ4ERJ-2
>
>
>
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