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[aprssig] New and improved APRS

Jim Lux jimlux at earthlink.net
Fri Jan 6 00:43:48 UTC 2006


Interestingly, there are a lot of people considering all those interesting 
questions:
How to do universal addressing
How to do delay tolerant networking
How to do position reporting
How to effectively utilize ephemeral low data rate links with a dynamically 
changing network configuration
How do you efficiently address things, without the use of a centralized 
Domain Name Service or ARP to translate names into IP address into physical 
address.
How do you efficiently route, without things like RIP.
etc.

All in the context of the NASA Exploration Missions Systems Directorate 
(ESMD).  Someone contemplating sending astronauts to the moon or mars or 
beyond, having them drive around on rovers, interacting with autonomous 
rovers, sending data back and between each other via relay stations faces 
exactly the same kind of problems.

It's a very different problem than, say, implementing the Internet (which 
is fast, low delay, and relatively fixed connectivity), or 802.11 ad-hoc or 
infrastructure networks (which don't do handoffs), or even GPS (which does 
Nav, but not comm)

And, there's a lot of good philosophical thought being put into it by 
people who know an awful lot about the topic (e.g. Vint Cerf is working on 
Delay Tolerant Networking for space networks with long delays).

I don't want to claim that we should all stand around and wait for the 
grand new communications architecture to be unveiled by NASA (if for no 
other reason than budget and time).  However, you don't want to be 
reinventing the wheel.  For instance, a lot of what was mentioned in 
earlier posts is covered in the MIL-STD-188 suite of protocols and routing 
stuff (including more robust modulations for both HF and VHF links).  The 
DoD has plenty of tactical comm needs, and has also given this a lot of 
thought.  Not only that, but there ARE (free) PC-based implementations of 
much of MIL-STD-188, including the HF modem and the ALE/Routing parts.

Jim, W6RMK






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