[ale] Dynamic Routing Within Mobile Networks

[Chuck Huber]

ALE'ers,

I have an application that utilizes a private network of mobile nodes
and need to implement a dynamic routing algorithm.

The scenario is that there's between one and 5 command nodes (CNodes),
and multiple execution nodes (ENodes), all of which are mobile.  The
network starts out where all nodes are in close proximity allowing any
of the CNodes to communicate directly with any of the ENodes.

In time, however, an ENode may drift out of comms range with any of the
CNodes.

What I'd like to do is to implement an algorithm in each of the ENodes
such that it can serve as a router.

I spoke with NASA about this.  The closest thing they had was a project
that flew on Columbia's last flight in which a linux machine was mounted
in the payload bay with a VHF link attached to its network port.  As the
shuttle flew along in its orbit, the next-hop gateway was changed to a
ground station within view of the shuttle and ground-based DNS's were
updated appropriately.  This, however, is very predictable and the
air/space-borne node can be told what its new IP address and next-hop
gateway would be at a certain time.  When the time arrived, it could
issue ifconfig and route commands appropriately.  BTW, the project was
considered 90% successful - 10% of the data was lost with the ship.  One
of the successes was that the project was able to maintain a TCP
connection throughout the entire orbit even though the mobile node's
address was constantly changing.

The scenario in which I find myself, however, is one of unpredictable
routes.

Does anyone know of an algorithm by which a node can inject itself as a
router on behalf of one or more other nodes?

Thanks,
    - Chuck