Virtual Mobile Nodes for Mobile Ad Hoc Networks
One of the most significant challenges introduced by mobile networks is the
difficulty in coping with the unpredictable movement of mobile nodes. If, instead, the mobile nodes
could be programmed to travel through the world in a predictable and useful manner, the task of
designing algorithms for mobile networks would be significantly simplified. Alas, users of mobile
devices in the real world are not amenable to following instructions as to where their devices may
travel. While real mobile nodes may be disinclined to move as desired, we propose executing
algorithms on virtual mobile nodes that move in a predetermined, predictable, manner through
the real world. In this paper, we define the Virtual Mobile Node Abstraction, and present
selected algorithms that take advantage of virtual mobile nodes to simply and efficiently
perform complicated tasks in highly dynamic, unpredictable mobile ad hoc networks. We then
present the Mobile Point Emulator, a new algorithm that implements robust virtual mobile nodes.
This algorithm replicates the virtual node at a constantly changing set of real nodes, choosing
new replicas as the real nodes move in and out of the path of the virtual node. We claim that the
Mobile Point algorithm correctly implements a virtual mobile node, and that it is robust as long as
the virtual node travels through well-populated areas of the network.