Date Added: Dec 2010
The authors present a model of a mobile ad-hoc network in which nodes can move arbitrarily on the plane with some bounded speed. They show that without any assumption on some topological stability, it is impossible to solve the geocast problem deterministically despite connectivity and no matter how slowly the nodes move. Moreover, even if each node maintains a stable connection with each of its neighbors for some period of time, it is impossible to solve the geocast problem if nodes move too fast. Additionally, they give a tradeoff lower bound which shows that the faster the nodes can move on a mono-dimensional space, the more costly it would be to solve the geocast problem.