On some challenges and design choices in ad-hoc communications

Ad-hoc networks are network architectures that can be rapidly (ideally immediately) deployed and that do not need to rely on pre-existing infrastructure. The salient feature of this breed of networks is that they can operate in different and differing propagation and network operational conditions, which cannot be predicted during the network design stage. We discuss some of the challenges and choices that need to be made while designing an ad-hoc network. In particular, we address the following three issues: hierarchical vs. flat network architectures, proactive vs. reactive (on demand) routing protocols vs. a hybrid approach, and sensing-based vs. dialog-based medium access control.