Developments in wireless, mobile communications combined with advancements in electronics have contributed to the emergence of a new class of networks: Wireless ad-hoc sensor networks. Tiny, smart, network-enabled sensing nodes can be deployed to construct sensor fields that form the infrastructure for various self-adaptive and autonomic applications. In this paper we identify the requirements and properties that still need to be addressed and discuss possible approaches that could be adopted in the design of efficient routing protocols for such networks.