A number of research challenges exist in the area of large scale wireless sensor networks. These are related to scalability, power efficiency, security and real world usage scenarios.
Scalability and adaptability require cross-layer protocol design. This involves agreeing on a set of protocols for linking sensor networks to the Internet for the purposes of management and control as well as local protocols for routing and storing data within the networks themselves.
Individual network nodes have limited power supplies and operate in harsh radio propagation environments. To increase overall network efficiency, tradeoffs must be made between communication and local processing.
Security and reliability play a major role. Distributed networks should have no single point that can cause failure. Stringent protection measures must be taken against attacks and due to privacy concerns. Some of the research, such as investigating low-power public key cryptography, ties in with the need for efficiency.
Finally, testing and deployment in real operating infrastructures is not an easy task! Asset owners need to be committed to provide assistance. We also need methods for automatically constructing and evaluating deployment strategies.