Real Time Sensor Networks – challenges and solutions Information Prioritization Proposed scheme: Design techniques for priority assignment to an information in a mission-specific manner, Identify a measure of effectiveness (MOE) to evaluate the prioritization algorithms, Design and implement algorithms for disseminating prioritized data, Evaluate different prioritization algorithms to identify their strength and limitations, and Fine-tune the IP stack for an efficient support of prioritized information dissemination. Application 2 : Video Surveillance Application with information prioritization Sandeep Kakumanu, Rajnish Kumar, Sriram Lakshmanan, Badri Narayanan, Nazanin Rahnavard, Junsuk Shin Faramarz Fekri, Umakishore Ramachandran, Raghupathy Sivakumar Real Time Sensor Networks The primary goal in designing protocols for conventional sensor networks is to optimize energy consumption of the sensors. Real time sensor networks however are dependent more on timely delivery of data rather than energy constraints. Applications include multimedia sensor and time critical sensor requirements. Challenges of Real time sensor networks Three main challenges of real-time sensor networks Timeliness Reliability (Packet level) Correctness (Application level) These requirements must be ensured in both the upstream and downstream directions. We work at different layers of the network stack to address these challenges. SCT Objective: Broadcasting in multihop wireless networks Energy-Efficient, Reliable, Scalable Low Complexity: Requires no topology knowledge Motivation: Updating software in already deployed sensor/actuator networks Broadcasting route query packets in reactive routing schemes Proposed scheme: CRBcast – a two phase data dissemination algorithm (employing rateless coding) that generalizes probabilistic broadcasting to further reduce the energy costs. ADV REQ, i packets REQ, j packets DATA, max(i,j) packets (i)(ii) (iii) CRBcast Objective: Right information at the right time Motivation: Moving from a centralized to a distributed solution Increase Information-Awareness (Cognitive-Awareness) Information Prioritization and Fidelity Adjustment Application 1 : IPTV enhancement using WSN. Two principles to enhance IPTV : 1.“What you see is what you fetch” –In cases where there is no active user but the television is on, streams can be sent from server at low priority, low data rate or even paused. 2.“Fetch possible next channel(s) just before the user switches” –Pre-fetching channels in the background to reduce the user perceived channel switching latency. Principle: Use sensor information to prioritize data from high- bandwidth video cameras. Details of the applications can be found in the individual posters Objective: Aggregate correlated data from different sensors (homogenous or heterogenous sensors) in order to save bandwidth, reduce latency, reduce energy consumption and provide application level correctness. Motivation: Two existing approaches for data aggregation: 1.Correlation unaware: Shortest path tree. Does not maximize the aggregations possible. 2.Correlation aware: Steiner Tree. Complex calculations at individual sensors. Maximal aggregations. Require efficient aggregation strategy that minimizes message complexity. Proposed scheme: SCT (Semantic/Spatial Correlation-aware Tree) – A distributed coordination scheme that achieves potential cost benefits of efficient aggregation. Can be used for spatial, temporal or semantic correlation of data.