Invited Talks.- Invited Talk I Actuator Nets: Folding, Reconfiguring and Deploying Sensors.- Invited Talk II The Power and Limitations of Simple Algorithms: A Partial Case Study of Greedy Mechanisim Design for Combinatorial Actions.- Sensor Field: A Computational Model.- Near-Optimal Radio Use for Wireless Network Synchronization.- Approximating Barrier Resilience in Wireless Sensor Networks.- Improved Approximation Algorithms for Maximum Lifetime Problems in Wireless Networks.- On Active Attacks on Sensor Network Key Distribution Schemes.- Key Levels and Securing Key Predistribution against Node Captures.- Revisiting DoS Attacks and Privacy in RFID-Enabled Networks.- Link Reversal: How to Play Better to Work Less.- Early Obstacle Detection and Avoidance for All to All Traffic Pattern in Wireless Sensor Networks.- A Note on Uniform Power Connectivity in the SINR Model.- Locating a Black Hole without the Knowledge of Incoming Link.- Energy Efficient Alert in Single-Hop Networks of Extremely Weak Devices.- Brief Announcement: Universal Data Aggregation Trees for Sensor Networks in Low Doubling Metrics.- Brief Announcement on MOGRIBA: Multi-Objective Geographical Routing for Biomedical Applications of WSN.- Routing on Delay Tolerant Sensor Networks.- Better Face Routing Protocols.- Building a Communication Bridge with Mobile Hubs.- Compressing Kinetic Data from Sensor Networks.- Relocation Analysis of Stabilizing MAC Algorithms for Large-Scale Mobile Ad Hoc Networks.- Deterministic Collision Free Communication Despite Continuous Motion.- Self-stabilizing Deterministic Gathering.- Gossiping in Jail.- Complexity and Approximation of a Geometric Local Robot Assignment Problem.

This book constitutes the reviewed proceedings of the 5th International Workshop on Algorithmic Aspects of Wireless Sensor Networks, ALGOSENSORS 2009, held in Rhodes, Greece, July 10-11, 2009. The 21 full papers and two brief announcements were carefully selected from 41 submissions. This workshops aimed at bringing together research contributions related to diverse algorithmic and complexity-theoretic aspects of wireless sensor networks. The topics include but are not limited to optimization problems, noise and probability, robots and tours.