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.

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.