Content: Introduction to Cognitive Approaches in Wireless Sensor Networks Introduction Related Work Generic Architecture for Cognitive Wireless Sensor Networks Conclusion References Cognitive Radio Networks and Dynamic Spectrum Access Introduction Spectrum Awareness Cooperative Sensing Dynamic Spectrum Access Conclusion References Adaptive Modulation, Adaptive Power Allocation, and Adaptive Medium Access Introduction System Model Adaptive Transmission and Feedback Communication System Multihop Relay Network and Energy-Constrained Network Analysis Simulation Examples and Illustrations Conclusions References Cross-Layer Approaches to QoS Routing in Wireless Multihop Networks Introduction Design Challenges and Considerations Taxonomy of QoS Routing Protocols in Multihop Networks Comparison between QoS Routing Protocols Challenges and Future Directions Conclusions References Cognitive Diversity Routing Overview of Routing Protocols in Wireless Sensor Networks System Models Cognitive Diversity Routing Priority Node Selection Performance Evaluation Conclusion References Enabling Cognition through Weighted Cognitive Maps Introduction Related Work Fundamentals of WCM Designing WCMs to Achieve Cognition in WSNs Simulation Results Conclusions References Hardware Architecture for GPS/INS-Enabled Wireless Sensor Networks Introduction Hardware Implementation System Software Design Test Results Conclusion References