Table of contents : Preface Contents Acronyms and Abbreviations 1 Overview and Definitions 1.1 Cognitive Radio in Wireless Communication 1.2 Cognitive Radio in Underwater Communication 1.3 Sonar Equation 1.4 Intra-/Inter-Knowledge References 2 Adaptivity at the Physical Layer 2.1 Physical-Layer Adjustments 2.1.1 Adapting the Source Level 2.1.2 Adapting the Data Rate 2.1.3 Other Physical Layer Adaptations 2.2 Input Parameters for Physical-Layer Adaptivity 2.2.1 Relevant User, Application and Platform Inputs for Adaptation 2.2.2 Adaptation Based on Environmental Awareness 2.3 Communication of Adaptions 2.3.1 Configuration Messages 2.3.2 Preamble Encoding 2.3.3 Waveform Detection and Classification 2.4 Adaptive Parameter Control 2.4.1 Negotiation and Switching Mechanisms 2.4.2 Optimization Methods and Decision Criteria 2.5 CSI Estimation, Prediction and Adjustment 2.6 Adaptive MAC 2.7 Summary of Adaptivity Parameters and Methods References 3 Distance Estimation 3.1 Inter-Knowledge 3.2 Intra-Knowledge References 4 Delay/Disruption Tolerant Networking 4.1 Store-Carry-Forward Paradigm 4.2 Bundle Protocol Specification 4.3 DTN for Underwater Acoustic Networks 4.4 Data Muling References 5 Multi Topology Routing References 6 Autonomous Ad Hoc Networks 6.1 JANUS 6.2 Kieler Approach 6.3 Address Assignment References 7 Summary Index