Time-domain cognitive sensor networking

Cognitive wireless networking is often considered in scenarios where a “secondary” network exploits opportunistically the frequency resources which are left unused by a “primary” network. In this book chapter, we consider the application of the cognitive networking paradigm to resource-constrained Wireless Sensor Networking (WSN) scenarios. In particular, we propose a time-domain cognitive sensor networking approach, where the secondary nodes transmit during time intervals left unused by a primary WSN. Assuming that both primary and secondary WSNs are IEEE 802.15.4, we first derive the exact statistical distribution of the idle times of the primary WSN. Then, we optimize the transmission time of the secondary WSN in order to minimize the probability of interference with the primary WSN, highlighting the existing trade-off with the throughput of the secondary WSN.