Evaluation of Interference Requirements in a Sensor Network Aided Cognitive Radio System

To better exploit the spectrum resources a wireless sensor network can be used to assists a secondary cognitive radio network by providing information about the current primary spectrum occupancy. In this paper we study the performance of the secondary network when it is co-located with and having similar cell size as a mobile primary network that uses a cellular reuse pattern with seven frequencies. Especially we study how relaxed requirements for the maximum interference generated by the cognitive radios affect the performance of the secondary and primary network in terms of throughput, packet loss, delay, coverage and connectivity. We show that it is possible to find interference limits for the cognitive radio that allow full throughput and coverage for the secondary system at the cost of a slight reduction in throughput and an increase in packet loss per user of 2% on average for the primary system.