Interference impact on throughput performance of Bluetooth scatternets under different traffic loads

Multiple Bluetooth piconets are likely to co-exist in a physical environment, supporting many wireless applications. An independently operating Bluetooth piconet will inevitably encounter mutual interference from collocated piconets, which results in individual piconet and overall scatternet performance degradation. In this paper, the throughput performance of Bluetooth piconet is studied and evaluated as the number of interfering piconets is increased considering that the frequency hopping mechanism in Bluetooth piconets is not a totally random process. Several different simulations were performed with varying inter-piconet time offset in order to represent the effects of different packet sizes, symmetric / asymmetric transmission, synchronized / unsynchronized data packets, and different traffic loads with non equal probabilities of collision for different packet sizes. Results proved that certain packets sizes can achieve higher throughput depending on type, size, and number of interferers. Throughput improvement may be achieved in the presence of interference by changing the packet size in the piconet. It was also verified that an optimum traffic load could be reached to achieve maximum throughput for each number of piconets.