Coexistence techniques for ism band wireless services
Fahed Hasan Awad, Ivan L. Howitt · 2002
Wireless local area networks (WLAN) and wireless personal area networks (WPAN) provide different levels of service that are often complementary rather than competing. Consequently, usage models are being discovered in which it is desirable and necessary for both networks to operate simultaneously and in close proximity. This adds to the need for methods to mitigate coexistence issues between WLAN and WPAN. The IEEE 802.11b standard supports packet fragmentation and the Bluetooth specifications support power control and, as such, each provides a potential non-collaborative mechanism for reducing Bluetooth interference on IEEE 802.11b. In this dissertation, analytical models are derived for evaluating the effectiveness of both the IEEE 802.11b packet fragmentation and the Bluetooth power control in mitigating Bluetooth interference on IEEE 802.11b in an arbitrary radio propagation environment where both network are collocated. For the IEEE 802.11b packet fragmentation, an expression for the optimal packet fragmentation is obtained based on the analytical model. Then, based on the optimal packet fragmentation, the performance is quantified. In addition, a method for estimating the optimal fragmentation solution based on an observable quantity is presented. For the Bluetooth power control, a model based on the received signal strength and received signal quality is developed, which takes into account the mutual interference between the IEEE 802.11b and Bluetooth. Based on the model, a power control mechanism is introduced and then based on the mechanism, the performance of the IEEE 802.11b is quantified. The performance evaluation results show that both mechanisms have potential for effectiveness in mitigating the Bluetooth interference on IEEE 802.11b, especially if they are used according to the recommended optimization strategies.