Design and evaluation of coexistence mechanisms for Bluetooth and IEEE 802.11b systems

Short-range wireless technologies are becoming increasingly important in enabling useful mobile applications. Bluetooth and IEEE 802.11b standards are the most commonly deployed technologies for WPAN and WLAN. However, because both standards share the same unlicensed ISM (Industrial, Scientific, Medical) radio spectrum, severe interference is inevitable and performance can be impaired significantly when heterogeneous devices using the two technologies come into close proximity. The most notable solution to this problem is a frequency domain noncollaborative coexistence mechanism called adaptive frequency hopping (AFH). However, we find that the efficiency of the 'channel classification' sub-process in noncollaborative mechanisms is by and large ignored in the literature. Moreover, we also find that there is no system resources awareness and no interference source genre concerns in IEEE 802.15 Task Group 2 AFH (TG2 AFH) design. Thus, we suggest a new approach called ISOAFH (Interference Source Oriented AFH). With the above considerations, we propose a customized channel classification process, thereby simplifying the time and space complexity of the mechanism. Through our detailed implementation of various coexistence mechanisms in MATLAB Simulink, it is observed that TG2 AFH performance is sensitive to memory and power limitations, while ISOAFH is much less sensitive to these constraints and can keep a much lower channel collision rate. On the other hand, We also study some open issues of a time domain mechanism called MDMS (Master Delay MAC Scheduling). We compare different coexistence mechanisms and find that the performance of each approach very much depends on the efficiency of its sub-processes.published_or_final_versio

On adaptive frequency hopping to combat coexistence interference between bluetooth and IEEE 802.11b with practical resource constraints

In contrast to traditional frequency hopping techniques, Adaptive Frequency Hopping (AFH) is a low cost and low power solution to avoid interference dynamically. While each AFH algorithm proposed previously is shown to be efficient, a detailed performance analysis of various AFH mechanisms under realistic resource constraints is yet to be done. In particular, based on our performance study on Bluetooth systems presented in this paper, we have found that the AFH mechanism adopted by IEEE 802.15 Task Group 2 (TG2) is very sensitive to memory and power limitations. We then propose a novel Interference Source Oriented Adaptive Frequency Hopping (ISOAFH) approach based on a cross-layer design, in which the baseband layer of Bluetooth considers not only the instantaneous channels condition but also the physical layer transmission characteristics of potential interference sources in determining the hop sequence. In our simulations using detailed MATLAB Simulink modeling, we find that our proposed method is much more robust in that it is insensitive to memory and energy constraints. Indeed, our approach generally achieves a lower collision rate and higher ISM spectrum utilization.published_or_final_versio

Design and evaluation of practical coexistence management schemes for Bluetooth and IEEE 802.11b systems

Bluetooth and IEEE 802.11b standards share the same unlicensed ISM (Industrial, Scientific, Medical) radio spectrum. As such, severe interference is inevitable and performance can be impaired significantly when heterogeneous devices using the two technologies come into close proximity. We propose a new approach called ISOAFH (Interference Source Oriented Adaptive Frequency Hopping) based on a memory and power efficient channel classification process, thereby reducing the time and space complexity of the mechanism. Through our MATLAB Simulink based simulations of various coexistence mechanisms, we find that the IEEE 802.15 Task Group 2 (TG2) AFH performance is sensitive to memory and power limitations, while ISOAFH is less sensitive to these constraints and can keep a lower channel collision rate. In view of the potential implementation difficulties for AFH based approaches, we also propose a time domain mechanism called ISOMDMS (ISO Master Delay MAC Scheduling). © 2006 Elsevier B.V. All rights reserved.link_to_subscribed_fulltex