Worst case response times in a Bluetooth piconet: scheduling combining 1-RR or E-RR with FIFO or EDF

In this paper, we focus on the Bluetooth wireless network, analyzing its ability to support the Quality of Service (QoS) requirements defined by QoS sensitive applications. The QoS perceived by the application depends on the scheduling mechanisms chosen at the medium access layer. Hence, we propose to evaluate the ability of different Bluetooth scheduling algorithms (1-RR/FIFO, 1-RR/EDF, E-RR/FIFO and E-RR/EDF) to guarantee bounded transmission delays. First, we establish a bound on the worst case response time of any sporadic message using a worst case analysis. We then compare the computed bounds with the worst case response times obtained by simulation for different traffic distributions and show in which configurations our bounds are tight. We finally compare those different schedulings and show how to extend our results on worst case response times taking into account message segmentation.