Modeling of Loosely Coupled Scatternets with Finite Buffers

This article deals with the performance of Bluetooth scatternets in a real-life environment where different queues are implemented with finite buffers. Finite buffer size will introduce packet blocking at different queues along the packet path, which in turn causes changes in effective traffic load as well as retransmissions and ultimately affects end-to-end packet delays. The authors assume that the piconet masters use E-limited intra-piconet polling, while bridge scheduling is performed using the walk-in approach without rendezvous points. They present a detailed simulation model that allows them to obtain accurate measurements of blocking probabilities, end-to-end-packet delays, and overall throughput in the network as functions of network and device parameters. Some practical recommendations about the buffer size that will keep the blocking probability within reasonable limits are also given.