Bluetooth Scatternet Formation and Scheduling: An Integrated Solution

Building and deploying multi-hop networks of Bluetooth devices (aka scatternets) concerns devising methods for forming piconets, connecting them through shared gateways, and scheduling the presence of these gateways among the piconets they interconnect (inter-piconet scheduling). There are several types of gateways, and their efficient scheduling is affected by the gateway type. Scatternet formation and scheduling have been dealt with separately in the past. This leads to network performance degradation because of the missed opportunity of designing scatternet formation protocols that best address scheduling requirements and vice-versa. In this paper we propose SS-Blue, an integrated mechanism for the joint design of scatternet formation and scheduling. Specifically, we enhance an efficient scatternet formation protocol by adopting methods for piconets interconnection that favor types of gateways which will result in a better performing inter-piconet scheduling. At the same time, a fair and traffic adaptive mechanism is proposed to schedule all types of gateways (inter-piconet scheduling), and for managing intra-piconet scheduling, i.e., for scheduling traffic transmission within a piconet. Our solution is evaluated through extensive simulations. Our results show that SS-Blue succeeds in producing scatternets whose gateways are efficiently scheduled. The combination of the proposed intra- and inter-piconet scheduling is shown to be remarkably effective in favoring packet forwarding with very low end-to-end latency.