Abstract
Bluetooth is a low power, short range and inexpensive wireless technology that has limited resources. Therefore, the performance of a scatternet is highly dependent on the number of relays and their degree. The existence of unnecessary relays may increase scheduling overhead and consume system resources. In another instance, a large number of links that pass through a single relay may also decrease the system performance. Therefore, an optimum number of relays must be obtained for an efficient scatternet performance, while the system works with limited resources. The dynamic relay management (DRM) protocol is proposed to achieve the said objective and the solutions will be based on relay reduction and load balancing strategies. Through the DRM, a master reduces unnecessary relays to an optimum number and subsequently assigns them the special role as backup relays. In the event when a large number of links pass through a single relay, the master activates one of the backup relays to resolve the bottleneck, by which the load is balanced over a number of relays. Using this relay management technique, analytically the DRM protocol has reduced control overhead from O(n(2)) to O(1). Empirically, through simulation of the DRM protocol, the backup relay activation has reduced delay and improved throughput (between 40% and 60%). Also, the simulation results have demonstrated an improvement on network lifetime and packet loss. All these results are evidence that the DRM has outperformed the RVM and LORP protocols for the same issue. Hence, the inefficiency of the inter-piconet scheduling in a scatternet of a Bluetooth network can be resolved by implementing the DRM protocol. (c) 2011 Elsevier Ltd. All rights reserved.