A COMPREHENSIVE FRAMEWORK FOR ENERGY EFFICIENT BRIDGE MANAGEMENT IN BLUETOOTH SCATTERNETS
Wireless Personal Area Networks (WPAN) are short range networks designed to allow various devices to communicate. One of the best examples of a WPAN today is a Bluetooth network. Bluetooth wireless technology has become the de facto standard, as well as a specification for small-form factor, low-cost, short-range radio links between mobile PCs, mobile phones and other portable devices. Devices form autonomous ad hoc networks of up to 8 active devices, referred to as piconet. The piconet is managed by a master, which regulates access to the medium by polling different slaves. Piconets may be inter-connected by one or more ‘bridges’ to form a scatternet. The bridges are essentially slaves which are time shared among different piconets. Research in Bluetooth today is based on scatternet models and includes optimal algorithms for scatternet formation, topology optimization, scheduling and traffic engineering. The bridges are the most important part of the scatternet as they bear the responsibility of a switch – relaying traffic from one piconet to another. Generally, the implicit assumption made is that the bridge already exists or that the bridge can be formed in some manner. However, the issues surrounding the bridge are complex and involve the masters of more than one piconet. In this paper we propose a framework – BEAM – for bridge formation and maintenance. We have enunciated the mechanisms by which a node may be made a bridge and how it may be used to add, replace or terminate bridges. The framework’s design is flexible and it may be used by any of the scatternet formation or traffic engineering algorithms. Bridges have the added responsibility of sharing their active time between the piconets that they are connected to. This could lead to a disproportionate energy usage pattern at the bridge nodes, as compared to other nodes. When a bridge node dies, it may create a partition in the scatternet, leading to packet loss and delays. In this Thesis, we have evolved a bridge management policy that distributes the responsibility of being a bridge among capable devices. It seeks to increase the scatternet lifetime by improving the energy utilization at the bridge nodes.
School:University of Cincinnati
School Location:USA - Ohio
Source Type:Master's Thesis
Keywords:bluetooth scatternets bridge management
Date of Publication:01/01/2003