Distributed topology construction of Bluetooth personal area networks

Abstract

In recent years, wireless ad hoc networks have been a growing area of research. While there has been considerable research on the topic of routing in such networks, the topic of topology creation has not received due attention. This is because almost all ad hoc networks to date have been built on top of a single channel, broadcast based wireless media, such as 802.11 or IR LANs. For such networks the distance relationship between the nodes implicitly (and uniquely) determines the topology of the ad hoc network.Bluetooth is a promising new wireless technology, which enables portable devices to form short-range wireless ad hoc networks and is based on a frequency hopping physical layer. This fact implies that hosts are not able to communicate unless they have previously discovered each other by synchronizing their frequency hopping patterns. Thus, even if all nodes are within direct communication range of each other, only those nodes which are synchronized with the transmitter can hear the transmission. To support any-to-any communication, nodes must be synchronized so that the pairs of nodes (which can communicate with each other) together form a connected graph.Using Bluetooth as an example, this paper first provides deeper insights into the issue to link establishment in frequency hopping wireless systems. It then introduces the Bluetooth Topology Costruction Protocol (BTCP), an asynchronous distributed protocol for constructing scatternets which starts with nodes that have no knowledge of their surroundings and terminates with the formation of a connected network satisfying all connectivity constraints posed by the Bluetooth technology. To the best of our knowledge, the work presented in this paper is the first attempt at building Bluetooth scatternets using distributed logic and is quite "practical" in the sense that it can be implemented using the communication primitives offered by the Bluetooth 1.0 specifications.

SF-DeviL: an algorithm for energy-efficient Bluetooth scatternet formation and maintenance

“…Bluetooth scatternet formation has recently attracted significant attention, where existing studies can be classified as formation algorithms [6][7][8][9][10][11][12] and performance related studies [13][14][15][16]. The algorithms for Bluetooth scatternet formation show differences in their approaches.…”

“…The algorithms for Bluetooth scatternet formation show differences in their approaches. A centralized approach [8] needs extensive messaging between nodes, and hence it is impractical to use centralized algorithms in dynamic environments. Distributed techniques provide the most appropriate solution for constructing scatternets.…”

“…Algorithms also differ in the resulting scatternet topology: some with tree [6,[8][9][10][11] and some with mesh topologies [7,12]. It is shown that the optimum Bluetooth scatternet topologies are application dependent [13].…”

“…Neighbor discovery phase SF-DeviL is a distributed algorithm where each device upon initialization starts the MAIN procedure given in Table 1. The generic device X calculates its DG and starts device discovery by alternating between I/IS modes [1,8] until a neighboring device Y is found. Upon establishment of a link to node Y, X executes the ArrangeRoles(X,Y) procedure given in Table 2.…”

A Self-Organizing Link Layer Protocol for UWB Ad Hoc Networks

“…The protocol is designed to perform well when devices that are in-range of each other become active in a short time interval. Some Bluetooth s catternet construction protocols [8] contain s elforganization procedures that cater for the case of nodes frequently joining and leaving the scatternet, leading tod ynamic topologies. However these protocols relyon the Bluetooth random-access inquiry mechanisms, which are reputed to be slow; delays of the order of 10s [9] are not unusual.…”