Joint Layer-Based Formation and Self-Routing Algorithm for Bluetooth Multihop Networks

• Main Authors: YU,YIH BIN, 余益濱
• Other Authors: YU,ZHI-MIN
• Format: Others
• Language: en_US
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/vcrsxt

博士 === 中華大學 === 工程科學博士學位學程 === 107 === In this dissertation, a joint layer-based formation and self-routing algorithm called Bluelayer is proposed for Bluetooth multi-hop networks. Without any prior topology information, the layer-based algorithm determines new roots by a root decision criterion, and generates individual web-shaped subnets by adopting three pre-configured network parameters. During the scatternet formation stage, a tier-ring addressing scheme is jointly introduced to achieve a distributed self-routing protocol for multi-hop networks. The routing protocol contains an address query phase to locate a destination, and a forwarder decision phase to determine the optimal master as forwarder. With moderate communication overhead, complexity analysis shows that Bluelayer achieves the least computation and route discovery overhead than all the other schemes. In addition, computer simulation shows that the layer-based algorithm renders topology controllable, and evenly configures the size of the subnet by appropriately selecting configured parameters. In the routing performance comparison, Bluelayer achieves almost same cost-performance ratio as BlueHMT, and achieves better routing performance than BlueHRT and Bluetree under high traffic load conditions. In a nutshell, Bluelayer demonstrates good network scalability and routing efficiency for Bluetooth multi-hop networks. A reconfigurable formation method is also proposed for Bluetooth scatternet. First, a designated root constructs a tree-shaped subnet and propagates parameters k and c in its downstream direction to determine new roots. Each new root asks its upstream master to start a return connection to convert the first tree-shaped subnet into a mesh-shaped subnet. At the same time, each new root repeats the same procedure as the root to build its own tree-shaped subnet until the whole scatternet is formed. In addition, a peak-search method was introduced in the designated root to determine the optimum mesh-tree configuration. The method designs three blocks including the connection link block to calculate the total links, the hop length block to compute the average query hop, and the optimum decision block to locate the optimum k layer. Simulation results showed that the peak-search method achieved the approximate performance in the average hop length in contrast to the ideal layer. As a result, the reconfigurable method generated an efficient scatternet configuration by achieving the desired path length of scatternet performance. This dissertation proposed an energy-aware routing method, P-AODV. Based on the AODV routing protocol, this study designed a passive power control (PPC) algorithm to enhance energy efficiency. The proposed method includes signal detection and power setting phases. During the signal detection phase, the source node broadcasts the route request packets (RREQ) and the downstream intermediate node calculates the optimum power level at the upstream intermediate node according to the received signal strength indicator (RSSI) after receiving the RREQ. During the power set phase, the destination node returns the RREQ packet to notify the power level of the upstream nodes to the source node. After that, all nodes from the source node to the destination node engaged in transmission will transmit data in a coordinated power level. As indicated by the computer simulation results, P-AODV could have 30% higher energy efficiency than traditional AODV. This PPC algorithm could also be used in wireless mesh networks (WMNs). The approaches proposed in this dissertation could be extended to the system application in the consumer electronics industry related to IoT (Internet of Things) or VANET (Vehicular Ad-hoc NETwork).