蓝牙分散网的形成算法

当前的蓝牙规范只对各个蓝牙设备的连接、通讯以及蓝牙微微网的形成作出了明确的规定,但是只是简单的描述了由微微网组成的分散网,没有对分散网的形成加以论述.针对这一问题提出了以蓝牙设备的电池电量为权值的组网算法,该算法能够保证设备工作最长的时间.该算法能够动态地适应网络的变化,网络的自愈合性,及动态自适应性良好.     

BGN：一种新的蓝牙传感器网络分散网构造算法

在蓝牙分散网中,桥节点的数量和每个桥节点的度是影响主干网性能的重要因素。在生长树的基础上提出一种新的蓝牙分散网构造算法——BGN。该算法利用生长树主干节点间预留的连接将树改造成网,所形成的分散网能够在保持一定程度连通性的同时避免过多的冗余链接。仿真实验的结果表明,该算法所生成的分散网结构在桥节点数量、平均路径长度、网络可靠性和网络最大传输流量方面具有优势。     

一种改进的蓝牙分散网分布式拓扑构成算法

蓝牙分散网是由多个微微网组成的自组网络,由于其应用前景广阔,已经成为当前研究热点之一。蓝牙分散网的网络拓扑构成复杂且移动性强,现行的蓝牙规范并未对分散网的拓扑构成作详细的说明,因此这是一个极具挑战性的课题。提出了一种改进的蓝牙分散网的分布式拓扑构成算法,使用对称/不对称连接机制产生一个超级结点,并由这个超级结点应用分布式拓扑构成算法形成最终的分散网拓扑结构。性能仿真分析表明:该算法具有较快的网络创建时间、延时低、结点数目不受限制并能适应网络的动态变化。     

一种蓝牙分散网拓扑形成算法的设计与实现

针对现有的蓝牙分散网拓扑形成算法的动态性和自愈性较差的问题，提出了一种新算法.该算法综合考虑了对分散网互连有显著影响的微微网的个数、负载均衡和结点移动性等因素，使最终得到的分散网拓扑是一个异构的、局部互连网状的结构，该结构具有较强自愈和容错能力.利用BlueHoc蓝牙扩展模块在NS-2仿真器上对算法进行了模拟.结果显示，提出的算法可以有效地用于蓝牙分散网拓扑结构的创建.     

多跳蓝牙设备分散网的动态组网算法

近几年无线自组网络发展迅速,而蓝牙自组网的拓扑构建问题已成为无线自组网络研究的一个重要分支.目前已有很多学者提出了蓝牙设备在多跳环境下的不同组网协议的算法,但大多是针对静态的组网问题.对于蓝牙设备不在直接通讯范围内的多跳通讯要求以及节点的动态变化情况,提出了一种新的蓝牙设备分散网的分布创建思想,同时该算法满足动态性的要求.形成的分散网的拓扑结构采用类似树形结构、没有根节点的无环连通图,因而具有控制简洁,组网快捷的特点.     

水声传感网中基于网络编码的协作传输算法

为提高水下数据传输可靠性,本文在随机线性网络编码的基础上提出一种协作数据传输算法。首先,为源节点寻找数据转发链路,让数据通过多条链路进行转发;其次,使用网络编码方法对数据包进行编码,避免转发节点转发重复数据包;最后,对各个节点的数据包传输时隙进行调度,避免节点间信号冲突。仿真结果表明,本文提出的算法在一定程度上提高了网络信道利用率和数据传输可靠性,且具有较好的稳定性。     

基于时序感知优化机制的无线传感网数据投递算法

为解决无线传感网数据投递算法存在的链路选取质量不高,且节点重投递现象严重,容易降低网络传输质量等不足,本研究提出一种基于时序感知优化机制的无线传感网数据投递算法。首先,算法通过感知节点接近状态的时序情形,设计了基于时序效应的链路筛选方法,通过优选中继节点的方式提升链路投递率,以降低网络链路丢包概率,进而增强数据传输质量。随后,算法通过自感知方式获取节点转发数据,设计了基于投递优选的拥塞控制方法,以提高多跳链路的稳健性,降低节点碰撞效应带来的拥塞现象,进而改善网络数据投递质量。仿真实验结果表明,本研究算法与当前无线传感网中常用的虫洞-路径投递算法和神经卷积深度投递算法相比,能够显著降低网络平均投递时延,且网络累计拥塞频次较低,网络数据投递成功率较高,具有较高的实际部署价值。     

一种改进的蓝牙分散网形成算法

当前的蓝牙规范对微微网的形成、调度和路由选择问题进行了规定，而多个微微网组成的分散网只做了简要的描述，没有对分散网的形成问题加以论述，针对这一问题，提出了许多分散网的形成算法，但有些算法没有考虑设备的移动性，本文就设备的移动性问题，对已提出的算法加以改进，改进后的算法提高了系统的性能，节省了有限的系统资源。     

蓝牙散射网的数据传输性能分析

在蓝牙微微网中,主设备决定跳频序列.由于各主设备独立跳频,因此在多个微微网中数据分组会由于跳至同一频隙而产生较高的误包率.文中建立了散射网下数据分组相互干扰的分析模型,在此基础上得出了蓝牙散射网在进行ACL分组传输时的网络吞吐量.针对不同的跳频方式和网络是否全局时隙同步的四种情况对单一类型的分组发送成功率进行了具体的分析,并进一步得出采用混合分组时的网络最大吞吐量,并得出达到最大吞吐量是应当采用的最佳分组及最佳分组的传输延迟.     

基于蚁群粒子适应机制的移动传感网簇头生成算法

传统移动传感网簇头生成算法在筛选簇头节点时中存在的节点密度较低及网络传输性能较差的不足.因此,提出了一种基于蚁群粒子适应机制的移动传感网簇头生成算法.首先选取具有较高能量值的节点作为初始簇头节点,采取粒子迭代方式设计了基于蚁群粒子感知覆盖机制的簇头生成方法,并通过权值评估方式来优化备选簇头节点能量,有效改善因链路抖动而导致的传输性能受限现象,有效提高簇头节点分布密度.基于极限标准差优选机制,通过定时更新备选簇头节点标准差,进一步选取性能较高的节点维持链路性能,改善链路抖动现象并提高网络传输带宽,降低信道噪声对数据传输带来的不利影响.通过仿真实验与基于改进能量均衡机制的传感网簇头生成算法和基于能量优化回收机制的传感网簇头生成算法进行对比,表明所提算法具有更高的簇头节点密度和网络传输带宽.     

一个两步蓝牙散射网形成算法TBSF

蓝牙是一门新兴的低功耗、低成本短距离无线技术，它使便携设备能方便快捷地形成短距离无线网，同时为构建成本低廉的移动自组网带来了新的选择方案．提出一个异步的、完全分布式蓝牙散射网构造算法——TBSF，首先由所有蓝牙节点生成一系列独立匹克网，然后互连匹克网成为散射网．基于节点邻居个数选择主或桥节点，通过一个节点角色转换图确定桥节点充当的角色．任意两个相邻匹克网之间通过惟一的连接路由互连，最终形成一个连通的散射网，主和桥节点构成散射网的一个连通支配集．仿真实验表明，TBSF算法创建散射网具有较好特性．     

Relay reduction and disjoint routes construction for scatternet over Bluetooth radio system

Bluetooth is a new technology for low-cost, low-power, and short-range wireless communication. By constructing a piconet, Bluetooth device establishes link and communicates with other device in a master–slave manner. Relay is a Bluetooth device that joins two or more piconets and forwards data from one piconet to another, providing multi-hop (or inter-piconet) communication services. In a Bluetooth scatternet, the number of relays and the degree of each relay are factors that significantly affect the performance of entire network. Unnecessary relays raise the difficulty of scheduling, leading to frequent packet loss. Relay switching among several piconets in turns also creates guard time overhead and increases the transmission delay. This study presents an effective protocol that can dynamically adjust the network topology by reducing the unnecessary relays. An efficient scatternet environment thus can be constructed with characteristics of connected, high bandwidth utilization and low maintenance cost. Additionally, a routing protocol is developed to reduce the path length and generate two disjoint routes for any pair of source and destination devices located in different piconets. Experimental results demonstrate that the proposed protocols perform well in terms of route length, bandwidth consumption, and transmission delay.     

Ring of Masters (ROM): A new ring structure for Bluetooth scatternets with dynamic routing and adaptive scheduling schemes

This paper attempts to address the scatternet problem in Bluetooth through a comprehensive approach. We propose a new decentralized ring structure to combat the formation of traffic bottlenecks. The adopted construction protocol ensures flexibility of node selection and a good level of fault tolerance. The routing protocol combines both simplicity and robustness by taking advantage of the ring structure and relying on the collective memory of piconets to make forwarding and discarding decisions. The intra- and inter-piconet scheduling algorithm, called ROM adaptive scheduling (RAS), dynamically allocates time slots and is responsive to the varying workload conditions. We demonstrate, through analysis and simulations, that the various components of ROM yield a system that has good performance in terms of throughput, latency, delivery, and link utilization.     

TARP: A traffic-aware restructuring protocol for Bluetooth radio networks

Bluetooth is a low-cost and short-range wireless communication technology. The Bluetooth device randomly searches and connects with other devices using the inquiry/inquiry scan and the page/page scan operations, resulting an uncontrolled scatternet topology. The unpredictable scatternet topology usually raises the problem of redundant traffic and causes inefficient communications. A traffic-aware restructuring protocol (TARP) is presented for partially restructuring a piconet or a pair of two neighboring piconets by applying role switch mechanism. The proposed TARP mainly consists of intra-piconet and inter-piconet restructuring protocols. According to the recent routes and their traffic load information, the intra-piconet restructuring protocol adjusts piconet structure by selecting the proper device to play a master role of a piconet and applies takeover operation to rapidly restructure the piconet topology. The inter-piconet restructuring protocol exchanges devices of two neighboring piconets to reduce the route length and thus improve the power and bandwidth consumptions and the end-to-end transmission delay. Performance results reveal that the proposed restructuring protocols reduce path length of recent routes and save power consumption, thus significantly improve the performance for a given connected scatternet.     

Novel route maintenance protocols for the Bluetooth ad hoc network with mobility

Bluetooth technology is specially designed for the wireless personal area networks to replace cable. Several challenges exist in Bluetooth scatternet formation and routing, since nodes can arrive and depart at arbitrary times. In this paper, novel route maintenance algorithms are proposed for the Bluetooth ad hoc networks, where nodes can enter or exit from the piconets time to time. Our protocols guarantee the connectivity among nodes and reconstruct the routes dynamically by considering location information of the nodes. Besides, it is proposed how to reduce the number of hops and to form the shortest route between the source and the destination due to addition of new nodes to a piconet. Performance analysis of our protocols show that they outperform in terms of end to end transmission delay, bandwidth consumption and average hop counts as compared to similar Bluetooth routing protocols that we have considered.     

An efficient reconstruction approach for improving Bluetree scatternet formation in personal area networks

Bluetooth is a communication technology for personal area networks (PANs). To support communication with more than eight bluetooth-enabled devices, a scatternet must be formed in the PAN. Bluetree is one commonly used topology for scatternet formation. To reduce traffic load of the Bluetree scatternet, we use the piconet transfer concept to move piconets on a well-formed Bluetree scatternet. The piconet movements are performed based on a distributed manner using two well-known tree traversal procedures: post-order traversal and level-order traversal. These two procedures do not take much computation time, where time complexities are O(n_p) and n_p is the number of piconets on a Bluetree scatternet (not the number of nodes on a Bluetree). Compared with previous approaches, the proposed approach can greatly reduce the traffic load and computational costs. Finally, simulation experiments show the effectiveness of the proposed approach in improving the formation of Bluetree scatternet.     

蓝牙自组织网性能研究与构建*

分析了微微网、通信链接、设备电力等级等因素对蓝牙自组织网性能的影响,提出一种新颖的蓝牙自组织网构建算法。仿真结果表明,该算法能优化微微网数目,降低桥单元设备负载,并能有效减少设备间冗余通信链接,从而提高了蓝牙自组织网的性能。     

Distributed Construction and Maintenance of Bandwidth and Energy Efficient Bluetooth Scatternets

Bluetooth networks can be constructed as piconets or scatternets depending on the number of nodes in the network. Although piconet construction is a well-defined process specified in Bluetooth standards, scatternet formation policies and algorithms are not well specified. Among many solution proposals for this problem, only a few of them focus on efficient usage of bandwidth in the resulting scatternets. In this paper, we propose a distributed algorithm for the scatternet formation problem that dynamically constructs and maintains a scatternet based on estimated traffic flow rates between nodes. The algorithm is adaptive to changes and maintains a constructed scatternet for bandwidth-efficiency when nodes come and go or when traffic flow rates change. Based on simulations, the paper also presents the improvements in bandwidth-efficiency and reduction in energy consumption provided by the proposed algorithm.