基于设备性能的蓝牙散列网构建算法

蓝牙规范中没有提供蓝牙散列网的构建方法。该文采用基于设备性能组建散列网的思想,提出一种散列网构建算法。算法选择性能优良的设备担任主节点和桥节点,并采取措施控制微网数、节点担任角色数、主/从型桥节点数。性能分析和仿真实验证明,该算法能够根据设备的性能分配合适的角色,并且多个性能指标良好。     

遗传算法在蓝牙scatternet组网中的应用

蓝牙a＆hoc网络包括微微网与散射网两种组网方式,可以实现短距离无线通信,并能较好的满足实际需求。其中,散射网的拓扑结构与组网方式很大程度上影响与制约着蓝牙技术的应用。为了提高蓝牙散射网的组网效率与性能,文中提出了基于遗传算法的组网方式,通过该算法可较好的改进散射网的形成速度。     

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.     

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。     

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.     

基于密度影响函数的聚类算法构造蓝牙分散网

针对蓝牙分散网本身具有的特殊限制和特性,文章提出了一种基于密度影响函数的聚类算法构造蓝牙分散网的方法。首先通过密度影响函数对所有结点进行分区后构建匹克网,然后利用聚类算法形成最终的分散网。经数学证明,该方法为有效构建蓝牙分散网节省了时间。     

基于蓝牙散射网的无线传感器网络研究

为适应网络拓扑高度变化的无线传感网络,结合国内外蓝牙技术在无线传感器网络中的应用,提出并实现一个新型的基于蓝牙散射网的体系结构模型。蓝牙层使用改进的TPSF算法,通过限制桥节点度数减轻通信负载,并引入新的时间分配机制构建网络。新的体系结构模型不仅能满足传感器网络放置灵活、移动性强、自组织性和可扩展性高的要求,还大大减少了网络通信负载和时延,既能节省成本,又给用户提供方便的操作接口,具有很大的灵活性、可控性和可靠性。     

蓝牙散射网的层次网络模型研究

蓝牙节点的带宽和存储器容量有限,在蓝牙散射网中构造一条QoS通信路由是一个重大挑战。通过将平面图划分为若干子图,再将子图抽象为高层图,提出了一个用于蓝牙散射网的层次网络模型;并给出了子图的划分原则。适用于大规模蓝牙网络的层次管理模型可以实现分层管理、分块计算,减少控制分组数量,使网络具有更好的可扩展性。     

多个蓝牙匹克网共存时的同频干扰性能分析

蓝牙匹克网之间的同频干扰是蓝牙应用面临的重要问题之一。在分析蓝牙匹克网发生同频干扰原因的基础上，通过理论分析和系统仿真，对同频干扰条件下蓝牙系统的两个重要性能参数误包率和吞吐量进行了评估，提出了增强蓝牙系统性能的方案。仿真结果显示在多个匹克网共存时，匹克网的数目对蓝牙系统的误包率和吞吐量有重要的影响，采用正交跳频序列可以有效改善蓝牙系统的性能。     

基于蓝牙散射网的无线传感器网络研究

为适应网络拓扑高度变化的无线传感网络,结合国内外蓝牙技术在无线传感器网络中的应用,提出并实现一个新型的基于蓝牙散射网的体系结构模型.蓝牙层使用改进的TPSF算法,通过限制桥节点度数减轻通信负载,并引入新的时间分配机制构建网络.新的体系结构模型不仅能满足传感器网络放置灵活、移动性强、自组织性和可扩展性高的要求,还大大减少了网络通信负载和时延,既能节省成本,又给用户提供方便的操作接口,具有很大的灵活性、可控性和可靠性.     

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。     

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.     

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.     

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.     

分布式动态蓝牙散列网形成算法*

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,但由多个微微网组成的散列网只作了简单的描述,没有对散列网的形成加以论述。针对这一问题提出了许多散列网的形成算法,但这些算法没有充分考虑设备的动态特性,就设备的动态特性提出了分布式动态算法。该算法提高了网络的自愈合性,及动态自适应性。     

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。     

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.     

蓝牙自组个人网监听模式下分散网调度算法

蓝牙自组个人区域网络是由具有蓝牙功能的设备组成一个不需额外网络设备,在某个区域内一起自主协调工作,相互间自由通信的独立无线移动网络.网络中的某些节点采用时分复用方式参与多个微微网中并转发网络数据.由于节点在某时刻只能加入其中一个微微网中,这就需要微微网间或者分散网调度算法.监听模式为分散网调度算法提供了一个比较灵活的方式并且无须更改协议.提出了一种基于监听模式的自适应分散网调度算法,有效解决了这个具有挑战性的课题.算法监控各个链路上的流量,并获得流量变化数据,根据这些数据实时改变节点在各个链路上的监听时隙分配比例.通过对算法仿真结果的对比和分析,证明算法能够提高吞吐量,减少传输延迟,改善网络性能.     

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。     

A scatternet formation algorithm for Bluetooth networks with a non-uniform distribution of devices

We address the problem of scatternet formation for network scenarios with a non-uniform distribution of Bluetooth devices. The assumption of having a non-uniform distribution of devices in a given area of interest is motivated by examples that can be encountered in real scenarios. We propose a new scatternet formation protocol called BlueHRT (Bluetooth Hybrid Ring Tree) that results in a hybrid ring tree topology. The proposed protocol operates in multiple phases that include node discovery, identification of a dense area within the network, role assignment with ring based piconets in the dense area and tree based piconets in the surrounding lightly loaded areas, and interconnection of the piconets to each other via slave–slave and master–slave bridges. General protocol design analysis and ns-2 simulation results are presented in order to highlight the main performance characteristics.