基于本地的无线传感器与执行器网络位置服务方法

文章分析了无线传感器与执行器网络位置服务的基本要求,介绍了无线传感器与执行器网络位置服务的主要类型,描述了执行器位置更新的策略,归纳了扁平式本地位置服务算法和分层式本地位置服务算法的工作原理。     

机会网络中基于ferry的低能耗路由算法

在节点移动规律无法预知、连通性较差的机会网络中,FIMF(Ferry-Initialed Message Ferrying)路由能够有效地提高网络中消息传递成功率.在FIMF路由机制中,普通节点在传递控制消息(如节点位置消息、Hello消息)时存在多余的通信开销,并且采用了大功率发送位置消息会耗费过多能量.提出了基于RSSI测距技术和跨层设计的消息摆渡节能路由算法AFIMF.AFIMF中采用基于RSSI测距技术,在普通节点上采用自适应调整功率技术和跨层检测技术按需发送Hello消息.仿真结果表明,AFIMF算法有良好的稳定性,在保证通信传递率的前提下,普通节点不仅有效地节约了能量,而且减少了开销.     

一种AODV协议邻域修复机制的设计与实现

提出了一种减小AODV协议路由开销的邻域修复机制.在机制中,当某节点失效时并不立刻发送RERR 消息,删除相关路由;而是首先发起基于下两跳的邻域修复过程,如果修复成功则路由愈合,否则再发送RERR消息进行路由更新与删除.分析表明,该机制有效地减少了路由开销和数据发送的延时.     

基于P2P架构的分布式虚拟环境中一种状态消息的随机分发方法

针对基于P2P通信架构的分布式虚拟环境中的视图一致性问题,在分析有限的网络带宽等影响因素的基础上,提出了一种随机广播算法进行状态消息分发.该算法需预先建立随机几何图结构,并利用给出的通信限制时延进行状态更新消息的发送.结合基于贪心的路由选择算法,通过已获得状态更新消息的节点转发,进而确定节点间的转发路由,获得节点间具有较少通信时延的消息传播时间.经实验分析及验证表明,该算法与其他几种算法相比较而言,在很大程度上减少了时空不一致性事件率,提高了系统性能.     

无线传感器与执行器网络组播技术研究

组播是将给定消息从一个源节点发送到若干个目标节点的通信模式。在组播中,给定消息沿着路由从一个节点发送到多个目标节点,这些目标节点的位置是任意的,且分布在整个网络内。文章给出了WSAN(无线传感器与执行器网络)中组播的定义与数学描述,分析了Ad hoc网络组播协议以及基于树与网格的组播协议特征与思路,描述了LAM(轻量级自适应组播)、DDM(差异目标组播)、GMP(地理组播协议)、PBM(基于位置的组播)、GMR(地理组播路由)、HRPM(分层汇聚点组播)、HGMR(分层地理组播路由)等地理组播协议的工作原理。     

无线传感器与执行器网络地理路由算法研究

在无线传感器与执行器网络中,源节点不断向目标节点传输测量报告,这需要建立一条从源节点指向目标节点的路由。路由算法的设计涉及到节点的地理位置信息,每个节点需要根据邻居节点和目标节点的位置信息做出路由决策,以尽可能地节省通信开销。文章介绍了基于记忆的保证传输地理路由算法、基于成本进度比的地理路由算法、基于自适应定位的地理路由算法和基于虚拟坐标、树坐标的地理路由算法的工作原理,分析了这些地理路由的实现方式。     

基于消息复用的位置服务隐私保护算法

提出一种基于消息复用的位置服务隐私保护(MSPP)算法,用于提供不同安全性需求的位置服务.首先对源消息集中的数据进行预伪装,将通过预伪装算法成功伪装的消息添加到复用消息集.然后,通过消息复用,形成多层伪装区域来保护用户的位置隐私.仿真结果表明,针对不同安全性需求的消息,该机制提高了匿名成功率,缩短了系统平均响应时间.     

基于室内可见光照明的位置服务系统

设计并实现了一种基于室内LED照明光源的位置服务系统。系统利用LED标签(LED ID)技术,LED提供照明的同时广播自身的位置ID信息,移动终端将接收到的ID信息与位置关联,实现自身的被动定位。可见光通信的调制编码以及解调解码模块均采用单片机处理器(PC)实现,并提供UART接口分别与PC控制端和手机显示端进行通信。PC控制端向LED信号源发送位置服务信息,LED信号源通过空间光传输方式将自身位置ID和接收到的位置服务信息广播出去。手机使用终端加载有Android操作环境下的室内定位导航软件,可以实时更新位置和位置服务信息。     

基于三维胞元空间的能量高效性多通道协作路由算法

针对无线传感器网络中因空洞引起路由效率降低的问题,该文提出了基于3维胞元空间的能量高效性多通道协助路由算法(3D-EEMCR)。该算法根据能量损耗模型,权衡考虑节点的剩余能量和位置信息来选举胞父节点,从而平衡网络能耗;另外,算法采用主通道和辅助通道相互协助的周边路由模式完成空洞区域的路由。仿真结果表明,3D-EEMCR相比3D-GPR(Grid Position-based Routing)和3D-CSR(Cell Space Routing)能够有效提高消息包的发送率,降低网络的平均能耗,延长网络的生存周期。     

涓流算法的原理及应用方法

涓流算法是一种适用于低能耗、拓扑经常变化的无线网络(或其它共享介质网络)的路由算法。涓流算法通过对于信息发送的速率控制,在降低路由维护成本的同时,保证了对于网络变化的敏感度,比较适用于物联网领域。     

Hash-Based Paging and Location Update Using Bloom Filters

We develop and analyze a hash-based paging and location update technique that reduces the paging cost in cellular systems. By applying a Bloom filter, the terminal identifier field of a paging message is coded to page a number of terminals concurrently. A small number of terminals may wake up and send what we call false location updates although they are not being paged. We compare the total number of paging and false location update messages with the cost of the standard paging procedure. Fortunately, the false location update probabilities can be made very small, and important bandwidth gains can be expected. The larger the size of the terminal identifier, the less probable are false location updates. Therefore, hash-based paging especially shows promise for IP paging in mobile IPv6 networks with 128-bit mobile host addresses.     

Locating strategies for personal communication networks, a noveltracking strategy

The partition of location areas is designed to minimize the total costs of finding users' location and tracking their movement in personal communication networks (PCNs). A new scheme to partition and track mobile users and its implementation based on cellular architecture are proposed. According to the tracking strategy, the mobile station (MS) transmits only update messages at specific reporting cells, while the search for a mobile user is done at the vicinity of the cell to which the user has just reported. We use the cost analysis model to demonstrate the feasibility of updating and searching costs to reduce the amount of resources when using wireless channels. Simulations are performed to compare the performance of three schemes: always update, always search, and our new scheme     

On the design of globally optimal communication strategies for real-time noisy communication systems with noisy feedback

A real-time communication system with noisy feedback is considered. The system consists of a Markov source, forward and backward discrete memoryless channels, and a receiver with limited memory. The receiver can send messages to the encoder over the backward noisy channel. The encoding at the encoder and the decoding, the feedback, and the memory update at the receiver must be done in real-time. A distortion metric that does not tolerate delays is given. The objective is to design an optimal real-time communication strategy, i.e., design optimal real-time encoding, decoding, feedback, and memory update strategies to minimize a total expected distortion over a finite horizon. This problem is formulated as a decentralized stochastic optimization problem and a methodology for its sequential decomposition is presented. This results in a set of nested optimality equations that can be used to sequentially determine optimal communication strategies. The methodology exponentially simplifies the search for determining an optimal real-time communication strategy.     

Scalable Routing Protocol for Ad Hoc Networks

In this paper we present a scalable routing protocol for ad hoc networks. The protocol is based on a geographic location management strategy that keeps the overhead of routing packets relatively small. Nodes are assigned home regions and all nodes within a home region know the approximate location of the registered nodes. As nodes travel, they send location update messages to their home regions and this information is used to route data packets. In this paper, we derive theoretical performance results for the protocol and prove that the control packet overhead scales linearly with node speed and as N ^3/2 with increasing number of nodes. These results indicate that our protocol is well suited to relatively large ad hoc networks where nodes travel at high speed. Finally, we use simulations to validate our analytical model.     

Associative IP paging based on hierarchical mobile IPv6

IP paging is a well‐known topic, which focuses on reducing amount of binding update (BU). Various IP paging architectures rely on multicast/broadcast to send their messages in wireless network. However, multicast/broadcast is unreliable and has limited bandwidth in power saving mode. This paper uses unicast to avoid exhaustion of the limited bandwidth and reliably page mobile nodes (MNs) by layer 2's supporting acknowledgment in nature. Furthermore, we successfully suppress the amount of BU by remembering and checking MNs' ever attached on‐link care of addresses (LCoAs) in the stack, which is maintained by least recently used (LRU) algorithm for efficiently paging while MNs moving in a localized pattern. We simulate this mechanism to obtain the optimal stack size, which can dramatically reduce the signals of location update and paging. Copyright © 2009 John Wiley & Sons, Ltd.     

HISF:一种基于智能冰箱的家庭物联网感知与服务系统

研究智能冰箱技术,并将其作为家庭物联网感知与服务系统的一种载体。设计一种新型的智能冰箱,实现基于RFID的自动化食品管理模式和可视化食品管理模式,并提供个性化菜谱查询和推荐等服务;提出以智能冰箱为载体的家庭物联网感知与服务系统(HISF),该系统采用分层架构设计,实现基于云端数据平台的服务聚合和终端智能应用服务接入与执行。     

物联网盲人智能手杖的设计

本文设计了一个基于物联网的盲人智能手杖,手杖采用超声波、红外避障、热释感应传感器检测行人和障碍物,用蓝牙语音和振动进行避障提醒,用GPS、GSM完成用户定位和呼救信息的报送。文中给出了手杖以及呼救中心的整体方案和软、硬件设计,并对手杖的避障、蓝牙通信、语音播报、振动提示、定位、短信发送和呼救中心等各项功能进行了测试。本设计能够实现盲人用户的行路引导、呼救信息报送和响应处理,具有一定应用推广价值。     

基于预算机制的非结构化P2P网络分段搜索策略

在非结构化P2P网络中,降低消息冗余,提高搜索的效率,一直是资源搜索的关键问题.目前非结构化P2P网络均采用生存时间（Time-To-Live）机制控制搜索算法的深度,但是同时产生了大量的冗余消息,严重影响了网络的利用率.为了能够在保持高搜索效率的前提下减少冗余消息的数量,提出了一种基于预算机制的非结构化P2P网络分段搜索策略DBudgetSearch.DBudgetSearch将搜索过程分为两个阶段,并在每个阶段中使用预算机制来控制消息转发的数量和导向,根据邻居节点的连接度大小来选择消息的转发对象.分析和试验结果表明,DBudgetSearch导向性好,算法搜索效率高,能够有效减少冗余消息.     

广播电视相关行业物联网业务发展状况的探讨

主要介绍了电信行业、电力行业的物联网(Internet of Ting,IOT)应用服务开展情况以及物联网网络整体规划和设计情况.探讨了基于广电网络开展物联网业务的优势,以及符合现有网络发展趋势,和适合广电网络开展的物联网应用服务类型.     

基于多跳蜂窝网的组位置管理策略

提出了一种成组进行位置管理的策略,分析了彼此临近的移动台组成一个自组织网的基本网络模型,提出了向中继点注册,由中继点进行信令压缩,组成组控制信令,成批向网络报告位置的位置更新的策略;采用M/M/n/n模型具体比较了批处理方案与传统方案的性能,说明作者的方案不仅减少了移动台的发射功率,还大量节省了频率资源,增加了系统的吞吐能力。