摘要：城轨交通传统车地通信依赖地面基站中转,导致较大的信号传输时延;传统通信系统易受基站故障和链路干扰的影响,降低了通信的可靠性,甚至对交通安全造成潜在风险;目前城轨交通轨旁设备多采用有线通信方式,建设与维护成本较高。基于无线自组织网络(ad-hoc)的城轨交通车地通信方案可以有效节约布网成本。通过构建以轨旁设备、列车和车站汇聚节点为核心的无线自组织网络,承载城轨交通业务数据传输,降低了控制环节与接口复杂度,能够实现实时的车车、车地安全通信。设计基于无线自组织网络的城轨交通车车通信综合承载系统,并利用无线自组网基站、信道仿真器、可调衰减器等设备在实验室环境下模拟城轨交通环境,验证了车车通信能力。测试结果表明:ad-hoc系统具有自组织无中心、低网络延时、强网络鲁棒性、多跳传输等特点,能够满足城轨交通业务的需求。

摘要：The support for multiple video streams in an ad-hoc wireless network requires appropriate routing and rate allocation measures ascertaining the set of links for transmitting each stream and the encoding rate of the video to be delivered over the chosen links. The routing and rate allocation procedures impact the sustained quality of each video stream measured as the mean squared error (MSE) distortion at the receiver, and the overall network congestion in terms of queuing delay per link. We study the trade-off between these two competing objectives in a convex optimization formulation, and discuss both centralized and dis- tributed solutions for joint routing and rate allocation for multiple streams. For each stream, the optimal allocated rate strikes a balance between the selfish motive of minimizing video distortion and the global good of minimizing network congestions, while the routes are chosen over the least-congested links in the network. In addition to detailed analysis, network simulation results using ns-2 are presented for studying the optimal choice of parameters and to confirm the effectiveness of the proposed measures.

摘要：在物联网系统中,需要终端设备采集数据并上传到服务器中进行计算和处理。如果终端设备中的通信模块信号不好或者出现异常情况,使得数据无法及时的上传到服务器中,会极大地影响到系统的正常工作。针对该上传异常情况,提出一种基于ad-hoc网络的系统方案。在终端设备原有的网络中增加一个Wi-Fi模块,用于终端设备之间组建ad-hoc网络,当一个设备的数据上传模块出现异常时,可以把数据通过ad-hoc网络发送到该网络中的其他设备上,并通过其他设备的数据上传模块,把实时数据上传到服务器中。通过测试表明,该方案能够把原来不能上传成功的数据通过ad-hoc网络及时上传到服务器中,保障了系统的稳定运行。

摘要：The monitoring of power consumption has become of a great interest in recent years as well as the innovative technologies available to realize Wireless Sensor Networks (WSNs) have experienced a great growth. While smart metering technologies for electric energy are already established, as sensors power supply comes directly from power lines, WSN nodes for gas metering should necessarily be equipped with long life batteries. The presented work describes a new prototypal low cost WSN designed ad hoc for gas smart metering. The network has a star topology: each sensor node can be completely integrated with standard reed relay gas meter, and it is capable to measure the gas consumption. The information is sent to the central node (the Access Point, AP) through an RF links. The sensor nodes have been designed with custom electronics and a proprietary firmware, in order to work with a common 3.6 V lithium battery which is able to ensure a life period of about 10 years for each node. Only the AP must be connected directly to electric power. The AP is connected through the RS-232 interface to a control embedded PC equipped with a LAMP (Linux, Apache, MySQL, PHP) framework: it stores all the information coming from each node in a coherent database and allows authorized users to check the network status using a web interface. The WSN is self-learning and it is capable to detect new nodes joining the network without altering the normal operative flow. Moreover e-mail and SMS alerts can be activated to alert if a node is disconnected from the network or some problems occur. A first prototype of the WSN has been already tested achieving good results.

摘要：ad-hoc路由协议依据路由发现的不同分为主动路由策略和按需路由策略,根据实际网络特点,结合两类协议的优点,提出一种适合快速拓扑更新的无线路由协议。并采用SDL语言工具设计验证了这种小型高移动性无线网络的路由协议。

摘要：Photovoltaic (PV) systems have attracted increasing attention in last years as well as Wireless Sensor Networks (WSNs), which have been used in many application fields. In PV plants, especially in ground installations, a lot of thefts and damages occur due to the still high cost of the modules. A new experimental WSN ad-hoc has been designed to be an anti-theft alarm system. Each node of the network is directly installed under each PV string and it is equipped with an accelerometer sensor capable to detect a minimum displacement of the panel from its steady position. The WSN presents a star topology: a master node cyclically interrogates the slave nodes through RF link. It collects all the nodes responses and communicates though a RS-232 interface with a control PC checking the network status. When a slave node detects an alarm, continuous messages are sent to the control PC which turns on all the alarm signaling systems. The control PC is equipped with an open source operative system and software and provides for SMS, e-mail and sound-light signaling in case of alarm. It also communicates with a remote server where all the WSN information is stored. A first low cost experimental WSN has been already installed and it is working properly.

摘要：针对现有无线传感器网络自定位算法难以脱离大量的静态信标节点的问题,利用ad-hoc的自组织特性,提出了一种基于分簇并只以簇头节点为移动信标的动态无线传感器网络自定位算法。该算法通过簇内动态混合定位的方式,有效提高了盲节点的定位精度。同时设计和实现了一个基于ArcGIS Engine的动态目标定位监控系统,利用GIS辅助将相对定位与基于地图环境下的绝对定位相结合,进一步提高了无线传感器网络的定位精度。MATLAB仿真实验以及系统实例表明了算法的实时性、有效性和系统的可行性。

摘要：以家庭模式为例,借助于LED灯具等用电器,设计出家庭光伏发电无线网络控制系统,在此基础上进行硬件及软件系统的设计,可推广至市政照明系统中。

摘要：随着信息时代的到来,移动电子设备的应用逐步广泛。针对传统多媒体通信方法具有的信息数据同步程度较低的问题,开展了基于ad-hoc在Android手机多媒体通信方法的设计。首先,根据通信流程,分析环形缓冲区域对手机通讯数据帧提取及处理,选择适宜的通讯路由协议,其次,计算Android手机通信路径参数,选择最优手机多媒体通信线路。最后,实验验证:设计方法具有一定的可实施性。建议在后期的发展中,应加大该种方法在多媒体通信开发中的应用。

摘要：设计并实现了基于802.11的无线移动自组网,网络主干采用Mobile ad-hoc Network,网络中的所有移动终端的IP地址采用手动设置,移动IP的路由选择通过移动代理信息表实现;多网卡多信道的分配与管理采用了TUN-TAP虚拟网络接口协议栈,系统支持三种方式的多径源路(ETX、ETT、WCETT),用户可以根据需要进行配置;最后基于Click Modular Router提供的功能模块编写实现了整个系统。