无线传感器网络LEACH路由协议的簇头多跳算法

针对无线传感器网络LEACH路由协议簇头分布不均匀、网络拓扑和能量消耗不均衡的问题,提出基于DCHS簇头选择策略的无线传感器网络LEACH路由协议的簇头多跳算法LEACH-MUL。该算法在非簇头节点中选择一个节点作为通信簇头节点,其它簇头节点进行融合后的数据发送到该簇头节点并进行数据再次融合,最后通信簇头节点将数据融合后的结果数据发送到基站BS。LEACH-MUL算法能够有效地均衡节点能耗,提高能量利用率,延长网络寿命。     

Optimized transmission coordination mechanisms for opportunistic routing

The successful rate of transmission coordination of opportunistic routing (OR) is analyzed systematically,and then two efficient transmission coordination mechanisms (TCMs) are proposed for OR:a batch sliding window-based TCM and a bit map-based TCM,to reduce the total number of packet transmissions and improve end-to-end throughput for OR.The batch sliding window-based TCM avoids the oscillation of the successful rate of transmission coordination by transmitting packets in continuous batch mode so as to improve the average successful rate of transmission coordination efficiently,while the bit map-based TCM improves end-to-end throughput of OR by reducing the overhead of transmission coordination.Exhaustive simulations show that the average end-to-end throughput gains of the two proposed TCMs are 15.4％ and 6.4％ over the batch map-based TCM,respectively.     

Experimental Analysis of Link Estimation Methods in Low Power Wireless Networks

Wireless sensor networks are envisioned to be an integral part of cyber-physical systems,yet wireless networks are inherently dynamic and come with various uncertainties.One such uncertainty is wireless communication itself which assumes complex spatial and temporal dynamics.For dependable and predictable performance,therefore,link estimation has become a basic element of wireless network routing.Several approaches using broadcast beacons and/or unicast MAC feedback have been proposed in the past years,but ...     

Delivery Digital Television Services over Ethemet

A new architecture for digital television (DTV) delivery based on Ethernet was presented.In this architecture,new protocol stack and packet encapsulation were proposed to help implementation of DTV services over Ethernet link.A simple quality of service (QoS) structure was provided in traffic control of nodes to achieve QoS requirements of DTV delivery.Experiments were proceeded successfully to implement the idea.Finally,a short evaluation to QoS provisions was given,achieving good results.     

卫星网络中基于蚁群优化的概率路由算法

为了提高空间信息传输的有效性和可靠性,针对传统蚁群优化(ant colony optimization,ACO)容易造成最优路径负载过重而发生拥塞的问题,提出了一种基于蚁群优化的概率路由算法(ant colony optimization based proba-bilistic routing algorithm,ACO-PRA).根据卫星网络拓扑动态周期时变的固有特点,将拓扑周期均匀分为若干个时间片,形成基于不同时间片的卫星网络拓扑连通图;根据网络拓扑连通图,将星间链路带宽和链路容量引入到目标函数中,建立时延最小的优化模型;根据蚁群算法的节点概率函数选择下一跳节点,进而找到一条能同时满足时延带宽和链路容量要求的最佳信号传输路径.仿真结果表明,提出的基于蚁群优化的概率路由算法不仅能够降低平均端到端时延和丢包率,而且能够有效地提高网络吞吐量、平衡网络负载.     

运营级Wi—Fi网络中的QoS研究

从Wi—Fi技术被广泛应用于语音、多媒体传输等的角度，引出Wi—Fi技术中对高速率传输业务的QoS保障机制——WMM（Wi—Fi Multimedia），通过对WMM的测试，以及从运营的角度对Wi—Fi网络应用和需求进行分析，提出Wi—Fi网络QoS保障需要解决的几个问题和建议，并对Wi—Fi技术的发展进行了展望。     

BDRouter:拐弯数密度驱动的总体布线算法

拐弯优化是布线阶段考虑的重要问题之一。该文提出了一种考虑拐弯优化的总体布线算法BDRouter来同时考虑减少布线拐弯数和拐弯密度。这有助于在布线阶段减少通孔并给必要的通孔增加可能的冗余通孔位置,以此来增强可制造性、可靠性和提高成品率。实验测试表明:该文算法与已有典型算法相比,在线长不增加或增加不超过10%的前提下,能够减少约50%的拐弯数,并降低约20%的拐弯数标准差。     

基于DiffServ的UMTS端到端QoS保证机制研究

3G多媒体业务的发展给UMTS的QoS保证机制提出更高的要求.从QoS需求出发,描述了无线接入网的网络结构以及3G核心网的承载业务类型,分析了网络组件、业务类型与协议栈之间的对应关系,讨论了UMTS QoS管理机制在各组件中的功能实现,引入因特网的区分服务模型在核心网中构建基于DiffServ的网络模型为不同业务提供QoS保证,最后指出UMTS端到端QoS机制有待发展的研究方向.     

基于服务质量的Web服务优化选择算法及仿真

提出一种基于服务非功能属性的Web服务优化选择的多目标遗传算法.考虑到在服务选择时组合方案中的控制结构、具体服务之间的关联性和多个服务质量指标之间的折衷这三方面的约束,对服务选择建立分层模型给出优化选择的形式化定义.在此基础上,采用多目标遗传算法求解优化服务选择.首先设计了适合的染色体编码方式,以表示可行的服务选择方案...