Energy-efficient multipath routing in wireless sensor network considering wireless interference

Due to the energy and resource constraints of a wireless sensor node in a wireless sensor network (WSN), design of energy-efficient multipath routing protocols is a crucial concern for WSN applications. To provide high-quality monitoring information, many WSN applications require high-rate data transmission. Multipath routing protocols are often used to increase the network transmission rate and throughput. Although large-scale WSN can be supported by high bandwidth backbone network, the WSN remains the bottleneck due to resource constraints of wireless sensors and the effects of wireless interference. In this paper, we propose a multipath energy-efficient routing protocol for WSN that considers wireless interference. In the proposed routing protocol, nodes in the interference zone of the discovered path are marked and not allowed to take part in the subsequent routing process. In this way, the quality of wireless communication is improved because the effects of wireless interference can be reduced as much as possible. The network load is distributed on multiple paths instead of concentrating on only one path, and node energy cost is more balanced for the entire wireless network. The routing protocol is simulated in NS2 software. Simulation result shows that the proposed routing protocol achieves lower energy cost and longer network lifetime than that in the literature.     

基于网络编码的定向扩散路由协议

提出一种新的基于网络编码的无线传感器网络定向扩散路由协议。在定向扩散路由建立的过程中利用随机线性网络编码,使中继节点对收到的分组进行网络编码后再转发,以减少网络中分组传输的次数,优化网络带宽利用率。基于网络仿真平台NS2的仿真结果表明,新协议的网络性能得到有效改善,节点的平均剩余能量和网络吞吐量有显著提高。     

A power efficiency routing and maintenance protocol in wireless multi-hop networks

In wireless multi-hop networks, selecting a path that has a high transmission bandwidth or a high delivery rate of packets can reduce power consumption and shorten transmission delay during data transmission. There are two factors that influence the transmission bandwidth: the signal strength of the received packets and contentions in the contention-based MAC layer. These two factors may cause more power to be consumed during data transmission. We analyze these two factors and propose a power-aware routing protocol called MTPCR. MTPCR discovers the desired routing path that has reduced power consumption during data transmission. In addition to finding a desired path to reduce power consumption, MTPCR also takes into account the situations in which the transmission bandwidth of the routing path may decrease, resulting in much power consumption during data transmission because of the mobility of nodes in a network. MTPCR is thus useful in a network: it analyzes power consumption during data transmission with the help of neighboring nodes, and it uses a path maintenance mechanism to maintain good path bandwidth. The density of nodes in a network is used to determine when to activate the path maintenance mechanism in order to reduce the overhead of this mechanism. With the proposed path maintenance mechanism, power consumption during data transmission can be efficiently reduced, as well as the number of path breakages. In our simulation, we compared our proposed routing protocol, MTPCR, with the following protocols: two classical routing protocols, AODV and DSR; two power-aware routing protocols, MMBCR and xMBCR; and one multiple path routing protocol, PAMP. The comparisons are made in terms of throughput of the routing path, power consumption in path discovery, power consumption in data transmission, and network lifetime.     

Signal strength based routing for power saving in mobile ad hoc networks

The transmission bandwidth between two nodes in mobile ad hoc networks is important in terms of power consumption. However, the bandwidth between two nodes is always treated the same, regardless of what the distance is between the two nodes. If a node equips a GPS device to determine the distance between two nodes, the hardware cost and the power consumption increase. In this paper, we propose using a bandwidth-based power-aware routing protocol with signal detection instead of using GPS devices to determine the distance. In our proposed routing protocol, we use the received signal variation to predict the transmission bandwidth and the lifetime of a link. Accordingly, the possible amount of data that can be transmitted and the remaining power of nodes in the path after data transmission can be predicted. By predicting the possible amount of data that can be transmitted and the remaining power of nodes after data transmission, we can design a bandwidth-based power-aware routing protocol that has power efficiency and that prolongs network lifetime. In our simulation, we compare our proposed routing protocol with two signal-based routing protocols, SSA and ABR, and a power-aware routing protocol, MMBCR, in terms of the throughput, the average transmission bandwidth, the number of rerouting paths, the path lifetime, the power consumed when a byte is transmitted, and the network lifetime (the ratio of active nodes).     

高能量节点驱动的按需距离矢量路由协议

无线自组织网络中的按需距离矢量路由协议(AODV)没有考虑到能量消耗的均衡性和网络生命期的问题。针对AODV的这一缺点,提出了一种高能量节点驱动的AODV协议(HN-AODV)。此协议将高能量节点驱动的策略应用于按需路由发现过程,尽量选择能量较高的节点来承担转发任务,以此来平衡网络能耗。仿真结果显示,HN-AODV在基本不降低数据传输性能的前提下,显著提高了网络生命周期。这种高能量节点驱动的方案同样可以运用在其它类似的反应式路由协议中。     

多跳无线网络中基于网络编码的多路径路由

提出了一种基于网络编码的多路径路由机制CAMP(network coding-aware multi-path routing).该机制能够根据路径的可靠性和编码机会,动态地在多条路径上进行数据包的传输.CAMP的路由发现机制能够向源节点返回多条可能的路径以及各条路径的每条边上的ETX(expected transmission count).与以往的多路径路由机制不同, CAMP可以通过转换它的传输路径来动态地创造而非仅仅等待编码机会.利用这一独特的路由机制,CAMP可以让多条路径分摊网络流量负载,并且最大化路径转换收益,从而改进网络的吞吐量.实验结果表明,在无线网络的数据传输过程中,CAMP能够取得比其他路由机制高得多的网络吞吐量.     

基于联合编码且负载均衡的AODV路由策略

在无线网状网中,为使AODV(Ad hoc On-demand Distance Vector routing)路由协议支持流间编码并解决流间编码带来的负载不均衡问题,提出了一种优化的路由策略 CLAODV (Coding-aware and Load balanced AODV)。该策略允许编码节点的多个下游节点共同解码同一个编码包,以增加路径上的编码机会。同时,设计了一个可以同时体现路径上编码增益、路径丢包率以及路径负载程度的新路由度量参数(Expected Coding-aware Transmission Count and Load balancing,ECTXL)。CLAODV路由策略可根据该参数进行路由选择。仿真结果表明:与其他相关路由策略相比,文中提出的CLAODV路由策略不仅能有效增加路径的编码机会,提高网络吞吐量,而且可以明显降低路由时延与带宽资源开销。     

具有高效确认机制的双层卫星网络多径路由协议

针对资源受限的LEO卫星网络中传统单路径路由协议数据传输速率较低的问题,基于GEO/LEO双层卫星网络模型提出一种基于网络编码（NC）的双层卫星网络多径路由协议（N-NCMR）。首先,通过GEO卫星为LEO卫星网络计算路由减轻LEO卫星的负担,结合NC技术动态地沿着多个不相交路径传输数据流的不同部分;其次,设计了一种高效的延迟确认机制加速数据传输,源节点在接收到前一组的确认（ACK）消息之前可以连续发送后续的组。仿真结果表明,该路由协议显著提高了LEO卫星网络的吞吐量和数据传输效率。     

网络编码下不可靠自组织网络高效路由算法

无线自组织网络(wireless ad hoc network)中链路的不可靠性与高丢包率是影响网络性能和应用的主要缺陷.为了优化多跳的不可靠无线网络中完成数据传输所需的数据分组发送次数,提出了融合路径切换思想的基于网络编码的路由协议(network coding routing with path switching,简称NCPS).为了发现潜在的适合网络编码的路径,首先分析并提出了网络中路径可编码与可解码条件;其次对比于传统的最优路径,分析得出了在网络编码下路径切换所能获取的编码收益;最后以优化网络中数据分组发送次数为目标,设计了网络编码下结合路径切换的路由协议.实验结果表明,在不同的网络环境参数下,NCPS能够有效减少网络中的数据发送次数,获取稳定的编码收益.     

Bandwidth-based routing protocols in mobile ad hoc networks

In this paper, we propose a high performance routing protocol and a long lifetime routing protocol by considering the fact that the bandwidth between two mobile nodes should be different when distances are different. In the high performance routing protocol, to reduce the number of rerouting times, we take the bandwidth issue into account to choose the path with the capability to transmit the maximum amount of data with the help of the GPS. With exchanging the moving vectors and the coordinates of two adjacent mobile nodes, the possible link lifetime of two adjacent mobile nodes can be predicted. Subsequently, a path with the maximal amount of data transmission can be found. With regard to our proposed long lifetime routing protocol, to maximize the overall network lifetime, we find a path with the maximal remaining power after data transmission. With the link bandwidth and the desired amount of data transmitted, the consumption power is computed to obtain the remaining power of a mobile node. Accordingly, we can choose the path with the maximal predicted remaining power to maximize the overall network lifetime. In the simulation, we compare our high performance routing protocol with the AODV and LAWS in terms of throughput, rerouting (path breakage), and route lifetime. With respect to power consumption, we compare our proposed power-aware routing protocol with the POAD and PAMP in terms of the overall network lifetime and the ration of survival nodes to the all nodes.     

Load-aware routing in mesh networks: Models, algorithms and experimentation

In this paper we consider wireless mesh networks (WMNs) used to share the Internet connectivity of sparsely deployed fixed lines with heterogeneous capacity, ranging from ISP-owned high-speed links to subscriber-owned low-speed connections. If traffic is routed in the mesh without considering the load distribution and the bandwidth of Internet connections, some gateways may rapidly get overloaded because they are selected by too many mesh nodes. This may cause a significant reduction of the overall network capacity. To address this issue, in this paper we first develop a queuing network model that predicts the residual capacity of network paths, and identifies network bottlenecks. By taking advantage of this model, we design a novel Load-Aware Route Selection algorithm, named LARS, which improves the network capacity by allocating network paths to upstream Internet flows so as to ensure a more balanced utilization of wireless network resources and gateways’ Internet connections. Using simulations and a prototype implementation, we show that the LARS scheme significantly outperforms the shortest-path first routing protocol using a contention-aware routing metric, providing up to 240% throughput improvement in some network scenarios.     

一种基于部分网络编码的无线网络机会路由算法

结合机会路由和网络编码两项新技术各自的优势,提出了一种新的基于部分网络编码的机会路由算法(Opportunistic Routing Algorithm for Wireless Network Based on Partial Network Coding,ORAPNC)。为了避免数据包分叉传输,同时利于执行转发节点间协调机制,ORAPNC首先以期望传输次数作为路由度量建立一条固定路由,并将候选转发节点集中在这条固定路径附近;为了充分减小网络中的冗余数据包,ORAPNC采用一种新的转发节点间协调机制(Forwarding Nodes Coordination Mechanism,FNCM)来实现每跳的数据包传输。仿真结果表明,与其他相关路由协议相比较,ORAPNC可以有效提高网络吞吐量,减小目的节点解出原始数据包的平均时延。     

无线网状网服务质量路由研究

无线网状网允许系统同时使用多个正交信道,以达到提高网络性能的目的.但是干扰问题仍然存在.基于TDMA提出了一种没有干扰的系统模型.基于这种模型,一种启发式的路径带宽计算方法被提出.将这个算法和AODV路由协议相结合,可以建立一条满足服务质量的最短路由.通过仿真实验结果证明了该路由协议相比SPR能明显提高QoS路由的请求成功率.     

一种基于链路状态组合度量的无线网状网路由协议

在分析Ad hoc网络中的经典路由协议AODV的基础上,结合无线网状网的特点,提出了基于链路加权的无线网状网路由协议MODVWLS.协议通过节点的可用带宽、缓冲队列和吞吐性能等计算每一跳的代价(即权重),选择从信源到信宿累计权重最小的路径作为路由.对链路权重计算、报文格式、路由发现和维护过程进行了详细阐述,并利用NS2对MODVWLS协议进行了仿真实现.结果表明,MODVWLS协议能合理利用空闲节点和链路资源,较好地均衡网络负载,在数据包转发率、端到端延迟和标准化路由负载等性能上均优于AODV协议.     

无线Mesh网中编码感知组播路由协议CAMR

网络编码是一种能够提高网络吞吐量的新技术,将网络编码应用于无线Mesh网组播对Mesh网络进一步实用化有重要意义.编码感知路由是一种能够充分识别和利用网络中的编码机会的路由.虽然已有若干个基于网络编码的单播路由协议,但无线网络中编码机会并没有被充分利用,到目前为止还没有无线Mesh网络中的编码感知组播路由协议.提出一个编码感知组播路由协议CAMR(coding-aware multicast routing).CAMR协议利用了一个新奇的编码感知路由度量CAM(coding-awarerouting metric),可以度量无线Mesh网络中节点的实际编码机会和编码能力的大小.基于CAM设计的CAMR协议可以充分利用无线Mesh网络中节点的编码机会,提高了无线Mesh网络组播的吞吐量.模拟实验验证了CAMR协议的优势及其有效性.     

基于网络编码的输电线路WSN传输协议

根据输电线路监测对无线传感器网络实时性和可靠性要求高的特点,设计了一种基于网络编码的WSN传输协议。该协议充分利用信道广播特性和节点间的协作通信,结合了机会路由和网络编码各自优势,将网络编码经典蝶形结构应用到输电线路WSN长链拓扑结构中,在节点数据包具体接收状态不确定的情况下,采取主动网络保护机制,选择线性编码包作为冗余包进行传输,直到节点解码出源包。性能分析与仿真实验表明,该传输协议提高了数据传输可靠性和系统吞吐量,缩短了网络传输时延,提升了无线传感器网络的性能。     

Complexity and design of QoS routing algorithms in wireless mesh networks

Quality of service (QoS) provisioning in wireless mesh networks (WMNs) is an open issue to support emerging multimedia services. In this paper, we study the problem of QoS provisioning in terms of end-to-end bandwidth allocation in WMNs. It is challenging due to interferences in the networks. We consider widely used interference models and show that except a few special cases, the problem of finding a feasible path is NP-complete under the models. We propose a k-shortest path based algorithmic framework to solve this problem. We also consider the problem of optimizing network performance by on-line dynamic routing, and adapt commonly used conventional QoS routing metrics to be used in WMNs. We find the optimal solutions for these problems through formulating them as optimization models. A model is developed to check the existence of a feasible path and another to find the optimal path for a demand; moreover, an on-line optimal QoS routing algorithm is developed. Comparing the algorithms implemented by the proposed framework with the optimization models shows that our solution can find existing feasible paths with high probability, efficiently optimizes path lengths, and has a comparable performance to the optimal QoS routing algorithm. Furthermore, our results show that contrary to wireline networks, minimizing resource consumption should be preferred over load distribution even in lightly loaded WMNs.     

WSN中基于FEC的自适应多径路由

在无线传感器网络中,节点失效和环境影响等因素会降低数据传输的可靠性。为此,提出一种基于前向纠错的自适应多径路由协议。根据当前的网络状况,利用RS纠删码自适应调整编码冗余,在选出的可用多路径上根据每条路径的剩余能量权重分配流量,Sink节点根据收到的数据片段进行数据包重构。仿真结果表明,该协议能达到较好的负载均衡,具有较高的成功传输率和吞吐率。     

An on-demand routing protocol for improving channel use efficiency in multichannel ad hoc networks

In wireless ad hoc networks, end-to-end delivery over network is a critical concern for routing protocols. The capacity of routing protocols is constrained by the intra-flow interference introduced by adjacent nodes on the same path, and inter-flow interference generated by nodes from neighboring paths. In this paper, we develop an on-demand routing protocol M-AODV-R that solves the channel assignment, reuse and routing problem jointly. The proposed channel reuse scheme and channel assignment scheme can enhance channel reuse rate. This cross-layer design approach can significantly improve the performance of multichannel ad hoc networks over existing routing protocols. Simulation results show that the proposed routing M-AODV-R can effectively increase throughput and reduce delay, as compared to AODV protocol.     

分组无线网缠绕多路径数据路由协议仿真

在分组无线网的路由协议中,传统路由协议在恶意节点数目较多时网络吞吐量较低,因此提出一种分组无线网缠绕多路径数据路由协议,利用获取的源节点数量信息与位置信息进行路由发现;根据路由发现结果建立从汇聚节点至源节点之间的路径,从而建立缠绕多径路由;对缠绕多径路由进行建簇与重构;进行支路径数优化,从而实现分组无线网缠绕多路径数据路由协议的构建。为了验证上述路由协议的网络吞吐量,将路由协议与基于链路状态的主动式多路径路由协议、基于动态源的按需式多路径路由协议、基于距离矢量的混合式多路径路由协议进行对比,上述四种路由协议在恶意节点数目为30时的网络吞吐量分别为69.5%、33.5%、23.6%、4.2%,通过比较可知,新提出的路由协议的网络吞吐量最高,证明了新路由协议的性能。