无线传感器网络中协作通信的能耗优化方法研究

针对能量受限的无线传感器网络,该文综合考虑了协作节点数量和调制方式对系统能量有效性的影响,提出一种能量最优的综合优化方法。文中首先给出了在Rayleigh衰落信道环境下,协作通信系统采用二相相移键控(BPSK)和M进制正交幅度调制(MQAM)时误码率的闭式表达,同时对协作通信的系统能耗进行了分析。在此基础上,根据能耗最小化原则对协作节点数量和调制方式进行了联合优化。仿真结果表明,与调制方式固定或协作节点数固定的系统相比,该方案能进一步降低协作通信的系统能耗。     

Optimal Transmit Power in Wireless Sensor Networks

Power conservation is one of the most important issues in wireless ad hoc and sensor networks, where nodes are likely to rely on limited battery power. Transmitting at unnecessarily high power not only reduces the lifetime of the nodes and the network, but also introduces excessive interference. It is in the network designer's best interest to have each node transmit at the lowest possible power while preserving network connectivity. In this paper, we investigate the optimal common transmit power, defined as the minimum transmit power used by all nodes necessary to guarantee network connectivity. This is desirable in sensor networks where nodes are relatively simple and it is difficult to modify the transmit power after deployment. The optimal transmit power derived in this paper is subject to the specific routing and medium access control (MAC) protocols considered; however, the approach can be extended to other routing and MAC protocols as well. In deriving the optimal transmit power, we distinguish ourselves from a conventional graph-theoretic approach by taking realistic physical layer characteristics into consideration. In fact, connectivity in this paper is defined in terms of a quality of service (QoS) constraint given by the maximum tolerable bit error rate (BER) at the end of a multihop route with an average number of hops.     

基于效用的无线传感器网络能量分配优化策略

该文对传感器网络在能量受限条件下的数据传输进行建模,提出了一种基于效用最大化的网络优化模型。该模型刻画了传感器网络节点之间在能量消耗方面的耦合关系。该文通过引入松弛变量和采用对偶分解技术,获得传感器网络能量控制的分布式算法。实验表明,该算法对所有的节点能收敛到速率和能量之间的帕累托(Pareto)最优平衡。     

Energy Optimization in Multihop Wireless Embedded and Sensor Networks

This paper provides an analytical model for the study of energy consumption in multihop wireless embedded and sensor networks where nodes are extremely power constrained. Low-power optimization techniques developed for conventional ad hoc networks are not sufficient as they do not properly address particular features of embedded and sensor networks. It is not enough to reduce overall energy consumption, it is also important to maximize the lifetime of the entire network, that is, maintain full network connectivity for as long as possible. This paper considers different multihop scenarios to compute the energy per bit, efficiency and energy consumed by individual nodes and the network as a whole. The analysis uses a detailed model for the energy consumed by the radio at each node. Multihop topologies with equidistant and optimal node spacing are studied. Numerical computations illustrate the effects of packet routing, and explore the effects of coding and medium access control. These results show that always using a simple multihop message relay strategy is not always the best procedure.     

无线网络能效的优化与评估

文章从能效测度入手,对已有的无线网络能效测度评价体系进行了讨论,并提出以碳排放量为标准和与网络负载相结合的能效测度模型。在能效测度模型的基础上,文章提出减少设备使用、无线资源调度、节点协作等一系列无线网络能效优化方法,并建议在无线网络协议架构中加入能效监控和能效评估模块。文章还对无线网络能效优化和评估方法中存在的技术挑战进行了展望。     

无线传感网络量化及能量优化策略

由于无线传感网络(WSN)存在能量和带宽的限制,在网络中直接传送模拟信号受到了极大地制约,因此对模拟信号量化是节省网络能量和保证有效带宽的重要手段。为此,该文以融合中心的重构绝对均值误差最小为原则,设计一种网络量化及能量优化方法。首先,针对单传感器,在能量固定的情况下推导了最优量化位数及在量化位数固定的情况下推导了最优能量分配。其次,在单传感器的基础上,进一步推导多传感器情况下最优量化位数及最优能量分配。以上两种情况都考虑了传感器测量噪声及信道衰落损耗。最后,通过数值仿真方法验证了文中所提方法的正确性,并将其与等能量分配进行了比较,获得了较好的效果。

     

基于能效优化的WSNs多径流量分配路由算法

该文针对传感器节点能量受限的特点建立能效优化模型,该模型兼顾网络传输能耗和能耗均衡特性,以最大化网络节点总剩余能量和最小化剩余能量的方差为目标,通过合理分配多条路径的流量来优化网络能效。利用权衡评价函数实现了模型的求解,进而提出一种多径流量分配路由(MFAR)算法。仿真实验表明,该算法能够合理配置各路径流量,显著提高网络能量效率,达到在降低网络能耗的同时保证能耗分布均衡的目标。     

Distributed Energy Optimization for Target Tracking in Wireless Sensor Networks

Energy constraint is an important issue in wireless sensor networks. This paper proposes a distributed energy optimization method for target tracking applications. Sensor nodes are clustered by maximum entropy clustering. Then, the sensing field is divided for parallel sensor deployment optimization. For each cluster, the coverage and energy metrics are calculated by grid exclusion algorithm and Dijkstra's algorithm, respectively. Cluster heads perform parallel particle swarm optimization to maximize the coverage metric and minimize the energy metric. Particle filter is improved by combining the radial basis function network, which constructs the process model. Thus, the target position is predicted by the improved particle filter. Dynamic awakening and optimal sensing scheme are then discussed in dynamic energy management mechanism. A group of sensor nodes which are located in the vicinity of the target will be awakened up and have the opportunity to report their data. The selection of sensor node is optimized considering sensing accuracy and energy consumption. Experimental results verify that energy efficiency of wireless sensor network is enhanced by parallel particle swarm optimization, dynamic awakening approach, and sensor node selection.     

面向能耗控制的无线传感器网络节点协议优化

能量受限是无线传感器网络一个显著的特征。对网络进行能耗优化并延长网络生命周期是无线传感器网络研究的重点。提出了面向能耗控制的无线传感器网络节点协议优化方法。针对网络中数据发送所占较大的能耗比重,通过对协议优化,对发送功率的参数设置方法进行改进,改变以往发射功率的固定参数设置法,通过终端节点之间的距离动态调整发送功率的方法,以达到节省能耗并延长网络生命周期的目的。仿真和实验结果表明,改进后的发射功率动态参数设置法较改进之前的固定参数设置方法能更多地节约网络能耗。     

Energy Efficiency Routing with Node Compromised Resistance in Wireless Sensor Networks

For the energy limited wireless sensor networks, the critical problem is how to achieve the energy efficiency. Many attackers can consume the limited network energy, by the method of capturing some legal nodes then control them to start DoS and flooding attack, which is difficult to be detected by only the classic cryptography based techniques with common routing protocols in wireless sensor networks (WSNs). We argue that under the condition of attacking, existing routing schemes are low energy-efficient and vulnerable to inside attack due to their deterministic nature. To avoid the energy consumption caused by the inside attack initiated by the malicious nodes, this paper proposes a novel energy efficiency routing with node compromised resistance (EENC) based on Ant Colony Optimization. Under our design, each node computes the trust value of its 1-hop neighbors based on their multiple behavior attributes evaluation and builds a trust management by the trust value. By this way, sensor nodes act as router to achieve dynamic and adaptive routing, where the node can select much energy efficiency and faithful forwarding node from its neighbors according to their remaining energy and trust values in the next process of data collection. Simulation results indicate that the established routing can bypass most compromised nodes in the transmission path and EENC has high performance in energy efficiency, which can prolong the network lifetime.     

Variable Bit Rate Flow Routing in Wireless Sensor Networks

Since energy constraint is a fundamental issue for wireless sensor networks, network lifetime performance has become a key performance metric for such networks. In this paper, we consider a two-tier wireless sensor network and focus on the flow routing problem for the upper tier aggregation and forwarding nodes (AFNs). Specifically, we are interested in how to perform flow routing among the nodes when the bit rate from each source node is time-varying. We present an algorithm that can be used to construct a flow routing solution with the following properties: (1) If the average rate from each source node is known a priori, then flow routing solution obtained via such algorithm is optimal and offers provably maximum network lifetime performance; (2) If the average rate of each source node is unknown but is within a fraction (epsiv) of an estimated rate value, then network lifetime by the proposed flow routing solution is within 2epsiv/1-epsiv from the optimum. These results fill in an important gap in theoretical foundation for flow routing in energy-constrained sensor networks.     

无线传感器网络中增加协作传输及其能量效率研究

该文研究了无线传感器网络中增加协作传输及其能量效率,解决了何时协作和协作的能效两个关键问题。导出了直接传输与协作传输的能效表达式,讨论了主要参数对协作传输性能的影响。仿真结果表明：当通信距离大于门限距离时,增加协作传输的能效优于直接传输的能效;通过优化所选中继节点的位置或调制阶数可以提高能效。     

无线传感器网络中协作ARQ协议能量效率分析及优化

文章研究了无线传感器网络中协作自动请求重传（Cooperative Automatic Repeat Request, CARQ）协议的能量效率及其优化问题。定义协议的能量效率为单位能耗所支持的分组成功传输的个数,导出了CARQ协议和传统ARQ协议的能量效率表达式以及CARQ协议相对ARQ协议的能效增益表达式,依此对两协议的能量效率进行了仿真研究,发现协作节点的位置对协议的能量效率有重要影响,当通信距离大于“门限距离”时,CARQ协议的能量效率才高于传统ARQ协议能效;进而提出了一种离散优化算法,通过优化调制水平,大大提高了CARQ协议的能效及能效增益。      

一维无线传感器网络分簇通信方案能量效率研究

为了提高无线传感器网络的能量有效性,该文在分析基于分簇的传统方案和协作分集数据传输方案的能量效率基础上,提出了一维传感器网络分簇多用户分集数据传送方案(CMDDTS)。理论分析表明能量开销依赖于数据融合比、簇内通信的发送功率、簇间通信的接收功率以及电路消耗的功率和簇内传感器的数目,仿真结果验证了所提方案的能量效率优于传统方案和协作分集数据传送方案。     

Joint Optimization of Power,Packet Forwarding and Reliability in MIMO Wireless Sensor Networks

In this paper, we study the reliable packet forwarding in Wireless Sensor Networks (WSNs) with the multiple-input multiple-output (MIMO) and orthogonal space time block codes (OSTBC) techniques. The objective is to propose a cross-layer optimized forwarding scheme to maximize the Successful Transmission Rate (STR) while satisfying the given end-to-end power consumption constraint. The channel coding, power allocation, and route planning are jointly considered to significantly improve the transmission quality in terms of STR. The joint optimization design is formulated as a global deterministic optimization and also a local stochastic optimization issues. It is found that the stochastic optimization approach can effectively model, analyze, and solve the routing problem. In order to substantially reduce the implementation complication of the global optimization, we propose a low-complexity distributed scheme. The determination of relaying nodes and power budgets are decoupled, i.e. performing route planning and power allocation separately. We have shown that the result in the distributed scheme is able to provide sufficiently accurate predication of the global optimization. In addition, the proposed scheme can clearly reduce the Symbol Error Rate (SER) and achieve higher STR compared with two existing energy-efficient routing protocols, in which no joint design is considered.     

Energy Efficient Routing Technique for Wireless Sensor Networks Using Ant-Colony Optimization

Wireless sensor networks (WSN) consists of numerous number of nodes fitted with energy reserves to collect large amount of data from the environment on which it is deployed. Energy conservation has huge importance in wsn since it is virtually impossible to recharge the nodes in their remote deployment. Forwarding the collected data from nodes to the base station requires considerable amount of energy. Hence efficient routing protocols should be used in forwarding the data to the base station in order to minimize the energy consumption thereby increasing the life-time of the network. In this proposed routing protocol, we consider a hierarchical routing architecture in which nodes in the outer-level forwards data to the inner-level nodes. Here we optimized the routing path using ant-colonies where data moves along minimal congested path. Further, when ant-colony optimization is used, certain cluster-head nodes may get overloaded with data forwarding resulting in early death due to lack of energy. To overcome this anomaly, we estimated the amount of data a neighboring Cluster-head can forward based on their residual energy. We compared the energy consumption results of this proposed Routing using Ant Colony Optimization (RACO) with other existing clustering protocols and found that this system conserves more energy thereby increasing lifetime of the network.

     

基于能量优化的无线传感器网络安全路由算法

针对无线传感器网络路由面临安全威胁和节点能量有限的不足,提出一种基于能量优化的安全路由算法(EOSR).该算法把优化能量、提高路由安全性和缩短传输时延同时作为设计目标,采用多目标决策,在保证安全性和快速传输的同时,让能量储备较多的节点承担较多的数据转发任务,可获得最优路由和延长网络生命期.通过预置公私密钥对,有效地提高了路由的安全性.给出了该算法中路由发现、路由选择和路由删除的具体步骤,通过仿真实验证明该算法的有效性.     

Achieving Energy Efficiency in Wireless Sensor Networks Using Dynamic Channel Polling and Packet Concatenation

There has been a significant interest of re-searchers to combine different schemes focused on op-timizing energy performance while developing a MAC protocol for...     

Energy Efficiency Optimization for Wireless Body Area Networks Under 802.15.6 Standard

Wireless Personal Communications - With the attractive applications in e-Health, a booming interest is granted to wireless body area network (WBAN). Through WBAN, healthcare professionals can...