Energy efficient all-to-all broadcast in all-wireless networks

All-to-all broadcast is a communication pattern in which every node initiates a broadcast. In this paper, we investigate the problem of building a unique cast tree of minimum total energy, which we call Minimum Unique Cast (MUC) tree, to be used for all-to-all broadcast. The MUC tree is unoriented and unrooted. We study three known heuristics for the minimum-energy broadcast problem: the Broadcast Incremental Power (BIP) algorithm, the Wireless Multicast Advantage-conforming Minimum Spanning Tree (WMA-conforming MST) algorithm, and the Iterative Maximum-Branch Minimization (IMBM) algorithm. Experimental results conducted on various types of networks are reported. We show that neither of these methods is best overall for building all-to-all broadcast trees.     

无线传感器网络中一种能量有效的分簇算法

无线传感器网络的一个重要特点是能量受限,必须设计能量效率高的路由算法以延长网络生存时间.基于经典的低能耗自适应分簇算法(LEACH),提出了一种能量有效分簇算法(EECA).它由基站根据节点剩余能量和簇首之间的距离选择簇首,从而使簇的分布更均匀,簇首的负载更均衡,提高了能量的利用率,延长了网络生存时间.仿真结果表明:EECA算法与LEACH算法相比,网络的生存时间可以延长约37%,能量利用率提高近16%.     

无线传感网中能量有效的多sink重定位算法

在无线传感器网络中只部署一个静止不动的sink节点会带来诸多弊端,如网络能耗不均衡、生存期短、丢包率大等。为解决上述问题,提出一种新的且容易操作的多sink重定位算法EEMSR,即在整个网络生存期的时间内,多个sink节点能以逐步逼近和协作的方式移动至各自的最优位置。经仿真验证,该算法能极大提升网络生存期和数据包交付率等网络性能。     

Energy efficient spatial TDMA scheduling in wireless networks

It is now widely acknowledged that packet scheduling can have a significant impact in the overall energy consumption levels of wireless networks. In this paper, a low complexity algorithm based on Local Search (LS) is proposed for spatial-TDMA networks such that the power consumption is minimized without sacrificing throughput or delay. More specifically, given a schedule of a pre-defined frame length we search for a low power schedule with the same length. Numerical investigations reveal that the proposed heuristic has a competitive performance and achieves considerable gains when compared to previously proposed scheduling techniques. Despite the centralized nature of the algorithm, its low complexity and high accuracy make it a very competitive solution for the power efficient scheduling problem.     

Sparse communication networks and efficient routing in the plane

Traditional approaches to network design separate the issues of designing the network itself and designing its management and control subsystems. This paper proposes an approach termed routing-oriented network design, which is based on designing the network topology and its routing scheme together, attempting to optimize some of the relevant parameters of both simultaneously. This approach is explored by considering the design of communication networks supporting efficient routing in the special case of points located in the Euclidean plane. The desirable network parameters considered include low degree and small number of communication links. The desirable routing parameters considered include small routing tables, small number of hops and low routing stretch. Two rather different schemes are presented, one based on direct navigation in the plane and the other based on efficient hierarchical tree covers. On a collection of n sites with diameter D, these methods yield networks with a total of communication links and some bounds on the degree, coupled with routing schemes with constant routing stretch, memory bits per vertex and routes with at most or hops. Received: October 2000 / Accepted: May 2001     

New efficient communication services for ISO 11898 networks

Fieldbus networks should be able to support several kinds of data exchanges, which are characterised by very different requirements. The most popular solutions available today have been designed with some sets of specific needs in mind and usually, they are not always able to satisfy, equally well, the different kinds of communications which can be found in the industrial and process control environments. Often, system integrators and designers are forced to trade responsiveness (needed in event-driven systems) for efficiency (mostly required in systems which are based on the periodic polling of the controlled devices), or vice-versa. In this paper, a modification of the basic ISO 11898 protocol is described which supports some new transmission services that significantly increase the communication efficiency for periodic exchanges of process data and for messages devoted to high level functions. These services maintain a good degree of compatibility with the original protocol and do not affect its very good responsiveness and flexibility.     

无线传感器网络中一种能量有效k度覆盖算法

覆盖率是衡量无线传感器网络性能的重要指标之一。在对目标节点进行k覆盖的过程中,会出现大量数据冗余迫使网络出现拥塞的现象,导致网络通信能力和覆盖能力降低、网络能量快速消耗等问题。为此,提出了一种能量有效[k]度覆盖算法（Energy Efficient k_degree Coverage Algorithm,EEKCA）。该算法利用节点之间的位置关系构造出覆盖网络模型,通过分析网络模型给出监测区域内节点覆盖期望值及对整个监测区域覆盖所需最少节点数量的求解过程;在能耗方面,给出了工作节点和邻居节点之间的能量转换函数比例关系,利用函数比例关系完成低能量节点的调度,进而达到全网能量平衡,优化了网络资源。最后,仿真实验结果表明,该算法不仅可以提高网络覆盖质量,还可有效抑制节点能量快速消耗,从而延长网络生存周期。     

Energy efficient multicast routing in ad hoc wireless networks

In this paper, we discuss the energy efficient multicast problem in ad hoc wireless networks. Each node in the network is assumed to have a fixed level of transmission power. The problem of our concern is: given an ad hoc wireless network and a multicast request, how to find a multicast tree such that the total energy cost of the multicast tree is minimized. We first prove this problem is NP-hard and it is unlikely to have an approximation algorithm with a constant performance ratio of the number of nodes in the network. We then propose an algorithm based on the directed Steiner tree method that has a theoretically guaranteed approximation performance ratio. We also propose two efficient heuristics, node-join-tree (NJT) and tree-join-tree (TJT) algorithms. The NJT algorithm can be easily implemented in a distributed fashion. Extensive simulations have been conducted to compare with other methods and the results have shown significant improvement on energy efficiency of the proposed algorithms.     

能量有效的无线传感器网络层次型路由协议

为改善LEACH中节点能耗不均而过早失效的情况,提出了一种能量有效的无线传感器网络层次型路由协议EEHRP,它采用一种智能延迟策略选取簇头,尽可能使得剩余能量越高的节点时延越小,它们能够先于周围剩余能量较低的节点发送簇头通告。在路由算法中引入了网关节点,能有效避免簇头远距离传送数据造成的能耗过多。仿真表明,EEHRP可使节点的能量消耗更均匀,有效地延长了网络生存时间。     

Energy efficient smart-relay-based cooperative MAC for wireless networks

An enormous number of papers investigated wireless cooperative networks over the last few years. Almost all have shown that cooperative transmission improves network performance significantly. However, none of these studies have considered the hidden and exposed terminal problems which appear due to the cooperative mechanisms of relay selection and transmission processes. The hidden terminal problems increase collisions and the exposed terminal problems increase bandwidth wastage, degrading the expected performance of cooperative networks. This paper addresses these problems of traditional wireless cooperative networks. We also propose a protocol called smart-relay-based-cooperative (SRcoop) MAC to optimally reduce the impacts of hidden and exposed terminal problems. We also illustrate an efficient relay selection mechanism that uses a back-up relay to increase transmission reliability. Our innovative model significantly improves the network throughput, end-to-end delay and energy efficiency over traditional cooperative MAC, 2rcMAC, LC-MAC, C-ARQ and Adere et al. protocols.     

传感器网络中一种能量有效的簇头选择机制

针对LEACH算法存在簇头节点个数和位置分布不稳定的现象,在簇头节点的选择过程中,充分考虑簇头节点的残余能量因素,通过设定簇头的能量阈值防止低能量的节点成为簇头。改进的算法解决了LEACH簇头选择算法存在的簇头节点可能能量不足的问题,从而达到均衡网络能量消耗,延长网络寿命的目的。仿真实验采用改进算法的网络与采用LEACH、DCHS以及LEACH-H算法的网络的比较结果,说明改进算法具有更好的收敛性,实验数据表明该算法能最大限度地均衡利用网络的能量,延长无线传感器网络的寿命。     

Energy efficient algorithms for enhancing lifetime in wireless sensor networks

Microsystem Technologies - A crucial research problem in the field of wireless sensor network is to maximize its lifetime. One approach to solve this problem is to group the nodes in clusters or...     

Energy efficient approximate self-adaptive data collection in wireless sensor networks

To extend the lifetime of wireless sensor networks, reducing and balancing energy consumptions are main concerns in data collection due to the power constrains of the sensor nodes. Unfortunately, the existing data collection schemesmainly focus on energy saving but overlook balancing the energy consumption of the sensor nodes. In addition, most of them assume that each sensor has a global knowledge about the network topology. However, in many real applications, such a global knowledge is not desired due to the dynamic features of the wireless sensor network. In this paper, we propose an approximate self-adaptive data collection technique (ASA), to approximately collect data in a distributed wireless sensor network. ASA investigates the spatial correlations between sensors to provide an energyefficient and balanced route to the sink, while each sensor does not know any global knowledge on the network.We also show that ASA is robust to failures. Our experimental results demonstrate that ASA can provide significant communication (and hence energy) savings and equal energy consumption of the sensor nodes.     

无线传感器网络中能量最优传输半径调整

在无线传感器网络中,为有效节省能量的消耗,一般将多跳路由上的冗余节点设置成休眠状态.针对节点均匀分布的线性网络,在候选路由节点随机确定,且各节点可有不同传输半径的情况下,利用动态规划算法选择合适的活动路由节点及其传输半径,达到总体最优能量消耗.数值结果证实算法的有效性.     

Distributed control of multi-agent systems over unknown communication networks using extremum seeking

In this paper, the solution of large-scale real-time optimization problems of multi-agent systems (MAS) is tackled in a distributed and a cooperative manner without the requirement of exact knowledge of network connectivity. Each agent in the communication network measures a local disagreement cost in addition to its local cost. The agents must work collaboratively to ensure that the system's unknown overall cost (i.e., the sum of the local cost of all the agents) is minimized. In order to minimize this cost, the local disagreement cost of all the agents must first be minimized. This minimization requires the solution of a consensus estimation problem and ensures that the agents reach agreement on their decision variables. To address this challenging problem, a distributed proportional-integral extremum seeking control technique is proposed, one that solves both problems simultaneously. Three simulation examples are included, they demonstrate the effectiveness and robustness of the proposed technique.     

一种能量高效的Ad hoc无线网络广播算法

广播在Ad hoc无线网络中有着广泛的应用,而Ad hoc网络节点资源、网络资源严重受限,广播引起的广播风暴问题加剧了资源的消耗。提出了一种能量高效的无冲突的广播策略,该策略利用所有两跳邻节点的剩余能量和度等信息选择前向转播节点,并将前向转播节点分为相互不干扰的独立子集,统一为独立子集设置退避时间,避免冲突的发生。该策略平衡了网络中节点的能量消费、延长了网络寿命,同时减少了广播延迟和转播冗余,确保了广播的可达性。仿真结果也表明提高了广播的效率。     

能量高效的无线传感器网络可靠转发协议

为了在链路质量不可靠的无线传感器网络(WSN)中提高数据传输的能效,提出一种基于模糊综合评判的WSN可靠转发协议FiaRD。FiaRD利用WSN节点部署稠密的特点和无线信道的广播特性,使传输路径上相互邻近的节点自发组织成多跳簇,进而通过各个簇成员间的协作转发来提高数据传输的可靠性和能效。每跳簇是通过分布式“模糊综合评判”与“回退竞争”相结合的机制动态选出的,此机制在对多个候选簇进行综合评判的基础上,能从中筛选出少数较优的来参与下一跳的竞争,从而降低簇间的碰撞概率,提高转发效率。仿真结果表明,FiaRD在保证可靠传输的同时,具有较低的传输能耗。     

A message combining approach for efficient array redistribution in non-all-to-all communication networks

The Array redistribution problem is the heart of a number of applications in parallel computing. This paper presents a message combining approach for scheduling runtime array redistribution of one-dimensional arrays. The important contribution of the proposed scheme is that it eliminates the need for local data reorganization, as noted by Sundar in 2001; the blocks destined for each processor are combined in a series of messages exchanged between neighbouring nodes, so that the receiving processors do not need to reorganize the incoming data blocks before storing them to memory locations. Local data reorganization is of great importance, especially in networks where there is no direct communication between all nodes (like tori, meshes, and trees). Thus, a block must travel through a number of relays before reaching the target processor. This requires a higher number of messages generated, therefore, a higher number of data permutations within the memory of each target processor should be made to assure correct data order. The strategy is based on a relation between groups of communicating processor pairs called superclasses.     

无线传感器网络中数据可靠传输的节能路由算法

提出了一种保证数据可靠传输的节能算法。该算法根据各节点的最多剩余能量（MRE）在感知区域内建立以sink节点为根的源路由树,以剩余能量少于ε的节点作为叶子节点。若数据传输过程中有中间节点死亡,则调用可靠路由算法;并利用ARQ机制检测是否有数据包丢失,采用hop by hop机制进行重传。     

An efficient link allocation algorithm for survivable ATM-based personal communication networks

The integration of the issue of survivability of wireless networks in the design process of the backbone network is addressed in this paper. The effectiveness of this integration plays a critical role in the success of the wireless network and the satisfaction of its mobile users. In this paper, we consider the design problem of allocating the backbone links in ATM-based personal communication networks (PCNs) that are survivable under single backbone link failures. Survivability is achieved by selecting two link-disjoint routes in the backbone network between every pair of ATM switches. We also take the novel approach of not only minimizing the diameter of the network as a primary objective but also minimizing the total length of the network as a secondary objective. We propose a new heuristic algorithm to optimize the design of the network based on both objectives. We report the results of an extensive simulation study that show that our algorithm generates backbone networks that can withstand single link failures, have shorter average diameters and smaller total lengths and achieve a higher percentage of admitted calls under a mobile environment.