Multi-constraint multi-objective QoS aware routing heuristics for query driven sensor networks using fuzzy soft sets

In this paper, a fuzzy based distributed power aware routing scheme considering both energy and bandwidth constraints, especially for query driven applications in the asynchronous duty-cycled wireless sensor networks are devised. The proposed multi-constraint, multi-objective routing optimization approach under strict resource constraints guarantees reliability and fast data delivery along with efficient power management in spite of unreliable wireless links and limited power supply. In query driven applications, the request from the sink to the individual sensor node will be a broadcast message, whereas the individual sensor nodes replies back to sink as unicast messages. In the proposed work, the fuzzy approach and “A Star” algorithm are utilized for satisfying energy and bandwidth constraints to route the broadcast messages of the sink while querying all the sensor nodes in the network. Every node will be provided with a guidance list, which is used to decide the next best neighbor node with good route quality for forwarding the received multi-hop broadcast messages. The route quality of the every node is estimated with fuzzy rules based on the network parameters such as maximum remaining energy, minimum traffic load and better link quality to increase the network lifetime. The provision of overhearing the broadcast messages and acknowledgements within the transmission range minimizes the effort to search for the active time of nodes while routing the broadcast messages with asynchronous scheduling. Further, in the proposed work only the time slot of its nearest neighbor relay node (to which packets are to be forwarded) is learnt to reduce the number of message transmissions in the network. For the unicast message replies, the fuzzy membership function is modified and devised based on the routing metrics such as higher residual energy, minimum traffic loads and minimum hop count under energy and bandwidth constraints. Also, the multi-hop heuristic routing algorithm called Nearest Neighbor Tree is effectively used to reduce the number of neighbors in the guidance list that are elected for forwarding. This helps to increase the individual sensor node’s lifetime, thereby maximizes the network lifetime and guarantees increased network throughput. The simulation results show that the proposed technique reduces repeated transmissions, decreases the number of transmissions, shortens the active time of the sensor nodes and increases the network lifetime for query driven sensor network applications invariant to total the number of sensor nodes and sinks in the network. The proposed algorithm is tested in a small test bed of sensor network with ten nodes that monitors the room temperature.     

一种新的传感器网络能量有效路由算法

基于对LEACH、PEGASIS经典分簇算法的研究,提出一种基于分簇的传感器网络能量有效的路由算法NCEER。NCEER每隔20轮进行一次簇重构,簇内利用贪心算法形成短链,选取剩余能量最大者为簇首。然后,以基站为树根,各簇首节点根据跳数和能量级别建立层次路由树。最后,各簇首通过最优路径将采集到的数据发送到基站。该算法减少了簇重构的开销,建立了一条负载均衡的簇内路由、能量有效的簇间路由,减少了数据的传输时延。仿真结果表明,该算法的性能优于LEACH和PEGASIS。     

An efficient void resolution method for geographic routing in wireless sensor networks

Geographic routing is an attractive choice for routing data in wireless sensor networks because of lightweight and scalable characteristics. Most geographic routing approaches combine a greedy forwarding scheme and a void resolution method to detour a void area that has no active sensor. The previous solutions, including the well-known GPSR protocol, commonly use the right-hand rule for void resolution. However, the detour path produced by the right-hand rule is not energy-efficient in many cases. In this paper, we propose a new void resolution method, called void resolution-forwarding, which can overcome voids in the sensor network energy-efficiently. It exploits the quadrant-level right-hand rule to select the next hop for the current node during circumventing a void area. We show by experiments that the proposed method is efficient and scalable with respect to the various voids and network density and that it outperforms the GPSR protocol significantly.     

Optimized query routing trees for wireless sensor networks

In order to process continuous queries over Wireless Sensor Networks (WSNs), sensors are typically organized in a Query Routing Tree (denoted as T) that provides each sensor with a path over which query results can be transmitted to the querying node. We found that current methods deployed in predominant data acquisition systems construct T in a sub-optimal manner which leads to significant waste of energy. In particular, since T is constructed in an ad hoc manner there is no guarantee that a given query workload will be distributed equally among all sensors. That leads to data collisions which represent a major source of energy waste. Additionally, current methods only provide a topological-based method, rather than a query-based method, to define the interval during which a sensing device should enable its transceiver in order to collect the query results from its children. We found that this imposes an order of magnitude increase in energy consumption.     

综合覆盖调度的无线传感器网络跨层路由研究

无线传感器网络由大量微小的传感器节点构成,各节点协作完成环境现象的分布式感知。覆盖控制作为无线传感器网络中的一个基本问题,反映了网络所能提供的"感知"服务质量。基于现有的集中式计算覆盖集合算法MLMC,通过改变计算覆盖集合条件,结合能量不均衡消耗的I-RDDD协议,观察了网络生存期的变化。仿真结果和分析表明,基于能量考虑和单组覆盖集合轮询的工作方式能获得更长的网络生存期。     

一种无线传感器网络路由协议的研究与改进

无线传感器网络由许多具有低功率无线收发装置的传感器节点组成,能够有效地感知、采集和处理网络覆盖区域中的相关信息,并发送给远处的基站进一步处理。由于传感器节点能量有限,路由协议必须尽可能地减少能量消耗,延长网络生命周期。对经典的LEACH路由协议进行研究,并针对簇头节点和基站的通信方式提出改进,用M atlab平台下对LEACH算法和改进后的算法进行仿真分析,结果显示:改进后的算法在延长网络生命周期和减少能量消耗上比LEACH算法有了很大改善。     

无线传感器网络中的能效优化路由算法*

根据无线传感器网络节点能量消耗和网络生存周期的特点,通过建立动态规划能量优化模型,在路由总能耗满足能量阈值约束条件下,均衡消耗网络中各节点能量,在此基础上提出一种适合无线传感器网络的动态规划路由算法。仿真结果表明,提出的路由算法能充分地利用有限的能量资源,较大地延长网络生存周期并降低节点的平均能耗。     

无线传感器网络优化路由树构造算法

针对无线传感器网络使用洪泛建立路由树时,传统的碰撞退避机制和路由树构造策略容易造成消息剧烈碰撞、路由容易瘫痪和建立非优化路由树等问题,提出了无线传感器网络优化路由树构造算法。算法定义路由有效期、父节点优先级队列,并结合跨层设计思想,修改MAC退避算法,提出交叉退避窗口策略,并经仿真实验证明能够有效地构造出较优的路由树。     

无线传感器网络中最大化网络寿命的数据聚合路由

针对数据聚合无线传感器网络寿命最大化问题,分析了网络流量和节点能耗,提出了数据聚合路由问题的网络流量模型,并将网络最大寿命与流量模型相结合设计了一组混合整数规划代价函数.采用对偶分解的方法,获得了近似最优的中继传输速率和路由.仿真实验表明,该算法能有效减少数据通信量,均衡各个节点的能量消耗,延长网络寿命.     

传感器网络中基于角度的数据汇集多径路由算法研究

传感器网络具有严格的能量限制,冗余的低速数据流和多对一的通信方式等不同于传统Ad Hoc网络的特点,针对这些特点,提出一种新的基于角度的数据汇集多径路由算法。算法结合数据汇集技术和基于角度的多径路由方法进行数据转发。理论分析和模拟实验表明,新算法在很大程度上节省了节点能量,具有良好的路由性能。     

无线传感器网络分层路由协议能量有效性研究

对无线传感器网络的路由协议进行了分析研究,重点对LEACH协议进行了深入的探讨,发现LEACH协议的随机选择簇头的方案没有做到最优,因为它在选择过程中没有考虑节点剩余能量,且簇头节点在与基站通信时采用单跳通信,针对LEACH存在的不足,进行了改进,提出了EECH协议。通过NS仿真比较表明,改进的协议有效地延长了网络的生存时间,提高了网络的效率。     

Energy-efficient distributed clustering in wireless sensor networks

The deployment of wireless sensor networks in many application areas requires self-organization of the network nodes into clusters. Clustering is a network management technique, since it creates a hierarchical structure over a flat network. Quite a lot of node clustering techniques have appeared in the literature, and roughly fall into two families: those based on the construction of a dominating set and those which are based solely on energy considerations. The former family suffers from the fact that only a small subset of the network nodes are responsible for relaying the messages, and thus cause rapid consumption of the energy of these nodes. The latter family uses the residual energy of each node in order to decide about whether it will elect itself as a leader of a cluster or not. This family’s methods ignore topological features of the nodes and are used in combination with the methods of the former family. We propose an energy-efficient distributed clustering protocol for wireless sensor networks, based on a metric for characterizing the significance of a node, w.r.t. its contribution in relaying messages. The protocol achieves small communication complexity and linear computation complexity. Experimental results attest that the protocol improves network longevity.     

拥塞敏感的无线传感器网络路由算法

如何延长无线传感器网络的生命周期是一个重要的挑战.提出了一种新的拥塞敏感的路由算法,该算法充分考虑了路由选择过程中的数据负载与邻节点的缓存、信道竞争等状态的关系,每个节点以此计算一个能反映本地拥塞状态的权值,节点选择权值最高的下游节点作为下一跳来平衡下游节点的能耗和数据负载,同时降低下游节点的拥塞可能性.模拟实验表明:...     

无线传感器网络聚类改进层次路由协议

无线传感器网络（WSN）是一种全新的信息获取和处理技术,通常被部署在恶劣的环境中。因此能源供应一直是WSN研究的一个重要问题。层次路由协议能够有效地延长网络生存时间,已经成为无线传感器网络研究中的热点。提出了一个新的层次路由协议MHLAH,结合了LEACH和HeeD的优点,它能够合理地分布簇头节点,采用多跳的路由传输协议,延长网络的生存时间。仿真实验结果表明,与传统的LEACH和HeeD协议相比,MHLAH协议有效地平衡了网络中传感器节点的能量消耗,延长了无线传感器网络的生存周期。     

Maximizing lifetime in wireless sensor networks with multiple sensor families

Wireless sensor networks are generally composed of a large number of hardware devices of the same type, deployed over a region of interest in order to perform a monitoring activity on a set of target points. Nowadays, several different types of sensor devices exist, which are able to monitor different aspects of the region of interest (including sound, vibrations, proximity, chemical contaminants, among others) and may be deployed together in a heterogeneous network. In this work, we face the problem of maximizing the amount of time during which such a network can remain operational, while maintaining at all times a minimum coverage guarantee for all the different sensor types. Some global regularity conditions in order to guarantee a fair level of coverage for each sensor type to each target are also taken into account in a second variant of the proposed problem. For both problem variants we developed an exact approach, which is based on a column generation algorithm whose subproblem is either solved heuristically by means of a genetic algorithm or optimally by an appropriate ILP formulation. In our computational tests the proposed genetic algorithm is shown to be able to dramatically speed up the procedure, enabling the resolution of large-scale instances within reasonable computational times.     

The balance of routing energy consumption in wireless sensor networks

In order to tackle the energy hole problem of sensor networks, the non-uniform node deployment strategy was presented recently. For achieving the expected performance of this deployment method, nodes need to transmit data to the sink node by selecting a node in the adjacent inner region decided by the deployment strategy. Since nodes near the outer boundary of a region will be covered by more nodes, the random selection method will cause the unbalanced energy consumption problem. In this paper, this issue is rigorously studied and a region constraint selection scheme is proposed based on the analytical result. By combining the region constraint strategy and the maximum energy node selection mechanism, a hybrid scheme is presented. Numerical and simulation results show that the region constraint scheme can achieve acceptable performance improvements over the random scheme and the hybrid mechanism also gains better performance in comparison to the maximum energy node selection scheme.     

MIMO多跳簇结构无线传感器网络的路由算法及其能耗研究

由于分层簇结构协议能有效地解决无线传感器网络的能耗问题,文中针对基于MIMO的多跳簇结构无线传感器网络,提出了一种基于距离矢量的改进路由算法,同时在J-sim仿真平台上进行了相应的仿真,从而证明了改进路由算法的有效性。另外也证明了该系统的节点能耗特点和MIMO技术对降低系统能耗所具有的一定作用,但在低信噪比时其效果不明显。     

On the efficiency of routing in sensor networks

In sensor networks, a key efficiency measure for routing protocols is the stretch of the computed paths, where the stretch is the ratio of the path length and the Euclidean distance covered. In the literature, many protocols have been evaluated via extensive simulations, and often come without any theoretical guarantees. For those whose performances are theoretically guaranteed there is an important gap between the theoretical predictions and the experimental results. The contribution of this paper is twofold. First, we give theoretical results that explain the observed efficiency of many of the algorithms proposed in the literature. Second, we propose ROAM2, a deterministic routing protocol, that requires a single bit of memory at each node and that ensures, with high probability (depending on the node distribution), that the paths have a constant stretch.     

基于模拟退火的无线传感器网络最大生命期路由*

将节点功率控制与数据聚合有机结合,为进一步降低网络能耗提供了可能,但是也给路由算法的设计带来了新的挑战。为此,针对WSNs中结合数据聚合的节能数据传递方式进行了研究,提出了一种新的最大化网络生命期的路由算法。该算法采用模拟退火算法最优化数据聚合点的选择,均衡节点能耗,最大化网络生命期。仿真结果表明该算法性能明显优于现有算法,达到了提高网络生命期的目的。     

无线多媒体传感器网络能量敏感多路径路由

针对节点能量分布不均匀的无线多媒体传感器网络中大数据量传输问题,提出一种无线多媒体传感器网络能量敏感多路径路由算法EACM。该算法通过平衡路由节点间剩余能量差异,调节多路径聚集程度来均衡网络能耗减少数据包在路径上的延迟。仿真结果表明EACM算法能有效地延长网络生存期,减少数据包在路径上的时延。