Energy-aware routing for delay-sensitive underwater wireless sensor networks

The energy reduction is a challenging problem in the applications of underwater wireless sensor networks （UWSNs）. The embedded battery is difficult to be replaced and it has an upper bound on its lifetime. Multihop relay is a popular method to reduce energy consumption in data transmission. The energy minimum path from source to destination in the sensor networks can be obtained through the shortest path algorithm. However, because of the node mobility, the global path planning approach is not suitable for the routing in UWSNs. It calls for an energy-efficient routing protocol for the high dynamic UWSNs. In this paper, we propose the modified energy weight routing （MEWR） protocol to deal with the energy-efficient routing of delay- sensitive UWSNs. MEWR is a low flooding routing protocol. It can tolerate the node mobility in UWSNs and achieve a low end-to-end packet delay. MEWR can provide lower energy consumption than the existing low delay routing protocols through the dynamic sending power adjustment. The simulation results demonstrate the effectiveness of MEWR.     

Dynamic cluster head for lifetime efficiency in WSN

Saving energy and increasing network lifetime are significant challenges in wireless sensor networks （WSNs）. In this paper, we propose a mechanism to distribute the responsibility of cluster-heads among the wireless sensor nodes in the same cluster based on the ZigBee standard, which is the latest WSN standard. ZigBee supports ad hoc on-demand vector （AODV） and cluster-tree routing protocols in its routing layer. However, none of these protocols considers the energy level of the nodes in the network establishing process or in the data routing process. The cluster-tree routing protocol supports single or multi-cluster networks. However, each single cluster in the multi-cluster network has only one node acting as a cluster head. These cluster-heads are fixed in each cluster during the network lifetime. Consequently, using these cluster-heads will cause them to die quickly, and the entire linked nodes to these cluster-heads will be disconnected from the main network. Therefore, the proposed technique to distribute the role of the cluster head among the wireless sensor nodes in the same cluster is vital to increase the lifetime of the network. Our proposed technique is better in terms of performance than the original structure of these protocols. It has increased the lifetime of the wireless sensor nodes, and increased the lifetime of the WSN by around 50% of the original network lifetime.     

Scoped Bellman-Ford Geographic Routing for Large Dynamic Wireless Sensor Networks

Routing is a fundamental problem in wireless sensor networks. Most previous routing protocols are challenged when used in large dynamic networks as they suffer from either poor scalability or the void problem. In this paper,we propose a new geographic routing protocol,SBFR(Scoped Bellman-Ford Routing),for large dynamic wireless sensor networks. The basic idea is that each node keeps a view scope of the network by computing distance vectors using the distributed BellmanFord method,and maintains a cost for routing to the sink. When forwarding a packet,a node picks the node with minimum cost in its routing table as a temporary landmark. While achieving good scalability,it also solves the void problem in an efficient manner through the combination of Bellman-Ford routing and cost-based geographic routing. Analytical and simulation results show that SBFR outperforms other routing protocols not only because of its robustness and scalability but also its practicality and simplicity.     

节能无线传感网络系统设计

Wireless sensor networks have already enabled numerous embedded wireless applications such as military, environmental monitoring, intelligent building, etc. Because micro-sensor nodes are supposed to operate for months or even years with very limited battery power source, it is a challenge for researchers to obtain long operating hour without scarifying original system performances. In this paper, the energy consumption sources of the wireless sensor networks are firstly analyzed, with the digital processing and radio transceiver units being emphasized. Then, we introduce the design scheme of our energy-aware wireless sensor network (GAINS). In GAINS, techniques to conserve the energy are exploited including the energy optimization node, software and energy-efficient communication protocol. The design architecture of our ultra low power wireless sensor network (WO-LPP) is specially presented.     

An energy-aware broadcast scheme for directed diffusion in wireless sensor network

Broadcast is a common communication means in mobile ad hoc network or wireless sensor network. In directed diffusion protocol, broadcast is used to disseminate interest, discover routing path and repair the routing path. However, straightforward broadcast scheme （such as flooding） may result in serious broadcast storm problem, especially with respect to large densely deployed wireless sensor network. This paper compares the performances of several broadcast schemes combining with directed diffusion and proposes an energy-aware broadcast scheme adapting to directed diffusion. This scheme combines the advantages of distance-based and counter-based broadcast schemes and considers the remainder energy of sensor node. Simulation results show that the proposed scheme has the following advantages： （1） simple, efficient and scalable; （2） more energy-balancing than other schemes; （3） longer network lifetime than other schemes.     

HierTrack: an energy-efficient cluster-based target tracking system forwireless sensor networks

Target tracking is a typical and important application of wireless sensor networks(WSNs).Existing target tracking protocols focus mainly on energy efficiency,and little effort has been put into network management and real-time data routing,which are also very important issues for target tracking.In this paper,we propose a scalable cluster-based target tracking framework,namely the hierarchical prediction strategy(HPS),for energyefficient and real-time target tracking in large-scale WSNs.HPS organizes sensor nodes into clusters by using suitable clustering protocols which are beneficial for network management and data routing.As a target moves in the network,cluster heads predict the target trajectory using Kalman filter and selectively activate the next round of sensors in advance to keep on tracking the target.The estimated locations of the target are routed to the base station via the backbone composed of the cluster heads.A soft handoff algorithm is proposed in HPS to guarantee smooth tracking of the target when the target moves from one cluster to another.Under the framework of HPS,we design and implement an energy-efficient target tracking system,HierTrack,which consists of 36 sensor motes,a sink node,and a base station.Both simulation and experimental results show the efficiency of our system.     

Random Walk Routing in WSNs with Regular Topologies

Topology is one of the most important characteristics for any type of networks because it represents the network's inherent properties and has great impact on the performance of the network. For wireless sensor networks (WSN), a well-deployed regular topology can help save more energy than what a random topology can do. WSNs with regular topologies can prolong network lifetime as studied in many previous work. However, little work has been done in developing effective routing algorithms for WSNs with regular topologies, except routing along a shortest path with the knowledge of global location information of sensor nodes. In this paper, a new routing protocol based on random walk is proposed. It does not require global location information. It also achieves load balancing property inherently for WSNs which is difficult to achieve by other routing protocols. In the scenarios where the message required to be sent to the base station is in comparatively small size with the inquiry message among neighboring nodes, it is proved that the random walk routing protocol can guarantee high probability of successful transmission from the source to the base station with the same amount of energy consumption as the shortest path routing. Since in many applications of WSNs, sensor nodes often send only beep-like small messages to the base station to report their status, our proposed random walk routing is thus a viable scheme and can work very efficiently especially in these application scenarios. The random walk routing provides load balancing in the WSN as mentioned, however, the nodes near to the base station are inevitably under heavier burden than those far away from the base station. Therefore, a density-aware deployment scheme is further proposed to guarantee that the heavy-load nodes do not affect the network lifetime even if their energy is exhausted. The main idea is deploying sensors with different densities according to their distance to the base station. It will be shown in this paper that incorporating the random walk routing protocol with the density-aware deployment scheme can effectively prolong the network lifetime.     

Topology control for directed diffusion in wireless sensor networks

Due to severely constrained energy, storage capacity and computing power for nodes in wireless sensor network, the routing protocols have become a hot research topic. Directed diffusion is a communication paradigm for information dissemination in sensor networks based on data-centric routing. An energy efficient hybrid adaptive clustering for directed diffusion is presented in the paper. The main goal is to curb the interests flooding overhead by clustering. Hybrid of active and passive clustering creation is used to make tradeoff between maintenance cost and delay. The adaptive turning off the radio of redundant nodes and rotation of cluster heads is used to save energy. The ns-2 simulating results show that the protocol has good performances in energy consuming, delivery ratio and delay without leading to too much overhead comparing with existing directed diffusion protocols.     

Reliable energy-efficient routing with novel route update in wireless sensor networks

In this paper we introduce a novel energy-aware routing protocol REPU (reliable, efficient with path update), which provides reliability and energy efficiency in data delivery. REPU utilizes the residual energy available in the nodes and the received signal strength of the nodes to identify the best possible route to the destination. Reliability is achieved by selecting a number of intermediate nodes as waypoints and the route is divided into smaller segments by the waypoints. One distinct advantage of this model is that when a node on the route moves out or fails, instead of discarding the whole original route, only the two waypoint nodes of the broken segment are used to find a new path. REPU outperforms traditional schemes by establishing an energy-efficient path and also takes care of efficient route maintenance. Simulation results show that this routing scheme achieves much higher performance than the classical routing protocols, even in the presence of high node density, and overcomes simultaneous packet forwarding.     

A simple, least-time, and energy-efficient routing protocol with one-level data aggregation for wireless sensor networks

The area of wireless sensor networks (WSN) is currently attractive in the research community area due to its applications in diverse fields such as defense security, civilian applications and medical research. Routing is a serious issue in WSN due to the use of computationally-constrained and resource-constrained micro-sensors. These constraints prohibit the deployment of traditional routing protocols designed for other ad hoc wireless networks. Any routing protocol designed for use in WSN should be reliable, energy-efficient and should increase the lifetime of the network. We propose a simple, least-time, energy-efficient routing protocol with one-level data aggregation that ensures increased life time for the network. The proposed protocol was compared with popular ad hoc and sensor network routing protocols, viz., AODV ( [35] and [12]), DSR (Johnson et al., 2001), DSDV (Perkins and Bhagwat, 1994), DD (Intanagonwiwat et al., 2000) and MCF (Ye et al., 2001). It was observed that the proposed protocol outperformed them in throughput, latency, average energy consumption and average network lifetime. The proposed protocol uses absolute time and node energy as the criteria for routing, this ensures reliability and congestion avoidance.     

SEEM: Secure and energy-efficient multipath routing protocol for wireless sensor networks

A Wireless Sensor Network (WSN) is a collection of wireless sensor nodes forming a temporary network without the aid of any established infrastructure or centralized administration. In such an environment, due to the limited range of each node’s wireless transmissions, it may be necessary for one sensor node to ask for the aid of other sensor nodes in forwarding a packet to its destination, usually the base station. One important issue when designing wireless sensor network is the routing protocol that makes the best use of the severely limited resource presented by WSN, especially the energy limitation. Another import factor required attention from researchers is providing as much security to the application as possible. The proposed routing protocols in the literature focus either only on increasing lifetime of network or only on addressing security issues while consuming much power. None of them combine solutions to the two challenges. In this paper, we propose a new routing protocol called SEEM: Secure and Energy-Efficient multipath Routing protocol. SEEM uses multipath alternately as the path for communicating between two nodes thus prolongs the lifetime of the network. On the other hand, SEEM is effectively resistive to some specific attacks that have the character of pulling all traffic through the malicious nodes by advertising an attractive route to the destination. The performance of our protocol is compared to the Directed Diffusion protocol. Simulation results show that our protocol surpasses the Directed Diffusion protocol in terms of throughput, control overhead and network lifetime.     

能量高效的无线传感器网络路由协议

针对目前无线传感器网络分簇路由协议存在的节点能耗不均衡的问题,提出一种基于分簇思想的能量高效的多跳路由协议(EEMR)。该协议首先基于节点临近度将网络划分成簇,采用簇首自适应轮转模式优化簇内节点通信的能量消耗,以高剩余能量短路径向心角的适应度路由算法均衡簇间通信负载和能量消耗,有效避免多跳路由中出现的能量消耗不均衡问题。仿真结果表明,EEMR协议能有效均衡网络内节点的能量消耗,显著延长无线传感器网络的生命期并提高网络能量利用率。     

基于蚁群的无线传感器网络能量均衡非均匀分簇路由算法

无线传感器网络(WSN)路由中,节点未充分考虑路径剩余能量及链路状况进行的路由会造成网络中部分节点网络寿命减少,严重影响网络的生存时间。为此,将蚁群优化算法与非均匀分簇路由算法相结合,提出一种基于蚁群优化算法的无线传感器非均匀分簇路由算法。该算法首先利用考虑节点能量的优化非均匀分簇方法对节点进行分簇,然后以需要传输数据的节点为源节点,汇聚节点为目标节点,利用蚁群优化算法进行多路径搜索,搜索过程充分考虑了路径传输能耗、路径最小剩余能量、传输距离和跳数、所选链路的时延和带宽等因素,最后选出满足条件的多条最优路径,完成源目的节点间的信息传输。实验表明,该算法充分考虑路径传输能耗和路径最小剩余能量、传输跳数及传输距离,能有效延长无线传感器网络的生存期。     

基于智能算法的层次型多链WSN路由协议

路由协议设计是无线传感器网络的一个重要领域,可靠性、低开销、易于维护是无线传感器网络路由协议的设计目标。本文基于层次型拓扑控制思想,并在成链算法PEGASIS基础上引入智能成链策略,提出新的路由协议——HMCRP（Hierarchical Multi-Chain Routing Protocol）。HMCRP基于虚拟网格方式将网络划分为两层自治区域,简化拓扑复杂度;区域内节点按照蚁群算法成链,保证形成全局最优或较优的传输路径;提出链头选取公式,综合考虑节点性能、区域链的数据传输代价。通过matlab与omnet++相结合的仿真实验,与PEGASIS协议及其改进协议相比较,验证了HMCRP在延长网络生命周期、降低数据传输平均能耗以及提高数据接收率等方面的优势。     

CRPD: a novel clustering routing protocol for dynamic wireless sensor networks

A wireless sensor network (WSN) consists of a large number of static or mobile, low-cost, and low-power sensor nodes. And energy is one of the most important factors that should be considered. In this paper, we propose clustering-based routing protocol for dynamic networks (CRPD) to reduce energy consumption and improve energy efficiency through clustering and routing algorithms. The basic idea is to periodically update the network topology and select the node with larger degree and high residual energy as the cluster head to be responsible for data aggregation and transmission. With the nodes moving, joining, and choosing the optimal clustering radius, the energy load of the whole network can be evenly distributed to each sensor node, which can significantly prolong the network lifetime. Extensive simulations show that CRPD is more energy-efficient than the existing protocols.     

认知无线Ad Hoc网络干扰约束和能量高效路由算法

为了减少认知无线Ad Hoc网络的传输中断概率,实现频谱和能量高效,提出一种干扰约束和能量高效（Interference Constraints and Energy-Efficient,ICEE）的路由算法。信道检测除了基于认知节点（Cognitive Radio,CR）对主用户（Primary Users,PU）的干扰约束外,还增加了CR节点的数据传输所需持续时间约束,以保证CR节点在有效利用空闲信道的同时减少传输中断事件的发生,减少故障重传所损耗的能量。在设计路由算法时采用了链路能耗和节点寿命作为度量,通过联合最优的链路选择方程实现网络能量高效,并延长网络的生命周期。实验仿真结果表明,相比较认知Ad hoc网络的自适应路由协议,基于联合信道分配和自适应功率控制的路由协议,ICEE算法在数据包平均能耗上分别减少了41.2%和24.5%,并且有效地延长了网络生命周期。     

基于活动区域的移动无线传感器网络路由协议

为了解决移动无线传感器网络中能量效率问题,提出了一种基于活动区域的移动无线传感器网络（WSN）路由协议。本方法使用源和sink节点相对位置来形成路由的活动区域,网络中的移动节点使用睡眠唤醒模式来节约能源。移动向量信息（如当前位置、方向和速度）以及节点的剩余能量,用于选择能够提供最大连接保留时间的邻居,移动向量信息也被用来唤醒活动区域中的移动节点。实验表明,与其他路由协议进行比较,该方法在分组传输过程中具有更高的可靠性。     

一种新的基于能量消耗速率模型的分簇路由协议

无线传感器网络中通常采用分簇路由协议来减少能耗,但仍然存在节点能量消耗快且不均匀的问题。鉴于经典的低功耗自适应集簇分层型协议LEACH的簇头选举过程中,没有考虑节点能量消耗速率和普通节点到sink节点距离的局限性,提出了一种新的分簇路由协议。仿真实验表明,新协议能够使节点能量均匀分布,降低节点能量消耗,延长传感器网络的生存周期。