Multiple token‐based neighbor discovery for directional sensor networks

Directional sensor networks (DSNs) can significantly improve the performance of a network by employing energy efficient communication protocols. Neighbor discovery is a vital part of medium access control (MAC) and routing protocol, which influences the establishment of communication between neighboring nodes. Neighbor discovery is a challenging task in DSNs due to the limited coverage provided by directional antennas. Furthermore, in these networks, communication can only take place when the beams of the directional antennas are pointed toward each other. In this article, we propose a novel multiple token‐based neighbor discovery (MuND) protocol, in which multiple tokens are transmitted based on an area exploration algorithm. The performance of the protocol is evaluated using the Cooja simulator. The simulation results reveal that the proposed MuND protocol achieves lower neighbor discovery latency, with a 100% neighbor discovery ratio, and has a relatively low communication overhead and low energy consumption.     

LoWaNA: low overhead watermark based node authentication in WSN

Nodes in a wireless sensor network (WSN) are generally deployed in unattended environments making them susceptible to attacks. Therefore, the need of defending such attacks is of utmost importance. The challenge in providing security in this network is that the securing mechanism must be lightweight to make it implementable for such resource-constrained nodes. A robust security solution for such networks must facilitate authentication of sensor nodes. So far, only data authentication has drawn much attention from the research community. In this paper, a digital watermark based low-overhead solution (LoWaNA) is proposed for node authentication. The proposed watermarking technique consists of three modules viz. watermark generation, embedding and detection. The robustness of the algorithm is measured in terms of cracking probability and cracking time. This robustness analysis helps us to set the design guideline regarding size of watermark. Performance of the scheme is analyzed in terms of storage, computation and communication overhead. The analytical results are compared with two of the existing schemes and that show significant reduction of all such overheads. Thus it proves the suitability of the proposed scheme for resource-constrained networks like WSN. Finally the entire scheme is simulated in Cooja, the Contiki network simulator to make it readily implementable in real life mote e.g. MICAz.

     

Low-overhead video compression combining partial discrete cosine transform and compressed sensing in WMSNs

Wireless multimedia sensor network (WMSN) is a special wireless sensor network (WSN) made up of several multimedia sensor nodes, specially designed to retrieve multimedia content such as video and audio streams, still images, and scalar sensor data from the environment. Due to strict inherent limitations in terms of processing power, storage and bandwidth, data processing is a challenge in such network. Further, energy is one of the scarcest resources in WSN, especially in WMSN and therefore, saving energy is of utmost importance. Data compression is one of the solutions of such a problem. This paper proposes an energy saving video compression technique for WMSN by judicious combination of partial discrete cosine transform and compressed sensing. This amalgamation exploits the benefits of both the techniques towards fulfilling the objective of saving energy along with achieving desired peak signal to noise ratio (PSNR). When the transform technique ensures low-overhead compression, compressed sensing guarantees the reconstruction of the same video with lesser amount of measurements. Performance of the scheme is measured both qualitatively and quantitatively. In qualitative analysis, overhead of the scheme is measured in terms of storage, computation, and communication overheads and the results are compared with a number of existing schemes including the base scheme. The results show considerable reduction of all such overheads thereby justifying the appropriateness of the proposed scheme for resource-constrained networks like WMSNs. In quantitative analysis, for both ideal and packet loss environment, the scheme is simulated in Cooja, the Contiki network simulator to make it readily implementable in real life mote e.g. MICAz. When compared with the existing state-of-the-art schemes, it performs better not only in terms of 34.31% energy saving but also in getting an acceptable PSNR of 35–37 dB and SSIM of 0.85–0.88 in ideal environment. In packet loss environment, these values are 32.9–35.5 dB and 0.81–0.85 respectively implying acceptable reconstruction even in packet loss environment. Further, it requires the least storage of 51.2 KB. The observation on simulation results is also justified by statistical analysis.

     

Range‐free intersecting chord‐based geometric localization scheme for wireless sensor networks

Recent advancement in wireless sensor network has contributed greatly to the emerging of low‐cost, low‐powered sensor nodes. Even though deployment of large‐scale wireless sensor network became easier, as the power consumption rate of individual sensor nodes is restricted to prolong the battery lifetime of sensor nodes, hence the heavy computation capability is also restricted. Localization of an individual sensor node in a large‐scale geographic area is an integral part of collecting information captured by the sensor network. The Global Positioning System (GPS) is one of the most popular methods of localization of mobile terminals; however, the use of this technology in wireless sensor node greatly depletes battery life. Therefore, a novel idea is coined to use few GPS‐enabled sensor nodes, also known as anchor nodes, in the wireless sensor network in a well‐distributed manner. Distances between anchor nodes are measured, and various localization techniques utilize this information. A novel localization scheme Intersecting Chord‐Based Geometric Localization Scheme (ICBGLS) is proposed here, which loosely follows geometric constraint‐based algorithm. Simulation of the proposed scheme is carried out for various communication ranges, beacon broadcasting interval, and anchor node traversal techniques using Omnet++ framework along with INET framework. The performance of the proposed algorithm (ICBGLS), Ssu scheme, Xiao scheme, and Geometric Constraint‐Based (GCB) scheme is evaluated, and the result shows the fact that the proposed algorithm outperforms the existing localization algorithms in terms of average localization error. The proposed algorithm is executed in a real‐time indoor environment using Arduino Uno R3 and shows a significant reduction in average localization time than GCB scheme and similar to that of the SSU scheme and Xiao scheme.     

Wireless Sensor Network Path Optimization Using Sensor Node Coverage Area Calculation Approach

The proposed work is based on the path optimization approach for wireless sensor network (WSN). Path optimization is achieved by using the NSG 2.1 Tool, TCL Script file and NS2 simulator to improve the quality of service (QoS). Path optimization approach finds best suitable path between sensor nodes of WSN. The routing approach is not only the solution to improve the quality but also improves the WSN performance. The node cardinally is taken under consideration using the ad-hoc on demand distance vector routing protocol mechanism. Ad hoc approach emphasize on sensor nodes coverage area performance along with simulation time. NSG 2.1 Tool calculates the sensor node packet data delivery speed which can facilitate inter-node communication successfully. An experimental result verified that the proposed design is the best possible method which can escape from slow network response while covering maximum sensor nodes. It achieves coverage support in sensor node deployment. The result outcomes show best path for transferring packet from one sensor node to another node. The coverage area of sensor node gives the percentage of average coverage ratio of each node with respect to the simulation time.

     

Lightweight distributed geographical: a lightweight distributed protocol for virtual clustering in geographical forwarding cognitive radio sensor networks

Recent literature characterizes future wireless sensor networks (WSN) with dynamic spectrum capabilities. When cognitive radio is introduced as a main component of a network, a network management protocol is needed to ensure network connectivity and stability especially in highly dynamic environments. Implementing such protocols in WSN opens more challenges because of the resource constraints in sensor networks. We propose a distributed lightweight solution that fulfills this need for WSN. With this protocol, a node in a multichannel environment is quickly able to establish a control channel with neighboring nodes. Lightweight distributed geographical either increases or reduces the coverage area of the control channel based on perceived interference and adequately takes care of intersecting nodes with minimal overhead. By identifying local minima nodes, it also has the potentiality of reducing route failure by 70% further reducing the time and energy overhead incurred by switching to angle routing or maximum power transmission schemes usually used to solve the local minima issue. The work shows best operating values in terms of duty cycle and signal to noise ratio threshold frequencies and the lightweight nature of lightweight distributed geographical in terms of energy and communication overhead, which suits network management protocols for cognitive radio sensor networks. Copyright © 2013 John Wiley & Sons, Ltd.     

Fish bone structure based data aggregation and routing in wireless sensor network: multi-agent based approach

Wireless sensor networks (WSNs) are constrained by limited node (device) energy, low network bandwidth, high communication overhead and latency. Data aggregation alleviates the constraints of WSN. In this paper, we propose a multi-agent based homogeneous temporal data aggregation and routing scheme based on fish bone structure of WSN nodes by employing a set of static and mobile agents. The primary components of fishbone structure are backbone and ribs connected to both sides of a backbone. A backbone connects a sink node and one of the sensor nodes on the boundary of WSN through intermediate sensor nodes. Our aggregation scheme operates in the following steps. (1) Backbone creation and identifying master centers (or nodes) on it by using a mobile agent based on parameters such as Euclidean distance, residual energy, backbone angle and connectivity. (2) Selection of local centers (or nodes) along the rib of a backbone connecting a master center by using a mobile agent. (3) Local aggregation process at local centers by considering nodes along and besides the rib, and delivering to a connected master center. (4) Master aggregation process along the backbone from boundary sensor node to the sink node by using a mobile agent generated by a boundary sensor node. The mobile agent aggregates data at visited master centers and delivers to the sink node. (5) Maintenance of fish bone structure of WSN nodes. The performance of the scheme is simulated in various WSN scenarios to evaluate the effectiveness of the approach by analyzing the performance parameters such as master center selection time, local center selection time, aggregation time, aggregation ratio, number of local and master centers involved in the aggregation process, number of isolated nodes, network lifetime and aggregation energy. We observed that our scheme outperforms zonal based aggregation scheme.     

无线传感器网络安全方案研究

本文分析TWSN的安全问题,提出了一种新的WSN安全方案.此方案在网络初始化时采用预分配密钥方法来建立网络安全体系,减少通信开销,在网络运行时采用基于能量的动态分簇算法维护网络安全,优化网络生命周期.并且在这个基础上,提出了一种基于能量的多路径冗余传输来识别恶意节点.     

Capsule network‐based data pruning in wireless sensor networks

The development of the wireless sensor networks (WSN) being deployed among numerous application for its sensing capabilities is increasing at a very fast tread. Its distributed nature and ability to extend communication even to the inaccessible areas beyond communication range that lacks human intervention has made it even more attractive in a wide space of applications. Confined with numerous sensing nodes distributed over a wide area, the WSN incurs certain limitations as it is battery powered. Many developed routing enhancements with power and energy efficiency lacked in achieving the significant improvement in the performance. So, the paper proposes a machine learning system (capsule network) and technique (data pruning) for WSN involved in the real world observations to have knowledge‐based learning from the experience for an intelligent way of handling the dynamic and real environment without the intervention of the humans. The WSN cluster‐based routing aided with capsule network and data pruning proffered in paper enables the WSN to have a prolonged network lifetime, energy efficiency, minimized delay, and enhanced throughput by reducing the energy usage and extending communication within the limited battery availability. The proposed system is validated in the network simulator and compared with the WSN without ML to check for the performance enhancements of the WSN with ML inclusions in terms of quality of service enhancements, network lifetime, packet delivery ratio, and energy to evince the efficacy of the WSN with capsule network‐based data pruning.     

一种规避传感器网络选择性转发攻击的方法

在以数据为中心的无线传感器网络中,当恶意节点出现并发起选择性转发攻击时,出现的问题是恶意节点未能转发来到的信息,而丢掉部分和全部的关键信息,会严重破坏数据的收集,降低网络的可用性。提出PDMCS(Polynomial-based Defense Mechanism Countering the Selective Forwarding Attacks),一个轻量级的防止选择性转发攻击的安全方案。方案中,事件数据包被划分成多个数据子包,通过多项式将这些子包转换成不同的数据片,结合动态多路径路由算法把数据发送到基站。使用这样的技术,可以减轻这种攻击的破坏,提高系统的鲁棒性。用理论分析和仿真探究了方案能够权衡通信负载和安全可靠性。仿真实验结果证明方案在面临大量恶意节点时能够获得高的成功接收率,同时通信量也在合理的范围内。     

A dynamic TDMA based scheme for securing query processing in WSN

Nodes in a wireless sensor network (WSN) are generally deployed in unattended environments making the nodes susceptible to attacks. Therefore, the need of defending such attacks becomes a big challenge. We propose a scheme to build a security mechanism in a query-processing paradigm within WSN. The scheme is capable of protecting replay attack while preserving essential properties of security such as authentication, data integrity and data freshness. The solution is made lightweight using symmetric key cryptography with very short-length key. Further, the key used in our scheme is neither pre-deployed nor is transmitted directly. The key information is established among nodes through an efficient use of one variant of dynamic TDMA mechanism which ensures security of key. Another variant of dynamic TDMA is used to make the scheme bandwidth saving, an essential quality of WSN. Performance of the scheme is analyzed in terms of storage, computation and communication overhead. Finally the analytical results are compared with two of the existing schemes including the previous version of the present scheme that show significant reduction of all such overheads thereby proving the suitability of the proposed scheme for a resource-constrained network like WSN.     

抵抗Sybil攻击的无线传感网中网络分布式密钥管理方案

Wireless sensor network nodes (WSN nodes) have limited computing power, storage capacity, communication capabilities and energy and WSN nodes are easy to be paralyzed by Sybil attack. In order to prevent Sybil attacks, a new key distribution scheme for wireless sensor networks is presented. In this scheme, the key information and node ID are associated, and then the attacker is difficult to forge identity ID and the key information corresponding to ID can not be forged. This scheme can use low-power to resist the Sybil attack and give full play to the resource advantages of the cluster head. The computing, storage and communication is mainly undertaken by the cluster head overhead to achieve the lowest energy consumption and resist against nodes capture attack. Theoretical analysis and experimental results show that compared with the traditional scheme presented in Ref. [14], the capture rate of general nodes of cluster reduces 40% , and the capture rate of cluster heads reduces 50% . So the scheme presented in this paper can improve resilience against nodes capture attack and reduce node power consumption.     

Energy‐efficient data transmission technique for wireless sensor networks based on DSC and virtual MIMO

In a wireless sensor network (WSN), the data transmission technique based on the cooperative multiple‐input multiple‐output (CMIMO) scheme reduces the energy consumption of sensor nodes quite effectively by utilizing the space‐time block coding scheme. However, in networks with high node density, the scheme is ineffective due to the high degree of correlated data. Therefore, to enhance the energy efficiency in high node density WSNs, we implemented the distributed source coding (DSC) with the virtual multiple‐input multiple‐output (MIMO) data transmission technique in the WSNs. The DSC‐MIMO first compresses redundant source data using the DSC and then sends it to a virtual MIMO link. The results reveal that, in the DSC‐MIMO scheme, energy consumption is lower than that in the CMIMO technique; it is also lower in the DSC single‐input single‐output (SISO) scheme, compared to that in the SISO technique at various code rates, compression rates, and training overhead factors. The results also indicate that the energy consumption per bit is directly proportional to the velocity and training overhead factor in all the energy saving schemes.     

一种基于二次型的无线传感器网络密钥管理方案

针对现有的基于多项式的密钥预分配管理方案受限于节点间密钥共享率和网络连通率等问题,文中提出了一种基于二次型的无线传感器密钥管理方案.该方案突破现有二元t次对称多项式建立共享密钥的思路,引入多元非对称二次型多项式,利用二次型特征值与特征向量之间的关系,分析证明二次型正交对角化的特性,生成密钥信息,节点则通过交换密钥信息实现身份认证,生成与邻居节点之间独立唯一的会话密钥.性能分析表明,与现有的密钥管理方案相比,方案在抗俘获性、连通性、可扩展性、通信开销和存储开销上有较大的改进.     

An efficient weighted trust‐based malicious node detection scheme for wireless sensor networks

The aim of wireless sensor networks (WSNs) is to gather sensor data from a monitored environment. However, the collected or reported information might be falsified by faults or malicious nodes. Hence, identifying malicious nodes in an effective and timely manner is essential for the network to function properly and reliably. Maliciously behaving nodes are usually detected and isolated by reputation and trust‐based schemes before they can damage the network. In this paper, we propose an efficient weighted trust‐based malicious node detection (WT‐MND) scheme that can detect malicious nodes in a clustered WSN. The node behaviors are realistically treated by accounting for false‐positive and false‐negative instances. The simulation results confirm the timely identification and isolation of maliciously behaving nodes by the WT‐MND scheme. The effectiveness of the proposed scheme is afforded by the adaptive trust‐update process, which implicitly performs trust recovery of temporarily malfunctioning nodes and computes a different trust‐update factor for each node depending on its behavior. The proposed scheme is more effective and scalable than the related schemes in the literature, as evidenced by its higher detection ratio (DR) and lower misdetection ratio (MDR), which only slightly vary with the network's size. Moreover, the scheme sustains its efficient characteristics without significant power consumption overheads.     

无线传感器网络中基于NDMA的跨层协作多包接收

本文研究了协作分集下的NDMA(网络辅助分集多址接入)机制,针对无线传感器网络特点和信道矩阵满秩性要求设计中继选择准则,提出了一个新的跨层协作多包接收机制.该机制在抗信道衰落的同时可有效限制数据包重传次数,从而大大提高多包接收的效率.对新机制的性能仿真以及该机制与NDMA、联合NDMA、时隙ALOHA之间的性能对比证实了新机制的有效性.     

Zone-based routing protocol with mobility consideration for wireless sensor networks

Hierarchical routing and clustering mechanisms in Wireless Sensor Networks (WSN) help to reduce the energy consumptions and the overhead created when all the sensor nodes in the network are sending information to the central data collection point. Most of the routing and clustering protocols proposed for WSN assume that the nodes are stationary. However, in applications like habitat monitoring or search and rescue, that assumption makes those clustering mechanisms invalid, since the static nature of sensors is not real. In this paper, we propose Zone-based Routing Protocol for Mobile Sensor Networks (ZoroMSN) that considers the design aspects such as mobility of sensors, zones and routes maintenance, information update and communication between sensor nodes. Simulation results show the effectiveness and strengths of the ZoroMSN protocol such as a low routing and mobility overhead, while achieving a good performance in WSN using small zone sizes and sensors with low speed. Simulation results also show that ZoroMSN outperforms existing LEACH-ME and LEACH-M protocols in terms of network lifetime and energy consumptions.     

An integrated framework for wireless sensor network management

Wireless sensor networks (WSNs) have significant potential in many application domains, ranging from precision agriculture and animal welfare to home and office automation. Although sensor network deployments have only begun to appear, the industry still awaits the maturing of this technology to realize its full benefits. The main constraints to large‐scale commercial adoption of WSN have been the lack of available network management and control tools, such as for determining the degree of data aggregation prior to transforming it into useful information, localizing the sensors accurately so that timely emergency actions can be taken at an exact location, routing data by reducing sensor energy consumption, and scheduling data packets so that data are sent according to their priority and fairness. Moreover, to the best of our knowledge, no integrated network management solution comprising efficient localization, data scheduling, routing, and data aggregation approaches exists in the literature for a large‐scale WSN. Thus, we introduce an integrated network management framework comprising sensor localization, routing, data scheduling, and data aggregation for a large‐scale WSN. Experimental results show that the proposed framework outperforms an existing approach that comprises only localization and routing protocols in terms of localization energy consumption, localization error, end‐to‐end delay, packet loss ratio, and network energy consumption. Moreover, the proposed WSN management framework has potential in building a future “Internet of Things”. Copyright © 2012 John Wiley & Sons, Ltd.     

Density‐adaptive network reprogramming protocol for wireless sensor networks

Network reprogramming is a process used to update program codes of sensor nodes that are already deployed. To deal with potentially unstable link conditions of wireless sensor networks, the epidemic approach based on 3‐way advertise‐request‐data handshaking is preferred for network reprogramming. Existing epidemic protocols, however, require a long completion period and high traffic overhead in high‐density networks, mainly due to the hidden terminal problem. In this paper, we address this problem by dynamically adjusting the frequency of advertisement messages in terms of the density of sensor nodes, which is the number of sensor nodes in a certain area. We compare the performance of the proposed scheme, called DANP (Density‐Adaptive Network Reprogramming Protocol), with a well‐known epidemic protocol, Deluge. Simulations indicate that, in the grid topologies, DANP outperforms Deluge by about 30% in terms of the completion time and about 50% in terms of the traffic overhead. Significant performance gain is observed in random topologies as well. The performance of DANP is further confirmed via measurements in an experimental test bed. Copyright © 2009 John Wiley & Sons, Ltd.     

Tree‐based channel assignment schemes for multi‐channel wireless sensor networks

Many sensor node platforms used for establishing wireless sensor networks (WSNs) can support multiple radio channels for wireless communication. Therefore, rather than using a single radio channel for whole network, multiple channels can be utilized in a sensor network simultaneously to decrease overall network interference, which may help increase the aggregate network throughput and decrease packet collisions and delays. This method, however, requires appropriate schemes to be used for assigning channels to nodes for multi‐channel communication in the network. Because data generated by sensor nodes are usually delivered to the sink node using routing trees, a tree‐based channel assignment scheme is a natural approach for assigning channels in a WSN. We present two fast tree‐based channel assignment schemes (called bottom up channel assignment and neighbor count‐based channel assignment) for multi‐channel WSNs. We also propose a new interference metric that is used by our algorithms in making decisions. We validated and evaluated our proposed schemes via extensive simulation experiments. Our simulation results show that our algorithms can decrease interference in a network, thereby increasing performance, and that our algorithms are good alternatives for static channel assignment in WSNs. Copyright © 2015 John Wiley & Sons, Ltd.