Kankar S. Dasgupta

Lifetime improvement of LEACH protocol for Wireless Sensor Network

The job of developing a generic protocol framework for Wireless Sensor Networks (WSN) is challenging because, limited processing capabilities, memory and power supply of sensor node make it difficult to cater requirements of versatile applications of these networks. This has forced researchers to dissect the traditional layered protocol design approach. As a result cross layer protocols and architectures that attempt to exploit richer interaction among communication layers to achieve performance gains with limited resources have emerged. From among the cross layer protocols proposed in the literature Low Energy Adaptive Clustering Hierarchy (LEACH), is well referred protocol architecture for WSN. This paper simulates using Network Simulator NS2, analyzes and identifies the shortcomings of LEACH protocol. LEACH does not take into account residual energy and distance of node from the Base Station (BS) for the Cluster Head (CH) selection. We propose Improved-LEACH, in which residual energy and distance of node from BS are used as parameters for CH selection. To save energy, we further propose to start the steady state operation of a node only if the value sensed by a node is greater than the set threshold value. The threshold value will be set by the end user at the application layer. Improved-LEACH is then qualitatively and quantitatively analyzed. The quantitative and qualitative metrics presented for comparison framework can be used to analyze tradeoffs produced by different WSN protocols. They can also be design guidelines for new WSN protocols.

Cluster Head Selection Protocol using Fuzzy Logic for Wireless Sensor Networks

trends in field of wireless networks is setting up Wireless Sensor Networks that, senses specified parameter(s) related to environment; processes sensed data and wirelessly communicates it to a base station. Such networks open up a whole new range of applications, including precision agriculture, monitoring and tracking vehicles, animals and humans, battle-field surveillance, civil structural monitoring etc. All these applications require extended network lifetime, scalability, and traffic balancing among nodes in the network. Clustering is one of the effectual techniques for achieving these requirements. In clustering, geographically adjacent nodes are organized into virtual groups called clusters. One of the cluster node acts as a cluster head and rest as cluster members. This paper presents Cluster Head selection protocol using Fuzzy Logic (CHUFL). It uses nodes parameters like: residual energy, reachability from its neighborhood, quality of communication link with its neighborhood and distance from base station as fuzzy input variables for cluster head selection. A comparative analysis of CHUFL with cluster head selection mechanism using fuzzy logic by Indranil et. al.; Cluster Head Election mechanism using Fuzzy logic (CHEF) by Kim et. al. and cluster head selection method for wireless sensor networks based on fuzzy logic by J. Anno et. al. shows that CHUFL is up to 20 % more energy efficient and sends 72% more packets to base station compared to protocol by J. Anno et. al., one of the energy efficient clustering protocol.

FAMACROW: Fuzzy and ant colony optimization based combined mac, routing, and unequal clustering cross-layer protocol for wireless sensor networks

Abstract This paper presents Fuzzy and Ant Colony Optimization Based Combined MAC, Routing, and Unequal Clustering Cross-Layer Protocol for Wireless Sensor Networks (FAMACROW) consisting of several nodes that send sensed data to a Master Station. FAMACROW incorporates cluster head selection, clustering, and inter-cluster routing protocols. FAMACROW uses fuzzy logic with residual energy, number of neighboring nodes, and quality of communication link as input variables for cluster head selection. To avoid hot spots problem, FAMACROW uses an unequal clustering mechanism with clusters closer to MS having smaller sizes than those far from it. FAMACROW uses Ant Colony Optimization based technique for reliable and energy-efficient inter-cluster multi-hop routing from cluster heads to MS. The inter-cluster routing protocol decides relay node considering its: (i) distance from current cluster head and that from MS (for energy-efficient inter-cluster communication), (ii) residual energy (for energy distribution across the network), (iii) queue length (for congestion control), (iv) delivery likelihood (for reliable communication). A comparative analysis of FAMACROW with Unequal Cluster Based Routing [33] , Unequal Layered Clustering Approach [43] , Energy Aware Unequal Clustering using Fuzzy logic [37] and Improved Fuzzy Unequal Clustering [35] shows that FAMACROW is 41% more energy-efficient, has 75–88% more network lifetime and sends 82% more packets compared to Improved Fuzzy Unequal Clustering protocol.

Comparative analysis of wireless sensor network motes

Wireless Sensor Network (WSN) applications range from simple data gathering to hard to imagine fields like Internet of Things. For all the applications the physical design space consists of sensors extended with storage, power supply, computation and communication capabilities, the so-called motes. These motes run the network protocol programs that most of the time sleep, and occasionally collect, process, store and communicate the data to Base Station (BS). The number of protocol proposals has increased but unfortunately the number of mote studies has not. This paper discusses the essential subsystems of motes, surveys and does a comparative analysis of well-known motes. The motes are selected based on a number of criteria including popularity, published results, interesting characteristics and features. The motes are analyzed using a number of different parameters and criteria, including processor used, lifetime, cost, software support, size, their strengths and weaknesses. Simulation of LEACH protocol using motes discussed in the paper is carried out and a comparative analysis of network lifetime, data transmitted and energy consumption of network is presented. The goal of work is to aid WSN application developers to select appropriate mote for their network or determine features that should be included on a custom built sensor node platform.

Wireless Sensor Network: Application led research perspective

A Wireless Sensor Network is a network of sensors that, senses specified parameter(s) related to environment; processes data locally or in a distributed manner and wirelessly communicates information to central Base Station. The Base Station analyzes information and initiates suitable response if required. Wireless Sensor Network research as a whole suffers a lack of practical application scenarios for which such networks are the best solution. Researchers generally do not emphasize on the application domains they are trying to address. Therefore they cannot accurately assess the efficiency of their proposal because for different application areas there are different technical issues. This paper discusses role of application in research and fleshes out from the literature applications of sensor networks ranging from billion dollar satellites to tiny RF tags. To aid in application led research we demonstrate that different applications take different directions in the design goals. Based on this observation the sensor network design goals and its various directions are characterized. Such explicit design direction works as a framework for discussing and structuring coordinated research (e.g., scrutinizing mutual dependencies between applications, software, hardware and hence avoiding duplicate work). It also provides a conceptual basis for the development of flexible software and hardware frameworks that can be adapted to meet different application needs.

Survey of Test Data Compression Technique Emphasizing Code Based Schemes

As a result of the emergence of new fabrication technologies and design complexities, standard stuck-at scan tests are no longer sufficient. The number of tests and corresponding data volume increase with each new fabrication process technology. The demand goes to well beyond 100X tester cycle reduction considering new fault models. The test data compression has been an emerging need of VLSI field and the hot topic of research for last decade. Still there is a great need and scope for further reduction in test data volume. This reduction must be lossless for input side test data. This paper summarizes the different methods based on coding theory applied for lossless compression of the input side test data. It covers starting with simple code based methods to combine/hybrid methods. The basic goal here is to prepare survey on current methodologies applied for test data compression and prepare a platform for further development in this avenue.

Optimizing the Block Cipher and Modes of Operations Overhead at the Link Layer Security Framework in the Wireless Sensor Networks

Due to the resource constrained environments under which the Wireless Sensor Networks (WSNs) operate, the security protocols and algorithms should be so designed to be used in WSNs, as to yield the optimum performance. The efficiency of the block cipher and the mode under which it operates are vital factors in leveraging the performance of any security protocol. In this paper, therefore, we focus on the issue of optimizing the security vs. performance tradeoff at the link layer framework in WSNs. We evaluate the resource requirements of the block ciphers characteristically distinct from each other, in conventional modes and the Authenticated Encryption (AE) modes. We use the Skipjack cipher in CBC mode, as the basis for comparison. To the best of our knowledge, ours is the first experimental evaluation of the AES cipher, the XXTEA cipher, the OCB mode and the CCM mode at the link layer security architecture for WSNs.

Hamming Distance Based Reordering and Columnwise Bit Stuffing with Difference Vector: A Better Scheme for Test Data Compression with Run Length Based Codes

Because of increased design complexity and advanced fabrication technologies, the number of tests and corresponding data volume increases rapidly. As the large size of test data volume is becoming one of the major problems in testing System-on-a-Chip (SoC), several compression coding schemes have been proposed in past. Run Length Coding is one of the most familiar coding methodologies for compression. In this paper, we present a new scheme named Hamming Distance Based Reordering and Column wise Bit Stuffing with Difference Vector (HDR-CBS-DV), which can be used with any run length based code technique for better compression ratio. Four techniques have been applied in this scheme: Selection of first vector, Hamming Distance Based Reordering, Columnwise Bit Stuffing and Difference Vector. Instead of directly applying any known run length code like Golomb, Frequency Directed Run Length (FDR), Extended FDR (EFDR), Modified FDR (MDFR) or Shifted Alternate FDR (SAFDR) to given test set, if we apply the proposed scheme to test set prior to applying the run length base code, the compression obtained is improved drastically. The experimental results on ISCAS89 Benchmark circuits shows that the test data compression ratio improves significantly for each case. It is also noteworthy that in most of the case, this scheme does not involve any extra silicon area over-head compared to the base code with which it used. For few cases, it requires an extra XOR gate and feedback path only. The proposed scheme can be easily integrated into the existing industrial flow.

Modified Selective Huffman Coding for Optimization of Test Data Compression, Test Application Time and Area Overhead

A compression-decompression scheme, Modified Selective Huffman (MS-Huffman) scheme based on Huffman code is proposed in this paper. This scheme aims at optimization of the parameters that influence the test cost reduction: the compression ratio, on-chip decoder area overhead and overall test application time. Theoretically, it is proved that the proposed scheme gives the better test data compression compared to very recently proposed encoding schemes for any test set. It is clearly demonstrated with a large number of experimental results that the proposed scheme improves the test data compression, reduces overall test application time and on-chip area overhead compared to other Huffman code based schemes.

Performance analysis of cross layer protocols for wireless sensor networks

Present age technologies like Micro-Electro-Mechanical Systems for development of smart sensors, small transceivers and low-priced hardware are fueling increased interest in Wireless Sensor Networks. The task of developing a generic protocol framework for optimizing Wireless Sensor Networks is challenging because limited processing capabilities, memory and power supply of sensor node make it difficult to cater requirements of versatile applications of these networks. This has forced researchers to dissect the traditional layered protocol design process. As a result cross layer protocols that attempt to exploit richer interaction among communication layers to achieve performance gains have emerged. This paper surveys, classifies, simulates using Network Simulator NS2 and analyzes well referred cross layer protocols namely Low Energy Adaptive Clustering Hierarchy, Self Organized TDMA Protocol, Flexible TDMA Protocol, Energy Efficient Fast Forwarding Protocol and D-MAC. We also identify possible risks associated with cross layer design and suggest precautionary guidelines for the same.