Shrikant N. Pradhan

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.

Data Dissemination Techniques in Vehicular Ad Hoc Network

local incidents occur on road networks daily, many of which may lead to congestion and safety hazards. If vehicles can be provided with information about such incidents or traffic conditions in advance, the quality of driving can be improved significantly in terms of time, distance, and safety. Vehicular Ad Hoc Networks (VANETs) have newly emerged as an effective tool for improving road safety through the dissemination of warning messages among the vehicles in the network about potential obstacles on the road ahead. Various Approaches of data dissemination in vehicular network can be used to inform vehicles about dynamic road traffic condition so that a safe and efficient transportation system can be achieved. Here we extensively reviewed various data dissemination techniques and identify the challenges with it. However, type of VANET applications and inherent VANET characteristics such as different network density, fast movement of vehicles make data dissemination quite challenging.

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.

Cross layer architectural approaches for Wireless Sensor Networks

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. The complexities introduced by severely limited processing capabilities, memory and power supply in the sensor node at one end and the design needs of versatile applications at the other end have forced researchers to dissect the layered protocol design process. As a result cross layer approaches which attempt to exploit a richer interaction among communication layers to achieve performance gains have emerged. Cross-layer interactions offer the possibility of dealing with the special properties of Wireless Sensor Network that cannot be handled well by layered architectures. For example, this can be handling the variations in link quality or adjusting the radio strength, which influences the transmission range, the number of collisions, and energy consumption. These parameters can further be used as routing metrics at Network Layer for efficient routing. This paper surveys cross layer architectures, presents performance benchmarking for the architectures and finally compares them on the basis of the introduced benchmarks.

Evaluation of routing protocols for Vanets in city scenarios

Vehicular Ad hoc Network (VANET) is a new communication paradigm that enables the communication between vehicles on the road network which falls in two categories: 1) Vehicle to Vehicle (V2V) and 2) Vehicle to Infrastructure (V2I). It has opened door to develop several new applications like traffic engineering, traffic management, dissemination of emergency information to avoid hazardous situations and other user applications. Various approaches of data dissemination in vehicular Network are to inform vehicles about dynamic road traffic condition so that a safe and efficient transportation system can be achieved. However, type of VANET Applications and inherent characteristics such as different network density, fast movement of vehicles make data dissemination quite challenging. To evaluate the performance of routing protocols in city traffic scenarios, we developed a realistic city mobility model with use of MOVE. The performance of routing protocols AODV, AOMDV, DSDV and DSR are examined on the basis of network simulations. Results are then analyzed based on the different Performance metrics to find their suitability of these protocols for vehicular area networks.

A novel approach using transformation techniques and decision tree algorithm on images for performing Digital Watermarking

Digital Watermarking is an emerging copyright protection technology. The paper presents a new robust watermarking technique based on combining the power of transform domain technique, the Discrete Cosine Transform (DCT) and the data mining technique such as Decision Tree Induction (ID3). The paper focuses on a technique through which the notion of decision tree can be applied on transformed vectors to build the decision tree. We train the image blocks for deriving the classification tree. The resulting decision tree provides decision making rules to identify good quality image blocks for insertion of watermark. The implementation results have shown that the algorithm has an acceptable robustness against the JPEG compression and addition of noise.

Comparative analysis of Medium Access Control protocols for Wireless Sensor Networks

The new 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. Functioning of Wireless Sensor Networks is distributed across nodes and there is no fixed infrastructure control. This in turn requires carefully designed Medium Access Control layer protocols. This paper surveys, classifies, simulates using Network Simulator NS2 and analyzes well referred Medium Access Control layer protocols namely IEEE 802.11, S-MAC, D-MAC, ATMA and Z-MAC for Wireless Sensor Networks. The quantitative and qualitative metrics presented for comparison framework can be used to analyze tradeoffs produced by different Medium Access Control design approaches. They can be design guidelines for Wireless Sensor Networks Medium Access Control layer protocols.

A unified technique for robust digital watermarking of colour images using data mining and DCT

Digital watermarking is an emerging copyright protection technology. The paper presents a new robust watermarking technique based on combining the power of transform domain technique; the discrete cosine transforms (DCT) and the data mining technique such as decision tree induction (ID3). The paper focuses on a technique through which the notion of decision tree can be applied on transformed vectors to build the decision tree. We train the image blocks for deriving the classification tree. The resulting decision tree provides decision-making rules to identify good quality image blocks for insertion of watermark. The implementation results have shown that the algorithm has an acceptable robustness against the JPEG compression and addition of noise.