Ajit Kumar Nayak

Load balanced routing in mobile ad hoc networks

We present a new protocol called Load Aware Routing in Ad hoc (LARA) networks protocol for efficient data transmission in mobile ad hoc networks. We also define a new metric for routing called traffic density to represent the degree of contention at the medium access control layer. During the route setup, this metric is used to select the route with the minimum traffic load. We have carried out extensive simulation studies to evaluate the performance of our proposed protocol vis-a-vis the existing protocols. Performance results show that our LARA protocol outperforms existing routing protocols in terms of end-to-end delay, throughput, packet delivery fraction, and battery power consumption at the nodes.

A Multi-Objective QoS Optimization with Fuzzy Based Parameter Setting for Real-Time Multicasting

We propose a multi-objective Pareto-optimal technique using Genetic Algorithm (GA) for group communication, which determines a min-cost multicast tree satisfying end-to-end delay, jitter, packet loss rate and blocking probability constraints. The model incorporates a fuzzy-based selection technique for initialization of QoS parameter values at each instance of multicasting. The simulation results show that the proposed algorithm satisfies on-demand QoS requirements (like high availability, good load balancing and fault-tolerance) made by the hosts in varying topology and bursty data traffic in multimedia communication networks.

Dynamic routing algorithm in wireless mesh network

Wireless mesh networks (WMNs) have attracted increasing attention and deployment as a high-performance and low-cost solution to last-mile broadband internet access. WMNs have been broadly accepted in the conventional application sectors of ad hoc networks because of their advantages over other wireless networks. Traffic routing has a critical role in determining the performance of wireless mesh networks. Routing protocol design for wireless mesh networks is critical to maintain the performance and reliability of wireless mesh networks. Thus a routing protocol or an algorithm for WMNs should be carefully designed taking into account the specific characteristics of that network. Traditional routing protocols send traffic along pre-determined paths and have been shown ineffective in coping with unreliable and unpredictable wireless medium. In this paper we propose to formulate the mesh network routing problem as an optimisation problem. In the formulation of the problem we have considered both the static and dynamic traffic demand. This paper proposes a dynamic routing algorithm that is able to provide the optimal performance on all possible traffic demands. Our simulation results show that the proposed method performs competitively.

Energy efficient adaptive sensing range for sensor network

The energy problem in wireless sensor networks (WSN) remains one of the major barriers preventing the complete exploitation of this technology. Sensor nodes are typically powered by batteries remains a limited resource to be consumed judiciously. Efficient energy management is thus a key requirement for optimal utilization of the sensor network technology. In this work we propose a novel method to optimize the sensor life by organizing the sensors into a maximal number of non-disjoint set covers with non-uniform sensing ranges. Sensors available in one set cover remain active at any instant of time while other sensors are in sleep mode to consume negligible energy. Each set cover is activated successively, thereby increasing the total lifetime of the network. It has been proved through extensive simulation work that the network lifetime can be increased by adjusting their sensing ranges as compared to sensors with fixed sensing ranges. This method employs genetic algorithm (GA) and greedy heuristic approach to determine optimal sensing range for efficient energy management in sensor network. Simulation results prove its efficiency over the fixed-range strategies.

Achieving energy efficiency by self-adjusting sensing range and positioning in wireless sensor networks

Wireless sensor nodes are mostly battery operated, tiny in size, and deployed in some specified area. The limited capacity of the battery power hinders the performance of the node as well as of the network. This requires efficient management of battery power for optimal utilization of the sensor network technology. In this work we propose a novel method to extend the life time of the sensor network by organizing the sensors into a maximal number of non-disjoint set covers with non-uniform sensing ranges. Sensors present in one set cover remain active at any instant of time while other sensors are in sleep mode, so they consume negligible battery power. Each set cover is activated successively, thereby increasing the total lifetime of the network. Each sensor can move towards the center of the set of nodes it covers to further reduce the sensing range and further diminishes the consumption of energy. It is observed through extensive simulation work that the network lifetime can be increased by adjusting their sensing ranges as compared to sensors with fixed sensing ranges. This method employs genetic algorithm (GA) and greedy heuristic approach to determine optimal sensing range for efficient energy management in sensor network. Simulation results show its efficiency over the fixed-range strategies.

Recognition of Odia Conjunct Characters Using a Hybrid ANN-DE Classification Technique

A good amount of research has been done on optical character recognition (OCR) for different languages and many research articles have been published on this topic throughout last few decades. However, not much works have been reported for conjunct character recognition of Indian languages although there are 12 major scripts used by the peoples of India. Odia is an Indian language and is used by a majority of population in Odisha. The work presented here focuses on recognition of Odia conjunct characters, which uses an optimization technique embedded within the soft computing paradigm, i.e., a neural network. The experimental results show significant improvement on recognition rate of conjunct characters compared to traditional neural network approach.

Odia character recognition using backpropagation network with binary features

Automatic recognition of printed characters has been an area of active research since last few decades. Though considerable work has been reported for Latin, CJK, and many other popular languages, but a few works has been reported for many Indian languages. In this work, we propose a complete model with effective techniques to recognise printed offline Odia language characters. First we develop a technique to segment the image to extract characters, and then features of these segmented characters are extracted using a binary feature extraction, as well as structural feature extraction. Finally, these extracted features are used to classify character symbols using a modified backpropagation network. In each of these phases it is found that the proposed technique outperforms existing techniques and yields high accuracy rate. Further, this work has tried to include all the possible characters (approx. 2,500 characters) in training/testing unlike other works, where a small set of characters are normally considered for testing.

A Pronunciation Rule-Based Speech Synthesis Technique for Odia Numerals

This paper introduces a model that uses a rule based technique to determine the pronunciation of numerals in different context and is being integrated with the waveform concatenation technique to produce speech from the input text in Odia language. To analyze the performance of the proposed technique, a set of numerals are considered in different context and a comparison of the proposed technique with an existing numeral reading algorithm is also presented to show the effectiveness of the proposed technique in producing intelligible speech out of the entered text.

An Exhaustive Comparison of ODMRP and ADMR Protocols for Ad hoc Multicasting

Currently, multicasting applications such as gaming and chatting are gaining popularity in wireless ad hoc networks. In this work, a rigorous comparison of two existing major protocols ODMRP and ADMR has been made from many different aspects. Also, the performance of each protocol is carefully examined and the conclusion is drawn accordingly. We found that ODMRP is a better protocol as compared to ADMRP in many different scenarios.