R. Mathur

Bio: R. Mathur is an academic researcher from Cork Institute of Technology. The author has contributed to research in topics: Service provider & Service assurance. The author has an hindex of 2, co-authored 3 publications receiving 63 citations.

Influence of people shadowing on optimal deployment of WLAN access points

Abstract: With their low cost and high-speed data rate capabilities, installations of IEEE 802.11-based wireless local area networks (WLANs) are growing exponentially. Although many organizations have started using WLANs, there are still very few tools available that can help the design of WLAN networks. As a result, the current deployment remains ad-hoc in nature. The objective of this work is to develop modeling tools for performance optimization of WLAN networks and WLAN access points. In particular, propagation models are available that can predict the signal strength and interference in a WLAN system by taking into account environment specific parameters such as the structure of the building, presence or absence of stationary obstacles etc. This paper investigates the influence of moving obstacles, such as people, on radio wave propagation inside a building and the effect on received signal quality in a WLAN. Our findings suggest that the presence of moving obstacles seriously affects the performance of the system by introducing heavy variations in the received signal strength.

Influence of people shadowing on bit error rate of IEEE802.11 2.4 GHz channel

Abstract: Installations of IEEE 80211-based wireless local area networks (WLANs) have been growing exponentially over the past two years due to their low cost and high-speed data rate capabilities Although many organizations have started using WLANs, there are still few tools available that assist in the design of WLAN networks As a result, the current deployment of WLAN networks remains ad-hoc in nature The objective of the research reported here is to develop modeling tools for performance optimization of WLAN networks In particular, we attempt to develop propagation models that can predict the signal strength and interference in a WLAN system by taking environment specific parameters into account such as the structure of the building, presence or absence of stationary obstacles, etc (COST231 Final Report, 1998) This paper investigates the influence of moving obstacles, such as people, on radio wave propagation inside a building and the effect on received signal quality, in particular the bit error rate in an IEEE80211 24 GHz channel Our findings suggest that the presence of moving obstacles, such as people, causes strong variations in the received signal, which seriously affects the quality of the received signal

Design and implementation of a distributed telecommunications supermarket

Abstract: TelecomSupermart is a 'Win-Win' solution for users and providers of communication services. In current communication systems, wired and wireless, subscribers are more or less tied to their service providers by means of long-term contracts - the business model is therefore rigid. In an ideal scenario, users should be free to buy telecommunications services just as they are able to buy other commodities in a super market without being obliged to buy products from a particular company. The service providers should also be able to maximize their revenues by means of intelligent strategies such as dynamic pricing based on demand and supply trends in the market. TelecomSupermart is a novel implementation of an agent-based system for telecommunication service provision. It encompasses the merits of an open and free market and facilitates revenue maximization for service providers while giving the users the choice of selecting a service provider based on their own requirements. The backbone of the TelecomSupermart is a decentralized network of individual service providers offering entrepreneurs and individuals an opportunity to become a listed service provider and offer communications services through the TelecomSupermart.

A testbed for evaluating human interaction with ubiquitous computing environments

Abstract: Core to ubiquitous computing environments are adaptive software systems that adapt their behavior to the context in which the user is attempting the task the system aims to support. This context is strongly linked with the physical environment in which the task is being performed. The efficacy of such adaptive systems is thus highly dependent on the human perception of the provided system behavior within the context represented by that particular physical environment and social situation. However, effective evaluation of human interaction with adaptive ubiquitous computing technologies has been hindered by the cost and logistics of accurately controlling such environmental context. This paper describes TATUS, a ubiquitous computing simulator aimed at overcoming these cost and logistical issues. Based on a 3D games engine, the simulator has been designed to maximize usability and flexibility in the experimentation of adaptive ubiquitous computing systems. We also describe how this simulator is interfaced with a testbed for wireless communication domain simulation.

Duty cycle learning algorithm (DCLA) for IEEE 802.15.4 beacon-enabled wireless sensor networks

Abstract: The current specification of the IEEE 802.15.4 standard for beacon-enabled wireless sensor networks does not define how the fraction of the time that wireless nodes are active, known as the duty cycle, needs to be configured in order to achieve the optimal network performance in all traffic conditions. The work presented here proposes a duty cycle learning algorithm (DCLA) that adapts the duty cycle during run time without the need of human intervention in order to minimise power consumption while balancing probability of successful data delivery and delay constraints of the application. Running on coordinator devices, DCLA collects network statistics during each active duration to estimate the incoming traffic. Then, at each beacon interval uses the reinforcement learning (RL) framework as the method for learning the best duty cycle. Our approach eliminates the necessity for manually (re-)configuring the nodes duty cycle for the specific requirements of each network deployment. This presents the advantage of greatly reducing the time and cost of the wireless sensor network deployment, operation and management phases. DCLA has low memory and processing requirements making it suitable for typical wireless sensor platforms. Simulations show that DCLA achieves the best overall performance for either constant and event-based traffic when compared with existing IEEE 802.15.4 duty cycle adaptation schemes.

InRout - A QoS aware route selection algorithm for industrial wireless sensor networks

Abstract: Wireless sensor networks are a key enabling technology for industrial monitoring applications where the use of wireless infrastructure allows high adaptivity and low cost in terms of installation and retrofitting. To facilitate the move from the current wired designs to wireless designs, concerns regarding reliability must be satisfied. Current standardization efforts for industrial wireless systems lack specification on efficient routing protocols that mitigate reliability concerns. Consequently, this work presents the InRout route selection algorithm, where local information is shared among neighbouring nodes to enable efficient, distributed route selection while satisfying industrial application requirements and considering sensor node resource limitations. Route selection is described as a multi-armed bandit task and uses Q-learning techniques to obtain the best available solution with low overhead. A performance comparison with existing approaches demonstrates the benefits of the InRout algorithm, which satisfies typical quality of service requirements for industrial monitoring applications while considering sensor node resources. Simulation results show that InRout can provide gains ranging from 4% to 60% in the number of successfully delivered packets when compared to current approaches with much lower control overhead.

IJCSI Publicity Board 2010

Abstract: In this paper we examine the behavior of Ad Hoc networks through simulations, using different routing protocols and various topologies. We examine the difference in performance, using CBR application, with packets of different size through a variety of topologies, showing the impact node placement has on networks performance. We show that the choice of routing protocol plays an important role on network’s performance. We also quantify node mobility effects, by looking into both static and fully mobile configurations. Our paper presents a systematic analysis of a variety of different ad hoc network topologies in terms of node placement, node mobility and routing protocols through several simulated scenarios.

AvroraZ: extending Avrora with an IEEE 802.15.4 compliant radio chip model

Abstract: This paper presents AvroraZ, an extension of the Avrora emulator -- The AVR Simulation and Analysis Framework -- which allows the emulation of the Atmel AVR microcontroller based sensor node platforms with IEEE 802.15.4 compliant radio chips thus allowing emulation of sensor nodes such as Crossbow's MicaZ. AvroraZ is based on design, implementation and verification of several extensions to Avrora: the address recognition algorithm, an indoor radio model, the clear channel assessment (CCA) and link quality indicator (LQI) of the IEEE 802.15.4 standard. We have AvroraZ and demonstrated its correctness in emulating MicaZ code.