Amitangshu Pal

Localization Algorithms in Wireless Sensor Networks: Current Approaches and Future Challenges

Recent advances in radio and embedded systems have enabled the proliferation of wireless sensor networks. Wireless sensor networks are tremendously being used in different environments to perform various monitoring tasks such as search, rescue, disaster relief, target tracking and a number of tasks in smart environments. In many such tasks, node localization is inherently one of the system parameters. Node localization is required to report the origin of events, assist group querying of sensors, routing and to answer questions on the network coverage. So, one of the fundamental challenges in wireless sensor network is node localization. This paper reviews different approaches of node localization discovery in wireless sensor networks. The overview of the schemes proposed by different scholars for the improvement of localization in wireless sensor networks is also presented. Future research directions and challenges for improving node localization in wireless sensor networks are also discussed.

A quality based routing protocol for wireless mesh networks

Abstract Wireless mesh networks can provide low-cost solutions for extending the reach of wireless access points by using multi-hop routing over a set of stationary wireless routers. The routing protocol for these networks may need to address quality considerations to meet the requirements of the user. In this paper, we present a quality based routing protocol for wireless mesh networks that tries to maximize the probability of successful transmissions while minimizing the end-to-end delay. The proposed routing protocol uses reactive route discoveries to collect key parameters from candidate routes to estimate the probability of success and delay of data packets transmitted over them. To achieve accurate route quality assessments, a new route quality metric is proposed that uses performance models of data packet transmissions as opposed to estimating route quality from the transmission of control packets, which have different transmission characteristics. These models are developed after careful evaluations of multi-hop wireless transmissions and validated by computer simulations. Relevant parameters that can be used to assess the route quality metric using these models are explained. Extensive performance evaluations of the proposed quality based routing protocol are presented and its benefits in comparison to some other known routing protocols are discussed.

DRCS: A Distributed Routing and Channel Selection scheme for multi-channel wireless sensor networks

We propose a joint channel selection and quality aware routing scheme for multi-channel wireless sensor networks to improve the network lifetime. A data collection traffic pattern is assumed, where all sensor nodes perform periodic sensing and forward data to a centralized base station (sink). The proposed scheme achieves improvement of the battery lifetime by reducing the energy consumed from overhearing and also by dynamically balancing the battery lifetimes of nodes. Performance evaluations are presented from experimental studies as well as from extensive simulation studies to show the effectiveness of the proposed scheme.

An RSSI based localization scheme for wireless sensor networks to mitigate shadowing effects

We propose a RSSI based localization scheme for wireless sensor networks that mitigates the effects of shadowing caused by obstacles that are scattered in the field of operation. The proposed scheme applies a spatial correlation mechanism to eliminate RSSI signals that are affected by obstructions. The effectiveness of the proposed scheme is validated using simulations as well as some initial experimental results.

A distributed channel selection scheme for multi-channelwireless sensor networks

We consider the channel assignment problem in multi-channel wireless sensor networks for maximizing the network lifetime. We assume a data collection traffic pattern where all nodes forward data periodically to a sink and propose a distributed channel selection scheme that tries to maximize the lifetime of the nodes by controlling the energy consumption from overhearing. Some initial experimental results are included to show the effectiveness of the proposed scheme.

Fault detection and localization scheme for multiple failures in optical network

This paper proposes fault detection and localization scheme to handle multiple failures in the optical network using wavelength-division multiplexing (WDM) technology. This proposed scheme is two-phased scheme containing (a) the detection of faults through monitoring devices raising alarms (fault detection) and (b) subsequently the localization of these faults (fault localization) by invoking an algorithm. The later phase will obtain a set of potential faulty nodes (links). We demonstrate the performance of the scheme on 14-node NSFNet and 28-node EuroNet. We compare our scheme with an existing algorithm [1] for locating faulty nodes (links). Our scheme outperforms the existing one.

Internet of Perishable Logistics

A novel networking model called the Internet of Perishable Logistics (IoPL) attempts to exploit the synergies between the cyber Internet carrying time-sensitive information packets and distribution logistics for perishable commodities such as fresh food. The article discusses the research challenges and opportunities brought about by the perishable commodity distribution logistics field and potential approaches that could enrich this domain as well as that of the cyber Internet.

JRCA: A joint routing and channel assignment scheme for wireless mesh networks

In this paper we consider the joint channel assignment and routing problem in multi-radio multi-gateway wireless mesh networks for improving the quality of communications in the network. This channel assignment problem is proven to be an NP-complete problem. We present a novel backtracking and genetic algorithm based channel assignment and quality aware route selection scheme to maximize the overall performance of communications while reducing the computational complexity. We perform extensive simulation studies that show that our proposed channel assignment and route selection scheme performs significantly better than single channel and random channel selection based schemes.

A quality aware anycast routing protocol for wireless mesh networks

In this paper we consider anycast routing for multi-gateway wireless mesh networks to maximize the overall quality of communications. For such networks, anycasting provides an effective mechanism to reduce problems due to congestion and interfence by appropriate selection of gateways, particularly at heavy traffic conditions. However, as proved in this paper, the optimal gateway selection problem is NP-hard. Hence, we propose a heuristic for route selection that tries to perform gateway and route selection to minimize interference. Simulation results show that our proposed anycasting scheme performs better than other well known anycasting protocols.

Performance analysis of IEEE 802.11 distributed coordination function in presence of hidden stations under non-saturated conditions with infinite buffer in radio-over-fiber wireless LANs

We present an analytical model to evaluate the performance of the IEEE 802.11 Distributed Coordination Function (DCF) with and without the RTS/CTS handshake in radio-over-fiber (RoF) wireless LANs. The model captures the effects of contending nodes as well as hidden terminals under non-saturated traffic conditions assuming large buffer sizes. The effect of fiber propagation delay is considered. The proposed models are validated using computer simulations. Comprehensive performance evaluations of RoF networks obtained from the proposed model as well as simulations are presented.