Department of Computer Science and Information Systems
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Item Implementation of multi-hop time synchronization on miniature test-bed setup of underwater acoustic sensor network(IEEE, 2014) Gudino, Lucy J.Time synchronization is an important part of any distributed networked embedded system. It is essentially the process of achieving and maintaining common time base among all network nodes of the system. This task is quite challenging for the systems or applications like sensor networks, since these systems are highly resource constrained, yet need to process time-sensitive data in collaborative manner. Though many protocols have been suggested for terrestrial sensor networks (RSB, TPSN, FTSP and LTS) and they perform reasonably well, very few protocols (THSL, Tri-message) have been suggested for the high-latency underwater acoustic networks, since achieving time-synchronization for high-latency networks is even more challenging issue. Here we describe a very simple extension and implementation of Tri-message time synchronization protocol for multi-hop Underwater Acoustic Sensor Network (UASN) on the miniature test-bed setup.Item Performance analysis of rectangular, triangular and E-shaped microstrip patch antenna arrays for wireless sensor networks(IEEE, 2014) Gudino, Lucy J.Generally wireless sensor nodes have been using omni-directional antennas to broadcast data. But these antennas are not very efficient as they suffer from poor spatial reuse, high collisions, decreased throughput and are not energy efficient. Usage of directional antennas which radiate in a particular direction is more efficient as it can lead to significant energy savings. They reduce beamwidth by concentrating power in a certain direction. In this paper, the performance of conventional omni-directional quarter wave monopole antenna, rectangular patch antenna array, triangular patch antenna array and E-shaped patch antenna array are compared. The antenna arrays have been designed, simulated and tested. The antenna arrays designed are fabricated and then are mounted on a sensor node. The performance analysis in terms of power consumption, received signal strength and packet delivery ratio is performed for individual antenna arraysItem Review of protocol stack development of Underwater Acoustic Sensor Network (UASN)(IEEE, 2015) Gudino, Lucy J.Underwater Acoustic Sensor Network (UASN) has become increasingly important, with numerous applications emerging from various areas such as commercial, environmental-research and defense. This paper provides a comprehensive view of current state-of-the-art in UASN by analyzing the research done by various communities. It briefly states the basics of underwater acoustic communication and cites advances in research and development at various layers of networking modules, namely physical, data link, network, transport and application layer. It also covers interesting new concepts of cross-layer protocol stack design along with requirement of network management protocols pertaining to UASN. Finally, various hardware, software tools and test-beds developed by prominent universities/research organizations are described. We also briefly provide information about the test-bed set-up at our laboratory at BITS -Pilani K K Birla Goa Campus.Item High bandwidth data streaming in Sensor Network with mobile nodes(IEEE, 2015) Gudino, Lucy J.Streaming multimedia data in WSN is a challenge due to constraints such as bandwidth, energy and delay. Moreover, it is not economical to have multimedia sensors integrated with static nodes in the field. In this paper, we propose the use of mobile sensor nodes, which are equipped with multimedia sensors for event monitoring. These mobile entities are capable of streaming high bandwidth data by splitting it and routing the packet to the base station using Frequency Division Multiplexer (FDM) modules. This is done with the support of multi-channel disjoint path routing aided with the static WSN deployed. Experiments were done using MicaZ and TelosB motes to evaluate the performance with the help of our custom designed robotic vehicle. The paper adopts a node disjoint multi-path routing protocol for establishing parallel paths between the sender and the receiver. Experimental results indicate that the proposed approach can be effectively used for transferring high bandwidth data to the base station.Item Realistic directional antenna suite for cooja simulator(IEEE, 2017) Gudino, Lucy J.The use of directional antennas in wireless ad-hoc and sensor networks is gaining immense popularity due to its features such as increased coverage range, security, enhanced throughput and energy efficiency. Only a few simulators such as Network Simulator 2 (NS2), NS3 and Qualnet are currently providing directional antenna support. Recently, a directional antenna model has been implemented in Cooja simulator, which we have enhanced further to provide a realistic approach for simulations relying on directional communications. In this paper, we propose a directional antenna suite which also has the features to support smart antennas. The proposed suite allows to load simulation results of desired antenna radiation pattern, simulated using High Frequency Structure Simulator (HFSS) or any other antenna design simulators. The simulations carried out in the proposed suite, to analyze the performance of directional antennas in terms of coverage range, packet delivery ratio and Received Signal Strength Indicator (RSSI) is in utmost accuracy with the real-time measurements. Using this newly designed suite eases the code portability from simulation to real-time deployment.Item Area based routing protocol for mobile wireless sensor networks(IEEE, 2018-01) Gudino, Lucy J.Certain applications including military, habitat monitoring, futuristic IoT, etc., require routing which needs to be done via mobile nodes with random mobility. This paper presents an energy efficient, area based routing protocol for mobile Wireless Sensor Networks (WSN). The proposed approach uses the relative positions of the source and sink to form an active region for routing. Mobile nodes in the network use a sleep-wakeup pattern to conserve energy. The mobility vector information such as current location, direction and speed, along with the node's residual energy is used to select a neighbour that can provide maximum connection retention time. Mobility vector information is also used to wake-up mobile nodes which are in the active region. The proposed approach is simulated and compared against other similar routing protocols.Item Collaborative Neighbor Discovery with Slow Scan for Directional Sensor Networks(IEEE, 2018) Gudino, Lucy J.Neighbor discovery forms a vital part of Medium Access Control (MAC) and routing protocols in Directional Sensor Network (DSN). Discovering neighbors in DSN is a challenging task due to limited coverage of directional antennae. The Collaborative Neighbor Discovery (COND) protocol suggests a time-efficient mechanism to discover neighbors but fails to discover all the neighbors. In this paper, we propose an improvement over COND protocol by employing Slow-Scan (SS) mode, which sets different nodes in SS mode at different time intervals. This model named COllaborative Neighbor Discovery with Slow Scan (COND-SS) aims to discover all the nodes in the network. The simulation results reveal that the COND-SS protocol has lower latency and it improves the neighbor discovery ratio considerably up to 100%. Keywords-Directional sensor networks, Sector antenna, Distributed discovery, Neighbor discovery.Item DCS-MAC: A Distributed Cross-Layer Communication Protocol for Directional Sensor Networks(Springer, 2019-03) Gudino, Lucy J.Employing directional antenna in Wireless Sensor Networks (WSNs) constitute Directional Sensor Networks (DSNs) which provides potential benefits such as longer coverage range, reduced interference, diminished power requirement and spatial reusability. In this paper, we propose a Distributed Cross-layer Sectored-antenna Medium Access Control (DCS-MAC) protocol. The proposed DCS-MAC employ distributed Time Division Multiple Access (TDMA) for MAC and Distributed Slow-Scan Routing (DSSR) protocol for routing purpose. The DCS-MAC eliminates the need for an exclusive neighbor discovery protocol as DSSR protocol itself serves this purpose. The performance of DCS-MAC is simulated using the Cooja simulator with directional antenna support. The simulation results reveal that DCS-MAC display reduced slot allocation delay, lower communication overhead and higher packet delivery ratio.Item Implementation of Multi - hop Bidirectional Communication Link with Time - Synchronization on Miniature Test - bed of Underwater Acoustic Sensor Network(ScienceGate, 2016) Gudino, Lucy J.energy efficiency. In Underwater Acoustic Sensor Network (UASN) it provides additional importance in terms of better utilization of the scarce acoustic bandwidth. For the convergence of various protocols in WSN and UASN such as Localization, Medium access control and Routing, nodes in the network are required to maintain time-synchronization. In this paper, we discuss the implementation details of multi-hop bidirectional communication link with time-synchronization on miniature test-bed of UASN. Successful implementation of this bidirectional link gives confidence and flexibility in developing higher layer protocols on the testbed and expanding the network topology.Item Hybrid area exploration–based mobility-assisted localization with sectored antenna in wireless sensor networks(Wiley, 2019-11) Gudino, Lucy J.In common practice, sensor nodes are randomly deployed in wireless sensor network (WSN); hence, location information of sensor node is crucial in WSN applications. Localization of sensor nodes performed using a fast area exploration mechanism facilitates precise location-based sensing and communication. In the proposed localization scheme, the mobile anchor (MA) nodes integrated with localization and directional antenna modules are employed to assist in localizing the static nodes. The use of directional antennas evades trilateration or multilateration techniques for localizing static nodes thereby resulting in lower communication and computational overhead. To facilitate faster area coverage, in this paper, we propose a hybrid of max-gain and cost-utility–based frontier (HMF) area exploration method for MA node's mobility. The simulations for the proposed HMF area exploration–based localization scheme are carried out in the Cooja simulator. The paper also proposes additional enhancements to the Cooja simulator to provide directional and sectored antenna support. This additional support allows the user with the flexibility to feed radiation pattern of any antenna obtained either from simulated data of the antenna design simulator, ie, high frequency structure simulator (HFSS) or measured data of the vector network analyzer (VNA). The simulation results show that the proposed localization scheme exhibits minimal delay, energy consumption, and communication overhead compared with other area exploration–based localization schemes. The proof of concept for the proposed localization scheme is implemented using Berkeley motes and customized MA nodes mounted with indigenously designed radio frequency (RF) switch feed network and sectored antenna.