Browsing by Author "Gudino, Lucy J."

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AMCCR: Adaptive Multi-QoS Cross-Layer Cooperative Routing in Ad Hoc Networks
(ACM Digital Library, 2017-01) Gudino, Lucy J.
The cooperative communication technique in an ad hoc network exploits the spatial diversity gains inherent in multiuser systems and mitigates the multipath fading. This technique is necessary but perhaps not sufficient to meet the QoS demands in ad hoc network. This is due to the fact that routing protocol at the network layer is more responsible for the successful packet delivery and QoS support. In this paper, we propose an adaptive multi-QoS cross-layer cooperative routing (AMCCR) protocol that enhances the performance through the cooperation of physical, MAC, and network layers. We first formulate an approach to analyze the channel state variations for effective communication schemes at the physical layer. Secondly, we dynamically select the transmission mode to employ cooperative MAC scheme by exploiting spatial diversity. Thereafter, the network layer chooses an optimized route from source to destination through the selected best relay candidates based on multiple QoS metrics. The paper is further extended to support dual-hop half-duplex communication via selected relay by coding technique. The proposed protocol is validated by extensive simulations and compared with CD-MAC and CODE protocols. The results clearly show that the proposed cooperative cross-layer design approach significantly improves the average delay, throughput, and network lifetime of the system.
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.
A Band-notched Ultra-wideband Compact Planar Monopole Antenna With U-shaped Parasitic Element
(Elsevier, 2016) Gudino, Lucy J.
In this paper, we propose a compact ultra-wideband (UWB) planar monopole antenna with integrated band-notch filtering. The proposed antenna is composed of a rectangular radiating patch, partial ground plane and U-shaped parasitic element on the bottom plane of the antenna symmetrical to the radiating patch. The dimensions of parasitic element have been optimized to achieve band-notch filtering, in order to avoid IEEE 802.11a interference in the frequency range 5.15 to 5.825GHz. The proposed antenna is compact (19x16x1.6mm) and also achieves VSWR ≤ 2 for frequency ranging from 3 to 10.3GHz except for the band-notched frequency. High Frequency Structure Simulator has been used to simulate the proposed antenna and analyze its performance in terms of resonating frequency, VSWR, gain and radiation pattern. Dominant factors affecting the centre frequency and bandwidth of the notched-band are also investigated.
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.
Congestion-adaptive and delay-sensitive multirate routing protocol in MANETs: a cross-layer approach
(Hindawi Publishing Corporation, 2019) Gudino, Lucy J.
With a growing demand of multimedia communication over MANETs, to support quality of service (QoS), the MAC standards such as 802.11a/b/g operate with multiple data rates to efficiently utilize the limited resources. Since the wireless channel is shared among the neighbors in MANETs, determining delay-sensitive and congestion-aware routes using the IEEE 802.11 MAC is still a challenging problem. This paper proposes a novel cross-layer approach called congestion-adaptive and delay-sensitive multirate (CADM) routing protocol in MANETs. The CADM protocol exploits the cross-layer interaction between the network layer, MAC, and physical layer. The CADM accesses the correlation between data rate, congestion metric, and MAC delay in delay-sensitive applications to provide enhanced network efficiency in MANETs. The protocol discovers multiple node-disjoint routes and facilitates optimal data rates between the links based on the estimated delay to admit a flow with the certain delay requirement in multirate MANETs. The proposed CADM protocol discovers the route through less congested nodes and also actively handles the congestion if it occurs. The performance of the CADM protocol is comprehensively assessed through the simulation, which highlights the advantages of our cross-layer mechanism.
Cross layer adaptive congestion control for best-effort traffic of IEEE 802.11e in mobile ad hoc networks
(IEEE, 2016) Gudino, Lucy J.
The dominance of multimedia traffic over the Internet, coupled with the rising number of applications of MANETs, has made Quality of Service (QoS) a major concern. The IEEE 802.11e standard enhanced distributed channel access(EDCA) has been proposed as an enhancement of 802.11 standard, which provides QoS at MAC layer with a service differentiation scheme for high priority traffic. But IEEE 802.11e has not adequately addressed the issue of handling best effort traffic data flows through contention-based networks which in turn results in TCP performance degradation. To enhance the best effort traffic performance in 802.11e with high-quality of service to maximize the system throughput, we propose a novel scheme called, Adaptive Best Effort Traffic Scheduler for EDCA(ABET-EDCA). In this scheme, TCP packets get prioritized by dynamically adapting to contention window parameters. In addition to this, traffic class monitors the MAC queue and computes TXOP limits value at runtime. This results in reduced delay and loss factor. Additionally, we incorporate the cross layer approach by exploiting the physical and MAC layer information to initiate corrective measures at the Transport and Network layer to enhance best effort traffic performance. The simulation conducted shows the significant improvement in TCP performance in terms of goodput, delay and throughput even under high loads compared to EDCA.
Cross layer approach for effective multi hop broadcast in VANET
(IEEE, 2017) Gudino, Lucy J.
Cooperative communication in VANET has become the de-facto in enabling technology to improve safety and efficiency on inter-vehicle communication (IVC). The safety related messages broadcast on emergency must have a minimum delay and high reliability. This paper proposes a cross-layer approach to efficiently broadcast the safety messages by minimizing the message redundancy and maintaining low end-to-end communication delays. We propose a scheme to select a one-hop neighbor relay as a potential forwarder for relaying the broadcast messages to improve the transmission reliability in a platoon of vehicles. The relay selection metrics compose of vehicular density, velocity, and the geographical location. The selected relay controls the broadcast messages with minimum overhead and with minimum bandwidth consumption. Similarly, a multimedia emergency message needs high priority with a shorter transmission delay. To provide the service differentiation to different traffic classes, we adopt 802.11e MAC. The cross layer is further extended to the transport layer to dynamically adapt the data transmission rate based on the physical channel state. The extensive simulation analysis conducted reveals that the proposed cross-layer scheme effectively propagates the critical broadcast messages with lesser packet latency and higher packet delivery ratio.
Cross Layer Approach for Efficient Dissemination of Emergency Messages in VANETs
(IEEE, 2017-07) Gudino, Lucy J.
This paper proposes a cross layer approach for efficient dissemination of emergency messages in VANETs (CLDEM) by minimizing the message redundancy and maintaining low end-to-end communication delays. We propose a scheme to select a one-hop neighbor relay as a potential forwarder for relaying the broadcast messages to improve the transmission reliability in a platoon of vehicles. The relay selection metrics compose of vehicular density, vehicular velocity, and the geographical location. The selected relay controls the broadcast messages with minimum overhead and with minimum bandwidth consumption. To provide the service differentiation to different traffic classes, we adopt 802.11e MAC. The cross layer is further extended to the transport layer to dynamically adapt the data transmission rate based on the physical channel state. The extensive simulation analysis conducted reveals that the proposed cross-layer scheme effectively propagates the critical broadcast messages with minimum latency.
Cross Layer Best effort QoS aware routing protocol for Ad Hoc Network
(IEEE, 2015) Gudino, Lucy J.
Mobile Ad Hoc Networks (MANETs) are a self organizing and adaptive wireless networks. Currently MANETs possess an advanced challenge in providing Quality of Service( QoS) support for real time application data streaming through the network. These applications are delay sensitive and get affected due to congestion in the network. Thus, performance degrades due to high data loss, frequent link breakage and excessive retransmission. The strict layered network structure makes even more difficult to provide solutions for such issues. We propose a protocol which cooperates between adjacent layers and performs cross layer communication. We propose a novel QoS routing for MANET called Cross Layer Best effort QoS aware routing protocol (CLBQ) which considers the metric of link quality, data rates and MAC delay as the QoS parameters. The proposed protocol implements cross layer interaction between PHY, MAC and Network layer. The simulation results conducted shows best effort QoS service to the network in discovering the route and data transfer. Our analysis shows that the protocol has improved throughput and low network overhead.
Cross layer congestion aware multi rate multi path routing protocol for ad hoc network
(IEEE, 2015) Gudino, Lucy J.
Modern wireless devices, which implement the 802.11b standard, utilizes multiple transmission rates in order to accommodate a varied range of channel conditions. Many rate adaptation algorithms proposed, utilizes the multi data rate, primarily according to the current channel quality. Most algorithms do not consider congestion around the network and proper determinant to identify it. In multi rate Ad hoc network, due to mismatched link rate, the node interface queues get overloaded. Thus causing congestion, which consequently result in packet loss, further reducing effective throughput. In this paper, we propose a novel Cross layer QoS aware Multi Rate routing protocol (CQMR) based on nodes queuing load and link state. CQMR focuses on cross-layer interactions between PHY, MAC and Network layer to utilize these multi-rate supports from 802.11b. CQMR algorithm chooses the optimal path with effective data rate and through a less congested network, which is compatible with existing 802.11 implementations. We have implemented CQMR in the NS-2 simulator and conducted extensive simulation studies over network diversity. Our analysis shows that CQMR protocol significantly increases the network performance in the packet delivery ratio and throughput.
Cross layer multi QoS metric routing for multimedia traffic in 802.11E over MANETs
(IEEE, 2016) Gudino, Lucy J.
To support QoS for a multimedia traffic, IEEE 802.11e standard Enhanced distributed channel access (EDCA) has been proposed. However, the EDCA is more focused on providing quality of service(QoS) solution at the MAC layer, which is necessary, but perhaps not sufficient as the layered TCP stack architecture does not satisfy the QoS demands in ad hoc network. This is due to the fact that routing protocol is responsible for the successful packet delivery and QoS Support. The conventional single scalar routing protocols are not suitable for high traffic QoS sensitive multimedia traffic load on Mobile ad Hoc Networks (MANETs). The paper proposes a Cross layer Multimetric link disjoint Multipath Routing (CMMR) protocol based on distinct QoS constraints. The paper uses cross-layer communications to consider multiple layer metrics like MAC queue utilization, node density degree, and mobility factor to achieve channel state awareness and keep the up to date status of the route in terms of QOS proficiency at each intermediate node. The proposed algorithm is validated with an extensive simulation with high real time traffic using NS3. The results show significant improvement of CMMR in terms of packet delivery, and end-to-end delay.
Cross layered adaptive cooperative routing mode in mobile ad hoc networks
(IEEE, 2016) Gudino, Lucy J.
A Cooperative communication technique has gained considerable attention in the recent time to improve the quality of service (QoS) of ad hoc networks. Cooperative communication significantly improves link capacity through physical layer technique, and spatial diversity gain is achieved by using neighboring nodes to retransmit the overheard information to the intended destination node. However, upper layer protocols are not elegantly designed to adequately exploit the spatial diversity to improve overall network performance in ad hoc networks. Limiting the cooperation to one network layer may not be the best solution. Thus, in this paper, we intend to achieve multilayer functionality from physical layer to the routing layer to provide cooperative communication. An adaptive cross layered cooperative routing algorithm (ACCR) is proposed to analyze the channel state variations and selectively choose the cooperative MAC scheme on demand by exploiting spatial diversity. The algorithm dynamically selects best relay candidates based on QoS metric, contention delay and node energy fairness. Network layer, then chooses an optimized path from source to destination through the selected relay nodes. We validate the algorithm with extensive simulations. The results clearly show that cooperative cross-layer design approach effectively improves the average throughput and average delay for each packet transmission.
A Cross-Layer Delay-Aware Multipath Routing Algorithm for Mobile Adhoc Networks
(AIRCJJ, 2014-05) Gudino, Lucy J.
Mobile Ad Hoc Networks (MANETS) require reliable routing and Quality of Service(QoS) mechanism to support diverse applications with varying and stringent requirements. Routing protocols such as AODV, AOMDV, DSR and OLSR use minimum hop count as the metric for path selection, hence are not suitable for delay sensitive real time applications. To support such applications delay constrained routing protocols are employed. These Protocols makes path selection based on the delay over the discovered links during routing discovery and routing table calculations. We propose a variation of a node-disjoint Multipath QoS Routing protocol called Cross Layer Delay aware Node Disjoint Multipath AODV (CLDM-AODV) based on delay constraint. It employs cross-layer communications between MAC and routing layers to achieve link and channel-awareness. It regularly updates the path status in terms of lowest delay incurred at each intermediate node. Performance of the proposed protocol is compared with single path AODV and NDMR protocols. Proposed CLDM-AODV is superior in terms of better packet delivery and reduced overhead between intermediate nodes.
A Cross-Layer Delay-Aware Node Disjoint Multipath Routing Algorithm for Mobile Ad Hoc Networks
(AIRCJJ, 2014) Gudino, Lucy J.
Mobile Ad Hoc Networks (MANETS) require reliable routing and Quality of Service(QoS) mechanism to support diverse applications with varying and stringent requirements. Routing protocols such as AODV, AOMDV, DSR and OLSR use minimum hop count as the metric for path selection, hence are not suitable for delay sensitive real time applications. To support such applications delay constrained routing protocols are employed. These Protocols makes path selection based on the delay over the discovered links during routing discovery and routing table calculations. We propose a variation of a node-disjoint Multipath QoS Routing protocol called Cross Layer Delay aware Node Disjoint Multipath AODV (CLDM-AODV) based on delay constraint. It employs cross-layer communications between MAC and routing layers to achieve link and channel-awareness. It regularly updates the path status in terms of lowest delay incurred at each intermediate node. Performance of the proposed protocol is compared with single path AODV and NDMR protocols. Proposed CLDM-AODV is superior in terms of better packet delivery and reduced overhead between intermediate nodes.
Cross-layer protocol stack development for three-dimensional underwater Acoustic Sensor Network
(Elsevier, 2017-08) Gudino, Lucy J.
There is a huge interest in the research community to explore the ocean using sensor networks. Various factors such as resource constraints of sensor networks, requirements of applications, properties of underwater acoustic communication and features of ocean environment have a big impact on the design and development of the network architecture as well as the protocol stack. For a long-term deployment of a network, energy efficiency is the most important design criteria. For achieving energy efficiency and overall improvement in network performance, a new approach of cross-layer protocol stack design is being explored by researchers. In this work, a cross-layer protocol stack has been developed for a three-dimensional Underwater Acoustic Sensor Network (UASN) that can be used for a long-term monitoring of ocean column. The proposed stack with cross-layer design combines physical layer, data link layer, network layer protocols along with time-synchronization, clustering and power level management. This protocol stack has been successfully implemented on the UnetSim which is an open source underwater network simulator. In this paper, the details of protocol stack, it's implementation on UnetSim along with results and analysis of results have been provided
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.
Design of novel sharp transition multiband FIR filter
(IEEE, 2010) Gudino, Lucy J.
This paper presents the synthesis of a linear phase, sharp transition, multiband FIR filter. The frequency response model of the filter is formulated with equiripple passband, stopband regions using trigonometric functions and well defined linear transition region. Employing trigonometric functions reduces Gibb's phenomenon which is further reduced using variable density of ripple cycles in passband and stopband regions. Large density of ripples cycles are introduced at the transition edges which reduces the abrupt discontinuities at these edges. Thus passband ripple reduces and stopband attenuation improves. Slope equalization technique is applied to further reduce Gibb's phenomenon. Using the filter model, for the desired filter specifications, a closed form expression for impulse response coefficients is derived. The design allows for variation in center frequency, number and width of passbands, transition bandwidth, passband ripple and stopband attenuation without the need of separate design. The proposed design is simple, analytical, gives narrow transition bandwidth, less passband ripple, good stopband attenuation with less filter order.
Development of adaptive beamforming algorithms for wireless communication networks
(IEEE, 2011) Gudino, Lucy J.
It is required to provide enough capacity in the wireless communication system due to increased number of users as well as new high bit rate services being introduced. One of the most promising techniques for increasing the capacity is smart antenna based space division multiplexing. One approach to implement smart antennas is based on array beamforming, where a narrow main beam is directed towards the desired user direction, while the nulls or the sidelobes with very low levels are adjusted towards other users. Recently, smart antennas have been proposed as a promising solution that can significantly increase the data rate and improve the quality of wireless transmission, which is limited by interference, local scattering, and multipath propagation. The antenna array is combined with digital signal processing to give a narrow beam pattern in response to the received signal by the smart antenna. The weights of the beamformer is calculated by using the adaptive approach which uses reference signal and the direction of the user based on the received signal. The main beam is then directed toward the specific user, while the nulls are adjusted toward the interferers.
DS-MMAC: dynamic schedule based MAC for mobile wireless sensor network
(ACM Digital Library, 2016-04) Gudino, Lucy J.
In this paper, we propose a medium access protocol for Mobile Wireless Sensor Network which uses dynamic scheduling of time slot for channel access. We have considered a mixed deployment of both mobile and static wireless sensor nodes. The static nodes, which act as cluster head, maintain a local schedule to service the mobile neighbors and also route data to the base station. The design goals of our MAC are energy efficiency, increased packet delivery and low control overhead. The request-reply mechanism for data transfer, used in our approach, plays a vital role in the handover process. Simulation results indicate that our approach performs better in terms of data rate, energy efficiency and control overhead when compared with Hybrid MAC protocol. Testbed results indicate that the proposed approach can be effectively used in WSN where topology change is frequent.
Energy Efficient Mobile MAC Protocol with Mobility Vector for Neighbor Selection in Wireless Sensor Networks
(Praise Worthy Prize, 2016) Gudino, Lucy J.
Scenarios where the sensors are mobile, introduce a new set of issues to be addressed in the design of their protocol stack. The layers that get affected the most are the Medium Access Control(MAC) and the network layer. This paper presents a multichannel mobile MAC protocol with Mobility Vector for neighbour discovery. Static nodes in the network use sleep wake pattern to conserve energy. The mobility vector information such as direction and speed, along with the nodes residual energy are used to select a neighbour that can provide maximum connection retention time. Mobility vector information is also used to wake those neighbours that are in the trajectory of the mobile node movement. The proposed multichannel protocol guarantees an interference-free communication. The proposed approach is simulated and compared against other similar MAC protocols, in terms of data-rate, control overhead and energy. Experimental results indicate that the multi-channel MAC gives better results when compared to single channel MAC protocols. Implementation of the proposed approach is tested using Berkley motes and by using custom designed mobile node.