Asadul Hoque - Profile on Academia.edu (original) (raw)

Papers by Asadul Hoque

Determination of Criticality of Freight Railroad Infrastructure Based on Flow Optimization under Heavy Congestion

ABSTRACT Freight transportation by railroads is an integral part of the U.S. economy. Identifying... more ABSTRACT Freight transportation by railroads is an integral part of the U.S. economy. Identifying critical rail infrastructures can help stakeholders prioritize protection initiatives or add necessary redundancy to maximize system resiliency. The criticality of an infrastructure element, link or yard, is based on the increased cost (delay) incurred when that element is disrupted. An event of disruption can cause heavy congestion and the capacity at links and yards should be considered when the fright flow is re-routed. This paper proposes an optimization model for making-up and routing of trains in a disruptive situation to minimize the system-wide total cost, including classification time at yards and travel cost time along the links. Train design optimization seeks to determine the optimal number of trains, their routes, and associated blocks, subject to various capacity and operational constraints at rail links and yards. An iterative heuristic algorithm is proposed to attack the computational burden for real-world networks. The solution algorithm considers the impact of volume on travel time in a congested or near-congested network. The proposed heuristics provide a quality solution with high speed, demonstrated by numerical experiments for small instances. A case study is conducted for the network of a major U.S. Class-1 railroad company based on publicly available data. The paper provides a map showing the criticality of infrastructure in the study area. The heuristic algorithm can also help in managing freight flow in response to a disruptive event.

IEEE Southeastcon 2009, 2009

Channel assignment algorithms revealed so far in the literature for multi-radio multi-channel wir... more Channel assignment algorithms revealed so far in the literature for multi-radio multi-channel wireless mesh networks (MRMC-WMN) mainly deals with orthogonal channels (non-overlapped channels). But considering the

Vehicular Communications, 2014

Vehicle to Vehicle (V2V) communication provides a flexible and real-time information disseminatio... more Vehicle to Vehicle (V2V) communication provides a flexible and real-time information dissemination mechanism through various applications of Intelligent Transportation Systems (ITS). Achieving seamless connectivity through multi-hop vehicular communication with sparse network is a challenging issue. In this paper, we have studied this multi-hop vehicular connectivity in an urban scenario using GPS traces obtained from San Francisco Yellow cabs. Our current work describes a new algorithm for the analysis of topological properties like connectivity and partitions for any kind of vehicular or mobile computing environment. The novel approach uses bitwise manipulation of sparse matrix with an efficient storage technique for determining multi-hop connectivity. The computation mechanism can be further scaled to parallel processing environment. The main contribution of this research is threefold. First, developing an efficient algorithm to quantify multi-hop connectivity with the aid of bitwise manipulation of sparse matrix. Second, investigating the time varying nature of multi-hop vehicular connectivity and dynamic network partitioning of the topology. Third, deriving a mathematical model for calculating message propagation rate in an urban environment.

2012 International Conference on Computing, Networking and Communications (ICNC), 2012

This paper analyzes urban taxi mobility traces obtained from San Francisco Yellow cabs. The paper... more This paper analyzes urban taxi mobility traces obtained from San Francisco Yellow cabs. The paper presents a rigorous analysis of taxi mobility pattern with the instantaneous velocity profile, spatio-temporal distribution, connectivity of vehicle communications, clustering, hotspots and other characteristics like trip duration and empty cruise interval. The empirical data analyses presented here can be a helpful resource for wireless researchers, government organizations, taxi companies and even for the drivers or passengers. While wireless researchers can estimate the capabilities and constraints of vehicular communication from connectivity and mobility patterns, government can plan and work on issues related to implementing proper DSRC infrastructure. Finally, taxi companies and drivers can benefit from maximizing the trip revenue and minimize empty cruise time though balanced loaddistribution and awareness of the hotspots.

GLOBECOM 2009 - 2009 IEEE Global Telecommunications Conference, 2009

Existing channel assignment algorithms designed for multi-radio multi-channel wireless mesh netwo... more Existing channel assignment algorithms designed for multi-radio multi-channel wireless mesh networks (MRMC-WMN) mainly deal with orthogonal or nonoverlapped channels. But in reality, the limited availability of orthogonal channel is a major issue where the network is very dense in terms of inter-nodal distances. On the other hand, partially overlapped channels (POC) are currently considered as a great potential for increasing the number of simultaneous transmissions and eventually upgrading the network capacity; especially in case of MRMC-WMN. In this paper, we address the limited orthogonal channel problem by exploring the usable POCs. The key technique lies in the fact that the interference between adjacent channels has to be considered intelligently in order to increase the overall capacity. Our contributions include a new interference model I-Matrix that helps selecting channels with less interference and a POCbased channel assignment algorithm. We evaluate the performance of our POC based algorithm in terms of capacity by comparing with the one using only orthogonal channels. Our results show capacity improvement as the increased link assignments at an average of more than 15 percent.

2008 3rd International Conference on Communication Systems Software and Middleware and Workshops (COMSWARE '08), 2008

One of the vital key elements for providing Quality of Service (QoS) for VoIP is the Call Admissi... more One of the vital key elements for providing Quality of Service (QoS) for VoIP is the Call Admission Control (CAC) capabilities of the Session Management /Call Session Control Function or gateway. Even though the network may be designed to meet a given performance and restoration objective for the engineered traffic loads, the actual traffic may be significantly higher. Without a CAC function in a VoIP network during overloads, links become congested and new calls keep getting admitted. All calls in progress, not just the new calls start dropping packets and experiencing longer delays. Contrast this to a circuit switched network, where new calls get blocked, but calls in progress experience good call quality. In the VoIP case, packet loss could become large enough that calls become unintelligible, callers hang-up their call, and most will reattempt. This paper gives an overview of potential CAC approaches, highlighting four basic alternatives; based on endpoint performance measurements, path-based bandwidth management, link-based bandwidth management, and per-call bandwidth reservation. The paper also recommends a link bandwidth management approach for its scalability and efficacy.

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IEEE Wireless Communications, 2010

2012 International Conference on Computing, Networking and Communications (ICNC), 2012

Techniques derived from biological systems explore a new dimension of research in Cognitive Radio... more Techniques derived from biological systems explore a new dimension of research in Cognitive Radio Networks (CRNs). In this paper, we address the stability issue of CRN routing, being motivated by the adaptive 'Attractor-Selector' model.Our work includes designing a routing protocolnamed Bio-inspired Stable Routing (BioStaR) that increases route stability by maximizing the Spectrum Opportunity (SOP)and also minimizes the channel switching delay and signaling overhead. To the best of our knowledge, this is by far the first bio-inspired CRN routing that takes into account the above mentioned factors. Our simulation results show that this protocol accounts for both higher stability of route and less signaling overhead in spectrum-agile CRN environments.

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IEEE Wireless Communications, 2010

Techniques derived from biological systems explore a new dimension of research in Cognitive Radio... more Techniques derived from biological systems explore a new dimension of research in Cognitive Radio Networks (CRNs). In this paper, we address the stability issue of CRN routing, being motivated by the adaptive `Attractor-Selector' model. Our work includes designing a routing protocolnamed Bio-inspired Stable Routing (BioStaR) that increases route stability by maximizing the Spectrum Opportunity (SOP)and also minimizes the channel switching delay and signaling overhead. To the best of our knowledge, this is by far the first bio-inspired CRN routing that takes into account the above mentioned factors. Our simulation results show that this protocol accounts for both higher stability of route and less signaling overhead in spectrum-agile CRN environments.

Existing channel assignment algorithms designed for multi-radio multi-channel wireless mesh netwo... more Existing channel assignment algorithms designed for multi-radio multi-channel wireless mesh networks (MRMC-WMN) mainly deal with orthogonal or nonoverlapped channels. But in reality, the limited availability of orthogonal channel is a major issue where the network is very dense in terms of inter-nodal distances. On the other hand, partially overlapped channels (POC) are currently considered as a great potential for increasing the number of simultaneous transmissions and eventually upgrading the network capacity; especially in case of MRMC-WMN. In this paper, we address the limited orthogonal channel problem by exploring the usable POCs. The key technique lies in the fact that the interference between adjacent channels has to be considered intelligently in order to increase the overall capacity. Our contributions include a new interference model I-Matrix that helps selecting channels with less interference and a POCbased channel assignment algorithm. We evaluate the performance of our POC based algorithm in terms of capacity by comparing with the one using only orthogonal channels. Our results show capacity improvement as the increased link assignments at an average of more than 15 percent. (Abstract)

One of the vital key elements for providing quality of service (QoS) for VoIP is the call admissi... more One of the vital key elements for providing quality of service (QoS) for VoIP is the call admission control (CAC) capabilities of the session management/call session control function or gateway. Even though the network may be designed to meet a given performance and restoration objective for the engineered traffic loads, the actual traffic may be significantly higher. Without a CAC function in a VoIP network during overloads, links become congested and new calls keep getting admitted. All calls in progress, not just the new calls start dropping packets and experiencing longer delays. Contrast this to a circuit switched network, where new calls get blocked, but calls in progress experience good call quality. In the VoIP case, packet loss could become large enough that calls become unintelligible, callers hang-up their call, and most will reattempt. This paper gives an overview of potential CAC approaches, highlighting four basic alternatives; based on endpoint performance measurements, path-based bandwidth management, link-based bandwidth management, and per-call bandwidth reservation. The paper also recommends a link bandwidth management approach for its scalability and efficacy.

GRSB - guaranteed, reliable, secure broadcast - is a protocol that provides reliable and secure b... more GRSB - guaranteed, reliable, secure broadcast - is a protocol that provides reliable and secure broadcast/multicast communications. It can be implemented in many types of networks - local area networks, wide area networks, as well as satellite communications. The methodology used in this protocol is surprisingly simple. Three logical nodes are enforced in the network - a central retransmiter, a designated acknowledger, and a playback recorder(s). Through the coordinated service of the three nodes, every user node can be guaranteed to receive all broadcast messages in the correct temporal order. A fourth logical node, the security controller, can be added to the protocol to provide security-related services such as user authentication, message encryption, etc. In this paper, we have proposed a multilevel broadcast model of GRSB (guaranteed, reliable and secure broadcast) protocol , where 1st level broadcast mostly maintains the traditional GRSB model. 2nd level broadcast has two types of nodes where nodes of Is' kind i.e. nodes that are directly connected with the attachment nodes, can be temporarily in 'not alive' condition and hence follow the traditional GRSB model as well. On the other hand, nodes of 2nd kind i.e. nodes that are not directly connected with the attachment nodes, must be 'alive' all the time and have to follow two phases to finish the broadcast.

Determination of Criticality of Freight Railroad Infrastructure Based on Flow Optimization under Heavy Congestion

ABSTRACT Freight transportation by railroads is an integral part of the U.S. economy. Identifying... more ABSTRACT Freight transportation by railroads is an integral part of the U.S. economy. Identifying critical rail infrastructures can help stakeholders prioritize protection initiatives or add necessary redundancy to maximize system resiliency. The criticality of an infrastructure element, link or yard, is based on the increased cost (delay) incurred when that element is disrupted. An event of disruption can cause heavy congestion and the capacity at links and yards should be considered when the fright flow is re-routed. This paper proposes an optimization model for making-up and routing of trains in a disruptive situation to minimize the system-wide total cost, including classification time at yards and travel cost time along the links. Train design optimization seeks to determine the optimal number of trains, their routes, and associated blocks, subject to various capacity and operational constraints at rail links and yards. An iterative heuristic algorithm is proposed to attack the computational burden for real-world networks. The solution algorithm considers the impact of volume on travel time in a congested or near-congested network. The proposed heuristics provide a quality solution with high speed, demonstrated by numerical experiments for small instances. A case study is conducted for the network of a major U.S. Class-1 railroad company based on publicly available data. The paper provides a map showing the criticality of infrastructure in the study area. The heuristic algorithm can also help in managing freight flow in response to a disruptive event.

IEEE Southeastcon 2009, 2009

Channel assignment algorithms revealed so far in the literature for multi-radio multi-channel wir... more Channel assignment algorithms revealed so far in the literature for multi-radio multi-channel wireless mesh networks (MRMC-WMN) mainly deals with orthogonal channels (non-overlapped channels). But considering the

Vehicular Communications, 2014

Vehicle to Vehicle (V2V) communication provides a flexible and real-time information disseminatio... more Vehicle to Vehicle (V2V) communication provides a flexible and real-time information dissemination mechanism through various applications of Intelligent Transportation Systems (ITS). Achieving seamless connectivity through multi-hop vehicular communication with sparse network is a challenging issue. In this paper, we have studied this multi-hop vehicular connectivity in an urban scenario using GPS traces obtained from San Francisco Yellow cabs. Our current work describes a new algorithm for the analysis of topological properties like connectivity and partitions for any kind of vehicular or mobile computing environment. The novel approach uses bitwise manipulation of sparse matrix with an efficient storage technique for determining multi-hop connectivity. The computation mechanism can be further scaled to parallel processing environment. The main contribution of this research is threefold. First, developing an efficient algorithm to quantify multi-hop connectivity with the aid of bitwise manipulation of sparse matrix. Second, investigating the time varying nature of multi-hop vehicular connectivity and dynamic network partitioning of the topology. Third, deriving a mathematical model for calculating message propagation rate in an urban environment.

2012 International Conference on Computing, Networking and Communications (ICNC), 2012

This paper analyzes urban taxi mobility traces obtained from San Francisco Yellow cabs. The paper... more This paper analyzes urban taxi mobility traces obtained from San Francisco Yellow cabs. The paper presents a rigorous analysis of taxi mobility pattern with the instantaneous velocity profile, spatio-temporal distribution, connectivity of vehicle communications, clustering, hotspots and other characteristics like trip duration and empty cruise interval. The empirical data analyses presented here can be a helpful resource for wireless researchers, government organizations, taxi companies and even for the drivers or passengers. While wireless researchers can estimate the capabilities and constraints of vehicular communication from connectivity and mobility patterns, government can plan and work on issues related to implementing proper DSRC infrastructure. Finally, taxi companies and drivers can benefit from maximizing the trip revenue and minimize empty cruise time though balanced loaddistribution and awareness of the hotspots.

GLOBECOM 2009 - 2009 IEEE Global Telecommunications Conference, 2009

Existing channel assignment algorithms designed for multi-radio multi-channel wireless mesh netwo... more Existing channel assignment algorithms designed for multi-radio multi-channel wireless mesh networks (MRMC-WMN) mainly deal with orthogonal or nonoverlapped channels. But in reality, the limited availability of orthogonal channel is a major issue where the network is very dense in terms of inter-nodal distances. On the other hand, partially overlapped channels (POC) are currently considered as a great potential for increasing the number of simultaneous transmissions and eventually upgrading the network capacity; especially in case of MRMC-WMN. In this paper, we address the limited orthogonal channel problem by exploring the usable POCs. The key technique lies in the fact that the interference between adjacent channels has to be considered intelligently in order to increase the overall capacity. Our contributions include a new interference model I-Matrix that helps selecting channels with less interference and a POCbased channel assignment algorithm. We evaluate the performance of our POC based algorithm in terms of capacity by comparing with the one using only orthogonal channels. Our results show capacity improvement as the increased link assignments at an average of more than 15 percent.

2008 3rd International Conference on Communication Systems Software and Middleware and Workshops (COMSWARE '08), 2008

One of the vital key elements for providing Quality of Service (QoS) for VoIP is the Call Admissi... more One of the vital key elements for providing Quality of Service (QoS) for VoIP is the Call Admission Control (CAC) capabilities of the Session Management /Call Session Control Function or gateway. Even though the network may be designed to meet a given performance and restoration objective for the engineered traffic loads, the actual traffic may be significantly higher. Without a CAC function in a VoIP network during overloads, links become congested and new calls keep getting admitted. All calls in progress, not just the new calls start dropping packets and experiencing longer delays. Contrast this to a circuit switched network, where new calls get blocked, but calls in progress experience good call quality. In the VoIP case, packet loss could become large enough that calls become unintelligible, callers hang-up their call, and most will reattempt. This paper gives an overview of potential CAC approaches, highlighting four basic alternatives; based on endpoint performance measurements, path-based bandwidth management, link-based bandwidth management, and per-call bandwidth reservation. The paper also recommends a link bandwidth management approach for its scalability and efficacy.

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IEEE Wireless Communications, 2010

2012 International Conference on Computing, Networking and Communications (ICNC), 2012

Techniques derived from biological systems explore a new dimension of research in Cognitive Radio... more Techniques derived from biological systems explore a new dimension of research in Cognitive Radio Networks (CRNs). In this paper, we address the stability issue of CRN routing, being motivated by the adaptive 'Attractor-Selector' model.Our work includes designing a routing protocolnamed Bio-inspired Stable Routing (BioStaR) that increases route stability by maximizing the Spectrum Opportunity (SOP)and also minimizes the channel switching delay and signaling overhead. To the best of our knowledge, this is by far the first bio-inspired CRN routing that takes into account the above mentioned factors. Our simulation results show that this protocol accounts for both higher stability of route and less signaling overhead in spectrum-agile CRN environments.

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IEEE Wireless Communications, 2010

Techniques derived from biological systems explore a new dimension of research in Cognitive Radio... more Techniques derived from biological systems explore a new dimension of research in Cognitive Radio Networks (CRNs). In this paper, we address the stability issue of CRN routing, being motivated by the adaptive `Attractor-Selector' model. Our work includes designing a routing protocolnamed Bio-inspired Stable Routing (BioStaR) that increases route stability by maximizing the Spectrum Opportunity (SOP)and also minimizes the channel switching delay and signaling overhead. To the best of our knowledge, this is by far the first bio-inspired CRN routing that takes into account the above mentioned factors. Our simulation results show that this protocol accounts for both higher stability of route and less signaling overhead in spectrum-agile CRN environments.

Existing channel assignment algorithms designed for multi-radio multi-channel wireless mesh netwo... more Existing channel assignment algorithms designed for multi-radio multi-channel wireless mesh networks (MRMC-WMN) mainly deal with orthogonal or nonoverlapped channels. But in reality, the limited availability of orthogonal channel is a major issue where the network is very dense in terms of inter-nodal distances. On the other hand, partially overlapped channels (POC) are currently considered as a great potential for increasing the number of simultaneous transmissions and eventually upgrading the network capacity; especially in case of MRMC-WMN. In this paper, we address the limited orthogonal channel problem by exploring the usable POCs. The key technique lies in the fact that the interference between adjacent channels has to be considered intelligently in order to increase the overall capacity. Our contributions include a new interference model I-Matrix that helps selecting channels with less interference and a POCbased channel assignment algorithm. We evaluate the performance of our POC based algorithm in terms of capacity by comparing with the one using only orthogonal channels. Our results show capacity improvement as the increased link assignments at an average of more than 15 percent. (Abstract)

One of the vital key elements for providing quality of service (QoS) for VoIP is the call admissi... more One of the vital key elements for providing quality of service (QoS) for VoIP is the call admission control (CAC) capabilities of the session management/call session control function or gateway. Even though the network may be designed to meet a given performance and restoration objective for the engineered traffic loads, the actual traffic may be significantly higher. Without a CAC function in a VoIP network during overloads, links become congested and new calls keep getting admitted. All calls in progress, not just the new calls start dropping packets and experiencing longer delays. Contrast this to a circuit switched network, where new calls get blocked, but calls in progress experience good call quality. In the VoIP case, packet loss could become large enough that calls become unintelligible, callers hang-up their call, and most will reattempt. This paper gives an overview of potential CAC approaches, highlighting four basic alternatives; based on endpoint performance measurements, path-based bandwidth management, link-based bandwidth management, and per-call bandwidth reservation. The paper also recommends a link bandwidth management approach for its scalability and efficacy.

GRSB - guaranteed, reliable, secure broadcast - is a protocol that provides reliable and secure b... more GRSB - guaranteed, reliable, secure broadcast - is a protocol that provides reliable and secure broadcast/multicast communications. It can be implemented in many types of networks - local area networks, wide area networks, as well as satellite communications. The methodology used in this protocol is surprisingly simple. Three logical nodes are enforced in the network - a central retransmiter, a designated acknowledger, and a playback recorder(s). Through the coordinated service of the three nodes, every user node can be guaranteed to receive all broadcast messages in the correct temporal order. A fourth logical node, the security controller, can be added to the protocol to provide security-related services such as user authentication, message encryption, etc. In this paper, we have proposed a multilevel broadcast model of GRSB (guaranteed, reliable and secure broadcast) protocol , where 1st level broadcast mostly maintains the traditional GRSB model. 2nd level broadcast has two types of nodes where nodes of Is' kind i.e. nodes that are directly connected with the attachment nodes, can be temporarily in 'not alive' condition and hence follow the traditional GRSB model as well. On the other hand, nodes of 2nd kind i.e. nodes that are not directly connected with the attachment nodes, must be 'alive' all the time and have to follow two phases to finish the broadcast.