The Experts below are selected from a list of 2130 Experts worldwide ranked by ideXlab platform

Luca Foschini - One of the best experts on this subject based on the ideXlab platform.

  • IMS-Compliant management of vertical handoffs for mobile multimedia Session Continuity
    IEEE Communications Magazine, 2010
    Co-Authors: Paolo Bellavista, Antonio Corradi, Luca Foschini
    Abstract:

    The recent advances in wireless client devices and the crucial role of multimedia communications in our society have motivated relevant standardization efforts, such as the IP multimedia subsystem, to support Session control, mobility, and interoperability in all-IP next-generation networks. IMS has already driven the design of commercial mobile multimedia, but exhibits limited support for service Continuity during handoffs. In particular, it omits advanced techniques to reduce/eliminate handoff delays, especially during vertical handoffs (i.e., change of the wireless technology employed by a client to access the wired Internet, e.g., from UMTS to WiFi). We propose an original solution for Session Continuity based on the primary design guideline of cleanly and effectively separating the signaling plane (for Session reconfiguration via SIP) from the media delivery plane (data transmission and related handoff management operations). Our optimized handoff management techniques exploit terminal-based decentralized predictions to minimize service-level handoff delays. Different from other recent related work, our proposal fully complies with the standard IMS infrastructure and works at the application level. The reported experimental results point out that our solution, available as an open source tool for the IMS community, reduces playout interruption times relevantly by introducing a limited and scalable signaling overhead.

  • sip based proactive handoff management for Session Continuity in the wireless internet
    International Conference on Distributed Computing Systems Workshops, 2006
    Co-Authors: Paolo Bellavista, Antonio Corradi, Luca Foschini
    Abstract:

    New challenging deployment scenarios are accommodating limited and heterogeneous portable devices that roam in wired-wireless best-effort networks with Session maintenance and Continuity requirements. In particular, continuous services, e.g., multimedia streaming, should not experience any interruption while clients roam between different wireless access localities during service provisioning. The paper describes how to exploit the Session Initiation Protocol (SIP) to build a middleware for Session Continuity, also by integrating with our novel context-aware SIP notification package. In particular, the proposed middleware makes use of SIP notifications to update Session information and to proactively activate Session reconfiguration for roaming clients. Experimental results show that, notwithstanding the portable Java-based implementation, our SIP-based solution is feasible in most common wireless Internet deployment scenarios and achieves good scalability.

  • ICDCS Workshops - SIP-Based Proactive Handoff Management for Session Continuity in the Wireless Internet
    26th IEEE International Conference on Distributed Computing Systems Workshops (ICDCSW'06), 2006
    Co-Authors: Paolo Bellavista, Antonio Corradi, Luca Foschini
    Abstract:

    New challenging deployment scenarios are accommodating limited and heterogeneous portable devices that roam in wired-wireless best-effort networks with Session maintenance and Continuity requirements. In particular, continuous services, e.g., multimedia streaming, should not experience any interruption while clients roam between different wireless access localities during service provisioning. The paper describes how to exploit the Session Initiation Protocol (SIP) to build a middleware for Session Continuity, also by integrating with our novel context-aware SIP notification package. In particular, the proposed middleware makes use of SIP notifications to update Session information and to proactively activate Session reconfiguration for roaming clients. Experimental results show that, notwithstanding the portable Java-based implementation, our SIP-based solution is feasible in most common wireless Internet deployment scenarios and achieves good scalability.

  • application level middleware to proactively manage handoff in wireless internet multimedia
    Lecture Notes in Computer Science, 2005
    Co-Authors: Paolo Bellavista, Antonio Corradi, Luca Foschini
    Abstract:

    New deployment scenarios tend to consider the requirement of Session Continuity for service provisioning, especially multimedia streaming, to limited heterogeneous portable devices roaming among wireless localities. In particular, multimedia streaming should not experience any interruption while clients roam in wired-wireless integrated networks based on the standard best-effort Internet. The paper proposes an application-level middleware approach to proactively overcome Wi-Fi handoff and maintain multimedia Session Continuity in the wireless Internet by exploiting mobile proxies running on the wired network. Mobile middleware proxies locally support resource-limited clients, avoid packet losses during handoffs, pre-fetch local buffers with multimedia contents before handoff occurrence, and possibly reconfigure/renegotiate ongoing Sessions after handoffs. Experimental results show that, notwithstanding the application-level implementation, mobile proxies can avoid streaming discontinuities with good efficiency in wireless-wired integrated networks even if their pro-activity is based on simple and lightweight handoff prediction techniques.

  • MMNS - Application-Level middleware to proactively manage handoff in wireless internet multimedia
    Management of Multimedia Networks and Services, 2005
    Co-Authors: Paolo Bellavista, Antonio Corradi, Luca Foschini
    Abstract:

    New deployment scenarios tend to consider the requirement of Session Continuity for service provisioning, especially multimedia streaming, to limited heterogeneous portable devices roaming among wireless localities. In particular, multimedia streaming should not experience any interruption while clients roam in wired-wireless integrated networks based on the standard best-effort Internet. The paper proposes an application-level middleware approach to proactively overcome Wi-Fi handoff and maintain multimedia Session Continuity in the wireless Internet by exploiting mobile proxies running on the wired network. Mobile middleware proxies locally support resource-limited clients, avoid packet losses during handoffs, pre-fetch local buffers with multimedia contents before handoff occurrence, and possibly reconfigure/renegotiate ongoing Sessions after handoffs. Experimental results show that, notwithstanding the application-level implementation, mobile proxies can avoid streaming discontinuities with good efficiency in wireless-wired integrated networks even if their pro-activity is based on simple and lightweight handoff prediction techniques.

Paolo Bellavista - One of the best experts on this subject based on the ideXlab platform.

  • IMS-Compliant management of vertical handoffs for mobile multimedia Session Continuity
    IEEE Communications Magazine, 2010
    Co-Authors: Paolo Bellavista, Antonio Corradi, Luca Foschini
    Abstract:

    The recent advances in wireless client devices and the crucial role of multimedia communications in our society have motivated relevant standardization efforts, such as the IP multimedia subsystem, to support Session control, mobility, and interoperability in all-IP next-generation networks. IMS has already driven the design of commercial mobile multimedia, but exhibits limited support for service Continuity during handoffs. In particular, it omits advanced techniques to reduce/eliminate handoff delays, especially during vertical handoffs (i.e., change of the wireless technology employed by a client to access the wired Internet, e.g., from UMTS to WiFi). We propose an original solution for Session Continuity based on the primary design guideline of cleanly and effectively separating the signaling plane (for Session reconfiguration via SIP) from the media delivery plane (data transmission and related handoff management operations). Our optimized handoff management techniques exploit terminal-based decentralized predictions to minimize service-level handoff delays. Different from other recent related work, our proposal fully complies with the standard IMS infrastructure and works at the application level. The reported experimental results point out that our solution, available as an open source tool for the IMS community, reduces playout interruption times relevantly by introducing a limited and scalable signaling overhead.

  • sip based proactive handoff management for Session Continuity in the wireless internet
    International Conference on Distributed Computing Systems Workshops, 2006
    Co-Authors: Paolo Bellavista, Antonio Corradi, Luca Foschini
    Abstract:

    New challenging deployment scenarios are accommodating limited and heterogeneous portable devices that roam in wired-wireless best-effort networks with Session maintenance and Continuity requirements. In particular, continuous services, e.g., multimedia streaming, should not experience any interruption while clients roam between different wireless access localities during service provisioning. The paper describes how to exploit the Session Initiation Protocol (SIP) to build a middleware for Session Continuity, also by integrating with our novel context-aware SIP notification package. In particular, the proposed middleware makes use of SIP notifications to update Session information and to proactively activate Session reconfiguration for roaming clients. Experimental results show that, notwithstanding the portable Java-based implementation, our SIP-based solution is feasible in most common wireless Internet deployment scenarios and achieves good scalability.

  • ICDCS Workshops - SIP-Based Proactive Handoff Management for Session Continuity in the Wireless Internet
    26th IEEE International Conference on Distributed Computing Systems Workshops (ICDCSW'06), 2006
    Co-Authors: Paolo Bellavista, Antonio Corradi, Luca Foschini
    Abstract:

    New challenging deployment scenarios are accommodating limited and heterogeneous portable devices that roam in wired-wireless best-effort networks with Session maintenance and Continuity requirements. In particular, continuous services, e.g., multimedia streaming, should not experience any interruption while clients roam between different wireless access localities during service provisioning. The paper describes how to exploit the Session Initiation Protocol (SIP) to build a middleware for Session Continuity, also by integrating with our novel context-aware SIP notification package. In particular, the proposed middleware makes use of SIP notifications to update Session information and to proactively activate Session reconfiguration for roaming clients. Experimental results show that, notwithstanding the portable Java-based implementation, our SIP-based solution is feasible in most common wireless Internet deployment scenarios and achieves good scalability.

  • application level middleware to proactively manage handoff in wireless internet multimedia
    Lecture Notes in Computer Science, 2005
    Co-Authors: Paolo Bellavista, Antonio Corradi, Luca Foschini
    Abstract:

    New deployment scenarios tend to consider the requirement of Session Continuity for service provisioning, especially multimedia streaming, to limited heterogeneous portable devices roaming among wireless localities. In particular, multimedia streaming should not experience any interruption while clients roam in wired-wireless integrated networks based on the standard best-effort Internet. The paper proposes an application-level middleware approach to proactively overcome Wi-Fi handoff and maintain multimedia Session Continuity in the wireless Internet by exploiting mobile proxies running on the wired network. Mobile middleware proxies locally support resource-limited clients, avoid packet losses during handoffs, pre-fetch local buffers with multimedia contents before handoff occurrence, and possibly reconfigure/renegotiate ongoing Sessions after handoffs. Experimental results show that, notwithstanding the application-level implementation, mobile proxies can avoid streaming discontinuities with good efficiency in wireless-wired integrated networks even if their pro-activity is based on simple and lightweight handoff prediction techniques.

  • MMNS - Application-Level middleware to proactively manage handoff in wireless internet multimedia
    Management of Multimedia Networks and Services, 2005
    Co-Authors: Paolo Bellavista, Antonio Corradi, Luca Foschini
    Abstract:

    New deployment scenarios tend to consider the requirement of Session Continuity for service provisioning, especially multimedia streaming, to limited heterogeneous portable devices roaming among wireless localities. In particular, multimedia streaming should not experience any interruption while clients roam in wired-wireless integrated networks based on the standard best-effort Internet. The paper proposes an application-level middleware approach to proactively overcome Wi-Fi handoff and maintain multimedia Session Continuity in the wireless Internet by exploiting mobile proxies running on the wired network. Mobile middleware proxies locally support resource-limited clients, avoid packet losses during handoffs, pre-fetch local buffers with multimedia contents before handoff occurrence, and possibly reconfigure/renegotiate ongoing Sessions after handoffs. Experimental results show that, notwithstanding the application-level implementation, mobile proxies can avoid streaming discontinuities with good efficiency in wireless-wired integrated networks even if their pro-activity is based on simple and lightweight handoff prediction techniques.

Dmitri Moltchanov - One of the best experts on this subject based on the ideXlab platform.

  • joint use of guard capacity and multiconnectivity for improved Session Continuity in millimeter wave 5g nr systems
    IEEE Transactions on Vehicular Technology, 2021
    Co-Authors: Vyacheslav Begishev, Dmitri Moltchanov, Andrey Samuylov, Sergey Andreev, Yevgeni Koucheryavy, Eduard Sopin, Roman Kovalchukov, Konstantin E. Samouylov
    Abstract:

    The intermittent nature of millimeter wave (mmWave) links caused by human-body blockage is an intrinsic property of the 5G New Radio (NR) technology that may cause drops of Sessions already accepted for service. To improve the Session Continuity, multiconnectivity and guard capacity mechanisms have been proposed recently. Multiconnectivity enables dynamic handover between multiple pre-established spatially-diverse links, while guard capacity reserves a fraction of radio resources for the already accepted Sessions by ensuring that they will have sufficient provisions in case of link blockage. In this study, we combine the tools of queuing theory and stochastic geometry to develop a mathematical framework for capturing the joint operation of these two schemes as well as the features of mmWave radio propagation. The metrics are related to user- and system-centric performance including the system resource utilization and the new and ongoing Session drop probabilities. Our results show that multiconnectivity benefits all of the considered parameters. However, the range of performance boost remains limited by the deployment density and the maximum supported degree of multiconnectivity. In its turn, guard capacity allows to further decrease the ongoing Session drop probability at the expense of the new Session drop probability and the system resource utilization. When implemented jointly with multiconnectivity, guard capacity does not produce noticeable negative effects on the system resource utilization as compared to its standalone use. Hence, one may prefer a joint implementation of these mechanisms for preserving the Session Continuity of users without compromising the resource utilization.

  • DCCN - Characterizing the Degree of LTE Involvement in Supporting Session Continuity in Street Deployment of NR Systems
    Distributed Computer and Communication Networks, 2019
    Co-Authors: Vyacheslav Begishev, Dmitri Moltchanov, Andrey Samuylov, Konstantin E. Samouylov
    Abstract:

    The prospective roll out of recently standardized New Radio (NR) systems operating in millimeter wave frequency band pose unique challenges to network engineers. In this context, the support of NR-based vehicle-to-infrastructure communications is of special interest due to potentially high speeds of user equipment and semi-stochastic dynamic blockage conditions of propagation paths between UE and BR base station (BS). In this conditions even the use of advanced NR functionalities such as multiconnectivity supporting active connections to multiple BSs located nearby may not fully eliminate outages. Thus, to preserve Session Continuity for UEs located on vehicles a degree of LTE support might be required. In this paper, we quantify the amount of LTE support required to maintain Session Continuity in street deployment of NR systems supporting multiconnectivity capabilities. Particularly, we demonstrate that it is heavily affected by the traffic conditions, inter-site distance between NR BSs and the degree of multiconnectivity.

  • Performance evaluation of bandwidth reservation for mmWave in 5G NR systems
    Information and Control Systems, 2019
    Co-Authors: Vyacheslav Begishev, Dmitri Moltchanov, Andrey Samuylov, Edward Sopin, Yuliya Gaidamaka, Konstantin E. Samouylov
    Abstract:

    Introduction: In 3GPP New Radio (NR) systems, frequent radio propagation path blockages can lead to the disconnection of ongoingSessions already accepted into the system, reducing the quality of service in the network. Controlling access to system resource byprioritizing for the ongoing Sessions can increase the Session Continuity. In this paper, we propose resource allocation with a reservationmechanism. Purpose: Development of a mathematical model for analyzing the effect of this mechanism on other system performanceindicators – dropping probabilities for new and ongoing Sessions and system utilization. The model takes into account the key featuresof the 3GPP NR technology, including the height of the interacting objects, the spatial distribution and mobility of the blockers, as wellas the line-of-sight propagation properties between the transceivers for mmWave NR technology. Results: We analyzed the reservationmechanism with the help of a developed model in the form of a resource queueing system with signals, where the base station bandwidthcorresponds to the resource, and the signals model a change in the line-of-sight conditions between the receiving and transmittingdevices. Creating a priority for ongoing Sessions whose service has not yet been completed provides a considerable flexibility forbalancing the Session Continuity and dropping of a new Session, with a slight decrease in the efficiency of the radio resource utility. Withthe developed model, we showed that reserving even a small bandwidth (less than 10% of the total resources) to maintain the ongoingSessions has a positive effect on their Continuity, as it increases the probability of their successful completion. Practical relevance: The proposed mechanism works more efficiently in overload conditions and with Sessions which have a high data transfer raterequirements. This increases the demand for the proposed mechanism in 5G NR communication systems.

  • characterizing the degree of lte involvement in supporting Session Continuity in street deployment of nr systems
    International Conference on Distributed Computer and Communication Networks, 2019
    Co-Authors: Vyacheslav Begishev, Dmitri Moltchanov, Andrey Samuylov, Konstantin E. Samouylov
    Abstract:

    The prospective roll out of recently standardized New Radio (NR) systems operating in millimeter wave frequency band pose unique challenges to network engineers. In this context, the support of NR-based vehicle-to-infrastructure communications is of special interest due to potentially high speeds of user equipment and semi-stochastic dynamic blockage conditions of propagation paths between UE and BR base station (BS). In this conditions even the use of advanced NR functionalities such as multiconnectivity supporting active connections to multiple BSs located nearby may not fully eliminate outages. Thus, to preserve Session Continuity for UEs located on vehicles a degree of LTE support might be required. In this paper, we quantify the amount of LTE support required to maintain Session Continuity in street deployment of NR systems supporting multiconnectivity capabilities. Particularly, we demonstrate that it is heavily affected by the traffic conditions, inter-site distance between NR BSs and the degree of multiconnectivity.

  • Improving Session Continuity With Bandwidth Reservation in mmWave Communications
    IEEE Wireless Communications Letters, 2019
    Co-Authors: Dmitri Moltchanov, Andrey Samuylov, Vitaly Petrov, Margarita Gapeyenko, Nageen Himayat, Sergey Andreev, Yevgeni Koucheryavy
    Abstract:

    Unexpected fluctuations in radio resource demands of active Sessions in millimeter-wave (mmWave) systems caused by dynamic blockage of the line-of-sight path may lead to accidental Session drops. Existing solutions addressing this problem incorporate multi-connectivity operation that reroutes an ongoing Session to another mmWave access point nearby. We introduce and analyze an alternative approach for improving Session Continuity based on the concept of bandwidth reservation. We develop an analytical model for the mmWave system that employs the proposed technique and quantify its benefits and drawbacks. We show that even a small fraction of reserved bandwidth may significantly improve Session Continuity.

Andrey Samuylov - One of the best experts on this subject based on the ideXlab platform.

  • joint use of guard capacity and multiconnectivity for improved Session Continuity in millimeter wave 5g nr systems
    IEEE Transactions on Vehicular Technology, 2021
    Co-Authors: Vyacheslav Begishev, Dmitri Moltchanov, Andrey Samuylov, Sergey Andreev, Yevgeni Koucheryavy, Eduard Sopin, Roman Kovalchukov, Konstantin E. Samouylov
    Abstract:

    The intermittent nature of millimeter wave (mmWave) links caused by human-body blockage is an intrinsic property of the 5G New Radio (NR) technology that may cause drops of Sessions already accepted for service. To improve the Session Continuity, multiconnectivity and guard capacity mechanisms have been proposed recently. Multiconnectivity enables dynamic handover between multiple pre-established spatially-diverse links, while guard capacity reserves a fraction of radio resources for the already accepted Sessions by ensuring that they will have sufficient provisions in case of link blockage. In this study, we combine the tools of queuing theory and stochastic geometry to develop a mathematical framework for capturing the joint operation of these two schemes as well as the features of mmWave radio propagation. The metrics are related to user- and system-centric performance including the system resource utilization and the new and ongoing Session drop probabilities. Our results show that multiconnectivity benefits all of the considered parameters. However, the range of performance boost remains limited by the deployment density and the maximum supported degree of multiconnectivity. In its turn, guard capacity allows to further decrease the ongoing Session drop probability at the expense of the new Session drop probability and the system resource utilization. When implemented jointly with multiconnectivity, guard capacity does not produce noticeable negative effects on the system resource utilization as compared to its standalone use. Hence, one may prefer a joint implementation of these mechanisms for preserving the Session Continuity of users without compromising the resource utilization.

  • DCCN - Characterizing the Degree of LTE Involvement in Supporting Session Continuity in Street Deployment of NR Systems
    Distributed Computer and Communication Networks, 2019
    Co-Authors: Vyacheslav Begishev, Dmitri Moltchanov, Andrey Samuylov, Konstantin E. Samouylov
    Abstract:

    The prospective roll out of recently standardized New Radio (NR) systems operating in millimeter wave frequency band pose unique challenges to network engineers. In this context, the support of NR-based vehicle-to-infrastructure communications is of special interest due to potentially high speeds of user equipment and semi-stochastic dynamic blockage conditions of propagation paths between UE and BR base station (BS). In this conditions even the use of advanced NR functionalities such as multiconnectivity supporting active connections to multiple BSs located nearby may not fully eliminate outages. Thus, to preserve Session Continuity for UEs located on vehicles a degree of LTE support might be required. In this paper, we quantify the amount of LTE support required to maintain Session Continuity in street deployment of NR systems supporting multiconnectivity capabilities. Particularly, we demonstrate that it is heavily affected by the traffic conditions, inter-site distance between NR BSs and the degree of multiconnectivity.

  • Performance evaluation of bandwidth reservation for mmWave in 5G NR systems
    Information and Control Systems, 2019
    Co-Authors: Vyacheslav Begishev, Dmitri Moltchanov, Andrey Samuylov, Edward Sopin, Yuliya Gaidamaka, Konstantin E. Samouylov
    Abstract:

    Introduction: In 3GPP New Radio (NR) systems, frequent radio propagation path blockages can lead to the disconnection of ongoingSessions already accepted into the system, reducing the quality of service in the network. Controlling access to system resource byprioritizing for the ongoing Sessions can increase the Session Continuity. In this paper, we propose resource allocation with a reservationmechanism. Purpose: Development of a mathematical model for analyzing the effect of this mechanism on other system performanceindicators – dropping probabilities for new and ongoing Sessions and system utilization. The model takes into account the key featuresof the 3GPP NR technology, including the height of the interacting objects, the spatial distribution and mobility of the blockers, as wellas the line-of-sight propagation properties between the transceivers for mmWave NR technology. Results: We analyzed the reservationmechanism with the help of a developed model in the form of a resource queueing system with signals, where the base station bandwidthcorresponds to the resource, and the signals model a change in the line-of-sight conditions between the receiving and transmittingdevices. Creating a priority for ongoing Sessions whose service has not yet been completed provides a considerable flexibility forbalancing the Session Continuity and dropping of a new Session, with a slight decrease in the efficiency of the radio resource utility. Withthe developed model, we showed that reserving even a small bandwidth (less than 10% of the total resources) to maintain the ongoingSessions has a positive effect on their Continuity, as it increases the probability of their successful completion. Practical relevance: The proposed mechanism works more efficiently in overload conditions and with Sessions which have a high data transfer raterequirements. This increases the demand for the proposed mechanism in 5G NR communication systems.

  • characterizing the degree of lte involvement in supporting Session Continuity in street deployment of nr systems
    International Conference on Distributed Computer and Communication Networks, 2019
    Co-Authors: Vyacheslav Begishev, Dmitri Moltchanov, Andrey Samuylov, Konstantin E. Samouylov
    Abstract:

    The prospective roll out of recently standardized New Radio (NR) systems operating in millimeter wave frequency band pose unique challenges to network engineers. In this context, the support of NR-based vehicle-to-infrastructure communications is of special interest due to potentially high speeds of user equipment and semi-stochastic dynamic blockage conditions of propagation paths between UE and BR base station (BS). In this conditions even the use of advanced NR functionalities such as multiconnectivity supporting active connections to multiple BSs located nearby may not fully eliminate outages. Thus, to preserve Session Continuity for UEs located on vehicles a degree of LTE support might be required. In this paper, we quantify the amount of LTE support required to maintain Session Continuity in street deployment of NR systems supporting multiconnectivity capabilities. Particularly, we demonstrate that it is heavily affected by the traffic conditions, inter-site distance between NR BSs and the degree of multiconnectivity.

  • Improving Session Continuity With Bandwidth Reservation in mmWave Communications
    IEEE Wireless Communications Letters, 2019
    Co-Authors: Dmitri Moltchanov, Andrey Samuylov, Vitaly Petrov, Margarita Gapeyenko, Nageen Himayat, Sergey Andreev, Yevgeni Koucheryavy
    Abstract:

    Unexpected fluctuations in radio resource demands of active Sessions in millimeter-wave (mmWave) systems caused by dynamic blockage of the line-of-sight path may lead to accidental Session drops. Existing solutions addressing this problem incorporate multi-connectivity operation that reroutes an ongoing Session to another mmWave access point nearby. We introduce and analyze an alternative approach for improving Session Continuity based on the concept of bandwidth reservation. We develop an analytical model for the mmWave system that employs the proposed technique and quantify its benefits and drawbacks. We show that even a small fraction of reserved bandwidth may significantly improve Session Continuity.

Konstantin E. Samouylov - One of the best experts on this subject based on the ideXlab platform.

  • joint use of guard capacity and multiconnectivity for improved Session Continuity in millimeter wave 5g nr systems
    IEEE Transactions on Vehicular Technology, 2021
    Co-Authors: Vyacheslav Begishev, Dmitri Moltchanov, Andrey Samuylov, Sergey Andreev, Yevgeni Koucheryavy, Eduard Sopin, Roman Kovalchukov, Konstantin E. Samouylov
    Abstract:

    The intermittent nature of millimeter wave (mmWave) links caused by human-body blockage is an intrinsic property of the 5G New Radio (NR) technology that may cause drops of Sessions already accepted for service. To improve the Session Continuity, multiconnectivity and guard capacity mechanisms have been proposed recently. Multiconnectivity enables dynamic handover between multiple pre-established spatially-diverse links, while guard capacity reserves a fraction of radio resources for the already accepted Sessions by ensuring that they will have sufficient provisions in case of link blockage. In this study, we combine the tools of queuing theory and stochastic geometry to develop a mathematical framework for capturing the joint operation of these two schemes as well as the features of mmWave radio propagation. The metrics are related to user- and system-centric performance including the system resource utilization and the new and ongoing Session drop probabilities. Our results show that multiconnectivity benefits all of the considered parameters. However, the range of performance boost remains limited by the deployment density and the maximum supported degree of multiconnectivity. In its turn, guard capacity allows to further decrease the ongoing Session drop probability at the expense of the new Session drop probability and the system resource utilization. When implemented jointly with multiconnectivity, guard capacity does not produce noticeable negative effects on the system resource utilization as compared to its standalone use. Hence, one may prefer a joint implementation of these mechanisms for preserving the Session Continuity of users without compromising the resource utilization.

  • DCCN - Characterizing the Degree of LTE Involvement in Supporting Session Continuity in Street Deployment of NR Systems
    Distributed Computer and Communication Networks, 2019
    Co-Authors: Vyacheslav Begishev, Dmitri Moltchanov, Andrey Samuylov, Konstantin E. Samouylov
    Abstract:

    The prospective roll out of recently standardized New Radio (NR) systems operating in millimeter wave frequency band pose unique challenges to network engineers. In this context, the support of NR-based vehicle-to-infrastructure communications is of special interest due to potentially high speeds of user equipment and semi-stochastic dynamic blockage conditions of propagation paths between UE and BR base station (BS). In this conditions even the use of advanced NR functionalities such as multiconnectivity supporting active connections to multiple BSs located nearby may not fully eliminate outages. Thus, to preserve Session Continuity for UEs located on vehicles a degree of LTE support might be required. In this paper, we quantify the amount of LTE support required to maintain Session Continuity in street deployment of NR systems supporting multiconnectivity capabilities. Particularly, we demonstrate that it is heavily affected by the traffic conditions, inter-site distance between NR BSs and the degree of multiconnectivity.

  • Performance evaluation of bandwidth reservation for mmWave in 5G NR systems
    Information and Control Systems, 2019
    Co-Authors: Vyacheslav Begishev, Dmitri Moltchanov, Andrey Samuylov, Edward Sopin, Yuliya Gaidamaka, Konstantin E. Samouylov
    Abstract:

    Introduction: In 3GPP New Radio (NR) systems, frequent radio propagation path blockages can lead to the disconnection of ongoingSessions already accepted into the system, reducing the quality of service in the network. Controlling access to system resource byprioritizing for the ongoing Sessions can increase the Session Continuity. In this paper, we propose resource allocation with a reservationmechanism. Purpose: Development of a mathematical model for analyzing the effect of this mechanism on other system performanceindicators – dropping probabilities for new and ongoing Sessions and system utilization. The model takes into account the key featuresof the 3GPP NR technology, including the height of the interacting objects, the spatial distribution and mobility of the blockers, as wellas the line-of-sight propagation properties between the transceivers for mmWave NR technology. Results: We analyzed the reservationmechanism with the help of a developed model in the form of a resource queueing system with signals, where the base station bandwidthcorresponds to the resource, and the signals model a change in the line-of-sight conditions between the receiving and transmittingdevices. Creating a priority for ongoing Sessions whose service has not yet been completed provides a considerable flexibility forbalancing the Session Continuity and dropping of a new Session, with a slight decrease in the efficiency of the radio resource utility. Withthe developed model, we showed that reserving even a small bandwidth (less than 10% of the total resources) to maintain the ongoingSessions has a positive effect on their Continuity, as it increases the probability of their successful completion. Practical relevance: The proposed mechanism works more efficiently in overload conditions and with Sessions which have a high data transfer raterequirements. This increases the demand for the proposed mechanism in 5G NR communication systems.

  • characterizing the degree of lte involvement in supporting Session Continuity in street deployment of nr systems
    International Conference on Distributed Computer and Communication Networks, 2019
    Co-Authors: Vyacheslav Begishev, Dmitri Moltchanov, Andrey Samuylov, Konstantin E. Samouylov
    Abstract:

    The prospective roll out of recently standardized New Radio (NR) systems operating in millimeter wave frequency band pose unique challenges to network engineers. In this context, the support of NR-based vehicle-to-infrastructure communications is of special interest due to potentially high speeds of user equipment and semi-stochastic dynamic blockage conditions of propagation paths between UE and BR base station (BS). In this conditions even the use of advanced NR functionalities such as multiconnectivity supporting active connections to multiple BSs located nearby may not fully eliminate outages. Thus, to preserve Session Continuity for UEs located on vehicles a degree of LTE support might be required. In this paper, we quantify the amount of LTE support required to maintain Session Continuity in street deployment of NR systems supporting multiconnectivity capabilities. Particularly, we demonstrate that it is heavily affected by the traffic conditions, inter-site distance between NR BSs and the degree of multiconnectivity.

  • Quantifying the Impact of Guard Capacity on Session Continuity in 3GPP New Radio Systems
    IEEE Transactions on Vehicular Technology, 2019
    Co-Authors: Vyacheslav Begishev, Dmitri Moltchanov, Andrey Samuylov, Sergey Andreev, Yevgeni Koucheryavy, Eduard Sopin, Konstantin E. Samouylov
    Abstract:

    Dynamic blockage of millimeter-wave (mmWave) radio propagation paths by dense moving crowds calls for advanced techniques to preserve Session Continuity in the emerging New Radio (NR) systems. To further improve user performance by balancing the new and ongoing Session drop probabilities, we investigate the concept of guard capacity – reserving a fraction of radio resources at the NR base stations exclusively for the Sessions already accepted for service. To this aim, we develop a detailed mathematical framework that takes into account the key effects in mmWave systems, including the heights of communicating entities, blocker geometry and mobility, modulation and coding schemes and antenna array geometry, as well as radio propagation and queuing specifics. Using our framework, which enables Sessions to change their resource requirements during service, we demonstrate that reserving even a small fraction of bandwidth (less than $10\%$ ) exclusively for the Sessions already accepted by the system allows to enhance Session Continuity at the expense of a slight growth in the new Session drop probability as well as a small decrease in the resource utilization (approximately $5\hbox{--}7\%$ ). Furthermore, guard capacity is shown to perform better in overloaded conditions and with Sessions having high data rate requirements, thus making it particularly useful for the NR systems. Our results indicate that guard capacity is a viable option for improving Session Continuity that can be used by the network operators in combination with other techniques, such as multi-connectivity, to maintain user experience.