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Ignacio Soto

Universidad Politécnica de Madrid, Departamento de Ingeniería de Sistemas Telemáticos, Faculty Member

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Ignacio Soto ([email protected]) received a telecommunication engineering degree in 1993, and a Ph.D. in telecommunications in 2000, both from the Universidad de Vigo, Spain. He was a Research and Teaching Assistant in telematics engineering at the University of Valladolid from 1993 to 1999. In 1999, he joined Universidad Carlos III de Madrid, where he was an Associate Professor from 2002 to 2021. In 2021, he joined Universidad Politécnica de Madrid where he currently works as Professor in telematics engineering. His research activities focus on vehicular networks, future transportation systems, mobility support in packet networks, network security (QKD), network slicing, software defined networks and network virtualization.

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Papers by Ignacio Soto

TOVAC Tele-Operated Vehicle Admission Control and Routing

IEEE Transactions on Vehicular Technology, volume 73, issue 12, 2024

Tele-operated Driving (ToD) is a challenging use case for mobile network operators. Video capture... more Tele-operated Driving (ToD) is a challenging use case for mobile network operators. Video captured by the built-in vehicle cameras must be streamed meeting a latency requirement of 5 ms with a 99% reliability. Although 5G offers high bandwidth, ultra-low latencies and high reliability; ToD service requirements are violated due to bad channel conditions. Ignoring the channel state may lead to over-estimating the number of ToD vehicles that can meet the service requirements, hence compromising the vehicle security. To fill this gap, in this letter we propose TOVAC, an algorithm that guarantees ToD service requirements by taking adequate admission control and routing decisions. This is achieved by using a channel-based capacity graph that determines the maximum number of vehicles that can be tele-operated in any road section. We evaluate TOVAC considering cellular deployments from Turin and show that, unlike a state of the art solution, TOVAC guarantees the ToD service requirements.

Experimental Evaluation of the ETSI DCC Adaptive Approach and Related Algorithms

IEEE Access (8), 2020

Decentralized Congestion Control (DCC) mechanisms have been a core part of protocol stacks for ve... more Decentralized Congestion Control (DCC) mechanisms have been a core part of protocol stacks for vehicular networks since their inception and standardization. The ETSI ITS-G5 protocol stack for vehicular communications considers the usage of DCC not only in the network or access layers, but also as a part of the cross-layer architecture that influences how often messages are generated and transmitted. ETSI DCC mechanisms have evolved from a reactive approach based on a finite state machine, to an adaptive approach that relies on a linear control algorithm. This linear control algorithm, called LIMERIC, is the basis of the mechanism used in the ETSI DCC Adaptive Approach. The behavior of this algorithm depends on a set of parameters. Different values for these parameters have been proposed in the literature, including those defined in the ETSI specification. A recent proposal is Dual-α, which chooses parameters to improve convergence and fairness when the algorithm has to react to fast changes in the use of the shared medium (transitory situations). This article evaluates, by means of simulations, the performance of the ETSI DCC Adaptive Approach and related algorithms, considering both steady state and transitory situations. Results show that a bad selection of parameters can make a DCC algorithm ineffective, that the ETSI DCC Adaptive algorithm performs well in steady state conditions, and that Dual-α performs as well in steady state conditions and outperforms the ETSI DCC Adaptive Approach in transitory scenarios.

Studying and improving the performance of ETSI ITS contention-based forwarding (CBF) in urban and highway scenarios: S-FoT

Computer Networks , 2023

This paper evaluates the performance of ETSI ITS Contention-Based Forwarding (CBF) and ETSI Simpl... more This paper evaluates the performance of ETSI ITS Contention-Based Forwarding (CBF) and ETSI Simple GeoBroadcast forwarding while disseminating warning messages over a Geographical Area in highway and urban scenarios. Our experimental evaluation considers the complete ETSI ITS architecture including the Decentralized Congestion Control (DCC) mechanism. We propose an enhanced CBF mechanism, named S-FOT+, which combines several improvements to the ETSI CBF algorithm. S-FoT+ has a similar or better performance than the ETSI forwarding algorithms regarding both reliability and end-to-end delay while requiring much fewer transmissions. The improvements are equally effective and efficient in both urban and highway scenarios with large Destination Areas. Finally, we evaluate the trade-offs that stem from using multi-hop broadcast mechanisms in urban settings with smaller Destination Areas when compared to single-hop broadcast. Results show that multi-hop mechanisms significantly improve coverage at the cost of an increased number of transmissions.

Reducing Unnecessary Alerts in Pedestrian Protection Systems Based on P2V Communications

Electronics, 2019

There are different proposals in the literature on how to protect pedestrians using warning syste... more There are different proposals in the literature on how to protect pedestrians using warning systems to alert drivers of their presence. They can be based on onboard perception systems or wireless communications. The evaluation of these systems has been focused on testing their ability to detect pedestrians. A problem that has received much less attention is the possibility of generating too many alerts in the warning systems. In this paper, we propose and analyze four different algorithms to take the decision on generating alerts in a warning system that is based on direct wireless communications between vehicles and pedestrians. With the algorithms, we explore different strategies to reduce unnecessary alerts. The feasibility of the implementation of the algorithms was evaluated with a deployment using real equipment, and tests were carried out to verify their behavior in real scenarios. The ability of each algorithm to reduce unnecessary alerts was evaluated with realistic simulations in an urban scenario, using a traffic simulator with vehicular and pedestrian flows. The results show the importance of tackling the problem of driver overload in warning systems, and that it is not straightforward to predict the load of alerts generated by an algorithm in a large-scale deployment, in which there are multiple interactions between vehicles and pedestrians.

Internet Engineering Task Force (IETF) LM. Contreras Request for Comments: 7161 Telefonica I+D

by the Subscription Information Acquisition through the LMA (SIAL) This document specifies an exp... more by the Subscription Information Acquisition through the LMA (SIAL) This document specifies an experimental multicast handover optimization mechanism for Proxy Mobile IPv6 (PMIPv6) to accelerate the delivery of multicast traffic to mobile nodes after handovers. The mechanism, called Subscription Information Acquisition through the LMA (SIAL), is based on speeding up the acquisition of mobile nodes ’ multicast context by the mobile access gateways. To do that, extensions to the current PMIPv6 protocol are proposed. These extensions are not only applicable to the base solution for multicast support in Proxy Mobile IPv6, but they can also be applied to other solutions developed to avoid the tunnel convergence problem. Furthermore, these extensions are also independent of the role played by the mobile access gateway within the multicast network (acting as either multicast listener discovery proxy or multicast router).

Experimental Evaluation using Overlay Networks

The commercial deployment of Mobile IPv6 has been hastened by the concepts of Integrated Wireless... more The commercial deployment of Mobile IPv6 has been hastened by the concepts of Integrated Wireless Networks and Overlay Networks, which are present in the notion of the forthcoming generation of wireless communications. Individual wireless access networks show limitations that can be overcome through the integration of different technologies into a single unified platform (i.e., 4G systems). This paper summarises practical experiments performed to evaluate the impact of inter-networking (i.e. vertical handovers) on the Network and Transport layers. Based on our observations, we propose and evaluate a number of inter-technology handover optimisation techniques, e.g., Router Advertisements frequency values, Binding Update simulcasting, Router Advertisement caching, and Soft Handovers. The paper concludes with the description of a policy-based mobility support middleware (PROTON) that hides 4G networking complexities from mobile users, provides informed handover-related decisions, and e...

RAMS: A Protocol Extension to PMIPv6 for Improving Handover Performance of Multicast Traffic

J. Wirel. Mob. Networks Ubiquitous Comput. Dependable Appl., 2011

IP multicast allows the efficient support of group communication services. The increase in the us... more IP multicast allows the efficient support of group communication services. The increase in the use of multicast has also triggered the need for supporting IP multicast in mobile environments. It is necessary to consider current unicast mobility management solutions in IP-based networks to smoothly extend multicast services to mobile users. Proxy Mobile IPv6 is a network-based mobility management solution, where the functionality to support the terminal movement resides in the network. Recently, a base solution has been adopted for supporting multicast in PMIPv6. Nevertheless, this solution has not special features to optimize performance during handovers and this can cause disruptions in the reception of multicast traffic by the mobile terminals. This paper proposes and evaluates RAMS, an extension to the PMIPv6 protocol for accelerating the multicast service delivery to mobile terminals after handovers. We explore the performance gain obtained by RAMS, compared against the base sol...

Network-based Localized IP mobility Management: Proxy Mobile IPv6 and Current Trends in Standardization

J. Wirel. Mob. Networks Ubiquitous Comput. Dependable Appl., 2010

IP mobility support has been a hot topic over the last years, recently fostered by the role of IP... more IP mobility support has been a hot topic over the last years, recently fostered by the role of IP in the evolution of the 3G mobile communication networks. Standardization bodies, namely IETF, IEEE and 3GPP are working on different aspects of the mobility aiming at improving the mobility experience perceived by users. Traditional IP mobility support mechanisms, Mobile IPv4 or Mobile IPv6, are based on the operation of the terminal to keep ongoing sessions despite the movement. The current trend is towards network-based solutions where mobility support is based on network operation. Proxy Mobile IPv6 is a promising speciﬁcation that allows network operators to provide localized mobility support without relying on mobility functionality or conﬁguration present in the mobile nodes, which greatly eases the deployment of the solution. This paper presents Proxy Mobile IPv6 and the different extensions that are been considered by the standardization bodies to enhance the basic protocol wit...

Experimental Evaluation of the ETSI DCC Adaptive Approach and Related Algorithms

IEEE Access, 2020

Decentralized Congestion Control (DCC) mechanisms have been a core part of protocol stacks for ve... more Decentralized Congestion Control (DCC) mechanisms have been a core part of protocol stacks for vehicular networks since their inception and standardization. The ETSI ITS-G5 protocol stack for vehicular communications considers the usage of DCC not only in the network or access layers, but also as a part of the cross-layer architecture that influences how often messages are generated and transmitted. ETSI DCC mechanisms have evolved from a reactive approach based on a finite state machine, to an adaptive approach that relies on a linear control algorithm. This linear control algorithm, called LIMERIC, is the basis of the mechanism used in the ETSI DCC Adaptive Approach. The behavior of this algorithm depends on a set of parameters. Different values for these parameters have been proposed in the literature, including those defined in the ETSI specification. A recent proposal is Dual-α, which chooses parameters to improve convergence and fairness when the algorithm has to react to fast changes in the use of the shared medium (transitory situations). This article evaluates, by means of simulations, the performance of the ETSI DCC Adaptive Approach and related algorithms, considering both steady state and transitory situations. Results show that a bad selection of parameters can make a DCC algorithm ineffective, that the ETSI DCC Adaptive algorithm performs well in steady state conditions, and that Dual-α performs as well in steady state conditions and outperforms the ETSI DCC Adaptive Approach in transitory scenarios.

Effect of content popularity, number of contents and a cellular backup network on the performance of content distribution protocols in urban VANET scenarios

Computer Communications, 2017

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 Intern... more

Proxy Mobile IPv6 (PMIPv6) Multicast Handover Optimization by the Subscription Information Acquisition through the LMA (SIAL)

This document specifies an experimental multicast handover optimization mechanism for Proxy Mobil... more This document specifies an experimental multicast handover optimization mechanism for Proxy Mobile IPv6 (PMIPv6) to accelerate the delivery of multicast traffic to mobile nodes after handovers. The mechanism, called Subscription Information Acquisition through the LMA (SIAL), is based on speeding up the acquisition of mobile nodes' multicast context by the mobile access gateways. To do that, extensions to the current PMIPv6 protocol are proposed. These extensions are not only applicable to the base solution for multicast support in Proxy Mobile IPv6, but they can also be applied to other solutions developed to avoid the tunnel convergence problem. Furthermore, these extensions are also independent of the role played by the mobile access gateway within the multicast network (acting as either multicast listener discovery proxy or multicast router). Status of This Memo This document is not an Internet Standards Track specification; it is published for examination, experimental implementation, and evaluation. This document defines an Experimental Protocol for the Internet community. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Not all documents approved by the IESG are a candidate for any level of Internet Standard; see Section 2 of RFC 5741. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7161. Contreras, et al.

Mobile Networking

Lecture Notes in Computer Science, 2003

We point out the different performance problems that need to be addressed when considering mobili... more We point out the different performance problems that need to be addressed when considering mobility in IP networks. We also define the reference architecture and present a framework to classify the different solutions for mobility management in IP networks. The performance of the major candidate micro-mobility solutions is evaluated for both real-time (UDP) and data (TCP) traffic through simulation and by means of an analytical model. Using these models we compare the performance of different mobility management schemes for different data and real-time services and the network resources that are needed for it. We point out the problems of TCP in wireless environments and review some proposed enhancements to TCP that aim at improving TCP performance. We make a detailed study of how some of micromobility protocols namely Cellular IP, Hawaii and Hierarchical Mobile IP affect the behavior of TCP and their interaction with the MAC layer. We investigate the impact of handoffs on TCP by means of simulation traces that show the evolution of segments and acknowledgments during handoffs.

Lessons learned from the deployment of a multihop IEEE 802.11g testbed using COTS devices

2010 European Wireless Conference, EW 2010, 2010

A lot of attention has been given to multihop wireless networks lately, but further research is n... more A lot of attention has been given to multihop wireless networks lately, but further research is needed. This attention has motivated an increase in the number of 802.11based deployments, both indoor and outdoor. These testbeds are used to run measurements in order to analyze and understand the limitation and differences between analytical or simulationbased figures and the results from real-life experimentation. In this paper we describe the lessons learned from the deployment of a wireless multihop testbed under the false floor of a laboratory in our Computer Science building. We assess the radio shielding provided by the false floor panels, and run exhaustive and controlled experiments to analyze the performance limits of commercial off-the-shelf hardware. The results obtained confirm that experimental measurements can severely deviate from the expected theoretical values.

FloorNet: Deployment and Evaluation of a Multihop Wireless 802.11 Testbed

Eurasip Journal on Wireless Communications and Networking, 2010

A lot of attention has been given to multihop wireless networks lately, but further research-in p... more A lot of attention has been given to multihop wireless networks lately, but further research-in particular, through experimentation-is needed. This attention has motivated an increase in the number of 802.11-based deployments, both indoor and outdoor. These testbeds, which require a significant amount of resources during both deployment and maintenance, are used to run measurements in order to analyze and understand the limitation and differences between analytical or simulation-based figures and the results from real-life experimentation. This paper makes two major contributions: (i) first, we describe a novel wireless multihop testbed, which we name FloorNet, that is deployed and operated under the false floor of a lab in our Computer Science building. This false floor provides a strong physical protection that prevents disconnections or misplacements, as well as radio shielding (to some extent) thanks to the false floor panels-this later feature is assessed through experimentation; (ii) second, by running exhaustive and controlled experiments we are able to analyze the performance limits of commercial off-theshelf hardware, as well as to derive practical design criteria for the deployment and configuration of mesh networks. These results both provide valuable insights of wireless multihop performance and prove that FloorNet constitutes a valuable asset to research on wireless mesh networks.

Securing route optimisation in NEMO

Proceedings - WiOpt 2005: Third International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks, 2005

The Network Mobility (NEMO) Basic Support protocol enables mobile networks to change their point ... more The Network Mobility (NEMO) Basic Support protocol enables mobile networks to change their point of attachment to the Internet, while preserving established sessions of the nodes within the mobile network. When only a nonnested mobile network is considered, the so-called triangle routing is the main problem that should be faced. In Mobile IPv6, the Route Optimisation mechanism solves this problem, and the Return Routability mechanism aims to limit the security concerns originated because of the Route Optimisation. Nowadays Return Routability is considered a weak solution (i.e., based on strong assumptions). In this article we explore different approaches to Route Optimisation in NEMO and we devise how to adapt some of the Terminal Mobility solutions to a NEMO environment, where, as we will propose, a delegation of signalling rights from the Mobile Network Node to the Mobile Router is necessary.

MobiSplit: A scalable approach to emerging mobility networks

MobiArch 2006 - Proceedings of First ACM/IEEE International Workshop on Mobility in the Evolving Internet Architecture, in conjunction with IEEE GLOBECOM 2006, 2006

This paper presents a novel architecture, MobiSplit, to manage mobility in future IP based networ... more This paper presents a novel architecture, MobiSplit, to manage mobility in future IP based networks. The proposed architecture separates mobility management in two levels, local and global, that are managed in completely independent ways. The paper describes the flexibility advantages that this architecture brings to operators, and how it is appropriate for the current trend to multiple and very different access providers and operators. Heterogeneity, support for seamless handovers and multihoming, and scalability issues are analyzed in the paper.

Impact of heterogeneous network controlled handovers on muhi-mode mobile device design

IEEE Wireless Communications and Networking Conference, WCNC, 2007

The availability of multiple technologies, with micro and macro wireless cells, for network acces... more The availability of multiple technologies, with micro and macro wireless cells, for network access combined with terminals capable of exploiting such diversity in wireless access requires the development of new mechanisms for optimized handover procedures. Appealing solutions should support network controlled handovers through heterogeneous technologies, preferably combined with a cross-layers two/three design. The IEEE 802.21 working group is currently standardizing the methods and the protocol potentially able to provide such a solution. In this paper we analyze the impact of signaling timing on network controlled handovers execution and performance in this environment. Through an extensive simulation study, we obtain results, that can be exploited in both terminal and handover procedure designs.

MobiSplit in a Virtualized, Multi-Device Environment

2007 IEEE International Conference on Communications, 2007

This paper details a novel architecture, MobiSplit [17], for managing mobility in future IP based... more This paper details a novel architecture, MobiSplit [17], for managing mobility in future IP based networks. The architecture separates mobility management in two levels, local and global, that are managed in completely independent ways. We describe how such a mobility architecture can be used to support a new paradigm in mobility. By combining the user's identity with a multi physical virtual terminal we treat the movement of people rather than their physical manifestations in one device. We conclude by analyzing the concrete system, built from this new architecture and existing protocols, in terms of scalability, flexibility and security.

Multi-domain issues of resilience

Proceedings of 2005 7th International Conference Transparent Optical Networks, 2005.

This paper gives an overview and classification of issues related to resilience in a multi-layer ... more This paper gives an overview and classification of issues related to resilience in a multi-layer multi-domain network environment. Then the work focuses on the Internet inter-AS context, where the introduction of G/MPLS capabilities for traffic engineering may enhance the way traffic is exchanged today. This paper shows that, in this context, network resilience based on fast rerouting can be achieved, complementing existing interdomain link protection strategies, by using alternative disjoint multi-domain backup paths through other domains. Furthermore, the paper proposes a specific method to apply MPLS label stacking to make such backup paths scalable to larger clusters of inter-protected domains by means of MPLS transit. This transit can be used as a temporary solution before BGP routes are stable. Finally, the latest standardisation activity on the provision of such multiple path information for BGP is also reviewed.

IPv6 address autoconfiguration in geonetworking-enabled VANETs: characterization and evaluation of the ETSI solution

EURASIP Journal on Wireless Communications and Networking, 2012

In this article we make a thorough characterization and evaluation of the solution standardized b... more In this article we make a thorough characterization and evaluation of the solution standardized by the European Telecommunications Standards Institute for IPv6 transmission of packets over geographical location aware vehicular networks. In particular, we focus on IPv6 address auto-configuration, one of the required pieces to enable Internet connectivity from vehicles. Communications in vehicular networks are strongly dependent on the availability of multi-hop connectivity to the fixed infrastructure, so also we analyze the probability of achieving this connectivity under different circumstances, and we use the results to identify interesting target scenarios for address autoconfiguration mechanisms. Keeping those scenarios in mind, we perform a characterization and deep evaluationanalytically and by means of simulations-of the standardized IPv6 address au-toconfiguration solution; proposing some configuration guidelines and highlighting the scenarios where complementary enhancements might be needed.

TOVAC Tele-Operated Vehicle Admission Control and Routing

IEEE Transactions on Vehicular Technology, volume 73, issue 12, 2024

Tele-operated Driving (ToD) is a challenging use case for mobile network operators. Video capture... more Tele-operated Driving (ToD) is a challenging use case for mobile network operators. Video captured by the built-in vehicle cameras must be streamed meeting a latency requirement of 5 ms with a 99% reliability. Although 5G offers high bandwidth, ultra-low latencies and high reliability; ToD service requirements are violated due to bad channel conditions. Ignoring the channel state may lead to over-estimating the number of ToD vehicles that can meet the service requirements, hence compromising the vehicle security. To fill this gap, in this letter we propose TOVAC, an algorithm that guarantees ToD service requirements by taking adequate admission control and routing decisions. This is achieved by using a channel-based capacity graph that determines the maximum number of vehicles that can be tele-operated in any road section. We evaluate TOVAC considering cellular deployments from Turin and show that, unlike a state of the art solution, TOVAC guarantees the ToD service requirements.

Experimental Evaluation of the ETSI DCC Adaptive Approach and Related Algorithms

IEEE Access (8), 2020

Decentralized Congestion Control (DCC) mechanisms have been a core part of protocol stacks for ve... more Decentralized Congestion Control (DCC) mechanisms have been a core part of protocol stacks for vehicular networks since their inception and standardization. The ETSI ITS-G5 protocol stack for vehicular communications considers the usage of DCC not only in the network or access layers, but also as a part of the cross-layer architecture that influences how often messages are generated and transmitted. ETSI DCC mechanisms have evolved from a reactive approach based on a finite state machine, to an adaptive approach that relies on a linear control algorithm. This linear control algorithm, called LIMERIC, is the basis of the mechanism used in the ETSI DCC Adaptive Approach. The behavior of this algorithm depends on a set of parameters. Different values for these parameters have been proposed in the literature, including those defined in the ETSI specification. A recent proposal is Dual-α, which chooses parameters to improve convergence and fairness when the algorithm has to react to fast changes in the use of the shared medium (transitory situations). This article evaluates, by means of simulations, the performance of the ETSI DCC Adaptive Approach and related algorithms, considering both steady state and transitory situations. Results show that a bad selection of parameters can make a DCC algorithm ineffective, that the ETSI DCC Adaptive algorithm performs well in steady state conditions, and that Dual-α performs as well in steady state conditions and outperforms the ETSI DCC Adaptive Approach in transitory scenarios.

Studying and improving the performance of ETSI ITS contention-based forwarding (CBF) in urban and highway scenarios: S-FoT

Computer Networks , 2023

This paper evaluates the performance of ETSI ITS Contention-Based Forwarding (CBF) and ETSI Simpl... more This paper evaluates the performance of ETSI ITS Contention-Based Forwarding (CBF) and ETSI Simple GeoBroadcast forwarding while disseminating warning messages over a Geographical Area in highway and urban scenarios. Our experimental evaluation considers the complete ETSI ITS architecture including the Decentralized Congestion Control (DCC) mechanism. We propose an enhanced CBF mechanism, named S-FOT+, which combines several improvements to the ETSI CBF algorithm. S-FoT+ has a similar or better performance than the ETSI forwarding algorithms regarding both reliability and end-to-end delay while requiring much fewer transmissions. The improvements are equally effective and efficient in both urban and highway scenarios with large Destination Areas. Finally, we evaluate the trade-offs that stem from using multi-hop broadcast mechanisms in urban settings with smaller Destination Areas when compared to single-hop broadcast. Results show that multi-hop mechanisms significantly improve coverage at the cost of an increased number of transmissions.

Reducing Unnecessary Alerts in Pedestrian Protection Systems Based on P2V Communications

Electronics, 2019

There are different proposals in the literature on how to protect pedestrians using warning syste... more There are different proposals in the literature on how to protect pedestrians using warning systems to alert drivers of their presence. They can be based on onboard perception systems or wireless communications. The evaluation of these systems has been focused on testing their ability to detect pedestrians. A problem that has received much less attention is the possibility of generating too many alerts in the warning systems. In this paper, we propose and analyze four different algorithms to take the decision on generating alerts in a warning system that is based on direct wireless communications between vehicles and pedestrians. With the algorithms, we explore different strategies to reduce unnecessary alerts. The feasibility of the implementation of the algorithms was evaluated with a deployment using real equipment, and tests were carried out to verify their behavior in real scenarios. The ability of each algorithm to reduce unnecessary alerts was evaluated with realistic simulations in an urban scenario, using a traffic simulator with vehicular and pedestrian flows. The results show the importance of tackling the problem of driver overload in warning systems, and that it is not straightforward to predict the load of alerts generated by an algorithm in a large-scale deployment, in which there are multiple interactions between vehicles and pedestrians.

Internet Engineering Task Force (IETF) LM. Contreras Request for Comments: 7161 Telefonica I+D

by the Subscription Information Acquisition through the LMA (SIAL) This document specifies an exp... more by the Subscription Information Acquisition through the LMA (SIAL) This document specifies an experimental multicast handover optimization mechanism for Proxy Mobile IPv6 (PMIPv6) to accelerate the delivery of multicast traffic to mobile nodes after handovers. The mechanism, called Subscription Information Acquisition through the LMA (SIAL), is based on speeding up the acquisition of mobile nodes ’ multicast context by the mobile access gateways. To do that, extensions to the current PMIPv6 protocol are proposed. These extensions are not only applicable to the base solution for multicast support in Proxy Mobile IPv6, but they can also be applied to other solutions developed to avoid the tunnel convergence problem. Furthermore, these extensions are also independent of the role played by the mobile access gateway within the multicast network (acting as either multicast listener discovery proxy or multicast router).

Experimental Evaluation using Overlay Networks

The commercial deployment of Mobile IPv6 has been hastened by the concepts of Integrated Wireless... more The commercial deployment of Mobile IPv6 has been hastened by the concepts of Integrated Wireless Networks and Overlay Networks, which are present in the notion of the forthcoming generation of wireless communications. Individual wireless access networks show limitations that can be overcome through the integration of different technologies into a single unified platform (i.e., 4G systems). This paper summarises practical experiments performed to evaluate the impact of inter-networking (i.e. vertical handovers) on the Network and Transport layers. Based on our observations, we propose and evaluate a number of inter-technology handover optimisation techniques, e.g., Router Advertisements frequency values, Binding Update simulcasting, Router Advertisement caching, and Soft Handovers. The paper concludes with the description of a policy-based mobility support middleware (PROTON) that hides 4G networking complexities from mobile users, provides informed handover-related decisions, and e...

RAMS: A Protocol Extension to PMIPv6 for Improving Handover Performance of Multicast Traffic

J. Wirel. Mob. Networks Ubiquitous Comput. Dependable Appl., 2011

IP multicast allows the efficient support of group communication services. The increase in the us... more IP multicast allows the efficient support of group communication services. The increase in the use of multicast has also triggered the need for supporting IP multicast in mobile environments. It is necessary to consider current unicast mobility management solutions in IP-based networks to smoothly extend multicast services to mobile users. Proxy Mobile IPv6 is a network-based mobility management solution, where the functionality to support the terminal movement resides in the network. Recently, a base solution has been adopted for supporting multicast in PMIPv6. Nevertheless, this solution has not special features to optimize performance during handovers and this can cause disruptions in the reception of multicast traffic by the mobile terminals. This paper proposes and evaluates RAMS, an extension to the PMIPv6 protocol for accelerating the multicast service delivery to mobile terminals after handovers. We explore the performance gain obtained by RAMS, compared against the base sol...

Network-based Localized IP mobility Management: Proxy Mobile IPv6 and Current Trends in Standardization

J. Wirel. Mob. Networks Ubiquitous Comput. Dependable Appl., 2010

IP mobility support has been a hot topic over the last years, recently fostered by the role of IP... more IP mobility support has been a hot topic over the last years, recently fostered by the role of IP in the evolution of the 3G mobile communication networks. Standardization bodies, namely IETF, IEEE and 3GPP are working on different aspects of the mobility aiming at improving the mobility experience perceived by users. Traditional IP mobility support mechanisms, Mobile IPv4 or Mobile IPv6, are based on the operation of the terminal to keep ongoing sessions despite the movement. The current trend is towards network-based solutions where mobility support is based on network operation. Proxy Mobile IPv6 is a promising speciﬁcation that allows network operators to provide localized mobility support without relying on mobility functionality or conﬁguration present in the mobile nodes, which greatly eases the deployment of the solution. This paper presents Proxy Mobile IPv6 and the different extensions that are been considered by the standardization bodies to enhance the basic protocol wit...

Experimental Evaluation of the ETSI DCC Adaptive Approach and Related Algorithms

IEEE Access, 2020

Decentralized Congestion Control (DCC) mechanisms have been a core part of protocol stacks for ve... more Decentralized Congestion Control (DCC) mechanisms have been a core part of protocol stacks for vehicular networks since their inception and standardization. The ETSI ITS-G5 protocol stack for vehicular communications considers the usage of DCC not only in the network or access layers, but also as a part of the cross-layer architecture that influences how often messages are generated and transmitted. ETSI DCC mechanisms have evolved from a reactive approach based on a finite state machine, to an adaptive approach that relies on a linear control algorithm. This linear control algorithm, called LIMERIC, is the basis of the mechanism used in the ETSI DCC Adaptive Approach. The behavior of this algorithm depends on a set of parameters. Different values for these parameters have been proposed in the literature, including those defined in the ETSI specification. A recent proposal is Dual-α, which chooses parameters to improve convergence and fairness when the algorithm has to react to fast changes in the use of the shared medium (transitory situations). This article evaluates, by means of simulations, the performance of the ETSI DCC Adaptive Approach and related algorithms, considering both steady state and transitory situations. Results show that a bad selection of parameters can make a DCC algorithm ineffective, that the ETSI DCC Adaptive algorithm performs well in steady state conditions, and that Dual-α performs as well in steady state conditions and outperforms the ETSI DCC Adaptive Approach in transitory scenarios.

Effect of content popularity, number of contents and a cellular backup network on the performance of content distribution protocols in urban VANET scenarios

Computer Communications, 2017

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 Intern... more

Proxy Mobile IPv6 (PMIPv6) Multicast Handover Optimization by the Subscription Information Acquisition through the LMA (SIAL)

This document specifies an experimental multicast handover optimization mechanism for Proxy Mobil... more This document specifies an experimental multicast handover optimization mechanism for Proxy Mobile IPv6 (PMIPv6) to accelerate the delivery of multicast traffic to mobile nodes after handovers. The mechanism, called Subscription Information Acquisition through the LMA (SIAL), is based on speeding up the acquisition of mobile nodes' multicast context by the mobile access gateways. To do that, extensions to the current PMIPv6 protocol are proposed. These extensions are not only applicable to the base solution for multicast support in Proxy Mobile IPv6, but they can also be applied to other solutions developed to avoid the tunnel convergence problem. Furthermore, these extensions are also independent of the role played by the mobile access gateway within the multicast network (acting as either multicast listener discovery proxy or multicast router). Status of This Memo This document is not an Internet Standards Track specification; it is published for examination, experimental implementation, and evaluation. This document defines an Experimental Protocol for the Internet community. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Not all documents approved by the IESG are a candidate for any level of Internet Standard; see Section 2 of RFC 5741. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7161. Contreras, et al.

Mobile Networking

Lecture Notes in Computer Science, 2003

We point out the different performance problems that need to be addressed when considering mobili... more We point out the different performance problems that need to be addressed when considering mobility in IP networks. We also define the reference architecture and present a framework to classify the different solutions for mobility management in IP networks. The performance of the major candidate micro-mobility solutions is evaluated for both real-time (UDP) and data (TCP) traffic through simulation and by means of an analytical model. Using these models we compare the performance of different mobility management schemes for different data and real-time services and the network resources that are needed for it. We point out the problems of TCP in wireless environments and review some proposed enhancements to TCP that aim at improving TCP performance. We make a detailed study of how some of micromobility protocols namely Cellular IP, Hawaii and Hierarchical Mobile IP affect the behavior of TCP and their interaction with the MAC layer. We investigate the impact of handoffs on TCP by means of simulation traces that show the evolution of segments and acknowledgments during handoffs.

Lessons learned from the deployment of a multihop IEEE 802.11g testbed using COTS devices

2010 European Wireless Conference, EW 2010, 2010

A lot of attention has been given to multihop wireless networks lately, but further research is n... more A lot of attention has been given to multihop wireless networks lately, but further research is needed. This attention has motivated an increase in the number of 802.11based deployments, both indoor and outdoor. These testbeds are used to run measurements in order to analyze and understand the limitation and differences between analytical or simulationbased figures and the results from real-life experimentation. In this paper we describe the lessons learned from the deployment of a wireless multihop testbed under the false floor of a laboratory in our Computer Science building. We assess the radio shielding provided by the false floor panels, and run exhaustive and controlled experiments to analyze the performance limits of commercial off-the-shelf hardware. The results obtained confirm that experimental measurements can severely deviate from the expected theoretical values.

FloorNet: Deployment and Evaluation of a Multihop Wireless 802.11 Testbed

Eurasip Journal on Wireless Communications and Networking, 2010

A lot of attention has been given to multihop wireless networks lately, but further research-in p... more A lot of attention has been given to multihop wireless networks lately, but further research-in particular, through experimentation-is needed. This attention has motivated an increase in the number of 802.11-based deployments, both indoor and outdoor. These testbeds, which require a significant amount of resources during both deployment and maintenance, are used to run measurements in order to analyze and understand the limitation and differences between analytical or simulation-based figures and the results from real-life experimentation. This paper makes two major contributions: (i) first, we describe a novel wireless multihop testbed, which we name FloorNet, that is deployed and operated under the false floor of a lab in our Computer Science building. This false floor provides a strong physical protection that prevents disconnections or misplacements, as well as radio shielding (to some extent) thanks to the false floor panels-this later feature is assessed through experimentation; (ii) second, by running exhaustive and controlled experiments we are able to analyze the performance limits of commercial off-theshelf hardware, as well as to derive practical design criteria for the deployment and configuration of mesh networks. These results both provide valuable insights of wireless multihop performance and prove that FloorNet constitutes a valuable asset to research on wireless mesh networks.

Securing route optimisation in NEMO

Proceedings - WiOpt 2005: Third International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks, 2005

The Network Mobility (NEMO) Basic Support protocol enables mobile networks to change their point ... more The Network Mobility (NEMO) Basic Support protocol enables mobile networks to change their point of attachment to the Internet, while preserving established sessions of the nodes within the mobile network. When only a nonnested mobile network is considered, the so-called triangle routing is the main problem that should be faced. In Mobile IPv6, the Route Optimisation mechanism solves this problem, and the Return Routability mechanism aims to limit the security concerns originated because of the Route Optimisation. Nowadays Return Routability is considered a weak solution (i.e., based on strong assumptions). In this article we explore different approaches to Route Optimisation in NEMO and we devise how to adapt some of the Terminal Mobility solutions to a NEMO environment, where, as we will propose, a delegation of signalling rights from the Mobile Network Node to the Mobile Router is necessary.

MobiSplit: A scalable approach to emerging mobility networks

MobiArch 2006 - Proceedings of First ACM/IEEE International Workshop on Mobility in the Evolving Internet Architecture, in conjunction with IEEE GLOBECOM 2006, 2006

This paper presents a novel architecture, MobiSplit, to manage mobility in future IP based networ... more This paper presents a novel architecture, MobiSplit, to manage mobility in future IP based networks. The proposed architecture separates mobility management in two levels, local and global, that are managed in completely independent ways. The paper describes the flexibility advantages that this architecture brings to operators, and how it is appropriate for the current trend to multiple and very different access providers and operators. Heterogeneity, support for seamless handovers and multihoming, and scalability issues are analyzed in the paper.

Impact of heterogeneous network controlled handovers on muhi-mode mobile device design

IEEE Wireless Communications and Networking Conference, WCNC, 2007

The availability of multiple technologies, with micro and macro wireless cells, for network acces... more The availability of multiple technologies, with micro and macro wireless cells, for network access combined with terminals capable of exploiting such diversity in wireless access requires the development of new mechanisms for optimized handover procedures. Appealing solutions should support network controlled handovers through heterogeneous technologies, preferably combined with a cross-layers two/three design. The IEEE 802.21 working group is currently standardizing the methods and the protocol potentially able to provide such a solution. In this paper we analyze the impact of signaling timing on network controlled handovers execution and performance in this environment. Through an extensive simulation study, we obtain results, that can be exploited in both terminal and handover procedure designs.

MobiSplit in a Virtualized, Multi-Device Environment

2007 IEEE International Conference on Communications, 2007

This paper details a novel architecture, MobiSplit [17], for managing mobility in future IP based... more This paper details a novel architecture, MobiSplit [17], for managing mobility in future IP based networks. The architecture separates mobility management in two levels, local and global, that are managed in completely independent ways. We describe how such a mobility architecture can be used to support a new paradigm in mobility. By combining the user's identity with a multi physical virtual terminal we treat the movement of people rather than their physical manifestations in one device. We conclude by analyzing the concrete system, built from this new architecture and existing protocols, in terms of scalability, flexibility and security.

Multi-domain issues of resilience

Proceedings of 2005 7th International Conference Transparent Optical Networks, 2005.

This paper gives an overview and classification of issues related to resilience in a multi-layer ... more This paper gives an overview and classification of issues related to resilience in a multi-layer multi-domain network environment. Then the work focuses on the Internet inter-AS context, where the introduction of G/MPLS capabilities for traffic engineering may enhance the way traffic is exchanged today. This paper shows that, in this context, network resilience based on fast rerouting can be achieved, complementing existing interdomain link protection strategies, by using alternative disjoint multi-domain backup paths through other domains. Furthermore, the paper proposes a specific method to apply MPLS label stacking to make such backup paths scalable to larger clusters of inter-protected domains by means of MPLS transit. This transit can be used as a temporary solution before BGP routes are stable. Finally, the latest standardisation activity on the provision of such multiple path information for BGP is also reviewed.

IPv6 address autoconfiguration in geonetworking-enabled VANETs: characterization and evaluation of the ETSI solution

EURASIP Journal on Wireless Communications and Networking, 2012

In this article we make a thorough characterization and evaluation of the solution standardized b... more In this article we make a thorough characterization and evaluation of the solution standardized by the European Telecommunications Standards Institute for IPv6 transmission of packets over geographical location aware vehicular networks. In particular, we focus on IPv6 address auto-configuration, one of the required pieces to enable Internet connectivity from vehicles. Communications in vehicular networks are strongly dependent on the availability of multi-hop connectivity to the fixed infrastructure, so also we analyze the probability of achieving this connectivity under different circumstances, and we use the results to identify interesting target scenarios for address autoconfiguration mechanisms. Keeping those scenarios in mind, we perform a characterization and deep evaluationanalytically and by means of simulations-of the standardized IPv6 address au-toconfiguration solution; proposing some configuration guidelines and highlighting the scenarios where complementary enhancements might be needed.