Proactive TCP mechanism to improve Handover performance in Mobile Satellite and Terrestrial Networks

Emerging standardization of Geo Mobile Radio (GMR-1) for satellite system is having strong resemblance to terrestrial GSM (Global System for Mobile communications) at the upper protocol layers and TCP (Transmission Control Protocol) is one of them. This space segment technology as well as terrestrial technology, is characterized by periodic variations in communication properties and coverage causing the termination of ongoing call as connections of Mobile Nodes (MN) alter stochastically. Although provisions are made to provide efficient communication infrastructure this hybrid space and terrestrial networks must ensure the end-to-end network performance so that MN can move seamlessly among these networks. However from connectivity point of view current TCP performance has not been engineered for mobility events in multi-radio MN. Traditionally, TCP has applied a set of congestion control algorithms (slow-start, congestion avoidance, fast retransmit, fast recovery) to probe the currently available bandwidth on the connection path. These algorithms need several round-trip times to find the correct transmission rate (i.e. congestion window), and adapt to sudden changes connectivity due to handover. While there are protocols to maintain the connection continuity on mobility events, such as Mobile IP (MIP) and Host Identity Protocol (HIP), TCP performance engineering has had less attention. TCP is implemented as a separate component in an operating system, and is therefore often unaware of the mobility events or the nature of multi-radios' communication. This paper aims to improve TCP communication performance in Mobile satellite and terrestrial networks.Comment: 5 pages, 2 figure

Prediction Model for Offloading in Vehicular Wi-Fi Network

It cannot be denied that, the inescapable diffusion of smartphones, tablets and other vehicular network applications with diverse networking and multimedia capabilities, and the associated blooming of all kinds of data-hungry multimedia services that passengers normally used while traveling exert a big challenge to cellular infrastructure operators. Wireless fidelity (Wi-Fi) as well as fourth generation long term evolution advanced (4G LTE-A) network are widely available today, Wi-Fi could be used by the vehicle users to relieve 4G LTE-A networks. Though, using IEE802.11 Wi-Fi AP to offload 4G LTE-A network for moving vehicle is a challenging task since it only covers short distance and not well deployed to cover all the roads. Several studies have proposed the offloading techniques based on predicted available APs for making offload decision. However, most of the proposed prediction mechanisms are only based on historical connection pattern. This work proposed a prediction model which utilized historical connection pattern, vehicular movement and driver profile to predict the next available AP.  The proposed model is compared with the existing models to evaluate its practicability

VANET-based optimization of infotainment and traffic efficiency vehicular services

The design, standardization and future deployment of vehicular communications systems have been driven so far by safety applications. There are two more aspects of the vehicular networking that have increased their importance in the last years: infotainment and traffic efficiency, as they can improve drivers’ experience, making vehicular communications systems more attractive to end-users. In this thesis we propose optimization mechanisms for both types of vehicular services. Infotainment services are related to the provision of classic IP applications, like browsing, reading e-mail or using social networks. Traffic efficiency services are those accessing new capabilities to the car-navigation systems, aiming at optimizing the usage of road infrastructures, reducing travel times and therefore minimizing the ecological footprint. Bringing infotainment services to the vehicular environment requires to comply with standard protocols and mechanisms that allow heterogeneous networks to be interconnected in the Internet. There are three main functionalities that have to be provided: i) address autoconfiguration, ii) efficient routing and iii) mobility management. Regarding infotainment services, this thesis proposes mechanisms tackling the abovenamed aspects: an overhearing technique to improve an already standardized address autoconfiguration protocol; a tree-based routing algorithm especially tailored for vehicleto- Internet communications and an optimized mobility management approach for vehicular environments. Regarding traffic efficiency, this thesis proposes two algorithms that make use of vehicular communication techniques to monitor and forecast short-term traffic conditions. We first improved our knowledge on drivers’ behavior by analyzing real vehicular data traces, and proposes a mixture model for the vehicles interarrival time. This outcome was used for validating the proposed infotainment optimization as well. All the algorithms and analytical models described in this thesis have been validated by simulations and/or implementations using standard hardware. ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------El diseño, normalización y futuro despliegue de los sistemas de comunicación vehiculares han sido principalmente impulsados hasta el momento por las aplicaciones de seguridad vial. Hay dos aspectos adicionales de las redes vehiculares que han visto crecer su relevancia en los últimos años: los servicios de Infotainment y los de eficiencia del tráfico. Estos servicios pueden mejorar la experiencia de los conductores y hacer que los sistemas de comunicación vehiculares resulten más atractivos para los usuarios finales. En esta tesis, se proponen mecanismos de optimización para ambos tipos de servicios vehiculares. Los servicios de Infotainment están relacionados con la provisión de las clásicas aplicaciones IP tales como, navegar, acceder al correo electrónico, o a las redes sociales. Los servicios de eficiencia de tráfico permiten añadir nuevas funcionalidades a los sistemas de navegación con los objetivos de: optimizar el uso de las infraestructuras viarias, reducir los tiempos de viaje y consecuentemente, minimizar el impacto ambiental. Acceder a los servicios de Infotainment desde redes vehiculares conlleva cumplir con los protocolos y mecanismos estandarizados que permiten la interconexión de redes heterogéneas a Internet. Hay tres funcionalidades principales que tienen que ser proporcionadas: configuración automática de direcciones, encaminamiento eficaz y gestión de la movilidad. Esta tesis propone mecanismos para hacer frente a los tres aspectos mencionados: una técnica basada en overhearing que mejora un protocolo de configuración automática de direcciones ya estandarizado, un algoritmo de encaminamiento basado en árboles especialmente diseñado para las comunicaciones desde el vehículo a Internet y, un algoritmo de gestión de la movilidad optimizado para entornos vehiculares. En cuanto a los servicios de eficiencia de tráfico, esta tesis propone dos algoritmos que utilizando las técnicas de comunicación vehículo a vehículo permiten monitorizar y pronosticar a corto plazo las condiciones en el tráfico, como es el caso de posibles atascos. Todos los algoritmos y modelos analíticos descritos en esta tesis han sido validados a través de simulaciones y/o implementaciones usando hardware estándar

Energy-efficient vertical handover parameters, classification and solutions over wireless heterogeneous networks: a comprehensive survey

In the last few decades, the popularity of wireless networks has been growing dramatically for both home and business networking. Nowadays, smart mobile devices equipped with various wireless networking interfaces are used to access the Internet, communicate, socialize and handle short or long-term businesses. As these devices rely on their limited batteries, energy-efficiency has become one of the major issues in both academia and industry. Due to terminal mobility, the variety of radio access technologies and the necessity of connecting to the Internet anytime and anywhere, energy-efficient handover process within the wireless heterogeneous networks has sparked remarkable attention in recent years. In this context, this paper first addresses the impact of specific information (local, network-assisted, QoS-related, user preferences, etc.) received remotely or locally on the energy efficiency as well as the impact of vertical handover phases, and methods. It presents energy-centric state-of-the-art vertical handover approaches and their impact on energy efficiency. The paper also discusses the recommendations on possible energy gains at different stages of the vertical handover process

Energy-efficient vertical handover parameters, classification and solutions over wireless heterogeneous networks: a comprehensive survey

In the last few decades, the popularity of wireless networks has been growing dramatically for both home and business networking. Nowadays, smart mobile devices equipped with various wireless networking interfaces are used to access the Internet, communicate, socialize and handle short or long-term businesses. As these devices rely on their limited batteries, energy-efficiency has become one of the major issues in both academia and industry. Due to terminal mobility, the variety of radio access technologies and the necessity of connecting to the Internet anytime and anywhere, energy-efficient handover process within the wireless heterogeneous networks has sparked remarkable attention in recent years. In this context, this paper first addresses the impact of specific information (local, network-assisted, QoS-related, user preferences, etc.) received remotely or locally on the energy efficiency as well as the impact of vertical handover phases, and methods. It presents energy-centric state-of-the-art vertical handover approaches and their impact on energy efficiency. The paper also discusses the recommendations on possible energy gains at different stages of the vertical handover process

Efficient content-distribution in a hybrid opportunistic network

Information or content centric networking is believed by many to have great potential to be the appropriate networking paradigm for the future Internet. In information centric networking, focus is shifted from the end-points in the network to the information objects themselves, with less care being placed on from where the information is fetched. In addition to the benefits this networking paradigm has in fixed networks, it also simplifies operation in mobile networks and has the potential to improve performance. In this paper, we describe one way in which the NetInf network architecture can be used in a hybrid mobile network in an urban setting, and run simulations to evaluate the benefits that this approach can yield, both to the end users (in terms of improved performance such as reduced latency with over 50%), as well as to the operators in terms of a reduction of traffic load in the cellular access networks with up to 97%

5GNOW: Challenging the LTE Design Paradigms of Orthogonality and Synchronicity

LTE and LTE-Advanced have been optimized to deliver high bandwidth pipes to wireless users. The transport mechanisms have been tailored to maximize single cell performance by enforcing strict synchronism and orthogonality within a single cell and within a single contiguous frequency band. Various emerging trends reveal major shortcomings of those design criteria: 1) The fraction of machine-type-communications (MTC) is growing fast. Transmissions of this kind are suffering from the bulky procedures necessary to ensure strict synchronism. 2) Collaborative schemes have been introduced to boost capacity and coverage (CoMP), and wireless networks are becoming more and more heterogeneous following the non-uniform distribution of users. Tremendous efforts must be spent to collect the gains and to manage such systems under the premise of strict synchronism and orthogonality. 3) The advent of the Digital Agenda and the introduction of carrier aggregation are forcing the transmission systems to deal with fragmented spectrum. 5GNOW is an European research project supported by the European Commission within FP7 ICT Call 8. It will question the design targets of LTE and LTE-Advanced having these shortcomings in mind and the obedience to strict synchronism and orthogonality will be challenged. It will develop new PHY and MAC layer concepts being better suited to meet the upcoming needs with respect to service variety and heterogeneous transmission setups. Wireless transmission networks following the outcomes of 5GNOW will be better suited to meet the manifoldness of services, device classes and transmission setups present in envisioned future scenarios like smart cities. The integration of systems relying heavily on MTC into the communication network will be eased. The per-user experience will be more uniform and satisfying. To ensure this 5GNOW will contribute to upcoming 5G standardization.Comment: Submitted to Workshop on Mobile and Wireless Communication Systems for 2020 and beyond (at IEEE VTC 2013, Spring

Intelligent Reward based Data Offloading in Next Generation Vehicular Networks

A massive increase in the number of mobile devices and data hungry vehicular network applications creates a great challenge for Mobile Network Operators (MNOs) to handle huge data in cellular infrastructure. However, due to fluctuating wireless channels and high mobility of vehicular users, it is even more challenging for MNOs to deal with vehicular users within a licensed cellular spectrum. Data offloading in vehicular environment plays a significant role in offloading the vehicle s data traffic from congested cellular network s licensed spectrum to the free unlicensed WiFi spectrum with the help of Road Side Units (RSUs). In this paper, an Intelligent Reward based Data Offloading in Next Generation Vehicular Networks (IR-DON) architecture is proposed for dynamic optimization of data traffic and selection of intelligent RSU. Within IR-DON architecture, an Intelligent Access Network Discovery and Selection Function (I-ANDSF) module with Q-Learning, a reinforcement learning algorithm is designed. I-ANDSF is modeled under Software-Defined Network (SDN) controller to solve the dynamic optimization problem by performing an efficient offloading. This increases the overall system throughput by choosing an optimal and intelligent RSU in the network selection process. Simulation results have shown the accurate network traffic classification, optimal network selection, guaranteed QoS, reduced delay and higher throughput achieved by the I-ANDSF module

A framework for supporting network continuity in vehicular IPv6 communications

The appearance of recent standards about cooperative ITS architectures towards a reference communication stack has been an inflection point in the research about vehicular networks. The ISO Communication Access for Land Mobiles (CALM) and the ETSI European ITS communication architecture have paved the way towards real and interoperable vehicular cooperative systems. Within these convergent proposals, IPv6 communications are recognized as a key component to enable traffic efficiency and infotainment applications. The proper operation of these applications and the achievement of value-added ITS services require an uninterrupted network connectivity. This paper addresses this problem by proposing a novel communication stack to support the provision of continuous and secure IPv6 vehicular communications. The solution follows the ISO/ETSI guidelines for the development of cooperative ITS systems and is based on standardized technologies such as Network Mobility (NEMO) protocol to provide an integral management of IPv6mobility. The solution integrates IEEE 802.21 media independent handover services for optimizing the handover process. While the support to the handover optimization offered by the proposed ITS communication stack is demonstrated through a mobility use case, a real testbed supporting most of the communications features is developed to validate and assess the real performance of the stack design.This work has been sponsored by the European Seventh Framework Program, through the ITSSv6 (contract 270519) and FOTsis (contract 270447) projects; the Ministry of Science and Innovation, through the Walkie-Talkie project (TIN2011-27543-C03); and the Seneca Foundation, by means of the GERM program (04552/GERM/06)