406 research outputs found

    Distance tracking scheme for seamless handover in IMS-based systems with UMTS access network

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    This paper proposes a fast and seamless handover scheme for systems based on IP Multimedia Subsystem (IMS) architectural framework with Universal Mobile Telecommunications System (UMTS) access network. In the scheme the location, direction and movement pattern of a Mobile Node (MN) in a network cell are proactively tracked in order to determine the exact moment to trigger the pre-handover process with one of the adjacent cells considering MN’s direction before the execution of Layer 2 handover. The performance of the proposed scheme was evaluated by comparing it with the traditional handover scheme and the evaluation shows that the traditional handover scheme introduced a handover delay of about 675.5 ms, whereas the proposed scheme introduced handover delay of about 96.25 ms, which is less than 100 ms, hence the handover delay introduced by the proposed scheme fall within the specified range of best class service for voice traffic and streaming media over IP networks.Keywords: IMS, Handover delay, Distance Tracking, pre-handover, UMT

    Provision of Quality of Service in IP-based Mobile Access Networks

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    ACUTA Journal of Telecommunications in Higher Education

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    In This Issue President\u27s Message From the ACUTA CEO RIP for TDM IPTV: The Future of Gable TV Not All SIP Trunking ls Problem Free lnterview: Four Campuses Look at lPv6, SIB and More lPv6: What You Don\u27t Know CAN Hurt You Moving from the Old to the New 2013 Award Winners lnstitutional Excellence Award Honorable Mention: Abilene Christian University Virtual La

    Threats and perspective for the Internet of Things

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    Il paradigma di ubiquitous computing sta lentamente entrando nella vita di tutti i giorni, gli utenti sono sempre connessi e una nuova esigenza di monitoraggio e controllo sta nascendo. Dispositivi di comunicazione intelligenti, le reti domestiche multimediali e l’automazione industriale sono alcune coniugazioni possibili del paradigma di ubiquitous computing che sono ora disponibili per l’utente finale. La diffusione di questi sistemi è infatti destinata a crescere, spinta da entrambi i mondi accademico e industriale la quantità di lavoro di ricerca in questo campo è in aumento, e diverse aziende hanno messo le proprie soluzioni sul mercato. Nella visione di molti, l’utente sarebbe poi in grado di godere dei vantaggi di un sistema intelligente e impercettibile che si adatta all’ambiente ed ai suoi bisogni e unisce tutte le applicazioni e i servizi in un unico sistema integrato e facile da controllare. In questo lavoro vengono valutate alcune delle sfide architettoniche di questo nuovo modo di interagire tra l’utente e il suo ambiente circostante. Vengono mostrate la progettazione e la realizzazione di un SIP-based Home Gateway per il controllo remoto di Smart Objects in un ambiente domotico. È presentata anche un’architettura basata sul protocollo SIP per realizzare un sistema di domotica capace di interagire con dispositivi eterogenei e con varie interfacce utente, l’architettura si basa sull’uso del protocollo SIP come piano di controllo comune ed è centrata sul SIP Gateway Home. Per valutare le capacità del sistema descritto abbiamo effettuato anche una valutazione delle prestazioni, considerando i due problemi principali per questo tipo di dispositivi: scalabilita ad un elevato numero di richieste di servizio per secondo e l’interferenza/coesistenza di dispositivi appartenenti a diverse tecnologie/standard (ZigBee, Bluetooth, e Wi-Fi) presenti sullo stesso dispositivo. Sono stati valutati anche i problemi di sicurezza attraverso lo studio sperimentale di un Intrusion Detection System per attenuare tali problemi

    A-Interface Over Internet Protocol For User-Plane Connection Optimization In GSM/EDGE Radio Access Network

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    This thesis will cover a detailed study about the main motivations and benefits from using IP as a transport protocol for specifically A-interface in GERAN for Circuit Switched User-Plane (CS-UP) connection, in addition to the required protocols. The main study in this document will be around Real Time Protocol (RTP), Real Time Control Protocol (RTCP) negotiation for RTP packets multiplexing, for both cases, with and without RTP header compression. The focus will be about the communication between the Base Station Controller (BSC) and the Media GateWay (MGW), the bandwidth gain in accordance to the multiplexing delay for processing and buffering, the voice Quality of Service (QoS) and some other parameters

    Support infrastructures for multimedia services with guaranteed continuity and QoS

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    Advances in wireless networking and content delivery systems are enabling new challenging provisioning scenarios where a growing number of users access multimedia services, e.g., audio/video streaming, while moving among different points of attachment to the Internet, possibly with different connectivity technologies, e.g., Wi-Fi, Bluetooth, and cellular 3G. That calls for novel middlewares capable of dynamically personalizing service provisioning to the characteristics of client environments, in particular to discontinuities in wireless resource availability due to handoffs. This dissertation proposes a novel middleware solution, called MUM, that performs effective and context-aware handoff management to transparently avoid service interruptions during both horizontal and vertical handoffs. To achieve the goal, MUM exploits the full visibility of wireless connections available in client localities and their handoff implementations (handoff awareness), of service quality requirements and handoff-related quality degradations (QoS awareness), and of network topology and resources available in current/future localities (location awareness). The design and implementation of the all main MUM components along with extensive on the field trials of the realized middleware architecture confirmed the validity of the proposed full context-aware handoff management approach. In particular, the reported experimental results demonstrate that MUM can effectively maintain service continuity for a wide range of different multimedia services by exploiting handoff prediction mechanisms, adaptive buffering and pre-fetching techniques, and proactive re-addressing/re-binding
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