3,651 research outputs found

    An eco-friendly hybrid urban computing network combining community-based wireless LAN access and wireless sensor networking

    Get PDF
    Computer-enhanced smart environments, distributed environmental monitoring, wireless communication, energy conservation and sustainable technologies, ubiquitous access to Internet-located data and services, user mobility and innovation as a tool for service differentiation are all significant contemporary research subjects and societal developments. This position paper presents the design of a hybrid municipal network infrastructure that, to a lesser or greater degree, incorporates aspects from each of these topics by integrating a community-based Wi-Fi access network with Wireless Sensor Network (WSN) functionality. The former component provides free wireless Internet connectivity by harvesting the Internet subscriptions of city inhabitants. To minimize session interruptions for mobile clients, this subsystem incorporates technology that achieves (near-)seamless handover between Wi-Fi access points. The WSN component on the other hand renders it feasible to sense physical properties and to realize the Internet of Things (IoT) paradigm. This in turn scaffolds the development of value-added end-user applications that are consumable through the community-powered access network. The WSN subsystem invests substantially in ecological considerations by means of a green distributed reasoning framework and sensor middleware that collaboratively aim to minimize the network's global energy consumption. Via the discussion of two illustrative applications that are currently being developed as part of a concrete smart city deployment, we offer a taste of the myriad of innovative digital services in an extensive spectrum of application domains that is unlocked by the proposed platform

    Implementación de un sistema SDN para la movilidad en redes OMNIRAN

    Get PDF
    This document details all the information needed to understand and test distributed mobility management using the SDN paradigm. This project stars by an analysis of the mobility problem in dense networks. Traditionally mobility has been managed with hierarchical approaches extending the current mobility protocols. But thinking in the future evolution of the network into dense environments some scalability problems appear. The traditional centralized elements may not be able to handle all the traffic in the network and bottlenecks appear at the Mobility Anchors. Nowadays, the problems related to scalability are mostly resolved with hardware upgrades, but in dense environments this couldn’t be enough and surely it would be quite expensive. To find a solution to this problem the IETF has chartered the Distributed Mobility Management (DMM) Group.This project focus on implementing a DMM-based mobility solution designed within the EU FP7 CROWD project. Once the analysis of the problem ended and the requirements of the theoretical solution were defined, we developed all the necessary elements to physically build a distributed network using SDN to manage layer 2 and layer 3.The entities of the network are defined by the CROWD projectin its related publications[9][10]. These districts were run using an SDN implementation called OpenFlow. With all the elements developed we proceed to perform the necessary tests in order to evaluate the distributed mobility management as a solution. This document explains the full design, execution and validationprocesses. Finally all the measurements and statistical data are detailed in order to have an approximation of the services that could achieve the developed network.Ingeniería Telemátic

    IP Flow Mobility support for Proxy Mobile IPv6 based networks

    Get PDF
    The ability of offloading selected IP data traffic from 3G to WLAN access networks is considered a key feature in the upcoming 3GPP specifications, being the main goal to alleviate data congestion in celular networks while delivering a positive user experience. Lately, the 3GPP has adopted solutions that enable mobility of IP-based wireless devices relocating mobility functions from the terminal to the network. To this end, the IETF has standardized Proxy Mobile IPv6 (PMIPv6), a protocol capable to hide often complex mobility procedures from the mobile devices. This thesis, in line with the mentioned offload requirement, further extends Proxy Mobile IPv6 to support dynamic IP flow mobility management across access wireless networks according to operator policies. In this work, we assess the feasibility of the proposed solution and provide an experimental analysis based on a prototype network setup, implementing the PMIPv6 protocol and the related enhancements for flow mobility support. *** La capacità di spostare flussi IP da una rete di accesso 3G ad una di tipo WLAN è considerata una caratteristica chiave nelle specifiche future di 3GPP, essendo il principale metodo per alleviare la congestione nelle reti cellulari mantenendo al contempo una ragionevole qualità percepita dall'utente. Recentemente, 3GPP ha adottato soluzioni di mobilità per dispositivi con accesso radio basato su IP, traslando le funzioni di supporto dal terminale alla rete, e, a questo scopo, IETF ha standardizzato Proxy Mobile IPv6 (PMIPv6), un protocollo studiato per nascondere le procedure di mobilità ai sistemi mobili. Questa tesi, in linea con la citata esigenza di spostare flussi IP, estende ulteriormente PMIPv6 per consentire il supporto alla mobilità di flussi tra diverse reti di accesso wireless, assecondando le regole e/o politiche definite da un operatore. In questo lavoro, ci proponiamo di asserire la fattibilità della soluzione proposta, fornendo un'analisi sperimentale di essa sulla base di un prototipo di rete che implementa il protocollo PMIPv6 e le relative migliorie per il supporto alla mobilità di flussiope

    Modeling and Implementation of Wireless Sensor Networks for Logistics Applications

    Get PDF
    Logistics has experienced a long time of developments and improvements based on the advanced vehicle technologies, transportation systems, traffic network extension and logistics processes. In the last decades, the complexity has increased significantly and this has created complex logistics networks over multiple continents. Because of the close cooperation, these logistics networks are highly dependent on each other in sharing and processing the logistics information. Every customer has many suppliers and vice versa. The conventional centralized control continues but reaches some limitations such as the different distribution of suppliers, the complexity and flexibility of processing orders or the dynamics of the logistic objects. In order to overcome these disadvantages, the paradigm of autonomous logistics is proposed and promises a better technical solution for current logistics systems. In autonomous logistics, the decision making is shifted toward the logistic objects which are defined as material items (e.g., vehicles, containers) or immaterial items (e.g., customer orders) of a networked logistics system. These objects have the ability to interact with each other and make decisions according to their own objectives. In the technical aspect, with the rapid development of innovative sensor technology, namely Wireless Sensor Networks (WSNs), each element in the network can self-organize and interact with other elements for information transmission. The attachment of an electronic sensor element into a logistic object will create an autonomous environment in both the communication and the logistic domain. With this idea, the requirements of logistics can be fulfilled; for example, the monitoring data can be precise, comprehensive and timely. In addition, the goods flow management can be transferred to the information logistic object management, which is easier by the help of information technologies. However, in order to transmit information between these logistic objects, one requirement is that a routing protocol is necessary. The Opportunistic relative Distance-Enabled Uni-cast Routing (ODEUR ) protocol which is proposed and investigated in this thesis shows that it can be used in autonomous environments like autonomous logistics. Moreover, the support of mobility, multiple sinks and auto-connection in this protocol enhances the dynamics of logistic objects. With a general model which covers a range from low-level issues to high-level protocols, many services such as real time monitoring of environmental conditions, context-aware applications and localization make the logistic objects (embedded with sensor equipment) more advanced in information communication and data processing. The distributed management service in each sensor node allows the flexible configuration of logistic items at any time during the transportation. All of these integrated features introduce a new technical solution for smart logistic items and intelligent transportation systems. In parallel, a management system, WSN data Collection and Management System (WiSeCoMaSys), is designed to interact with the deployed Wireless Sensor Networks. This tool allows the user to easily manipulate the sensor networks remotely. With its rich set of features such as real time data monitoring, data analysis and visualization, per-node management, and alerts, this tool helps both developers and users in the design and deployment of a sensor network. In addition, an analytical model is developed for comparison with the results from simulations and experiments. Focusing on the use of probability theory to model the network links, this model considers several important factors such as packet reception rate and network traffic which are used in the simulation and experiment parts. Moreover, the comparison between simulation, experiment and analytical results is also carried out to estimate the accuracy of the design and make several improvements of the simulation accuracy. Finally, all of the above parts are integrated in one unique system. This system is verified by both simulations in logistic scenarios (e.g., harbors, warehouses and containers) and experiments. The results show that the proposed model and protocol have a good packet delivery rate, little memory requirements and low delay. Accordingly, this system design is practical and applicable in logistics

    HDMM: deploying client and network-based distributed mobility management

    Get PDF
    Mobile operators are now facing the challenges posed by a huge data demand from users, mainly due to the introduction of modern portable devices and the success of mobile applications. Moreover, users are now capable to connect from different access networks and establish several active sessions simultaneously, while being mobile. This triggered the introduction of a new paradigm: the distributed mobility management (DMM) which aims at flattening the network and distributing the entities in charge of managing users' mobility. In this article, we review existing DMM proposals and describe a hybrid solution which benefits from combining a network-based and a client-based approach. We analyze the signaling cost and the handover latency of our proposal, comparing them with their centralized alternatives. We also include validation and performance results from experiments conducted with a Linux-based prototype, which show that achievable enhancements depend on the underlying network topology. We argue that the proposed hybrid DMM solution provides additional flexibility to the mobile network operators, which can decide when and how to combine these two approaches.The research leading to these results has received funding from the European Community’s Seventh Framework Programme (FP7-ICT-2009-5) under Grant agreement n. 258053 (MEDIEVAL project) and from the Spanish Government, MICINN, under research grant TIN2010-20136-C0

    Handover in Mobile WiMAX Networks: The State of Art and Research Issues

    Get PDF
    The next-generation Wireless Metropolitan Area Networks, using the Worldwide Interoperability for Microwave Access (WiMAX) as the core technology based on the IEEE 802.16 family of standards, is evolving as a Fourth-Generation (4G) technology. With the recent introduction of mobility management frameworks in the IEEE 802.16e standard, WiMAX is now placed in competition to the existing and forthcoming generations of wireless technologies for providing ubiquitous computing solutions. However, the success of a good mobility framework largely depends on the capability of performing fast and seamless handovers irrespective of the deployed architectural scenario. Now that the IEEE has defined the Mobile WiMAX (IEEE 802.16e) MAC-layer handover management framework, the Network Working Group (NWG) of the WiMAX Forum is working on the development of the upper layers. However, the path to commercialization of a full-fledged WiMAX mobility framework is full of research challenges. This article focuses on potential handover-related research issues in the existing and future WiMAX mobility framework. A survey of these issues in the MAC, Network and Cross-Layer scenarios is presented along with discussion of the different solutions to those challenges. A comparative study of the proposed solutions, coupled with some insights to the relevant issues, is also included

    Improved Handover Through Dual Connectivity in 5G mmWave Mobile Networks

    Full text link
    The millimeter wave (mmWave) bands offer the possibility of orders of magnitude greater throughput for fifth generation (5G) cellular systems. However, since mmWave signals are highly susceptible to blockage, channel quality on any one mmWave link can be extremely intermittent. This paper implements a novel dual connectivity protocol that enables mobile user equipment (UE) devices to maintain physical layer connections to 4G and 5G cells simultaneously. A novel uplink control signaling system combined with a local coordinator enables rapid path switching in the event of failures on any one link. This paper provides the first comprehensive end-to-end evaluation of handover mechanisms in mmWave cellular systems. The simulation framework includes detailed measurement-based channel models to realistically capture spatial dynamics of blocking events, as well as the full details of MAC, RLC and transport protocols. Compared to conventional handover mechanisms, the study reveals significant benefits of the proposed method under several metrics.Comment: 16 pages, 13 figures, to appear on the 2017 IEEE JSAC Special Issue on Millimeter Wave Communications for Future Mobile Network
    corecore