332 research outputs found

    Wireless Broadband Access: Policy Implications of Heterogeneous Networks

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    A wireless heterogeneous network can help increase the access transmission speed and contribute thereby to the broadband deployment policies of administrations and telecommunications operators. Given the technical particularities of wireless heterogeneous networks, the deployment of wireless heterogeneous networks raises a number of challenges that need to be addressed by regulatory authorities. This article analyses the following regulatory implications: standardisation and technology neutrality, spectrum management, market analysis, open access and infrastructure sharing, interconnection pricing and charging, broadband deployment policies, and privacy and security issues. --4G,heterogeneous networks,cooperative networks,spectrum management,regulation,wireless networks

    DragonNet: a robust mobile internet services system for long distance trains

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    Wide range wireless networks often suffer from annoying service deterioration due to ever-changing wireless environments. This is especially the case with passengers on long-distance trains (LDT, such as intercity, interprovincial, and international commuter trains) connecting to the Internet. To improve the service quality of wide-area wireless networks, we present the DragonNet system and protocol with practical implementations. The DragonNet system is a chained gateway that consists of a group of interlinked DragonNet routers running the DragonNet protocol for node failure amortization across the long stretching router chain. The protocol makes use of the spatial diversity of wireless signals when not all spots on a surface see the same level of radio frequency radiation. In the case of an LDT of around 500 meters, it is highly possible that some of the DragonNet routers in the gateway chain still see sound signal quality when the LDT is partially blocked from the wireless Internet. The DragonNet protocol fully utilizes this feature to amortize single-point router failure over the whole router chain by intelligently rerouting traffic on failed ones to sound ones. We have implemented the DragonNet system and tested it in real railways over a period of three months. Our results have pinpointed two fundamental contributions of the DragonNet protocol. First, DragonNet significantly reduces the average temporary communication blackout (i.e., no Internet connection) to 1.5 seconds compared with 6 seconds without the DragonNet protocol. Second, DragonNet nearly doubles the aggregate system throughput compared with gateway without running the DragonNet protocol

    Future Trends and Challenges for Mobile and Convergent Networks

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    Some traffic characteristics like real-time, location-based, and community-inspired, as well as the exponential increase on the data traffic in mobile networks, are challenging the academia and standardization communities to manage these networks in completely novel and intelligent ways, otherwise, current network infrastructures can not offer a connection service with an acceptable quality for both emergent traffic demand and application requisites. In this way, a very relevant research problem that needs to be addressed is how a heterogeneous wireless access infrastructure should be controlled to offer a network access with a proper level of quality for diverse flows ending at multi-mode devices in mobile scenarios. The current chapter reviews recent research and standardization work developed under the most used wireless access technologies and mobile access proposals. It comprehensively outlines the impact on the deployment of those technologies in future networking environments, not only on the network performance but also in how the most important requirements of several relevant players, such as, content providers, network operators, and users/terminals can be addressed. Finally, the chapter concludes referring the most notable aspects in how the environment of future networks are expected to evolve like technology convergence, service convergence, terminal convergence, market convergence, environmental awareness, energy-efficiency, self-organized and intelligent infrastructure, as well as the most important functional requisites to be addressed through that infrastructure such as flow mobility, data offloading, load balancing and vertical multihoming.Comment: In book 4G & Beyond: The Convergence of Networks, Devices and Services, Nova Science Publishers, 201

    CFT: Co-operative file transfer algorithm for multi network interface sessions

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    File transfer is one of the important operations on the Internet. Generally files are transferred from one machine to another machine through one interface. File transfer can occur through multiple interface connections also. Protocols such as SCTP, transfers data in multiple data stream within a single connection and LFTP transfers file sourced from multiple servers to a single host. Here, we present the concept of using multiple network interfaces for transferring files from a single server. This would ensure the utilization of combined bandwidth of all the interfaces used, so that the rate of file transfer would increase considerably compared to single bandwidth transfer. In this work, we use two interfaces i.e, IEEE 802.3 (Ethernet) and IEEE 802.11 (WiFi) to accomplish the above task. We use a non pre-emptive context switching framework Twisted where threading is avoided for an effective resource utilization. The required file is downloaded utilizing two interfaces instead of one unlike normal file transfer. We analyze the improvement in performance by observing the time taken to download a file using two different interfaces (Ethernet and WiFi) and comparing that with a single interface download (using either Ethernet or WiFi) in real time scenario. We attempt to deal with the issue of when and how to connect through two interfaces which combines the bandwidths of both these interfaces, aiding in improving the performance of file transfer when compared to file transfer using single interface

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

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    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

    A Fairness Load Balancing Algorithm in HWN Using a Multihoming Strategy

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    Due to the growth of the number of intelligent devices and thebroadband requirements, between others technical requirements, of the newapplications, suppose a new challenge in planning, maintenance and resourceallocation in mobile networks for the telecommunication operators. Serviceproviders must ensure a quality of service for users in a new environmentbased in Heterogeneous Wireless Networks (HWN). A good way to achievethis goal is to prevent the quantity of services of each mobile users beingconnected to the same access networks and therefore reducing the possibilityof overloading it. This paper presents a load balancing optimization schemethat enables operators to make decisions about re-allocation of each of theservices in different access networks, keeping the required Quality of Service(QoS). In this paper, we propose 1) a mathematical model addressed as afairness resource allocation in order to obtain a global load balancing, and 2) atwo-step algorithm based on the anchor-adjustment heuristic to solve it. Ouralgorithm contribute to unload the network with maximum load while at thesame time, the other networks are balanced. As a result, we show that ouralgorithm finds (near)-optimal solutions while keeps low complexity
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