1,348 research outputs found

    Seamless Handover of Video Streamingin 4G Wireless Network

    Get PDF
    This paper presents QoS aware seamless vertical handover system for video streaming over wireless network. When the user is moving, the signal strength varies which may resultin buffering of the video. Various modulation techniques are used for continuous streaming of video and to resolve this issue. OFDM technique is used for multi carrier transmission with modulation formats such as BPSK and 16QAM.The system modulator switches between the two modulation schemes depending upon the Signal to Noise Ratio (SNR).In order to achieve continuous streaming of video the video is compressed at the time of handover. Experimental results shows that the performance of the system is better

    Mobility management across converged IP-based heterogeneous access networks

    Get PDF
    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 8/2/2010.In order to satisfy customer demand for a high performance “global” mobility service, network operators (ISPs, carriers, mobile operators, etc.) are facing the need to evolve to a converged “all-IP” centric heterogeneous access infrastructure. However, the integration of such heterogeneous access networks (e.g. 802.11, 802.16e, UMTS etc) brings major mobility issues. This thesis tackles issues plaguing existing mobility management solutions in converged IP-based heterogeneous networks. In order to do so, the thesis firstly proposes a cross-layer mechanism using the upcoming IEEE802.21 MIH services to make intelligent and optimized handovers. In this respect, FMIPv6 is integrated with the IEEE802.21 mechanism to provide seamless mobility during the overall handover process. The proposed solution is then applied in a simulated vehicular environment to optimize the NEMO handover process. It is shown through analysis and simulations of the signalling process that the overall expected handover (both L2 and L3) latency in FMIPv6 can be reduced by the proposed mechanism by 69%. Secondly, it is expected that the operator of a Next Generation Network will provide mobility as a service that will generate significant revenues. As a result, dynamic service bootstrapping and authorization mechanisms must be in place to efficiently deploy a mobility service (without static provisioning), which will allow only legitimate users to access the service. A GNU Linux based test-bed has been implemented to demonstrate this. The experiments presented show the handover performance of the secured FMIPv6 over the implemented test-bed compared to plain FMIPv6 and MIPv6 by providing quantitative measurements and results on the quality of experience perceived by the users of IPv6 multimedia applications. The results show the inclusion of the additional signalling of the proposed architecture for the purpose of authorization and bootstrapping (i.e. key distribution using HOKEY) has no adverse effect on the overall handover process. Also, using a formal security analysis tool, it is shown that the proposed mechanism is safe/secure from the induced security threats. Lastly, a novel IEEE802.21 assisted EAP based re-authentication scheme over a service authorization and bootstrapping framework is presented. AAA based authentication mechanisms like EAP incur signalling overheads due to large RTTs. As a result, overall handover latency also increases. Therefore, a fast re-authentication scheme is presented which utilizes IEEE802.21 MIH services to minimize the EAP authentication process delays and as a result reduce the overall handover latency. Analysis of the signalling process based on analytical results shows that the overall handover latency for mobility protocols will be approximately reduced by 70% by the proposed scheme

    Securing Handover in Wireless IP Networks

    Get PDF
    In wireless and mobile networks, handover is a complex process that involves multiple layers of protocol and security executions. With the growing popularity of real time communication services such as Voice of IP, a great challenge faced by handover nowadays comes from the impact of security implementations that can cause performance degradation especially for mobile devices with limited resources. Given the existing networks with heterogeneous wireless access technologies, one essential research question that needs be addressed is how to achieve a balance between security and performance during the handover. The variations of security policy and agreement among different services and network vendors make the topic challenging even more, due to the involvement of commercial and social factors. In order to understand the problems and challenges in this field, we study the properties of handover as well as state of the art security schemes to assist handover in wireless IP networks. Based on our analysis, we define a two-phase model to identify the key procedures of handover security in wireless and mobile networks. Through the model we analyze the performance impact from existing security schemes in terms of handover completion time, throughput, and Quality of Services (QoS). As our endeavor of seeking a balance between handover security and performance, we propose the local administrative domain as a security enhanced localized domain to promote the handover performance. To evaluate the performance improvement in local administrative domain, we implement the security protocols adopted by our proposal in the ns-2 simulation environment and analyze the measurement results based on our simulation test

    Secure Middlebox-Assisted QUIC

    Full text link
    While the evolution of the Internet was driven by the end-to-end model, it has been challenged by many flavors of middleboxes over the decades. Yet, the basic idea is still fundamental: reliability and security are usually realized end-to-end, where the strong trend towards ubiquitous traffic protection supports this notion. However, reasons to break up, or redefine the ends of, end-to-end connections have always been put forward in order to improve transport layer performance. Yet, the consolidation of the transport layer with the end-to-end security model as introduced by QUIC protects most protocol information from the network, thereby eliminating the ability to modify protocol exchanges. In this paper, we enhance QUIC to selectively expose information to intermediaries, thereby enabling endpoints to consciously insert middleboxes into an end-to-end encrypted QUIC connection while preserving its privacy, integrity, and authenticity. We evaluate our design in a distributed Performance Enhancing Proxy environment over satellite networks, finding that the performance improvements are dependent on the path and application layer properties: the higher the round-trip time and loss, and the more data is transferred over a connection, the higher the benefits of Secure Middlebox-Assisted QUIC

    Survey on WI-MAX System Based on Wavelet Packet Modulation Technique

    Get PDF
    A study within the field of Worldwide ability for Microwave Access system or communication system is way required as communication services. rippling Packet Modulation is AN helpful technique of multicarrier modulation that has high information measure, potency and adaptability. This paper inquires, simulation of IEEE802.16 in MATLAB software package victimization rippling packet modulation in WIMAX. The results show that BER performance of words per minute system is best than OFDM that uses cyclic prefix and consequently has higher SNR. The study is simulated over AN AWGN channel and frequency selective Rayleigh channel. BER performance of various rippling families is planned for this channel conditions OFDM is being wide utilized in wireless communication systems for its ability to cut back the information measure and enhance the information rate. The scheme provides lustiness against interference and may adapt simply to weakening eventualities. This paper offers a comparison of channel performance victimization numerous modulation techniques over completely different weakening environments. Modulation schemes include BPSK, QPSK, 64- QAM that are utilized beneath the influence of AWGN, Rayleigh, flat weakening, frequency selective and Rican attenuation channels. BER (Bit Error Rate) and SNR (Signal to Noise ratio) functions are wont to analyze the performance of information transmitted over these channels Mat research lab is employed to develop the OFDM model and analysis the performance of WiMAX system

    Applications and Simulation of Femtocells in a Cognitive Radio Environment

    Get PDF
    Femtocells are small base stations that provide radio coverage for mobile devices in offices or homes.Throughout our project work we put forth a femtocell based cognitive radio architecture for enabling efficient multi-tiered access in next generation broadband wireless systems. The key requirements for femtocell deployment, its benefits, the usage model, design challenges and market issues will be investigated. This architecture combines the conventional femtocell concept with an infrastructure based overlay of a cognitive network. The merits of using a femtocell is enhanced coverage minimized interference and increased capacity. By incorporating a femtocell in a cognitive radio environment problems such as spectrum under-utilization can be solve. This is achieved by allowing secondary users to use the free and available spectrum. We provide experimental results to demonstrate the feasibility of such a model. The advantages and several bottlenecks in administering this concept are also illustrated. The purpose of this project is to explore the use of femtocells in present cellular systems to provide better coverage and deal with resource allocation by employing it in a cognitive radio environment

    Inter-subnet localized mobility support for host identity protocol

    Get PDF
    Host identity protocol (HIP) has security support to enable secured mobility and multihoming, both of which are essential for future Internet applications. Compared to end host mobility and multihoming with HIP, existing HIP-based micro-mobility solutions have optimized handover performance by reducing location update delay. However, all these mobility solutions are client-based mobility solutions. We observe that another fundamental issue with end host mobility and multihoming extension for HIP and HIP-based micro-mobility solutions is that handover delay can be excessive unless the support for network-based micro-mobility is strengthened. In this study, we co-locate a new functional entity, subnet-rendezvous server, at the access routers to provide mobility to HIP host. We present the architectural elements of the framework and show through discussion and simulation results that our proposed scheme has achieved negligible handover latency and little packet loss

    A survey on mobility management protocols in Wireless Sensor Networks based on 6LoWPAN technology

    Get PDF
    International audienceMobility has the advantage of enlarging WSN applications. However, proposing a mobility support protocol in Wireless Sensor Networks (WSNs) represents a significant challenge. In this paper, we propose a survey on the mobility management protocols in Wireless Sensor Networks based on 6LoWPAN technology. This technology enables to connect IP sensor devices to other IP networks without any need for gateways. We highlight the advantages and drawbacks with performances issues of each studied solution. Then, in order to select a typical classification of mobility management protocols in WSNs, we provide some classification criteria and approaches on which these protocols are based. Finally, we present a comparative study of the existing protocols in terms of the required performances for this network type

    Security-centric analysis and performance investigation of IEEE 802.16 WiMAX

    Get PDF
    fi=vertaisarvioitu|en=peerReviewed
    • 

    corecore