Study on QoS Guarantee Mechanisms in Next Generation Networks

1系统级间的QoS映射方法考虑到各系统实体之间可传递或可理解的QoS参数的差异，研究了应用级QoS、网络级QoS和端系统级QoS之间的QoS映射方法。通过对实际视频数据和系统的实验，我们展示了编码/解码视频数据所需的CPU资源（CPU周期）和实时传输编码数据所需的网络资源（带宽）之间的关系。2在每个系统实体中提供QoS的机制我们考虑每个系统实体，即服务器，客户端和网络，如何保证实时视频应用的QoS。结果表明，在终端系统中采用实时操作系统，在网络中采用基于带宽预留的协议，可以有效地提供高质量和实时的视频传输。我们还提出了如何端系统相互通信，以获得必要的资源分配信息的方法。3 QoS保证的基础上综合资源分配schemeIn分配资源的实时视频传输，我们应该考虑每个实体上的系统资源的可用性。我们提出的综合资源分配方案，实现了高质量的视频传输与有限的资源，同时最大限度地提高用户的效用，这是通过分配的资源和成本支付他们之间的关系表示。4实施和评估建议schemeWe实施和评估的综合资源分配方案，以分配网络和服务器CPU资源的客户端在一个综合的方式。我们澄清了一些实施问题，并提出了解决方案。通过视频传输实验，我们表明，我们可以实现有效的资源分配，符合系统环境，并提供高品质的视频给用户。

1 QoS mapping method among different system levelsWe investigate QoS mapping method among application-level QoS, network-level QoS and end-system-level QoS, considering the fact that deliverable or understandable QoS parameters differ among those system entities. Through experimentation on actual video data and systems, we show relationship among CPU resource (CPU cycles) required to encode/decode video data and network resource (bandwidth) required to transfer coded data in real-time fashion.2 Mechanisms to provide QoS in each system entityWe consider how each system entity, i.e. server, client and network, guarantee QoS to real-time video application. It is shown that employing real-time OS in end-systems and bandwidth reservation-based protocol in networks is effective to provide high-quality and real-time video transfer. We also propose the method on how end-systems communicate with each other to obtain information necessary for the resource allocation.3 QoS guarantees based on integrated resource allocation schemeIn allocating resources to real-time video transfer, we should consider availability of system resources on each entity. We propose the integrated resource allocation scheme which achieves the high-quality video transfer with limited resource while maximizing user's utility, which is represented as relation between benefit obtained through allocated resources and cost paid for them.4 Implementation and evaluation of proposed schemeWe implement and evaluate the integrated resource allocation scheme to allocate both of network and server CPU resources to clients in an integrated manner. We clarify some implementation issues and propose the solutions for them. Through experimentation on video transfer, we show that we can achieve efficient resource allocation in compliance with the system environment and provide high-quality video to users.