摘要
在无线网络和智能终端广泛普及的基础上,移动运营商、设备制造商和内容提供商共同推动,促使无线流媒体业务得到了迅猛发展。同时,高质量流媒体传输对带宽、时延和丢包率等性能的要求不断提高,用户规模呈现海量增长趋势,对流媒体服务器处理能力、无线网络承载能力、资源调度机制及用户管理策略均提出诸多挑战。
在Wi-Fi无线网络环境下,高质量无线流媒体普遍采用单播进行数据传输,对于海量用户群和大数据传输需求,需要创建并维护大量.的通信链路。由于无线带宽资源有限、多终端共享信道资源、无线环境多变等因素,这将导致服务器压力过大、传输冲突机率增涨、带宽资源紧张、时延性能下降、丢包率增加等问题,难以满足用户数增长和提高视频质量的需求。
面对这种矛盾问题,本文提出了一种在Wi-Fi网络下,使用基于IP组播和P2P技术的多终端协同流媒体数据传输技术,并辅以基于动态状况监测的自适应数据传输资源调度策略、基于内容的用户管理和基于中心辅助的P2P补偿机制,将这两种传输方式在无线网络下有机结合,形成优势互补,在优化带宽、减轻网络和服务器负载的同时,保证客户端接收数据的可靠性和完整性,实现用户与网络的双赢。
在理论研究的基础上,详细描述了设计实现并搭建基于IP组播和P2P补偿的多终端协同流媒体实验系统平台的过程,及其主要业务的实际测试执行状况。通过对其复杂度及性能指标的合理分析和评估,验证了本系统设计方案中相关关键技术的有效性和可行性。最后,根据实验结果,提出后续改进和研究方向。
Currently, On the basis of the widespread popularity of wireless networks and intelligent terminals, the jointly promotion of mobile operators, device manufacturers and content providers make wireless streaming media business rapidly develop. At the same time, for high-quality streaming media transmission, the performance demands of bandwidth, delay and packet loss rate are continuously increasing and the user scale presents a massive growth trends, which will lead to many challenges in the aspects of processing power of streaming media server, carrying capacity of wireless network, resource scheduling mechanism and user management strategies.
In Wi-Fi wireless network environment, unicast is usually used for high-quality wireless streaming media transmission. As a result, when faced with massive user and large data transmission demand, streaming server will must create and maintain a large number of communication links. Due to the limited resources of wireless bandwidth, multi-terminal shared channel resources and continuous changing of wireless environment, it is easy to cause many issues, such as excessive pressure in server, collisions probability rise, bandwidth resource constraints, delay and packet loss rate increase and so on, which will make it difficult to meet the demands of user growth and the increasing quality needs.
Faced with such contradiction, based on IP Multicast and P2P technology, this paper designed a multi-terminal collaborative streaming transmission method in Wi-Fi, which is supplemented by adaptive data transmission resource scheduling strategy based on dynamic condition monitoring, content-based user management and P2P compensation mechanism based on center auxiliary to make the two technologies organically combined in wireless network. Though their complementary advantages, we can optimize bandwidth utilization and reduce network load and server burden. At the same time, the reliability and integrity of client data can be effectively guaranteed, achieving a win-win situation between users and networks.
On the basis of theoretical analysis, a multi-terminal collaborative streaming experiment platform based on IP Multicast and P2P compensation has been built to test important process. Through analysis and evaluation of complexity and performance indicators, the effectiveness and feasibility of related key technologies has been verified. At the end, based on the experimental results, the improvement and research directions are proposed for future study.
引文
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