NeTS: Small: QoS Assured Multimedia Communication over Non-stationary Wireless Channels

下一代无线网络的目标是支持语音、数据和多媒体等各种应用。然而，无线信道是不可靠的，无线衰落信道的容量是时变的，这可能会导致视频/音频质量的严重下降。因此，设计无线网络多媒体通信的服务质量保证机制和多媒体压缩技术就显得尤为具有挑战性。本项目旨在为在非平稳无线信道上实现保证服务质量的多媒体通信开发新的理论和技术。为实现这一目标，开展了以下研究工作：1)发展了一种新的进化谱方法，它能够准确地模拟一般非平稳衰落信道的动态特性；2)发展了非平稳衰落信道上保证服务质量的滑模拥塞控制和调度机制；3)发展了伽玛率理论用于信源编码中的因果率控制，并发展了跨层设计，以实现多媒体编码和传输的网络友好性和观众友好性。本项目所开发的技术将填补在非平稳无线信道上对保证服务质量的多媒体通信的基本认识上的一些重要空白，并为系统设计和算法实现提供理论基础。

The next-generation wireless networks are targeted at supporting various applications such as voice, data, and multimedia. However, wireless channels are unreliable and the capacity of a wireless fading channel is time-varying, which may cause severe degradation to video/audio quality. Therefore, it is particularly challenging to design quality of service (QoS) assurance mechanisms and multimedia compression techniques for multimedia communication over wireless networks. This project aims to develop new theories and techniques for QoS assured multimedia communication over non-stationary wireless channels. To accomplish this goal, the following research tasks are conducted: 1) developing a novel evolutionary spectrum approach, which is able to accurately model the dynamics of general non-stationary fading channels; 2) developing QoS-assured sliding-mode congestion control and scheduling mechanisms for multimedia communication over non-stationary fading channels; and 3) developing gamma rate theory for causal rate control in source coding, and developing cross layer design to achieve both network friendliness and viewer friendliness for multimedia coding and transmission. Techniques developed in this project will fill some important gaps in fundamental understanding of QoS-assured multimedia communication over non-stationary wireless channels, and provide the theoretical underpinning for system design and algorithm implementation.