Dynamic Resource Control for Shared Downlink Wireless Channel
This project explores dynamic resource control and system optimization for shared downlink wireless channel such as 3GPP HSDPA (High Speed Downlink Packet Access). We propose a new resource control framework and particularly a dynamic multi-class traffic scheduling mechanism to provide QoS (Quality of Service) for multimedia services. Inter-layer resource interaction and the entire system optimization are also studied in this project.
Background & Objective: It can be foreseen that multimedia services and applications such as video cellular phone and web browsing will proliferate in the next generation wireless network. Quality of Service (QoS) provision for multimedia services is regarded as a challenging task due to special characteristics of wireless links such as fading and mobility. This project aims to provide effective resource control techniques for multimedia over wireless networks.
Technical Discussion: We propose a new dynamic resource control framework integrated with adaptive modulation and coding (AMC) and hybrid automatic repeat request (H-ARQ) to support class-based applications. Within the framework, transmission requests are sent to the Admission Control module. The Admission Control module makes the decision whether or not to admit new transmission streams by computing the available resource from physical-layer resource measurement and existing traffics. Once admitted, traffic streams enter the Traffic Shaping and Classification module, and then are passed to different queues according to traffic. Traffic streams are classified according to delay and packet loss requirements. These QoS parameters decide the queue length, the weight of a queue and RED (Random Early Detection) configuration. Because H-ARQ retransmission may introduce large amount of extra traffic load when wireless channels are in bad condition, we assign two queues to each traffic class: original transmission queue and re-transmission queue. For each class, sub-classes (different colors) are specified according to MCS (Modulation and coding scheme). Both spreading codes and time frames are scheduled to UEs. We propose a new wireless scheduling algorithm, delay-sensitive Dynamic Fair Queueing (DSDFQ), to meet delay and loss requirements of multimedia applications as well as maintain high network efficiency. Our approach can easily adapt to load fluctuations from different traffic classes and dynamic wireless channel status affected by user mobility, fading and shadowing.
Technology Area: Digital Communications
Modification Date: July 7, 2008