| Summary: | 碩士 === 國立臺灣科技大學 === 電子工程系 === 96 === According to the popularization of consumer electronic products such as cell phone, vehicle digital television, notebook and PDA (Personal Digital Assistance), etc. and the promotion of digital television, the perceived video quality on mobile device becomes more important in the future. Video encoding and multicasting technology have huge influence on digital television service. The major issue in multicasting is that channel condition may vary with the mobility of users. AMC (Adaptive Modulation and Coding), which is a technology used when channel condition changes, is adapted in Mobile WiMAX.
SVC (Scalable Video Coding) is a video coding scheme used for different bandwidth level users. SVC encodes a video into one base layer and several enhancement layers. User receives different number of encoded layers based on their channel condition. AMC in WiMAX and SVC are combined to enhance the user perceived video quality in the system.
BS (Base Station) multicasts the SVC-encoded layers which is encoded in multimedia server to MS (Mobile Station) according to the channel condition. We propose an ICS (Intermediate Control Server) to deal with the signaling between the multimedia server and BS. The major task of ICS is to re-package the packets of the encoded layers received from multimedia server. BS multicasts different number of layers to users according to different channel condition. Besides, simulation results are used to prove that the proposed scheme is used to enhance the user perceived video quality effectively.
|
|---|
