行動廣播服務與無線網路服務匯集到行動終端， 例如收看行動電視節目時透過無線網路上網，為行動服務使用模式的重要趨勢之一。但是為了克服行動終端使用環境容易造成資料傳輸錯誤問題，必須有資料復原機制。本文使用網路編碼架構，提出優先權網路編碼機制，解決透過無線網路及時復原行動廣播錯誤問題。模擬結果顯示所提方法可以對有需求的行動終端增加其復原的資料量， 同時減少未能及時復原而被排除的資料量， 提升及時資料復原效率。

Mobile broadcasting services have received lots of attention recently. Due to the feature of wireless broadcasting, data losses are inevitable and the related recovery issue needed to be addressed. This paper studies the data recovery for mobile devices that associate with mobile broadcast (e.g., DVB-H) and wireless networks (e.g., WiMAX). DVB-H continually broadcasts videos to mobile devices. WiMAX serves as a recovery channel for mobile devices to request for retransmissions, which is modeled by repetitive time slots of a submission period followed by a short recovery period. Mobile devices submit their requests in the submission periods while the WiMAX base station sends the lost packets in the recovery periods. To make mobile devices recover as most number of the urgent and lost packets, we develop a prioritized network coding scheme based on XOR coding. The scheme constructs a weighted bipartite graph to reflect the influence of each coded packet and then adopts a greedy strategy to find a maximum weight minimum dominating set for coded packets. Simulation results verify that the scheme can increase the number of recovered packets by all mobile devices while reduce the number of dropped packets that are out of their recovery deadlines.