This document summarizes a research paper about accelerating channel zapping time for IP video delivery systems like IPTV. It proposes using time-shifted subchannels and destination-oriented multicast. First, it analyzes the properties of time-shifted subchannels, showing there is an optimal data rate to minimize redundant traffic. It also identifies a potential "start-up effect" issue and proposes a solution. Second, it introduces a destination-oriented multicast assisted zapping acceleration scheme that allows subscribers to seamlessly switch channels without control messages, improving scalability. Simulation results demonstrate the analysis and performance of the proposed scheme.