Analysis and Improvements of Zapping Times in IPTV Systems

IPTV is becoming a serious alternative to traditional broadcast schemes, such as cable, satellite or terrestrial, to deliver TV to the home. However, the expectation of the user is that IPTV provides the same or even better quality of experience (QoE). An important part of QoE for linear TV services is the channel change time (CCT) also known as zapping time. Due to its relevance many ideas and concepts have been published which describe how to optimize or speed up the CCT. First, to be able to judge the challenges and benefits of the available concepts, a common understanding of the contributors to the CCT is necessary. This article provides an overview of all elements in the IPTV end-to-end chain influencing the CCT from the head end down to the set-top box (STB) and finally to the display. Second, various techniques for reducing the CCT are presented and discussed.