Caching Scheme for Handheld Device in Mobile Video-on-Demand System

Mobile Video on demand (VOD) system is that allows mobile clients to browse and watch videos anywhere and anytime. In this system, the video server employs staggered broadcasting protocol to disseminate video to mobile clients within the MANET environment. In this protocol, video is divided into small segments and are repeatedly broadcasted within server´s channel in periodic basis. Clients can join any of the channels to receive the segments and begin to watch the video. The drawback of periodic broadcasting is it leads mobile clients to have a long waiting time (range in several minutes) due to the issue of channel transitions period. In this paper we focus on reducing the waiting time by proposing two caching schemes. This paper proposed first, a Neighbour-based caching scheme allows clients to get help from neighbour´s buffer for the playback, and a Relay-based caching scheme uses middle clients to relay the video from client to another client. Simulation shows that our two caching schemes can reduce clients delay tremendously in comparison with the case of no caching scheme.