Popularity Aware Scheduling for Network Coding based Content Distribution in Ad Hoc Networks

Network coding has attracted much interest recently since considerable research indicates that it can offer significant capacity gains. This paper applies network coding to mobile ad hoc networks, especially for large scale content distribution, where each network node is able to generate and transmit encoded blocks of incoming information. Furthermore, it introduces a novel scheduling approach named popularity aware scheduling (PAS) for such network coding based content distribution systems. Here, popularity refers to how much one new data block is wanted by neighboring nodes. The value is calculated based on the number of blocks that already cached by current node which generates the new block (NB-PAS), or correlation between the new block and neighbors´ cached blocks (CB-PAS). Then the popularity value is used to make the content distribution more efficient by assigning different levels of channel access priorities to blocks at MAC (media access control) layer. The higher the popularity value, the higher priority is assigned. Performance evaluation indicates that the cooperation of network coding and MAC layer scheduling is quite necessary and efficient from the point view of content dissemination speed, and information transmission efficiency.