A novel localised network coding-based overhearing strategy

Network coding is a very effective approach to improve network throughput and reduce end-to-end delay. However, the existing approaches cannot thoroughly solve the problem of how to deal with newly overheard packets when the buffer is full, meanwhile, coding node does not schedule the packets in coding queue according to the packets' information in overhearing buffer. As a result, these methodologies lack flexibility and require quite a few assumptions. To address these limitations, we propose a new network coding overhearing strategy which is based on data packet switching and scheduling (DPSS) algorithm. First, when overhearing buffer is full and the sink nodes have overheard new packets, sink nodes will drop the recently overheard packets but record their IDs; second, sink nodes report the packets' information to the coding node that schedules the packets in coding queue for ease of encoding. Finally, sink nodes delete the packets which have been used for decoding, and call for the ever dropped packets when decoding ratio reaches the threshold. Theoretical analysis and simulation demonstrate that, compared with traditional overhearing policies, our scheme gets higher coding ratio and less delay.