Adaptive Random Network Coding in WiMAX

The IEEE 802.16 standard, or WiMAX, has emerged as one of the strongest contenders for broadband wireless access technology. In our previous work, we proposed a protocol using random network coding in WiMAX MAC layer, which has indeed offered important advantages. In this paper, we propose adaptive random network coding in WiMAX by introducing two algorithms in order to further improve the performance. First, we utilize the channel state information feedback to dynamically construct the packets that could be better matched to the fluctuating channel conditions, so as to obtain a higher throughput. Second, we design the algorithm by adapting the number of upstream nodes, which helps to minimize the overhead of sender push of redundant coded blocks to the receiver even after the receiver has completely received the data segment. Coupled with random network coding, both algorithms offer salient performance improvement as evidenced in our simulation evaluation.