Multi packet reception and network coding†

We consider throughput and delay gains resulting from network coding used to complement multi-packet reception in a fully connected network with broadcast traffic. The network is comprised of N nodes, J of which have data packets to be distributed to all other nodes. Owing to half-duplex constraints, a transmitting node is not able to receive data from other transmitting nodes in the same time slot. This requires a node to be back-filled with the information that it is missing. We consider single-packet reception, (for which network coding alone yields no gain), multi-packet reception without network coding, and combined multi-packet reception and network coding. We show that the initial transmissions and the back-filling process can be greatly sped up through a combination of network coding and multi-packet reception. In particular, we show that MPR capability of 2 will not reduce the total delivery time for packets within a data network unless network coding is used. We also demonstrate that a combination of network coding and multi-packet reception can reduce this time by a factor of m, where m is the MPR capability of the system. We demonstrate that network coding can substitute for some degree of MPR and achieve the same, or almost the same, performance as the higher degree of MPR without network coding. In effect, network coding allows almost double the traffic for a given level of MPR.