Network coding schemes for underwater networks: the benefits of implicit acknowledgement

Underwater acoustic communications are characterized by a long propagation delay and limited bandwidth. Power consumption is an additional constraint for underwater networks. Network layer schemes for that minimize both transmission time and power consumption are thus of interest. Conventional routing schemes have limitations in both power consumption and delay performance. Application of network coding schemes in rateless fashion results in better delay performance; however, power consumption is greater than for most routing schemes when the network is lightly loaded. This paper proposes a new method for network coding that relies on implicit acknowledgements to improve power consumption performance. Numerical results demonstrate superior performance of the scheme proposed. The method is also applicable to other wireless channels.