Adjustable redundancy for secure network coding in a unicast scenario

Within this paper, we investigate efficient communication by means of network coding in a unicast scenario. Packets can be lost due to errors or attacks, hence, redundant data packets are necessary to ensure a successful transmission. In the ideal case, the level of redundancy should correspond to the given loss rate. However, the loss rate may be unknown in practice. We investigate methods for determining the number of redundant packets based on estimating the delivery rate. The estimation utilizes feedback by the recipient. Each of the investigated methods is characterized by a certain trade-off between communication overhead and delay. Depending on system conditions and application requirements, these goals can have different importance. Thus, we introduce a method for adjusting the redundancy according to individual needs regarding communication overhead and delay. Simulation results confirm that the estimation of the delivery rate is suitable for determining the level of redundancy and that it is possible to adapt to individual optimization goals: minimizing communication overhead and/or delay.