Effect of Feedback Loss on instantly decodable network coding

In this paper, we study the effect of probabilistic and prolonged packet feedback loss events on the broadcast completion time of instantly decodable network coding (IDNC). These feedback loss events result in a lack of knowledge about the reception status at different subsets of receivers, which creates a challenge in selecting efficient IDNC packet combinations in subsequent transmissions. To solve this problem for both probabilistic and prolonged feedback loss, we first identify the different possibilities of feedback loss events at the sender and determine their probabilities in both cases. Given these probabilities and the nature of the IDNC completion time problem, we design three blind instantly decodable network coding approaches that perform coding decisions similar to the algorithms proposed in, but on blindly updated graphs to account for feedback events. These three approaches are then compared through extensive simulations. Results show that the full consideration and the full negligence of all the attempted packet requests with probabilistic and prolonged feedback loss events, respectively, in subsequent coding decisions can achieve a tolerable degradation against the perfect feedback performance for relatively high feedback loss probabilities and periods.