An Efficient Fragmentation Congestion Control Algorithm in Satellite DTN

The satellite delay- and disruption-tolerant networking (DTN) with limited resources usually encounters serious congestion problem. Traditional passive congestion control algorithms, such as Drop Oldest (DO) and DF (Drop Most Forward), may lead to unnecessary bundle drop without considering the different sizes between bundles in satellite DTN. In order to avoid unnecessary bundle drop in satellite DTN, we propose a fragmentation congestion control (FCC) algorithm to achieve better utility function values and more bundles. We also carry out joint simulation with STK and OPNET to validate the proposed algorithm. Results show that combining the proposed FCC algorithm with conventional bundle drop congestion control algorithms would improve the delivery probability of small bundles without affecting the transmission of large bundles. In our simulation with 12 LEO satellites and 7 earth stations, joint use of FCC with DO and DF can enhance the average delivery probability by about 14% and 8%, respectively.