Congestion Control by Traac Shaping for Ground/satellite Network

This paper discusses the issues to consider when selecting congestion control scheme for an integrated ground radio and satellite network engaging primarily in transmitting multi-media traac, and then it proceeds to discuss eeects (both positive and negative) of smoothing rendered on the input traac as a congestion control scheme. We chose traac shaping by smoothing rendered on the input traac as the congestion control scheme to use for our mixed ground/satellite network due to the considerations of satellite's long propagation delay, high bandwidth of ground network, and the real-time nature of the traf-c. Traac shaping in our case, involves smoothing and policing the traac by using the \virtual token buckets" and our original \multi-buckets" (i.e., virtual token buckets plus one additional leaky bucket). The simulation results show that in the case of congestion, virtual token buckets and multi-buckets algorithms, improve throughput signiicantly for the ground/satellite network, with virtual token buckets slightly outperforming multi-buckets. Our experimental multi-buckets algorithm is useful, because it is capable of rendering additional smoothing, and thus aaording us more exibility to examine the impact of smoothing. The fact that virtual token buckets outperforms slightly the multi-buckets shows that more smoothing does not always render better throughput, and connrms that factors such as the tradeoos between smoothing and network utilization, burstiness of the streams, and the number of congested hops traversed need to be considered when examining the usefulness of smoothing.