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  1. P. Kuusela and P. Lassila, Modeling the impact of delay spikes on TCP performance on a low bandwidth GPRS wireless link, in Proceedings of 16th ITC Specialist Seminar, pp. 241-248, 2004, Antwerpen, Belgium (pdf)(bib)
    Abstract: We model the goodput of a single TCP source on a low bandwidth lossless GPRS link experiencing sudden increases in RTT, i.e., delay spikes. Such spikes trigger spurious timeouts that reduce the TCP goodput. Renewal reward theory is used to derive a straightforward expression for TCP goodput that depends on the bandwidth limitation, RTT and delay spike properties through average spike duration and distribution of the spike intervals. The basic model is for i.i.d. spike intervals, and correlated spike intervals are modelled by using a modulating background Markov chain. Also a simple deterministic p-formula is given. Validation by ns2 simulations shows excellent agreement and good accuracy even when modeling assumptions are mildly violated,e.g., regarding our lossless assumption.