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This paper presents a link model which captures the queue dynamics in response to a change in a transmission control protocol (TCP) source's congestion window. By considering both self-clocking and the link integrator effect, the model generalizes existing models and is shown to be more accurate by both open loop and closed loop packet level simulations. It reduces to the known static link model when flows' round trip delays are identical, and approximates the standard integrator link model when there is significant cross traffic. We apply this model to the stability analysis of fast active queue management scalable TCP (FAST TCP) including its filter dynamics. Under this model, the FAST control law is linearly stable for a single bottleneck link with an arbitrary distribution of round trip delays. This result resolves the notable discrepancy between empirical observations and previous theoretical predictions. The analysis highlights the critical role of self-clocking in TCP stability, and the proof technique is new and less conservative than existing ones. Index Terms--Acknowledgments (ACKs), fast active queue management scalable transmission control protocol (FAST TCP).

In this paper, we propose a novel probabilistic method for evaluating concurrent search in all-Internet protocol (IP) networks. It is expected that the next-generation Internet will consist of a variety of wireless-access networks. To be independent of wireless-access technology and to reduce the cost of mobility management in a heterogeneous environment, we propose integrating IP Paging with concurrent search, which was originally proposed for homogeneous cellular networks. We focus on the case in which the call-arrival process is general and has stationary independent increments. Since a number of calls could arrive simultaneously, the blocking probability is not equal to the probability with the system that is full. Therefore, we resort to renewal theory to accurately derive the blocking probability. Furthermore, we obtain the throughput, the average system size, and the average system delay. Our analytical results are consistent with simulation results. Index Terms--All-IP networks, concurrent search, mobility management, paging, performance analysis.

This paper proposes and analyzes the performance of a hybrid selective repeat (SR)/multicopy (MC) automatic repeat request (ARQ) scheme to transmit fragmented internet protocol (IP) packets. The ARQ scheme works in SR mode until the last IP packet fragment is transmitted. If a fragment is negatively acknowledged after the last fragment is transmitted, then the system goes in MC mode. In MC mode, multiple copies of the erroneous fragment are transmitted. After all IP fragments are received without error, the system goes back to SR mode. Performance of the proposed scheme is evaluated in terms of bit error rate (BER), IP packet size, and fragmentation size with and without Bose Chaudhuri Hocquenghem (BCH) error correction codes. Both the results are obtained under additive white Gaussian noise (AWGN) as well as fiat Rayleigh fading channels. The proposed scheme gives a throughput of 0.9, even at high BER conditions, for any IP packet size under AWGN channel while, an 8-dB improvement is achieved, when using BCH(63, 51, 2) for throughput of 0.9, over selective repeat + stutter scheme 2 (SR+ST 2) under a fiat Rayleigh fading channel. Index Terms - Fading channel, IP packet transmission, multicopy retransmission, selective-repeat ARQ, spread spectrum, wireless communication.