Multicasting flow control for hybrid wired/wireless ATM networks

Multipoint communication has been an increasingly focused topic in computer communication networks, including the Internet, the ATM, and the wireless/ mobile networks. The major challenges of designing multicast flow control p rotocols for a combined wired/wireless network are the varying transmission characteristics (bandwidth, error, reliability, and propagation delay) of the wireless and wired media, and the irregular, different, possibly confli cting flow control requests from multiple receivers in the point-to-multipo int (branching) setting, or from multiple senders in the multipoint-to-poin t (merging) setting. To address these issues, in this paper we design, anal yze, and evaluate both branch-point and merge-point algorithms; we also pro vide a comparison on the major issues and solutions of the two multicasting scenarios. On point-to-multipoint ABR flow control, we examine an existing max-min fai r branch-point algorithm proposed by Siu and Tzeng, and formally analyze it s maximum cell loss. A new algorithm is then proposed. Both the maximum cel l loss and max-min fairness of new algorithm are analyzed. With extensive s imulation, we compare three branch-point algorithms (including a third one proposed by Fahmy, Jain et al.). On multipoint-to-point flow control, we extend the "essential fairness" con cept, which was first proposed by Wang and Schwartz to flow control of mult icast and unicast TCP traffic in the Internet to the multipoint-to-point AB R flow control. We design a general switch algorithm, which provides essent ial fairness to the multipoint-to-point ABR flow control. Three major varia tions of the algorithm, each of them guarantees different fairness (of favo r) to unicast or multicast sessions, are then presented. These three scheme s are evaluated by simulation. The significance of our approach is illustrated by the formal analysis of c ell loss, feedback delay and max-min fairness properties, the generalized f airness definition for multicasting flow control, and the comparisons we ma de for (1) point-to-multipoint vs. multipoint-to-point scenarios, (2) three branch-point algorithms, and (3) three fairness definitions and mechanisms of multipoint-to-point multicasting. The work may be applied to multicast services in various high speed networks, such as supporting differentiated multicast service over IP, supporting flexible billing schemes, and providi ng QoS services over hybrid networks. (C)2000 Published by Elsevier Science B.V. All rights reserved.