On multicasting ABR protocols for wireless ATM networks

Abstract

The major challenges of designing multicast ratecontrol protocols f o r a combined wired/wireless network are the varying transmission characteristics (bandwidth, error, and propagation delay) of the wireless and wired media, and the different, possibly conflicting flow control requests from multiple receivers. To address these issues, in this paper we study multicasting rate-control ABR algorithms for a combined wired/wireless network with unreliable links and irregular network feedback. W e propose a new ABR multicast extension algorithm that can readily extend any unicast ABR rate control scheme for multicast services. By formal analysis, we show that it is max-min fair, and that its maximum cell loss is less than or equal to that of a n existing algorithm proposed by Siu and Tseng [15]. W e also extend the definition of global feasibility t o multicast flows, and propose a dekayedincrease policy t o ensure global feasibility. Both the waiting time of the delayed-increase policy, and the maximum cell loss in the absence of the policy are formally analyzed. The new algorithm requires a waiting time n o longer than, and has a maximum cell loss less than or equal to, that of the existing algorithm. The significance of our approach i s illustrated by the formal analysis, which allows u s t o design a new multicast extension algorithm that is max-min fair, results in a small cell-loss bound, and achieves global feasibility. The analytical method m a y also assist the design and analysis of other multicasting flow algorithms over A X M and wireless A T M , and other network: protocols such as multicast IP and mobile IP.

Performance Comparison of Branch Point Algorithms for Multicast ABR Flow Control

“…Recently, a number of consolidation algorithms with fast overload indication functions have been proposed in [2,4,6,8] to facilitate an immediate warning about congestion when a severe overload condition occurs in a network. Table 2 summarises the characteristics of the existing consolidation algorithms with fast overload indication.…”

“…Although, this algorithm can also limit the total consolidation delay within the longest round-trip time (RTT) of the multicast tree regardless of the number of branch points, it still exhibits a higher queue length due to consolidation delay particularly when an initial period with high initial cell rate (lCR) or a severe overload condition. Recently, fast overload indication functions have been proposed by many researchers in order to reduce consolidation delay [1,2,4,6,8]. The main idea behind this is that a severe overload situation should be reported to the source as soon as it is detected.…”

“…Most previous researches on multicast ABR flow control have focused on the development of basic consolidation algorithms and their performance evaluation [3,7,9,10,1 I]. Some papers have evaluated performance according to various fast overload indication functions for a particular algorithm [2,4,6,8]. However, relatively little has been reported on the performance comparison of basic consolidation algorithms with the same fast overload indication function.…”

<title>Fairness for ABR multipoint-to-point connections</title>

“…The idea of Ren and Siu's algorithm is very similar to point-to-multipoint algorithms see 16,17 . The algorithm operates as follows.…”

ABR Flow Control for Multipoint Connections

“…There are several ways to implement the consolidation algorithm at branch points4,7,8,11,13 . Each method o ers a tradeo in complexity, scalability, o v erhead, transient response, and consolidation noise.…”