Hop-by-Hop Congestion Control Over a Wireless Multi-Hop Network

• Published in: IEEE/ACM transactions on networking Vol. 15; no. 1; pp. 133 - 144
• Main Authors: Yung Yi, Shakkottai, S.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-02-2007; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Access control; Ad hoc networks; Bandwidth; Constraint optimization; Control algorithms; Control theory; Delay; Feedback; IP networks; mathematical programming/ optimization; Media Access Protocol; Spread spectrum communication; Studies; Time factors; Wireless networks
• ISSN: 1063-6692; 1558-2566
• DOI: 10.1109/TNET.2006.890121

This paper focuses on congestion control over multi-hop, wireless networks. In a wireless network, an important constraint that arises is that due to the MAC (Media Access Control) layer. Many wireless MACs use a time-division strategy for channel access, where, at any point in space, the physical channel can be accessed by a single user at each instant of time. In this paper, we develop a fair hop-by-hop congestion control algorithm with the MAC constraint being imposed in the form of a channel access time constraint, using an optimization-based framework. In the absence of delay, we show that this algorithm are globally stable using a Lyapunov-function-based approach. Next, in the presence of delay, we show that the hop-by-hop control algorithm has the property of spatial spreading. In other words, focused loads at a particular spatial location in the network get "smoothed" over space. We derive bounds on the "peak load" at a node, both with hop-by-hop control, as well as with end-to-end control, show that significant gains are to be had with the hop-by-hop scheme, and validate the analytical results with simulation