Costs and benefits of adaptation: evaluation in network congestion control

University Of California-San Diego, La Jolla CA

Investigators

Abstract

Abstract In cellular communications, the mobile phone and the base station need to adapt their model of the channels connecting them in order to remove reflected signals. This adjustment is made with every data packet and the overhead is that about one seventh of all the data traffic is known to both ends and so is information-free. That is the price of adaptation. The benefit is that the call remains clear despite the motion of the cell phone. In network communications, the environmental variable is the competing traffic and the data send-rate serves two purposes; to convey data to the other end, and to probe the network to estimate the maximal throughput. A significant portion of the capacity for transmission is consumed in assessing these limits. The objective of this research is to explore the trade-offs present in such adaptive systems so that more highly performing approaches can be developed. How much capacity must be lost to achieve effective use of the variable channel? By commencing with a familiar system, we hope to recognize both the design adjustments already made and the opportunities for practical advances based on new theory. The intellectual merit of the work lies in extension of technical concepts from systems theory to the realm of random evolution of networks, such as describe the traffic behavior. This brings new perspectives and mathematical tools into that are rooted in engineering practice. The broader impact of the research is its connection to people?s experience. Today?s children are very familiar with the variability of download speeds and the behavior of computers to adjust to this. Thus an entrée is provided to involve students in hard theory to address everyday problems and therefore engage them early in the value provided by technical sophistication.