A New delay control method for real-time flows

This paper presents a novel control algorithm to decrease the worst-case delay bound for high rate homogeneous and heterogeneous real-time flows when the network traffic load becomes heavy. The algorithm is adaptive based on the instantaneous network situations. It employs a generalized form of traditional (σ,ρ) regulator called the generalized (σ,ρ,λ) regulator that operates like the (σ,ρ) regulator under the normal network traffic load situation, but provides more regulations for the heavy network traffic load situation. For a set of real-time flows, we can show that Drg≤Dg where Drg and Dg are the worst-case delay bounds with the (σ,ρ,λ) regulator and the (σ,ρ) regulator respectively. More specifically, we have developed a set of formulas to set the parameters for the new regulator so as to reduce the worst-case delay bounds for the real-time flows. We can prove that there exists a threshold input rate ρ* such that Drg = Dg for ρ≤ρ* and Drg < Dg for ρ > ρ*. When the average input rate of real-time flows is very high, the generalized regulator can effectively control the delay. The extensive experiment data match our theoretical results.