Beyond Virtual Delay: Improving Packet Delay Bound in Network Calculus

2026-06-11

AI Summary

This work addresses the well-known conservatism of packet delay bounds derived from virtual delay in classical network calculus, which often fail to accurately capture the actual worst-case delay. Revisiting packet delay analysis, the paper proposes a novel upper bound that relies solely on arrival and service curves without requiring additional assumptions. The authors theoretically prove that the maximum packet delay is always no greater than the maximum virtual delay and leverage this insight to derive a tighter delay bound that strictly improves upon classical results. Experimental evaluation in time-sensitive networking (TSN) scenarios demonstrates that the proposed bound significantly enhances analytical accuracy.

Abstract

In network calculus, a fundamental result is the classical delay bound given by the horizontal deviation between the arrival and service curves. While widely used, the classical bound is derived from the notion of virtual delay. In this work, we first show that the maximum packet delay is always upper-bounded by the maximum virtual delay, revealing inherent conservatism when applying the virtual-delay-based bound to packet delay. Motivated by this insight, we revisit packet delay analysis and derive a new packet delay bound that requires no assumptions beyond the arrival and service curves. Specializing the new bound to a system with leaky-bucket arrival curve and rate-latency service curve shows strict improvement over the classical bound, which is further demonstrated through a case study in time-sensitive networking (TSN).

Problem

• packet delay bound
• network calculus
• virtual delay
• arrival curve
• service curve

Innovation

• network calculus
• packet delay bound
• virtual delay
• arrival curve
• service curve