# Improved Delay Bound for a Service Curve Element with Known Transmission Rate

## TL;DR

This paper presents a new, tight delay bound for FIFO systems with rate-latency service curves that leverages full line rate transmission, providing more accurate per-packet delay estimates.

## Contribution

It introduces a novel delay bound that incorporates full line rate transmission and packet length, improving upon existing bounds in network calculus.

## Key findings

- The new delay bound is tight and per-packet.
- It explicitly depends on packet length.
- The bound improves delay estimations in deterministic networks.

## Abstract

Network calculus is often used to prove delay bounds in deterministic networks, using arrival and service curves. We consider a FIFO system that offers a rate-latency service curve and where packet transmission occurs at line rate without pre-emption. The existing network calculus delay bounds take advantage of the service curve guarantee but not of the fact that transmission occurs at full line rate. In this letter, we provide a novel, improved delay bound which takes advantage of these two features. Contrary to existing bounds, ours is per-packet and depends on the packet length. We prove that it is tight.