Packet scheduling based on message length

Abstract

A system using two algorithms for scheduling packets in a multi-hop network. The objective of the algorithms is to reduce end-to-end message (not packet) transmission delays. Both algorithms schedule packet transmissions based on the length of the original message to which the package belongs. The first algorithm is preemptive and is based on the shortest-message-first principle and the second is based on the shortest-remaining-transmit-time principle. We develop simulation models for analyzing the algorithms. The simulations show that when message sizes vary widely, these algorithms can significantly reduce average end-to-end message delays compared to the First-Come-First-Serve scheduling.

Description

BACKGROUND OF THE INVENTIONThe present invention relates generally to multi-hop networks and more specifically the invention pertains to a system for packet scheduling based on message length.Network protocols, such as IP or ATM, transport data in packets. The algorithms used by these protocols, for routing, scheduling, flow and access control, are usually designed to satisfy performance measures at the packet level (e.g., average packet delay). However, user applications, such as file transfer (FTP), exchange data messages which are not limited in size to that of a network protocol packet. This separation between the application data and the way in which networks manage that data often results in sub-optimal performance when measured in terms of application layer messages. This paper describes packet scheduling algorithms that attempt to reduce end-to-end message delays by taking into account message information in the scheduling of packets across the network.Network layer packets ...

AI Technical Summary

Problems solved by technology

If packets are scheduled on the basis of their length, then it has been shown that a scheduling policy that serves the shortest packet first results in minimum delays.

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