Optimal Control for Network Coding Broadcast

TL;DR

This paper proves the optimality of a packet scheduling policy for network coding broadcast with two receivers, using Markov Decision Processes and Dynamic Programming, and provides experimental verification for multiple receivers.

Contribution

It establishes the optimality of the Least Received policy for two receivers and explores its potential optimality for more receivers through experiments.

Findings

Proves optimality of the Least Received policy for N=2 receivers.

Provides experimental evidence suggesting the policy's effectiveness for more than two receivers.

Models the system as a Markov Decision Process to analyze scheduling policies.

Abstract

Random linear network coding (RLNC) has been shown to efficiently improve the network performance in terms of reducing transmission delays and increasing the throughput in broadcast and multicast communications. However, it can result in increased storage and computational complexity at the receivers end. In our previous work we considered the broadcast transmission of large file to N receivers. We showed that the storage and complexity requirements at the receivers end can be greatly reduced when segmenting the file into smaller blocks and applying RLNC to these blocks. To that purpose, we proposed a packet scheduling policy, namely the Least Received. In this work we will prove the optimality of our previously proposed policy, in terms of file transfer completion time, when N = 2. We will model our system as a Markov Decision Process and prove the optimality of the policy using Dynamic Programming. Our intuition is that the Least Received policy may be optimal regardless of the number of receivers. Towards that end, we will provide experimental results that verify that ntuition.