On Improving the Balance between the Completion Time and Decoding Delay in Instantly Decodable Network Coded Systems

TL;DR

This paper introduces two heuristic algorithms for instantly decodable network coding that effectively balance completion time and decoding delay over wireless broadcast channels with memory, improving fairness and efficiency.

Contribution

It formulates the packet selection as a statistical shortest path problem and proposes two heuristics tailored for different memory conditions to enhance performance.

Findings

Algorithms outperform existing methods in specific memory scenarios.

Proposed methods improve fairness in decoding delay across receivers.

Balance between throughput and delay is effectively managed.

Abstract

This paper studies the complicated interplay of the completion time (as a measure of throughput) and the decoding delay performance in instantly decodable network coded (IDNC) systems over wireless broadcast erasure channels with memory, and proposes two new algorithms that improve the balance between the completion time and decoding delay of broadcasting a block of packets. We first formulate the IDNC packet selection problem that provides joint control of the completion time and decoding delay as a statistical shortest path (SSP) problem. However, since finding the optimal packet selection policy using the SSP technique is computationally complex, we employ its geometric structure to find some guidelines and use them to propose two heuristic packet selection algorithms that can efficiently improve the balance between the completion time and decoding delay for broadcast erasure channels with a wide range of memory conditions. It is shown that each one of the two proposed algorithms is superior for a specific range of memory conditions. Furthermore, we show that the proposed algorithms achieve an improved fairness in terms of the decoding delay across all receivers.