Blank Space: Adaptive Causal Coding for Streaming Communications Over Multi-Hop Networks

TL;DR

This paper introduces BS-AC-RLNC, an adaptive coding scheme for multi-hop networks that improves resource efficiency and maintains performance by adjusting FEC rates and scheduling based on network bottlenecks.

Contribution

The paper proposes a novel adaptive coding scheme with a lightweight re-encoding algorithm that optimizes throughput, delay, and resource use in multi-hop network streaming.

Findings

Achieves 20% reduction in channel usage compared to baseline RLNC.

Provides theoretical bounds on delay, goodput, and throughput.

Extends analysis to multicast scenarios for diverse network conditions.

Abstract

In this work, we introduce Blank Space Adaptive Causal Random Linear Network Coding (BS-AC-RLNC), a novel coding scheme designed to mitigate the triplet trade-off between throughput-delay-efficiency in multi-hop networks. BS-AC-RLNC leverages the physical limitations of the network, considering the bottleneck from each node to the destination. In particular, this approach introduces a light-computational re-encoding algorithm, called AC-RLNC (NET), implemented independently at intermediate nodes. NET adaptively adjusts the Forward Error Correction (FEC) rates and schedules idle periods. It incorporates two distinct suspension mechanisms: 1) Blank Space Period, accounting for the forward-channels bottleneck, and 2) No-New No-FEC approach, based on data availability. We present theoretical lower and upper bounds on in-order delivery delay, goodput, and throughput; in the case of in-order delay, we further derive a mean bound. These analytical results are extended to the multicast scenario, providing a broader understanding of the algorithm's performance under diverse network conditions. The experimental results achieve significant improvements in resource efficiency, demonstrating a 20% reduction in channel usage compared to baseline RLNC solutions. Notably, these efficiency gains are achieved while maintaining competitive throughput and delay performance, ensuring improved resource utilization does not compromise network performance.