LINC: An In-Network Coding Approach to Tame Packet Loss in Hybrid Wireless-Fiber Backbones

2025-09-17

AI Summary

In hybrid wireless-optical backbone networks, sporadic packet loss caused by environmental factors—such as adverse weather, construction activities, and line-of-sight obstructions—is misinterpreted by conventional transport protocols as network congestion, degrading performance of ultra-low-latency applications (e.g., financial trading). Method: This paper proposes a link-level, in-network systematic coding mechanism that requires no end-host cooperation. Forwarding nodes dynamically perform packet encoding and decoding, and a throughput–redundancy trade-off model enables adaptive optimization of coding parameters. Contribution/Results: To the best of our knowledge, this is the first approach to achieve purely network-side, link-granular, intrinsic fault tolerance—thereby preventing protocol-layer congestion misresponse. Evaluations on realistic backbone topologies demonstrate up to 18% reduction in end-to-end latency and significantly improved transmission reliability and efficiency for time-critical services.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Cognitive Modeling & Cognitive Systems: Neural Spike Coding
• Search and Optimization: Mixed Discrete/Continuous Search

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization
• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems
• Responsible Web: Measurement, analysis, and circumvention of Web censorship

Abstract

The emergence of ultra-low latency applications, such as financial transactions, has driven the development of hybrid backbone networks that rely on fiber, satellite, and microwave links. Despite providing low latencies, these hybrid networks suffer from occasional environmental packet loss caused by poor weather, construction, and line of sight blockage. Paradoxically, today's hybrid backbones rely on conventional transport protocols that take packet loss to signal network congestion, as opposed to transient environmental obstacles. A common approach to address this challenge is to use network coding (NC) between the end hosts to recover from these occasional packet loss events. However, current NC proposals assume full access to the end-hosts' stack to perform end-to-end encoding/decoding operations. In this paper, we introduce LINC, a novel system that provides in-network NC capabilities to mitigate environmental packet loss events without requiring cooperation from the end hosts. LINC uses a systematic block coding approach on a link-by-link basis, encoding and decoding packets inside the network. We model the tradeoff in goodput between end-to-end retransmissions and redundant packets introduced by LINC, and propose an optimization formulation to determine the optimal choice of coding parameters. Our simulations on real-world backbone topologies demonstrate that LINC reduces the end-to-end latency by up to 18% by eliminating unnecessary retransmissions.

Problem

• Mitigating environmental packet loss in hybrid wireless-fiber networks
• Providing in-network coding without end-host cooperation
• Optimizing coding parameters to reduce latency and retransmissions

Innovation

• In-network coding without end-host cooperation
• Link-by-link systematic block coding approach
• Optimization formulation for coding parameters