Analysis of information freshness in converging server streams
Age of Information in Queueing Systems with Merging Server Streams
Networking and Internet Architecture
Summary
Keeping information up to date in networks that combine data from multiple servers can be tricky. The authors study situations where different streams of data merge into one, like multiple paths sending updates that come together. They corrected earlier mistakes in one known setup and also analyzed a new type where duplicate data streams merge. Their work helps find the best ways to route and control data flow to keep information as fresh as possible.
What this means in practice
- •For network schedulers: Optimize routing and traffic rates to minimize information delays in networks combining multiple data streams.
- •For edge computing engineers: Design low-latency edge systems that maintain fresh status updates by effectively merging multiple server streams.
Authors
Lucrezia Rossi, Leonardo Badia, Andrea Munari
Abstract
We present a novel analytical framework for evaluating the age of information (AoI) in multi-path queueing topologies where output streams from multiple servers converge into a single pipeline. This theoretical scenario finds immediate application in ultra-reliable low-latency networks and edge computing architectures, where multi-path routing and stream merging can be vital strategies for maintaining fresh status updates. Specifically, we investigate two setups: a split-merge network and a duplicate-merge network. The split-merge case has been addressed in prior work, but we show that existing studies are incorrect, and our approach provides instead an exact analytical formulation. Moreover, building on similar reasoning, we provide the first formal analysis of the previously unexplored duplicate-merge scenario. Finally, we show how to leverage our theoretical results to solve key system-level optimization problems, deriving the optimal randomized routing probabilities and traffic injection rates that minimize average AoI.