The Dual Horizon: A Rendezvous of Computing and Communication Services at the Optical Layer in Optical Computing-Communication Integrated Network

TL;DR

The paper addresses the lack of computing capabilities at the optical layer by proposing an optical computing-communication integrated network that enables in-network optical aggregation of lightpaths. It introduces the RWCA problem, an extension of RWA, to jointly optimize routing, wavelength assignment, and computing node selection for computing requests. Through COST239 topology simulations, it demonstrates spectral-efficiency gains over traditional optical-bypass networks, highlighting the potential of performing computation directly at the optical layer. The work lays a foundation for optical-layer intelligence and motivates future joint optimization of computing and communications in photonic networks.

Abstract

With the significant advancements in optical computing platforms recently capable of performing various primitive operations, a seamless integration of optical computing into very fabric of optical communication links is envisioned, paving the way for the advent of \textit{optical computing-communication integrated network}, which provides computing services at the ligthpath scale, alongside the traditional high-capacity communication ones. This necessitates a paradigm shift in optical node architecture, moving away from the conventional optical-bypass design that avoids lightpath interference crossing the same node, toward leveraging such interference for computation. Such new computing capability at the optical layer appears to be a good match with the growing needs of geo-distributed machine learning, where the training of large-scale models and datasets spans geographically diverse nodes, and intermediate results require further aggregation/computation to produce the desired outcomes for the destination node. To address this potential use case, an illustrative example is presented, which highlights the merit of providing in-network optical computing services in comparison with the traditional optical-bypass mode in the context of distributed learning scenarios taking place at two source nodes, and partial results are then optically aggregated to the destination. We then formulate the new \textit{routing, wavelength and computing assignment problem} arisen in serving computing requests, which could be considered as an extension of the traditional routing and wavelength assignment, that is used to accommodate the transmission requests. Simulation results performed on the realistic COST239 topology demonstrate the promising spectral efficiency gains achieved through the \textit{optical computing-communication integrated network} compared to the optical-bypass model.

Figures (3)

• Figure 1: Serving a computing request in the traditional optical-bypass network and in the novel optical computing-communication integrated network employing optical aggregation
• Figure 2: COST239 network
• Figure 3: Performance Comparison