PipSwitch: A Circuit Switch Using Programmable Integrated Photonics

TL;DR

PipSwitch tackles the problem of implementing flexible circuit switching on programmable integrated photonics (PIP) meshes by formulating the port-to-PUC routing as an Integer Linear Program over binary edge-usage variables $x_{r,e}$. The objective minimizes circuit length while obeying edge losses, a per-route length cap, Kirchhoff's flow conservation, and exclusive arm usage to prevent conflicts, improving on heuristic routing by guaranteeing feasible solutions. The approach integrates rotor-like matching (O(radix)) to ensure all-port connectivity and demonstrates scalability to $32$ ports on a $9×9$ PIP mesh, supported by end-to-end measurements showing lossless operation up to $17$ PUCs and a per-PUC configuration latency of about $47.189$ ms. The work advances programmable optical switching by delivering a verifiably optimal, scalable, and end-to-end viable architecture for large-port PIP-based switches.

Abstract

We present an optical circuit switch design for programmable integrated photonics (PIPs). Our solution finds the correct and optimal set of matchings that provides all-to-all network connectivity and demonstrates scalability to 32 ports.

Figures (3)

• Figure 1: (a): Programmable integrated photonics. (b): Two network interfaces were connected via two routes configured in iPronics (only one is shown). More servers can be connected to construct a rack.
• Figure 2: (a): Illustration for the ILP. Every cell has an ID numbered from top to bottom, left to right. Every endpoint has a local ID within the cell. There is one route with (cell 0, port 3) as source and (cell i-1, port 2) as drain. Its length is 3. Integer variables for the blue lines are set to 1. (b): Sample matchings for a rotor switch.
• Figure 3: (a): Scaling radix. (b): Configuration latency across different PIP sizes with 1, 2, and 4 routes.