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arxiv: 2604.18374 · v1 · submitted 2026-04-20 · 💻 cs.NI

Spectrum Configuration Framework for Throughput Maximization in Open Systems with Roll-Off-Based QoT Optimization

Peyman Pahlevanzadeh , Venkata Virajit Garbhapu , Agastya Raj , Dmitrii Briantcev , Dan Kilper , Marco Ruffini This is my paper

Pith reviewed 2026-05-10 03:23 UTC · model grok-4.3

classification 💻 cs.NI
keywords spectrumframeworkopenoptimizationthroughputfactorfixedoptical
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The pith

A knapsack-based optimizer tunes transceiver roll-off and other parameters to raise aggregate throughput under fixed spectrum and QoT constraints in open optical systems.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

Optical networks send data as light signals through fiber. When many signals share the same spectrum slice, filters and pulse shaping affect how cleanly each signal arrives. The authors first measured that changing the roll-off factor of the pulse-shaping filter improves signal quality when light passes through multiple wavelength-selective switches. They then built an optimization routine that treats each possible service configuration as an item in a knapsack problem: the goal is to pack as much total data rate as possible into a fixed spectrum width while keeping enough quality margin and respecting limited transceiver hardware. Experiments on a metro-scale open testbed showed the routine could trade off throughput against margin in a controlled way.

Core claim

Experimental validation on a metro-scale open testbed confirms the effectiveness of the proposed approach in achieving efficient spectrum utilization and adaptive throughput-margin trade-offs.

Load-bearing premise

That the measured QoT gains from roll-off optimization in the presence of cascaded WSS filtering remain valid and additive when the knapsack optimizer selects multi-channel configurations under real traffic and hardware constraints.

Figures

Figures reproduced from arXiv: 2604.18374 by Agastya Raj, Dan Kilper, Dmitrii Briantcev, Marco Ruffini, Peyman Pahlevanzadeh, Venkata Virajit Garbhapu.

Figure 1
Figure 1. Figure 1: Workflow of the proposed spectrum-configuration framework for [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: Maximum throughput versus number of transceivers for different [PITH_FULL_IMAGE:figures/full_fig_p003_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: RRC pulse shaping in the time and frequency domains for different [PITH_FULL_IMAGE:figures/full_fig_p003_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: Topologies used to evaluate ROF optimization and spectrum-configuration performance. (a) Five-span configuration with 6 WSSs. (b) Four-span [PITH_FULL_IMAGE:figures/full_fig_p004_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: Measured Q vs. ROF for single channel DP-64QAM@31 GBd and [PITH_FULL_IMAGE:figures/full_fig_p004_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: Optimum roll-off and launch-power operating points under WSS filtering for (a) DP-16QAM and (b) DP-32QAM. [PITH_FULL_IMAGE:figures/full_fig_p005_6.png] view at source ↗
read the original abstract

We propose a spectrum-configuration framework for open and disaggregated optical systems that maximizes throughput while guaranteeing the quality of transmission (QoT) margins. The framework jointly optimizes transceiver parameters, including modulation format, symbol rate, pulse-shaping roll-off factor, and wavelength-selective switch (WSS) bandwidth, under fixed spectral allocation constraints. The impact of roll-off factor optimization is first experimentally evaluated in the presence of cascaded WSS filtering, demonstrating measurable QoT gains for both single- and multi-channel transmission. Building on these observations, a knapsack-based optimization is applied in the context of Optical Spectrum as a Service (OSaaS) to select service configurations that maximize aggregate throughput within a fixed spectrum width and limited transceiver resources. Experimental validation on a metro-scale open testbed confirms the effectiveness of the proposed approach in achieving efficient spectrum utilization and adaptive throughput-margin trade-offs.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Axiom & Free-Parameter Ledger

0 free parameters · 2 axioms · 0 invented entities

The framework rests on standard knapsack optimization and empirical QoT observations; no new physical entities are introduced and no parameters are explicitly fitted in the abstract.

axioms (2)
  • standard math Knapsack optimization can be applied to select discrete service configurations under linear capacity and margin constraints
    Invoked when the paper states a knapsack-based optimization is applied to select service configurations.
  • domain assumption Roll-off factor changes produce measurable QoT gains that remain additive across channels under fixed spectral allocation
    Stated in the experimental evaluation section of the abstract as the basis for including roll-off in the joint optimizer.

pith-pipeline@v0.9.0 · 5473 in / 1404 out tokens · 52352 ms · 2026-05-10T03:23:14.594937+00:00 · methodology

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Reference graph

Works this paper leans on

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