"technical challenges involving signal amplification, noise control and transmission stability have restricted the use of other parts of the optical spectrum" [signal amplification]
This quote identifies the specific technical barriers that, once overcome, allow existing fibre to carry far more data — directly supporting the signal's claim that the bottleneck is shifting from physical deployment to signal-processing technology.
Reasoning from this article
The article describes a general constraint — most global long-haul fibre is locked into C-band and L-band because S-band was too noisy — and then presents a solution. If this solution is replicable and exportable, it implies that the world's installed fibre base could be substantially re-rated upward without new trenching, a structural shift in how network capacity is grown. The mechanism (spectrum engineering over physical build-out) is the generalizable dynamic, not the specific Chinese deployment.