Spectral Aggregation of Turbulence-Resilient FSO Links as Feeders for Capillary Access Networks

Free-space optical (FSO) communication provides fibre-grade connectivity even in fibre-scarce environments. As such, it is an ideal candidate to trunk capillary radio networks in the far-access segment. However, FSO links are prone to degradation due to misalignment and atmospheric effects. In response to this, we leverage optical antenna configurations with up to 91 elements as FSO air-interfaces that accomplish alignment-tolerant and turbulence-resilient coupling between two single-mode fibre ports. Despite exploiting the spectral domain to achieve a greatly simplified yet spectrally inefficient implementation for diversity reception, we prove that a total of up to eight FSO links at the access segment can be jointly and transparently fed over a single C-band aggregation link.