Software layer: This layer defines how higher-level applications can access the network to initiate data transfer. The fourth generation of fiber-optic communication systems utilized optical amplification to lessen the need for repeaters and wavelength-division multiplexing (WDM) to boost info potential. The introduction of WDM was the start of optical networking, https://history-of-aikido70247.look4blog.com/72076322/a-secret-weapon-for-cctv