How does a single optical fiber simultaneously carry 4-channel video, 8 groups of E1 and 30 PCM channels?

The IDM-30FNV4 multi-service optical multiplexer maps the four types of service onto different channels of the 155M optical link for transmission. The video channel uses 8-bit digital encoding and is transmitted onto the optical fiber in an all-digital uncompressed manner. The 8 E1 channels use transparent transmission and carry 2.048Mbps services with HDB3 line coding in accordance with the ITU-T G.703 standard; the device only performs optical-to-electrical conversion and clock recovery and does not parse the voice channels or time slots inside the E1. The 2 Ethernet interfaces each share a line-rate bandwidth of 100M, and VLAN partitioning forms two logically independent network channels. The 30 PCM channels provide voice, data and image services at 64K or n×64K rates through plug-in cards, each type of service being carried in its own time slots; at the planning stage, the bandwidth is aggregated to check the optical path margin.