32-Channel Demultiplexer Cards

Two types of 32-channel demultiplexer (DMX) cards exist: 32 DMX-O and 32 DMX. Each has the general function of demultiplexing a composite fiber signal containing 32 100 Ghzspaced ITU-T wavelength channels.

32 DMX-O Demultiplexer Card

Channel demultiplexing is accomplished using an on-board AWG. The optical outputs of the 32-channel demultiplexer are equipped with a VOA. ITU-T wavelength channels are extracted from the 32 DMX-O card using four MPO ribbon connectors on the front faceplate. Each ribbon connector contains eight receive pairs for interfacing to a fiber cross-connect or termination panel.

The 32 DMX-O is a double-slotted interface card. It can be inserted in the ONS 15454 shelf assembly Slots 15 or 1216.

Note

The card cannot be inserted in Slots 6 or 17 because it must occupy dual adjacent universal interface slot positions.

Figure 9-12 shows the faceplate layout of the 32 DMX-O.

Figure 9-12. The 32 DMX-O Card Faceplate Diagram

32 DMX Demultiplexer Card

The 32 DMX performs the same functions as the 32 DMX-O; however, the 32 DMX uses a single software-controlled VOA for all the channels on the common receive port. There are no individual software-controlled VOAs on each drop port, as with the 32 DMX-O.

The 32DMX is a single-slotted interface card. It can be inserted in the ONS 15454 shelf assembly Slots 16 or 1217. Figure 9-13 shows a faceplate layout of the 32 DMX interface module.

Figure 9-13. The 32 DMX Card Faceplate Diagram

The 32 DMX and 32 WSS work in concert to provide ROADM capability. As noted earlier, the composite input signal is interfaced at the WSS, where an 80/20 splitter drops the 32 channels to the 32 DMX card and also distributes the channels to the corresponding East/West 32 WSS card as pass-through channels. A software-controlled switch in the 32 WSS determines whether the wavelength channel is added to the composite line spanand, thus, dropped at the 32 DMXor whether the channel is passed through. Channels can be either added or passed through, but not both. Figure 9-14 illustrates the ROADM operation.

Figure 9-14. ROADM Block Diagram