When the fiber core bottoms out, there are usually two options: lay new optical cables, or expand the existing fiber core according to wavelength. The former is expensive in civil construction and network disconnection windows, and the latter is expensive in wavelength-side equipment and maintenance capabilities. The two accounts should be placed on the same table during the planning stage for comparison.

Three wavelength divisions commonly used for capacity expansion

• Single fiber bidirectional: one fiber on one hair 1310, one hair 1550, the existing core is folded in half,Gigabit single mode single fiber one optical one electrical fiber optic transceiverBelong to this category
• Coarse wavelength division CWDM: multiple wavelengths in one core, wide channel spacing, and relatively loose device requirements
• Dense wavelength division DWDM: wavelengths are denser, mainly used for long-distance and large-capacity backbones

The most common first step in the transformation of parks and sites is to upgrade point backhaul to single-fiber bidirectional; multi-wavelength common fiber is required, which involves splitting and combining devices and wavelength planning. Before placing an order, confirm the equipment range and subsequent maintenance capabilities with the supplier.

WDM is more expensive than just the components

With the addition of wavelengths, the end face, wavelength and insertion loss of each channel must be separately recorded, and the complexity of splicing and troubleshooting increases; a terminal board failure will affect multiple services on the same fiber, and the backup plan must be redone. Long-distance segments also require wavelength-by-wavelength dispersion and power budget, and the channel margin at the edge of the band is usually the tightest.

In three cases, it is recommended to lay the cable directly

• There are still holes in the pipes, and the windows can be drained when the network is disconnected at night.
• The nature of the business requires physical network separation, for exampleOptical isolation transformation of communication network in a 220kV substationThat kind of isolation need
• The existing cable connectors are too dense, the readings of both wavelengths are critical, and the common fiber has no safety margin.

The order of judgment is generally: first double the single fiber bidirectionally, then multi-wavelength common fiber, and finally lay the cable. EB-LINK technical support can compare the two routes based on the entire length and number of channels. Tel: 0755-83179002.