Difference Between OA and OBU?

Hello,

Fiber amplifiers or OA boards amplify optical signal power to extend the signal transmission distance.

For a traditional WDM system, before a multiplexed wavelength is received at the OA board, you need to adjust the EVOA at the IN port on the OA board, so that the output power reaches the nominal multiplexed-wavelength optical power. You can obtain the nominal value by querying the OA specifications. In a flexible ROADM system, where wavelengths with various channel spacings are in the same fiber, the nominal value of the OA board cannot be used as the output optical power of the OA board. Use a calculator to calculate the output optical power of the OA board. The following example introduces how to use the Calculator, as shown in Figure 3.

For example, assume that the OA board is OBU103, calculate the output optical power of the OUT port on the OA board at point B in Figure 1.

In principle, the WDM-side optical power on a wavelength conversion board in a 40G WDM system should be commissioned to +1 dBm. In practical application, however, a long span often has high attenuation. To offset the high attenuation, OAU05 or OBU05 boards must be used because they have high output optical power.

This guarantees proper OSNR on the network.

Thanks

Dear friend!
In the literal sense, OA stands for optical signal amplification. The OA board is a general term for all optical amplifier boards. The OBU board is a type of optical amplifier board.
According to your screenshot, OA refers to the OAU board. The difference between the OAU board and the OBU board is as follows:
1. The OAU board consists of two EDFA modules. The OBU board has only one EDFA module.
2. The OAU board has TDC and RDC ports. A dispersion compensation module(DCM) can be connected between the two ports. The OBU board, however, does not have TDC and RDC ports. So, the OAU boards are more suitable for optical fiber signals of the receiving end.

OAU board：

OBU board：

3. The early OBU has a fixed gain and fixed output optical power. Therefore, the OBU needs to work with the VOA to adjust the attenuation to meet link application requirements, which wastes power. The OAU is flexible, supports adjustable gain, and can adapt to different spans and insertion loss scenarios.
4. The OBU structure is simple and the cost is low. The OAU structure is complex and the cost is relatively high.

Thank you!