The remarkable features of the OptiX NG-WDM equipment are as follows:
The OptiX OSN 6800 supports two dynamic ADM models:
* WSD9 + RMU9
* WSD9 + WSM9
The two models function similarly. This article focuses on the differences between the two models.
Disadvantages of the RMU9:
1. The RMU9 is subject to higher adding and pass-through insertion losses than the WSM9. The adding insertion loss of the RMU9 is 6 dB higher than that of the WSM9. The pass-through insertion loss of the RMU9 is 0.5 dB higher than that of the WSM9. Therefore, a site with the RMU9 requires a higher optical power budget. As a result, the site must consider a more intense OSNR budget. In other words, in a given optical amplification environment, the equipment offers less transmission capability when it uses the RMU9 than when it uses the WSM9.
2. The RMU9 hardware cannot prevent a wavelength collision. In addition, the RMU9 cannot adjust optical power for each wavelength on a channel. The reason is that the input interfaces of the RMU9 are independent of wavelength. Regardless of that, the OptiX OSN 6800 software can check for a logical wavelength collision (through optical cross-connections) and ensure good cooperation between the RMU9 and WSD9.
3. In the case of inter-ring connections, the RMU9 offers one fewer ring interface than the WSM9 does. It is recommended that the RMU9 work in 8x1 mode for inter-ring connections. Therefore, the number of ring interfaces on the RMU9 is one fewer than the number of ring interfaces on the WSM9. Regardless of that, the RMU9 supports 8-dimensional scheduling.
Advantages of the RMU9:
1. The RMU9 is much cheaper than the WSM9.
2. The RMU9 can add and drop signals in any wavelength. In addition, the RMU9 is easier to control than the WSM9. The reason is that the input interfaces of the RMU9 are independent of wavelength.
3. In terms of optical power budget, the RMU9 applies to most local add/drop scenarios. The RM9 performs local add/drop in the same way as the WSM9 does. The RMU9, however, cannot compare with the WSM9 in the optical power budget for 5- to 8-dimentional scheduling.