8CH DWDM one fiber each


At a time when the market demand for data speeds is increasing, and fiber optics physically do not want to magically multiply, many companies are faced with the difficult decision of how to effectively expand their network.

Customer problem:

Our customer needed to run a network carrying 8 10G Ethernet transmissions, with a single optical fiber available for a total distance of 142 km with one intermediate point. Insertion losses of the optical track were about 0.25 dB per kilometer.

Requirements to be met:

  • The network must be prepared to expand up to 8 transmissions at no additional cost.
  • The entire network must work on a single fiber between locations A-B and B-C.
  • All active devices must have a redundant power supply.
  • The entire solution must fit a maximum of 3U.
  • Active devices must be able to be remotely managed due to the location of the devices in the field locations.

Applied solution:

In order to increase the bandwidth of fiber, we have adopted 8-channel simplex multiplexers and demultiplexers in the technologyGBC Drawer DWDM. Due to the transmission of one fiber, it was necessary to use other channels for the direction of transmission and others for reception. The right choice of channels at the end locations was crucial due to the large distance and thus the need to amplify the signal. Long distance causes large insertion losses, which forces the use of optical amplifiers. Utilized EDFA type amplifiers.In long-distance transmission in the III optical window we are dealing with the phenomenon of chromatic dispersion, therefore it was necessary to use also suitable chromatic dispersion compensators.

Benefits for the customer:

Thanks to the solution used, the customer easily received 8 transmissions over a distance of 142 km using only one fiber, which allowed to increase its capabilities 8 times between locations A and C, keeping operating costs unchanged. Keeping operating costs low while maintaining an optimal investment approach allows ISPs to maintain the competitiveness of their own services. In addition, thanks to the use of elements with a remote management system, the client gained the possibility of surveillance and diagnostics of the transmission, which was previously impossible due to the lack of local support.