Fujitsu Develops Technology to Accurately Estimate Optical Network Transmission Performance

Improves network system throughput by about 20%

Fujitsu Laboratories Ltd. and Fujitsu Laboratories of America, Inc. today announced the development of a new technology to estimate the transmission performance, and to improve the throughput of optical networks.

When adding communication paths to existing optical networks using new wavelengths, the transmission speed was previously set at a safe operation level based on design specifications of optical fibers and communication devices. This was done as it was difficult to accurately determine the actual transmission performance of the optical fibers and communication devices that make up specific communication paths. This is why networks are operated under more restrictive conditions that lead to lower network throughput than the network should be able to support.

Now Fujitsu Laboratories and Fujitsu Laboratories of America have developed a technology to learn the actual characteristics of an optical network, and accurately estimate the supported transmission speed of newly added communication paths by observing the bit error ratio (BER)(1) of the optical signals of communication paths already in operation. This newly developed technology was experimentally evaluated on a testbed simulating an optical network in which the largest transmission distance was about 1,000km, and it was confirmed that the estimates erred by less than 15%. In addition, in network simulations carried out based on the results of this experimental evaluation, it was confirmed that the throughput of the network as a whole could be improved by about 20%. This technology has enabled the maximization of the throughput of networks to provide highly efficient communication infrastructure.

Details of this technology will be announced at the Optical Networking and Communications Conference & Exhibition (OFC2017), an international conference held in Los Angeles from March 19.

Development Background

The optical networks that support advanced ICT societies connect numerous locations within the optical network with high volume, low-latency connections by using wavelength division multiplexing technology, which combines optical signals of different wavelengths for transmission on a single optical fiber. Going forward, however, in order to meet the increasing communication demands that accompany further expansion of cloud-based services and the commercialization of 5G mobile communications systems, there will be an unprecedented demand for technologies that increase the throughput of optical networks as a whole.


In the operation of an optical network, when there is additional demand for communication between certain locations, the achievable throughput is calculated by estimating transmission performance, and signals on new wavelengths are added based on these results. Because it is difficult to accurately determine all the physical parameters of the numerous specific optical fibers and communications devices that make up an optical network, such as loss in an optical fiber or the amount of noise in an amplifier, transmission performance has previously been estimated based on the design specifications of optical fibers and communications devices. In order to guarantee stable network operation, however, it was necessary to make estimates lower than actual transmission performance, resulting in the network operating under more restrictive conditions that lead to lower network throughput than the network should have been able to support.