The Fujitsu OLS “1FINITY” series adopted for the metro network’s inter-station transmission lines

Japanese telco KDDI, Cisco Systems and Fujitsu announced the recent launch of operations of a metro, regional network that combines the IP layer network and optical transmission layer network for streamlined operations.

In a release, Fujitsu explained that the metro network features a configuration that integrates the IP layer and optical transmission layer by using Cisco NCS5500 series routers, which can directly transmit and receive optical signals for WDM and Fujitsu’s 1FINITY series Open Line System (OLS), which can be connected to other companies’ products through an open interface.

The Japanese vendor noted that this approach makes it possible to reduce the number of devices compared to a conventional configuration that connects a router and a transponder for WDM, reducing power consumption by approximately 40%. The new configuration also makes it easier to expand capacity, enabling rapid response to increases in communications traffic, it added. KDDI plans to deploy the metro network across Japan by the end of fiscal 2028.

“With the nationwide rollout of 5G services in Japan, which are now in widespread use, the number of users of video and other data-intensive services is increasing, and the volume of communications is growing rapidly. KDDI aims to achieve net-zero CO2 emissions in its non-consolidated business activities by fiscal year 2030, which will make it necessary to reduce power consumption throughout its business. The rapid expansion of network infrastructure to cope with the increases in communication volume present an ongoing challenge to this objective,” said Fujitsu.

KDDI has introduced this configuration to its metro network in some areas of Japan starting in 2021. As KDDI has confirmed stable operation, it will start full-scale operations to accommodate multiple services such as 5G, au HIKARI, and corporate VPN.

Fujitsu highlighted that the new configuration eliminates the need for an enclosure to mount the WDM transponder, which was previously installed externally, thereby reducing power consumption and saving equipment installation space. The WDM transponder is miniaturizedan optical module and mounted in a Cisco router. The optical module itself has been optimized for low-power consumption through improvements in the semiconductor manufacturing process.

The Fujitsu OLS “1FINITY” series adopted for the metro network’s inter-station transmission lines supports open interfaces, allowing connection to a variety of equipment, including products from other manufacturers, the vendor added.

“KDDI is promoting the construction of an all photonic network that can achieve high capacity with low power consumption, whereas the convergence of the IP layer and optical transmission layer represents the first step toward an all photonic network. KDDI will continue to realize sustainable networks and contribute to the reduction of CO2 emissions by introducing architectures that contribute to the reduction of power consumption, and by making networks open,” Fujitsu said.