Vodafone conducted trials of programmable infrastructure that taps software-defined networking (SDN) principles to control capacity on its optical network. The trials are part of a broader plan to automatically adapt and adjust wavelength capacity to maintain better service continuity.
Eva Rossi, head of transport product at Vodafone, noted in a blog post that the trials included the FlexEthernet (FlexE) client interface standard from the Optical Internetworking Forum (OIF) and a flexible spectrum bandwidth controller based on a Ciena platform.
The FlexE trial resulted in test speeds up to 400 Gb/s over a single wavelength. It ran on top of Vodafone’s IP-based Red Stream converged core network in the United Kingdom.
That network has more than 200 core sites connected by more than 11,000 kilometers of optical fiber and supported by more than 1,000 MPLS-enabled aggregation nodes. Vodafone uses the network for converged connectivity of its mobile base stations, consumer broadband services, and enterprise voice and data services.
The OIF launched the FlexE project in early 2015 to better scale optical link bandwidth using software control. It provides tools to connect one or more Ethernet medium access controls (MACs) using standard Ethernet physical medium dependent layers between equipment.
Vodafone also tested flexible spectrum using technology from Ciena’s WaveLogic Ai platform. That platform is based on an optical chipset designed to tune wavelengths between 100 Gb/s to 400 Gb/s in 50 Gb/s increments on a single wavelength. Rossi explained that the flexibility in the system could allow enterprise customers to sublease part of the bandwidth they purchase from Vodafone.
“The combination of these technologies will enable Vodafone in the future to automatically adapt and adjust wavelength capacity to keep services available at all times without the need for additional hardware or manual intervention,” Rossi wrote.
SDN control over optical networks can allow operators to manage port speeds, protocols, and wavelengths; support more advanced modulation and detection schemes; and provide for flexible wavelength routing via dynamic reconfigurable optical add/drop multiplexer (ROADM) technology.
These efforts revolve around a multitude of different technologies like transport software-defined networking (T-SDN), NG-PON2, and XGS-PON. There are also open source efforts led by different organizations, including the Open ROADM MultiSource Agreement, the Telecom Infra Project’s Open Optical Packet Transport Group, the Open Networking Foundation (ONF), and OIF.
IHS Markit noted last year that the optical networking market was seeing increased pressure to adopt open software solutions “to deliver more open and interoperable optical networks.”
IHS defines an open optical network architecture as a combination of hardware and software. The hardware is typically in the form of transponders/terminals, a ROADM, amplifiers, and associated products. The software includes network management, SDN control, analytics, and other applications abstracted from the hardware.
These two worlds are linked by APIs enabling northbound and southbound communications. The northbound interface transports information on the state of the network up to the applications, while the southbound interface provides operational instructions down to the hardware.