Higher broadband demands from burgeoning services including 5G, IoT and 4K TV pressured Telefónica's transport networks, so the service provider partnered with NTT Docomo in Japan as part of the Telecom Infra Project (TIP) to develop its partial optical transport disaggregation project.
After all, traffic will only grow more -- soon -- and Telefónica needed to resolve the challenge without relying on expensive solutions.
"The demands of ultra-broadband services means the traffic in the transport network is increasing typically at 40% per year. With 5G, this increase could be even higher," Juan Pedro Fernandez-Palacios, head of Transport Technology and Planning at Telefónica GCTIO, told Broadband World News in an interview. "We need to transfer more traffic with the same budget, so we have to reduce the cost per unit. That's our main challenge."
No disagreement on disaggregation
Disaggregation has at least two major advantages, according to Telefónica. First, it reduces the time it takes the service provider to introduce new technologies into the network. The second: It drives completion among vendors as long as they meet certain standards.
"If we want to deploy a technology such as a cfp2-dco or sliceable bandwidth variable transponders or packet optical integration, we have to wait for our system vendor to include that in their roadmap -- if they want to do it," said Fernandez-Palacios. "With optical disaggregation, we could deploy the technology as soon as it is available on the market, provided the vender fulfills the technical requirements for optical disaggregation that we apply."
Keeping Data Traffic Speeding Along
With demands of ultra-broadband services driving transport-network traffic up about 40% annually, operators seek cost-effective disaggregation.
This means Telefónica no longer must await a vendor's completed solution. Rather, it can pick and choose which vendors to work with, depending on specific requirements. This drives competition and competitive pricing wherever there is disaggregation.
"We can increase competition in our purchasing processes and reduce prices because any vendor fulfilling the requirements could be invited to participate. This is an important motivation and drives a measurable increase in competition," Fernandez-Palacios said.
To realize these benefits, simplicity is key, he emphasized.
"Telefónica is not considering a full disaggregation architecture, where any single subsystem could be provided by a different vendor. We are considering a partial disaggregation approach, where the transmission elements -- the transmitters and receivers or the transponders -- are decoupled from the optical transport and switching infrastructure," said Fernandez-Palacios. "We are just dividing the network into parts: transmission and transport. If we just decouple the transmission and the optical infrastructure, we could have it with a minimum effort."
The complexity of this approach is more manageable than a full disaggregation architecture, which would require the development of complete software control support for the whole network.
Key elements in Telefónica's project include a software-defined network (SDN) controller in the optical domain, a T-API as a Northbound interface. Southbound, an interface, was only needed to control the open terminal -- the transponders from third parties -- on both the open terminal and the SDN controller, supporting a Southbound interface based on Open Config.
"We are trying to define a solution that is a simple as possible in order to make it feasible," said Fernandez-Palacios.
Adios proprietary mindsets
So far, the project has proved successful.
"We have demonstrated that partial optical disaggregation is feasible," he said. "We have proven that we can have automatic provisioning and dynamic restoration of one channel from one vendor over the optical infrastructure of another vendor and interact through these interfaces with full compatibility in the SDN."
The challenge now? To make the interface requirements a standard for vendors to follow. This is vital because Telefónica wants to run no proprietary hardware or software, preferring everything to be standards-based, said Fernandez-Palacios.
Telefónica worked with vendors including Nokia, Huawei, ZTE, Ciena, Infinera, FiberHome, Coriant and Adva. It continues to test and validate vendor solutions to see if there is support for the interfaces it needs. From there, Fernandez-Palacios said Telefónica will include the requirements for partial disaggregation in network upgrades in Brazil and Germany.
"By the end of 2019 there will have been trials with optical disaggregation in some of the operations in Telefónica. For wider deployment, we will need to wait until 2021," he said.
Collaboration, especially with NTT and Telefónica's vendor partners, is another essential component for success. To drive collaboration, events like the upcoming NGON World in Nice are vital, said Fernandez-Palacios.
"These events are very useful," he noted. "We can have direct and personal contact with other operators and system vendors. We can talk with the system vendors that are working on completely different areas or related to technology or to even R&D companies about their product development, so it definitely helps."
NGON & DCI World 2019 runs 21-23 May at the Acropolis in Nice. For more information on this year's show follow this link.
— Niall Hunt, Digital Lead, Content & Communities, KNect365. Follow him on Twitter @Niall_Hunt and learn more about Broadband World Forum here.