Despite the size of its optical network, the challenge for AT&T is that many of the platforms it has deployed can’t interoperate with one another because they’re built on proprietary systems.
John Mendamana, VP of packet-optical network for AT&T, said that each optical system is purchases are relegated to each geography it serves.
What this means is that AT&T has to deploy one vendor’s optical box for Miami and another for its network segment in Orlando, for example.
“The way I describe optical is it is a part of the network where vendors have geographic exclusivity,” Mendamana said. “This is because I can only deploy one vendor’s equipment in each geography since these things won’t interwork.”
Enter Open ROADM
To alleviate the issues with proprietary optical platforms, AT&T is focused on helping to create two concepts in next-generation ROADM technology for its own network via the Open ROADM consortium it helped create: software controlled ROADMs and open hardware.
During the Optical Fiber Conference (OFC) in March, AT&T joined up with Ciena, Fujitsu, and Nokia to create a Multi-Source Agreement (MSA) for the open ROADM group.
This group has been charged with building and publishing open standards for ROADMs. It is making the ROADM specs openly available to other companies that want to take advantage of them.
A software-controlled ROADM can automatically detect and adjust bandwidth and move traffic to different lanes as needed.
“It’s not a completely white box model, but a disaggregated model we call Open ROADM,” Mendamana said.
Mendamana added that the key challenge with driving new concepts like OpenROADM is getting established players on board.
“The problem with these things is the reluctance for an established player to join,” Mendamana said. “A number of these companies have brought their technology into the community and there’s licensing arrangements.”
Focus on testing
Now that AT&T has been able to get some of the main suppliers to get on board with the OpenROADM concept, the focus for AT&T and other Open ROADM partners is to test how these platforms will work.
Thus far, Open ROADM has 13 members. Besides AT&T and various vendors, other large global service providers include SK Telecom, Orange, Rostelecom, Saudi Telecom Company, Telecom Italia, and Deutsche Telekom.
“Open ROADM is already playing out,” Mendamana said. “Products are available and we’re testing with plans to start deploying it next year.”
As it starts deploying Open ROADM components, the focus will be on shorter spans of AT&T’s network followed by longer distances over time as products get proven out.
“Initially, we’ll only do it in the 80 km or sub-80 km metro network,” Mendamana said. “It will expand to longer distance once we prove the first deployment.”