IEEE aims to help transition HFC networks to EPON

The IEEE today announced an initiative that could provide a platform for the next generation of cable company high-speed services by leveraging technology originally developed for telephone companies.

“We’re very encouraged to see there has been a huge amount of interest from cable companies,” said Howard Frazier, senior technology director at Broadcom and appointed chairman of a new IEEE study group focusing on EPON protocol-over-coax (EPoC), in an interview.

As Frazier explained, the new IEEE group will seek to define a way of transitioning existing hybrid fiber coax (HFC) networks into EPON networks. Initially the two networks could co-exist over the same physical infrastructure.

EPON has a strong heritage
Although EPON has been overshadowed by GPON in the U.S., it has been widely deployed in other parts of the world and is especially popular in Asia. Telcos in the U.S. opted initially for BPON and later for GPON because those technologies were based on ATM, Frazier said, and the telcos already had made significant ATM deployments.

“Cable companies have no such investment or interest,” said Frazier. “They want the biggest bang for the buck and the lowest cost.”

Where they can justify bringing fiber to a building to serve a business customer, cable companies already are deploying Ethernet over fiber using DOCSIS provisioning over Ethernet (DPoE), Frazier explained. But, he added, “They would like to connect to businesses where they haven’t taken fiber all the way there.”

The new IEEE working group will be tasked with defining a new physical layer standard for EPON that uses coax for the final hundreds of meters to a customer.

“Everything else about EPON can remain unchanged,” noted Frazier—and that means cable companies will be able to benefit from years of EPON development that already have occurred.

Technical challenges
In order for EPoC-based services to co-exist with existing services running over existing HFC infrastructure, Frazier said, the working group will look at “the frequency spectrum available on the coaxial plant” which includes “different slices of spectrum at different frequencies.”

Eventually cable companies likely will want to migrate residential broadband services to the EPON platform. Instead of 100 or 200 subscribers sharing 300 Mb/s as they do in a typical HFC system, the goal is for them to share a 10 Gb/s connection, Frazier said.

From a technology standpoint, the goals of the EPoC standard should not be difficult to deliver, said Frazier. He noted that several possible approaches have been discussed and there undoubtedly will be some debate about which one would work best.

“We’re not talking about a research project,” said Frazier. “The problems and challenges are pretty well understood.”