A Variety of PON Technologies to Chose From:
Passive Optical Network (PON) technology is changing, moving from older GPON’s 2.5Gbit/s and 1.25Gbit/s data rates to XGS-PON’s maximum 10Gbit/s symmetric speeds and technologies such as NGPON2 and 25G PON (described at the end of this article).
“We didn’t see a lot of adoption of the XG, XGS-PON and 10G EPONs (Ethernet PONs) particularly because of cost within these networks, but what we have started seeing is the next generation or the NG-PON2 that uses time wave division multiplexing,” said Jason Morris, marketing manager at Corning Optical Communications during a webinar sponsored by Light Reading. Using up to eight wavelengths to create multiple transmission channels on a single strand of fiber “you can actually get up to 80G with this technology with channel bonding,” he added.
Rich Loveland, director of product management at Vecima Networks, pointed to explosive growth in fiber optic development, spurred by government broadband stimulus funding and connections to MDUs. In these broadband upgrade projects, “you don’t have to put PON in for it, but most are choosing it they are unserved anyway. It’s primarily a greenfield-type of operation.”
Among telcos, the choices are expanding beyond older GPON technology toward more advanced standards such as XGS-PON, which is “starting to come up quite a bit now over some of the NG-PON2 types of technologies,” Loveland said. “They are developing 25G. The ITU-T is defining 50G single-wavelength, and NG-PON2 seems to be adopted by one major operator right now.”
One year ago, AT&T deployed XGS-PON as per this IEEE Techblog post. It went live in 40 markets AT&T serves.
For most cable operators, it’s not realistic to replace all their coax access network with fiber, said Jorge Figueroa, manager of PON Solutions at Harmonic. Instead, he pointed to cloud-native platforms to provide a better migration path to PON fiber, with lower-cost, off-the-shelf programmable hardware that can manage DOCSIS or PON architectures simultaneously.
“Distributed Access Architecture allows us to go fiber-deeper, and by doing that we can provide Gigabit symmetric feeds by going maybe to DOCSIS 4.0,” he said. “The goal here is to squeeze the most out of that HFC, while at the same time giving us an easy transition to PON.”
Viavi has seen providers move from 1Gbit/s to 10Gbit/s services, with new builds favoring newer transmission schemes such as XGS-PON or 10G EPON options, said Douglas Clague, solutions marketing manager at Viavi.
A live Light Reading webinar poll indicates operators are exploring different PON upgrade options. With the ability to choose more than one option, about 29.9% said they were deploying next-generation PON technologies, while 18.2% said their companies were opting to go fiber-deep and an equal number were looking to deploy FTTP. About 15.6% were implementing DAA, while 13% were expecting to deploy DOCSIS 4.0 and 5.2% were moving to network virtualization.
In a IEEE Techblog post last week, Dell’Oro analyst Jeff Heynen said: