The narrowing cost and performance gaps between passive and active optical networking (see Passive vs. Active FTTH: Is the Gap Closing? in the June issue of xchange) have gotten the attention of North America’s ILEC community.
New research, expected to be published in May 2006 by RVA LLC, shows active optical, also known as active Ethernet in the FTTH context, is the single most-used FTTH architecture among non-Bell providers with 34 percent of homes passed in 2005. The number was 40 percent in 2004.
However, active Ethernet has widened its appeal in the last year. “Active Ethernet has traditionally been strong among the public utilities, municipalities and some CLECs, but now it is showing up in the second-tier (non-Bell) ILEC and rural ILEC networks,” says RVA President Michael Render, the author of the report. “This is a fairly new phenomenon.”
He adds, few ILECs are using BPON; instead they are choosing active Ethernet, GPON or EPON. “When you get beyond the RBOCs, who are focused on cost, the providers are looking at higher bandwidth per user,” says Render.
Active Ethernet supports 100mbps symmetrical to the home, notes Matt Roman, senior product manager for Pannaway Technologies Inc. This compares to GPON, which provides 2.5gbps that is shared among 32 households, for about 78mbps to the home. That’s downstream. The upstream link is less than 40mbps (1.25gbps shared among 32 users). While users can burst up to 100mbps and much higher, it is not a consistent rate that is achieved with active Ethernet.
Roman also says active Ethernet is becoming attractive to rural ILECs because it can be deployed in far-flung areas. “You can actually service homes 100 kilometers away from the CO, compared to 20 kilometers in a PON scenario,” he says. He explains that single-mode fiber can run up to 80 kilometers from the CO to a remote cabinet where the OLT resides and an additional 20 kilometers from the OLT to each home.
“With PON, you have 28db of reach,” notes Steve Kemp, senior director of access product marketing for Alcatel. “The splitters take 10 to 20db out of the optical budget so you’ve got a 12-mile reach. If you have 20 miles [from the CO to the home], you have to put electronics in the outside plant no matter what.”
The drawback for active Ethernet in this scenario is running fibers to every subscriber. “If you had a million subscribers, is that a scalable solution? The answer is, no. If you have 100 subscribers, it might be just what the doctor ordered,” Kemp says. “These guys have to weigh their costs.”
Brad Hansen, vice president and COO of Nsight Telservices, an IOC based in Green Bay, Wis., knows this decision first-hand. His company began upgrading in the late ‘90s to support broadband services in its 183-square-mile territory. Existing homes were served by fiber runs to remote terminals and copper to the homes. New homes were outfitted with copper and fiber drops.
“As we ran the PON numbers, it became clear there is no business model for our demographic,” he says, noting PON requires cabinets – costing from $150,000 to $250,000 – to multiplex the optical signals on shared wavelengths that only can be run 12 miles due to splitter loss. “When you have small, dispersed subdivisions, as rural telcos do, the 12-mile limit is quickly exceeded.”
In addition, he says, active Ethernet helps “future proof” Nsight’s network by allowing it to provide higher speeds per premises than PON. “Since PON is a multiplexed system and all customers downstream share a fixed bandwidth, the capacity isn’t infinite,” he says. “As video and data services demand higher and higher speeds, the PON gear needs to be changed in order to keep pace. That gets expensive.”
Nsight chose Pannaway’s Service Convergence Network, a hybrid active optical/copper solution that overlays the telco’s physical infrastructure and supports copper-based POTS and DSL services from the same platform as fiber-based services.
Philip Yim, executive vice president of global market and R&D for Allied Telesyn, says its customers are taking a similar approach with Allied Telesyn’s iMAP integrated Multiservice Access Platform, which he describes as a “smart OLT” that can support copper and fiber – both active and passive. iMAP enables operators to use the same platform to provide active Ethernet and to leverage legacy splitters to upgrade BPON customers to gigabit EPON, he says.
Similarly, Zhone Technologies is coming out with a new addition to its EtherXtend product line that will support active Ethernet with a line card that fits into its MALC broadband loop carrier chassis. The new product, expected to be announced at GLOBALCOMM this month, supports 10 customers at speeds from 10mbps to 1gbps. With the new addition, the MALC now support POTS, ADSL2+, SHDSL, VDSL2, T1/E1, BPON and active Ethernet in the same chassis.
“It’s just a line card in the existing chassis – that’s the beauty of it,” says David Markowitz, Zhone’s vice president of marketing. “Carriers want to be able to offer their existing voice and DSL services without having to learn a new type of platform with new sets of spares and new technicians.”
Alcatel
www.alcatel.com
Allied Telesyn
www.alliedtelesyn.com
Pannaway Technologies Inc.
www.pannaway.com
RVA LLC
www.rvallc.com
Nsight Teleservices
www.nsight.com
