Cable Tech

Quantum Bridge Slots In ATM

Quantum Bridge Communications Inc. today added a number of features designed to support a wider array of telecom carrier technologies.

The company's switch, the QB5000 OAS, will now include OC3 TDM (time-division multiplexing) interfaces that support ATM (asynchronous transfer mode), Sonet transport, digital crossconnect systems (DCS), and Class 5 switches.

The announcement is interesting on two counts. First, it represents a move by a leading vendor of so-called passive optical networking (PON) equipment to bust out of the limited role of delivering low-cost access gear. Second, Quantum Bridge is taking aim at a controversy raging in the optical access world -- namely, the value of ATM technology as a delivery mechanism.

Quantum Bridge has a vested interest in tackling both issues: Having announced plans to go public in December (see Quantum Bridge Aims for IPO), the company's eager for acceptance by as many carriers as possible. Going IPO is tough enough right now, especially for vendors in the low-end access market that haven't yet had widespread success.

Here's why: PONs use low-cost optical couplers to split one strand of fiber into multiple channels of bandwidth that can be shared among users (see PONs: Passive Aggression and Last Mile Lexicon). Because they're a shared-access method, PONs are perceived as an access option mainly for small business and residential customers (see CIBC: PON Market to Reach $1B in 2004 and PONs on the Home Front). As a result, PON vendors have waged an uphill battle getting sizeable carrier contracts. As interest in metro networks has exploded, they've been left behind, languishing in seemingly interminable RBOC "fiber to the home" trials.

With this announcement, Quantum Bridge is billing itself as a supplier of higher-cost ATM access as well. "PON was and is a great entree for us carriers seeking small and medium-sized enterprise subscribers," says Jeff Gwynne, VP for marketing. "Our product extends past that. This announcement shows we're not just offering PON for small and medium-sized businesses."

The move is a fairly aggressive split from the norm. Quantum Bridge started out basing its equipment on ATM, because many existing PON standards are based on ATM in addition to supporting Ethernet connectivity. Lately, however, a cadre of PON newcomers, including Alloptic Inc. and OnePath Networks, are advocating a heavy reliance on Ethernet, not ATM (see Ethernet in the 'Hood ). They say ATM's overhead limits its ability to deliver bandwidth to end users.

Quantum Bridge says it supports Ethernet with a change of ASICs (application-specific intergrated circuits), but company officials believe ATM has lots to offer in a PON product, including control of bandwidth via software.

The company also says its underlying support of ATM enables it to offer other access options, such as aggregating traffic from a bunch of devices used in the last mile, including DSLAMs (digital subscriber-line access multiplexers), DLCs (digital loop carriers), wireless equipment, and CMTSs (cable modem termination systems). This eliminates the need for extra hardware and gives metro carriers more options, it claims.

Quantum Bridge isn't alone in using this approach. Rival Terawave Communications hasn't yet released its product, but it's as bullish on ATM technology as Quantum Bridge. "ATM is part of the carrier mindset. It's established in their networks," a Terawave spokesperson says. "We'll do an Ethernet PON if need be, but convincing carriers to use it won't be easy."

Not everyone thinks ATM is a necessary element of any access network, PON or otherwise. LuxN Inc., for instance, says its WavSystem doesn't require ATM to interconnect different types of traffic in metropolitan area networks.

"ATM equipment costs will always be higher than Ethernet-based equipment," says Eugene Park, LuxN's director of international marketing. "When was the last time you had an ATM connection to your desktop and phone?"

-- Mary Jander, senior editor, Light Reading http://www.lightreading.com

Scott Raynovich 12/4/2012 | 8:56:49 PM
re: Quantum Bridge Slots In ATM ATM in a PONS product: Genius or suicide?
fiber_r_us 12/4/2012 | 8:56:47 PM
re: Quantum Bridge Slots In ATM suicide... Ethernet will win.
Pilen 12/4/2012 | 8:54:52 PM
re: Quantum Bridge Slots In ATM Definitely Suicide...Ethernet will have some marketshare - I think though that RPR will come up with the best and cheapest solution.
Wait and see.
fibertoall 12/4/2012 | 8:54:29 PM
re: Quantum Bridge Slots In ATM I agree!! Ethernet will win this battle.
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