>Metro DWDM is here!!! GG says this is the next step towards the edge...the LAN. Once it hits the enterprise; gigantic market (We'll be rich!).<
speaking of the Futurist, i read a rather droll dig on GG the other day that i thought i'd share with you:
"Among more cynical high-tech insiders, the word Gilder verges on being used as an adjective, such as 'How Gilder of you to believe the quality of life is improving.' There is even some debate as to which form of the adjective will prevail. If everybody working for the government is Orwellian, then Gilderian would be nobody working for the government. If waking up as a cockroach is Kafkaesque, then Gilderesque would be waking up as George Jetson's boy, Elroy."
ha!
btw, thanks for the contributions you continue to make to 'your' board, kent. if it wasn't going to be such a glorious weekend in DC (and the annual U.Va - Va. Tech intrastate rivalry wasn't on the tube), i just might've cozied up with a few of your hardcopies.
and while this article obviously came out pre-NFOEC, i'm posting it for new acronym value: move over DWDM, there's a new sheriff in town. SWDM anyone?
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Electronic Engineering Times
September 27, 1999, Issue: 1080
Section: News
Conference finds fiber headed for metro-area nets
Loring Wirbel
CHICAGO - The common message at this week's National Fiber Optics Engineers Conference will be the enhanced uses of fiber optics in metropolitan-area networks, with rollouts spanning transceiver components to full-scale transmission systems.
Chromatis Networks Inc. (Bethesda, Md.), for example, will demonstrate a concept called selective wavelength-division multiplexing, or SWDM. With that technique, ring nodes can be brought up to support both WDM and time-division multiplexed Sonet in a common infrastructure, but nodes are only brought up to WDM capacity when bandwidth demands it. A 1,310-nm ring on the Chromatis net operates as a single-wavelength network, while a 1,550-nm ring is a true dense WDM system, though the two appear as a single logical dual-ring.
Chromatis was formed by former Scorpio Communications Inc. founders Rafi Gidron and Orni Petruschka. It will not be shipping systems until 2000, but vice president of marketing Doug Green said the notion of such wavelength selectivity was radical enough that Chromatis was approaching potential carriers now to explain how networks can be brought up as partial DWDM metro rings. The dual-identity networks handle all Sonet, asynchronous transfer mode and Internet Protocol stacks, and appear to network elements as raw bandwidth capacity that can be partitioned at will.
Green stressed that the SWDM systems Chromatis will launch in early 2000 have very little similarity with 1,310 bypass systems that have backup rings using 1,550-nm optics. The bypass networks are provisioned independently at the two wavelengths, he said, and have no fault-management correlation.
By contrast, Chromatis will launch its systems with integrated provisioning and fault-management software that treat the two light rings as a common entity. Rings were implemented initially due to the predominance of Sonet in metropolitan networks, though the SWDM technology also can be implemented in hubs, multiple rings or meshes.
Meanwhile, Wavesplitter Technologies Inc., the former AFO Optics Inc. (Fremont, Calif.), is introducing a Mach-Zehnder "comb" technology. The process, which the company premiered at February's Optical Fibers Conference in San Diego, allows easy fan-out of DWDM access systems in metropolitan environments. The unbalanced, bidirectional Mach-Zehnder interferometers, which Wavesplitter originally implemented in simple channelized DWDM systems, have been implemented into a new 100-GHz 1 x 4 system called WaveXpander, allowing wavelengths to be assigned to any channel spacing within the International Telecommunications Union (ITU) grid that an erbium-doped fiber amp can meet, such as 3.2-nm, 1.6-nm or 0.8-nm channel spacing.
Wavesplitter's chief technology officer, Jerry Bautista, said that a key to the development of the simple cascading structure was that the availability of a low-insertion-loss structure, on the order of 3 decibels, could give carriers an easy way to scale both bandwidth and reach (in unamplified networks) for metropolitan regions. Cascading actually is used in larger structures within Wavesplitter's existing products, he said, so coming up with WaveXpander was a matter of asking, "What could a simpler cascading structure give us?" Bautista said.
The WaveXpander core unit is a four-channel base-wave device, which can be augmented with additional Mach-Zehnder filters set up in a cascade or tree configuration, allowing anywhere from 4 to 64 DWDM channels to be implemented on a standard ITU grid. WaveXpander also can serve as a retrofit add-on to legacy 200-GHz and 400-GHz first-generation DWDM systems, allowing those systems to hit channel spacing of 50 or 100 GHz. Since WaveXpander is fiber-based, its operating window also covers the 1,550- to 1,650-nm operating window.
Metro Gbit Ethernet
On the transceiver-component front, Cielo Communications Inc. (Broomfield, Colo.) will be offering its first Gigabit Ethernet/Fibre Channel transceiver modules based on 1,550-nm long-haul optics, allowing either Gigabit Ethernet or Fibre Channel networks to extend to 100-km distances.
Tim Bour, senior vice president of business development at Cielo, said that this move recognizes the number of local carriers who want to use dark fiber for networks other than Sonet, and also takes advantage of the number of companies, such as Adva Inc., Alcatel/Packet Engines and Nortel Networks/Cambrian Systems, that have demonstrated DWDM interfaces with Gigabit Ethernet in recent years.
Cielo's GBE1250ELX transceivers use the standard Gigabit interface circuit, or GBIC, but integrate distributed-feedback lasers into the GBIC modules so that single-mode fiber systems that use a Gigabit Ethernet topology can span large cities. Cielo appears to be the only company offering GBIC modules with three different laser sources for different markets: vertical cavity surface emitting lasers with multimode fiber for enterprise environments; Fabry-Perot lasers with single-mode fiber for campus-area networks; and the new distributed-feedback lasers with single-mode fiber for metropolitan reach.
Bour said that local carriers are slowly increasing their knowledge of using Gigabit Ethernet as a carrier-managed service, but there is still a bit of an education process that OEMs must go through. Those OEMs who produce enterprise local-area-network equipment will be aware of city-reach GBIC components right away, he said, but those OEMs traditionally producing switches for telecommunications company central offices still may think in terms of Sonet transceivers.
The ELX family of GBIC modules will be priced initially at $1,300 each in quantities of 100.
Meanwhile, Lucent Technologies Inc.'s microelectronics group used the European Conference on Optical Communications to introduce several transmitter products designed to cut the cost of WDM deployments. Lucent showed a new 2.5-Gbit wavelength-selectable transmitter for DWDM systems. The four-channel transmitter is based on an electroabsorptive modulated laser, and eliminates the need for any external modulation, while providing four tunable 50-GHz channels, stable to plus/minus 2.5 GHz. Lucent also officially introduced its rumored lithium niobate electro-optic modulator, a 40-Gbit/second device for use with Sonet OC-768 rates, operating in the 1,525- to 1,565-nm range, and based on a Mach-Zehnder configuration.
Lucent announced several partnerships at the European Conference on Optical Communication (Nice, France), including a pact for multisourcing transmitters among Lucent, Alcatel Optronics, Ericsson Components AB, Mitsubishi Electric and Sumitomo Electric. The pact covers Lucent's 2.5-Gbit/s C48 cooled-laser transmitter modules. Lucent signed a separate dual-sourcing agreement with Fujitsu Quantum Devices (Yamanashi, Japan), covering the 10-Gbit R192 optical receiver operating in the 1,300- to 1,600-nm range. |
