CWDM CrossConnect for Datacenters
The CWDM CrossConnect Data Center system is based on the use of the CWDM wavelength multiplex technology for short-distance transmission. With CWDM technology, it is possible to share multiple transmitted channels on one or two optical fibers.
This reduces the number of fiber-optic cables within the datacenter between individual switchboards and technologies. In principle, the length of the connection is not limited by the size of the datacenter, but within the technology and in conjunction with the optical transceivers used, distances up to several tens of kilometers can be achieved.
The cost-effectiveness of the CWDM CrossConnect deployment depends on the particular lease conditions of the optical paths in the datacenter and the number of saved fiber optic.
CrossConnect system properties
- Miniature CWDM module for 8 wavelengths (1470-1610 nm) with LC / UPC or LC / APC connectors.
- Versions of Multiplexer and Demultiplexer used in pair to minimize insertion attenuation.
- Can be used for single or double-stranded applications.
- Additional 1310nm broadband also for 40G and 100G.
- Combination of 10/40 Gbit / s or 100 GBit / s signals.
- Integrated output ports for monitoring signals during operation.
- The Mini CWDM module is integrated into the optical cartridge from variety of manufacturers based on customer preference.
- Passive module without power requirement.
- Saving the number of optical cables used to connect the cabinets in the datacenter.
CWDM CrossConnect Optical Characteristics
|Operating Wavelength CWDM 8ch by ITU||nm||1470||ITU ± 6.5||1610|
|1310 port Bandwidth||nm||1260||1360|
|Insertion Loss CWDM Port (1470, …, 1610nm)||dB||1.9||3.0|
|Insertion Loss CWDM Ports MUX + DEMUX||dB||3.8||4.5|
|Insertion Loss 1310 Port||dB||0.7||1.1|
|Insertion Loss 1310 Ports MUX + DEMUX||dB||1.5||2.2|
|Insertion Loss monitor port 10% M FIB||dB||10.0||11.3|
|Insertion Loss monitor port 10% M MUX||dB||10.0||11.3|
|Polarization Dependent Loss||dB||0.2|
|Polarization Mode Dispersion (PMD)||ps||0.2|
|Maximum Optical Power||mW||300|
CWDM CrossConnect application
The system uses conventional CWDM technology with up to 18 wavelengths at 20 nm (1270, 1290, … to 1610 nm) according to ITU-T G.694.2. CrossConnect uses 8 wavelengths (1470-1610 nm). The “O” 1310 nm band is left entirely for 40G and 100G Ethernet applications.
One-fiber CWDM technology uses adjacent wavelengths for one wavelength for one direction and a second wavelength for the reverse direction. Transceivers must always be used according to the wavelength of the transmitter. The photodiode of the transceiver receiver is broadband and can accept a different wavelength.
Image – Linking one 10Gbit Ethernet channel to one thread
Use of high speed transceivers at 40 GBit / s or 100 GBit / s
For a 40Gbit or 100GBit transceiver connection , a 1310nm wide band (bandwidth 1260-1360nm) can be used. Two optical fibers are required for these applications.
We can use a variety of optical interfaces (which use the 1310 nm band), such as the standards:
40GBASE-LR4 (uses wavelengths 1270/1290/1310/1330 nm)
100GBASE-LR4 (uses wavelengths 1295.56 / 1300.05 / 1304.58 / 1309.14 nm)
100GBASE-CWDM4 , or 100GBASE-CLR4 (uses wavelengths 1270/1290/1310/1330 nm).
Figure – Linking one 40 / 100Gbit Ethernet channel to two threads
The CWDM CrossConnect system is suitable for connecting multiple switchboards (nodes) in the datacenter with each other by switching the wavelengths of the main node through the interconnecting patch cables.
Figure – Interconnection of four knots through a central switchboard, different wavelengths used on one fiber
The Optical Splitter, which divides 10% of optical performance into monitor ports, is integrated into the CrossConnect optical cassette for tracking operation, power measurements for individual wavelength performance and for service purposes. You can monitor traffic from both directions of signal propagation.
Port M FIB (Fiber Monitor) outputs 10% of the level of signals coming from the fiber – from the FIBER port.
Port MUX (MUX Monitor) outputs 10% of the signal level going to the fiber – into the FIBER port from each CWDM input port (1470 to 1610 nm) and 1310.
This way you can conveniently monitor and monitor individual signal levels in both directions (both outgoing and incoming from the FIBER port) even in the single-thread configuration of the system.
Image – CWDM channel performance monitoring
For monitoring multiple CWDM parallel signals, it is possible to use a standard Optical Spectrum Analyzer OSA, or in a simple form the Optical CWDM Power Meter recommended by us to measure all 18 CWDM signals at once in a single thread.
Performance Balance Sheet
For data transfer using CrossConnect’s Multiplexer and Demultiplexer, an in-depth attenuation will have to be overcome, including the insertion loss of the MUX + DEMUX combination, the attenuation of the fiber itself, the attenuation of the optic connectors, and the system’s safety margin (or dispersion). The bridging transceiver attenuation requirements for different line lengths and configurations are in the table (values in dB):
|Line type, length and number of Mux + Demux||Attenuation Mux + Demux||Fiber attenuation||Connector attenuation||Reserve||Total attenuation [dB]|
|1310 nm, 300 m, 1x M + D||1 x 2.2||0.3 x 0.4||0.8||1.0||4.1|
|1310 nm, 1 km, 1x M + D||1 x 2.2||1.0 x 0.4||0.8||1.5||4.9|
|1310 nm, 5 km, 1x M + D||1 x 2.2||5.0 x 0.4||0.8||2.0||7.0|
|1310 nm, 300 m, 2x M + D||2 x 2.2||0.3 x 0.4||1.6||1.0||7.1|
|1310 nm, 1 km, 2 x M + D||2 x 2.2||1.0 x 0.4||1.6||1.5||7.9|
|1310 nm, 5 km, 2x M + D||2 x 2.2||5.0 x 0.4||1.6||2.0||10.0|
|CWDM, 300 m, 1x M + D||1 x 4.5||0.3 x 0.25||0.8||1.0||6.3|
|CWDM, 1 km, 1x M + D||1 x 4.5||1.0 x 0.25||0.8||1.5||7.0|
|CWDM, 5 km, 1x M + D||1 x 4.5||5.0 x 0.25||0.8||2.0||8.5|
|CWDM, 300 m, 2x M + D||2 x 4.5||0.3 x 0.25||1.6||1.0||11.6|
|CWDM, 1 km, 2x M + D||2 x 4.5||1.0 x 0.25||1.6||1.5||12.3|
|CWDM, 5 km, 2x M + D||2 x 4.5||5.0 x 0.25||1.6||2.0||13.8|
Typical bridging attenuation for different types of optical transceivers:
|Transceiver type||technology||Wavelength||Overload attenuation [dB]|
|SFP + 10G LR||10GBE LR 10km||1310||6.2|
|SFP + 10G LR20||10GBE LR 20km||1310||12|
|SFP + 10G CWDM 10km||10GBE 10km||CWDM 47-61||6.3|
|SFP + 10G CWDM 40km||10GBE 40km||CWDM 47-61||15|
|SFP + FC 16G 20km||4/8 / 16G FC 20km||CWDM 47-61||13|
|QSFP + 40G LR4||40G LR4 10km||CWDM 27-33||6.7|
|QSFP28 100G LR4||100G LR4 10km||DWDM 1310||6.3|
|QSFP28 100G CWDM4||100G CWDM4 2km||CWDM 27-33||5|
Order codes for CrossConnect
|CrossConnect system cartridges with 12 x LC connector
|CWDM8M47-61-31 + 2MON
|CrossConnect CWDM Mux 8 + 1 channel 1470-1610nm, 1310nm + 2x monitor. Port, LC / UPC|
|CWDM8M47-61-31 + 2MON-A
|CrossConnect CWDM Mux 8 + 1 channel 1470-1610nm, 1310nm + 2x monitor. Port, LC / APC|
|CWDM8D47-61-31 + 2MON
|CrossConnect CWDM DeMux 8 + 1 channel 1470-1610nm, 1310nm + 2x monitor. Port, LC / UPC|
|CWDM8D47-61-31 + 2MON-A
|CrossConnect CWDM DeMux 8 + 1 channel 1470-1610nm, 1310nm + 2x monitor. Port, LC / APC|
|CWDM wavelength measuring instrument and power levels|
|OCPM-18||Optical CWDM Power Meter, 18ch CWDM 1270-1610 nm, SC input port, Power +10 ÷ -40 dBm|
|SFP + SM-31-10-O||Transceiver SFP +, SM, 10G LR, 1310nm, 10km, DFB, DDM|
|SFP + SM-31-20-O||Transceiver SFP +, SM, 10G LR, 1310nm, 20km, DFB, DDM|
|SFP + SM-CWDM-xx-10-O||Transceiver SFP +, 10G, SM, CWDM 1470-1610nm, 10km, DFB, 6.3dB, DDM|
|SFP + SM-CWDM-xx-40-O||Transceiver SFP +, 10G, SM, CWDM 1470-1610nm, 40km, EML, 15dB, DDM|
|SFP + SM-16G-CWDM-XX-20-BRO
|Transceiver SFP +, SM, Multirate, CWDM 1470-1610nm, 4x / 8x / 16x FC, 13dB, 20km, DDM, Brocade Compatible|
|QSFP + SM-LR4-CWDM-10-O
|Transceiver QSFP +, SM, 40G, LR4, 4xCWDM, 10km, DDM|
|Transceiver QSFP28, SM, 100G, LR4, 4xDWDM, 10km, DDM|
|Transceiver QSFP28, SM, 100G, CWDM4, 4xDWDM, 2km, DDM|
|Interconnecting patch cables with LC / UPC connectors|
|OPKRLC09LC / LC0.5S-1,2-YEL||Patchcord 09/125, LC / LC, simplex, 1×1,2mm, 0,5m, fiber G.657.A|
|OPKRLC09LC / LC1S-1,2-YEL||Patchcord 09/125, LC / LC, simplex, 1×1,2mm, 1m, fiber G.657.A|
|OPKRLC09LC / LC1.5S-1,2-YEL||Patchcord 09/125, LC / LC, simplex, 1×1,2mm, 1,5m, fiber G.657.A|
|OPKRLC09LC / LC2S-1,2-YEL||Patchcord 09/125, LC / LC, simplex, 1×1,2mm, 2m, fiber G.657.A|
|OPKRLC09LC / LC2.5S-1,2-YEL||Patchcord 09/125, LC / LC, simplex, 1×1,2mm, 2,5m, fiber G.657.A|
|OPKRLC09LC / LC3S-1,2-YEL||Patchcord 09/125, LC / LC, simplex, 1×1,2mm, 3m, fiber G.657.A|
|Accessories for cleaning optical connectors|
|CLEANER-H125||Connector Cleaner with Ferrule 1.25mm, Stick, LC, MU, 525x Cleaning, Coupling Attachment|