Do you know SWDM? This post will explain the SWDM basic definition, the advantages of SWDM, the SWDM optics types, and the applications of SWDM.
What is SWDM?
SWDM, which stands for Shortwave Wavelength Division Multiplexing, is a technique in fiber optic transmission for using multiple short light wavelengths to send data over the same medium. It is a new WDM technology proposed and defined by the SWDM MSA Industry Alliance. Unlike conventional CWDM and DWDM technologies, SWDM uses multiple VCSELs at different wavelengths around the multimode 850nm to generate separate data streams, all multiplexed onto a single fiber pair, which is a lower-cost WDM technology. Shortwave data center connections are typically powered by VCSELs operating at near 850nm wavelengths, and SWDM technology is proposed primarily to accommodate this application scenario.
What are SWDM’s advantages?
Reach: 40G SWDM transceiver can operate at distances of up to 240, 350, and 440 meters on OM3 fiber, OM4 fiber, and OM5 fiber. These ranges are compatible with the physical dimensions of data centers built for 10G but are now upgrading to higher 40G or 100G data rates.
Lower Power Dissipation: SWDM modules have a lower power dissipation than SR4 modules because they use a 4x WDM optical architecture corresponding to the 4x electrical interface. For 40G, this translates to a maximum power dissipation of 1.5W per QSFP+ module, allowing SWDM QSFP+ modules to be easily integrated into system ports designed for standard 40GBase-SR4. Sometimes, duplex solutions that require more power, up to 3.5W, may be incompatible with system ports designed for low-power modules such as 40G SR4 QSFP+.
Easy tapping for network security appliances: Because SWDM has a simple Tx and Rx port, it is simple to tap for network security appliances using a simple optical power coupler.
Complete DDM/DOM: SWDM can support all five digital diagnostics functions(DDM/DOM), including temperature, voltage, bias current, Rx power, and Tx power.
Easy to Use: datacenter technicians are independently familiar with Tx and Rx fibers. In the data center, WDM is already a well-known concept. On the other hand, bi-directional solutions require technicians to connect fibers that transmit light in both directions, which is counterintuitive. The SWDM solution lacks this level of complexity. Additionally, SWDM solutions can be tested using optical equipment operating at standard data rates per lane.
SWDM vs. CWDM vs. DWDM, What is the difference?
This table makes some comparisons between SWDM, CWDM, and DWDM, showing the differences as below.
What is the SWDM technology application?
Current SWDM technologies can facilitate the transition from 10G to 40G to 100G Ethernet. 40G-SWDM4 QSFP+, 100G-SWDM4 QSFP28, and 100G-SWDM2 QSFP28 are the three more prevalent varieties.
Some manufacturers have released 40G BiDi SR bi-directional (BiDi) transceivers, which allow duplex multimode fiber pairs for 40G connections by employing two wavelengths (850nm and 900nm) in the same fiber in opposing directions, with actual bit speeds of 20 Gbps per channel.
An introduction to SWDM optical transceiver
40G SWDM4 QSFP+ Optics
The 40G SWDM4 QSFP+ optics is a QSFP+ transceiver that features SWDM4 technology. This transceiver supports a 40G data rate with a built-in LC Duplex interface. The principle is identical to the 40GBASE-CWDM4 QSFP+ transceiver, but the 40G SWDM4 QSFP+ optics is used in a multimode fiber cabling environment and has a lower cost.
100G SWDM4 QSFP28 Optics
The 100G SWDM4 QSFP28 optics differ from the typical 100GBASE-SR4 MPO QSFP28 transceiver, based on the SWDM4 technology and utilizes an LC Duplex interface to provide 100Gbps bandwidth transmission over duplex MMF fiber. A 100G SWDM4 QSFP28 transceiver can be used for links up to 75 meters in length using OM3 fiber or 100 meters using OM4 fiber, according to the 100G SWDM4 MSA specification. The TX and RX wavelengths of this 100G SWDM4 transceiver are four different. It then multiplexes/demultiplexes these four wavelengths into a pair of multimode fibers, supporting 100G bandwidth.
SWDM technology enhances transmission bandwidth by employing four wavelengths on a single fiber to convey multiple signals. SWDM technology enables using the existing 10G duplex OM3/OM4 multimode fiber infrastructure without deploying new OM5 multimode fiber.
This technology maximizes user investment protection while providing the lowest total cost of ownership option for enterprise data center upgrades to 40G and 100G Ethernet.
As more suppliers begin to offer 40G SWDM4 and 100G SWDM4 optical transceivers, more users will become aware of and interested in this solution. If you have any concerns or need assistance with this SWDM4 optical transceiver, please do not hesitate to contact OPTCORE.