Editing Gigabit Ethernet (section)

===1000BASE‑CWDM===
1000BASE-CWDM is a non-standard but industry accepted term<ref name="Cisco-CWDM-SFP" /><ref name="FS-DWDM-info" /> to refer to Gigabit Ethernet transmission. It is very similar to 1000BASE-LX10 but achieves longer distances up 40–120&nbsp;km, and up to 18 parallel channels over a pair of single-mode fibers due to higher quality optics than LX10 and use of CWDM, running on 1270-1610&nbsp;nm wavelength lasers.

Use of CWDM requires a Mux/Demux unit at both ends of the fiber link, a CWDM MUX/DEMUX with corresponding wavelengths, and SFP with corresponding wavelengths.<ref name="FS-DWDM-info" /> is it also possible to DWDM in serie to increase number of channels.

Most uses Wavelengths: 1270&nbsp;nm, 1290&nbsp;nm, 1310&nbsp;nm, 1330&nbsp;nm, 1350&nbsp;nm, 1370&nbsp;nm, 1390&nbsp;nm, 1410&nbsp;nm, 1430&nbsp;nm, 1450&nbsp;nm, 1470&nbsp;nm, 1490&nbsp;nm, 1510&nbsp;nm, 1530&nbsp;nm, 1550&nbsp;nm, 1570&nbsp;nm, 1590&nbsp;nm and 1610&nbsp;nm

CWDM is cheaper to use than DWDM, about 1/5-1/3 of the cost.<ref>{{cite web |title=CWDM vs. DWDM： What Are the Differences？ |url=https://medium.com/@opticalfibersolutions/cwdm-vs-dwdm-what-are-the-differences-67c1c8adeccc |website=Medium.com |access-date=March 22, 2020 |language=en |date=November 30, 2017}}</ref><ref>{{cite web |title=CWDM - Cost-Effective Alternative to Expand Network Capacity |url=https://community.fs.com/blog/cwdm-cost-effective-alternative-to-expand-network-capacity.html |website=fs.com|access-date=March 22, 2020 |language=en |date=June 17, 2014}}</ref> CWDM is about 5-10 times more expensive the if you have the fiber available, then traditional  -LX/-LZ transceivers.