Adding CWDM to single wavelength NetworksThis application note describes how to use a passive optic MUX/DEMUX to addCWDM wavelengths to 1310/1550nm single wavelength network rings.Enterprises and service provider have traditionally been building their gigabit speedmetro networks with 1310nm and 1550nm wavelengths. This network has consisted of apair of fibers connected between two or more buildings with a SONET ADM (or Ethernetswitch) at each building. Figure 1 shows a diagram of this application. B u ild in g 2 B u ild in g 1 SONETSONET O C -1 9 2 ADM ADM 1310nm 40km Figure 1. Single wavelength 1310nm link applicationWhen additional bandwidth is needed between the two buildings the user adds eithermore fiber between the buildings or implements an expensive DWDM solution.With the advent of CWDM transceivers and passive optics, a simple low cost solution ispossible by adding a WDM MUX/DEMUX at each end with additional CWDMwavelengths. Figure 2 depicts an example of this solution. Note that with two additionalCWDM wavelengths an Ethernet and Fibre Channel switch are deployed.
Adding CWDM to Single Wavelength Networks Building 2 Building 1 1310nm/OC-192 1470nm/1.25G Ethernet 1510nm/2G Fibre Channel 40km SONET 1310/CWDM MUX 1310/CWDM MUX ADM SONET ADM Ethernet Sw itch FC Sw itch Ethernet Sw itch FC Sw itch Figure 2. 1310nm link upgraded with additional CWDM Wavelengths.Implementing the SolutionThe upgrade solution is simple and cost effective. At each node in the network add apassive MUX/DEMUX with a single network side port and a 1310nm port withadditional CWDM ports on the equipment side. The 1310nm wavelength is completelytransparent to the added CWDM wavelengths. Up to 8 CWDM wavelengths can be addedas the bandwidth requirements grow without interruption to the existing service.The following block diagrams show how to upgrade a network using passiveMUX/DEMUXs to insert and de-assert optical CWDM wavelengths from an existingsingle 1310 wavelength ring. Each step in the process of building the ring is shown belowwith an equipment view, node view and network view. 2 (650) 324-1283www.opticscentral.com
Adding CWDM to Single Wavelength NetworksEquipment ViewThe equipment block diagram view, shown below, illustrates how to add/drop CWDMwavelengths to/from a 1310 wavelength ring network by connecting a 1310/CWDMMUX/DEMUX to a four channel CWDM MUX/DEMUX. The 1310/CWDMMUX/DEMUX connects to the network and splits the 1310nm wavelength from theCWDM group of wavelengths. After being connected to the 1310nm CWDM port, theCWDM MUX/DEMUX breaks out each of the individual CWDM wavelengths, which inturn go to an Ethernet switch. Jumper CWDM Port to Network To Network Port of CWDM MUX/DEMUX SC SC Network 1310/CWDM MUX/DEMUX Net k wor CWDM MUX/DEMUX Expansion Plug-In Plug-In Port 1310 CWDM Port 1470 1510 1550 1590 SC SC SC SC SC SC1RU Rack Mount To 1310 Transceiver To Ethernet SwitchPlug-In front panels views of the DEMUX/DEMUX equipment: 1310/CWDM MUX/DEMUX CWDM MUX/DEMUX-4-EX 3 (650) 324-1283www.opticscentral.com
Adding CWDM to Single Wavelength NetworksNode ViewThe node view, shown below, illustrates two sets of 1310/CWDM MUX/DEMUXs withCWDM MUX/DEMUXs connected to an Ethernet switch to make a protected node. The1310 wavelengths are cabled separately to the 1310 network equipment. To Network WEST To Network EAST1310/CWDM Network Newor t k Network Newor t k CWDMMUX/DEMUX 1310 CWDM Port 1470 1530 1570 1590 1310 CWDM Port 1470 1530 1570 1590 MUX/ Plug-In DEMUX Plug-In CWDM To 1310 CWDM Transceivers To 1310 Equipment Transceivers Equipment Ethernet Switch 4 (650) 324-1283www.opticscentral.com
Adding CWDM to Single Wavelength NetworksNetwork ViewThe network view, shown below, shows how to build a three node network with theprotected node design shown above. 1310 1310 Equipment Equipment Long Distance Fiber Link Network WEST Network WEST 1310/ 1310/ CWDM CWDM MUX/ MUX/ DEMUX DEMUX Pair Pair Ethernet Ethernet Switch Switch 1310/ 1310/ CWDM CWDM Network MUX/ MUX/ DEMUX WEST DEMUX Pair Pair Network EAST Long Distance Fiber Link Ethernet NODE 2 Switch Long Distance Fiber Link NODE 3 Network Network WEST EAST 1310/CWDM MUX/ 1310/CWDM MUX/ DEMUX Pair DEMUX Pair CWDM 1310 CWDM 1310 Ethernet Equipment NODE 1 Switch 5 (650) 324-1283www.opticscentral.com
Adding CWDM to Single Wavelength NetworksSummaryThe solution shown in this application note illustrates how to simply upgrade a 1310nmsingle wavelength network ring to a WDM network ring with four additionalwavelengths. Further, the expansion need not be limited to four wavelengths. By adding a8 channel CWDM MUX/DEMUX in place of the 4 channel CWDM MUX/DEMUX, 8CWDM wavelengths become available on the network ring. For future bandwidth that isbeyond the capability of 8 CWDM wavelengths, insert a DWDM MUX/DEMUX into theCWDM MUX/DEMUX for creating 45 more wavelengths with DWDM on CWDM (seeOptics Central’s app note for DWDM on CWDM).Finally, this solution is also available to single wavelength networks deployed with1550nm. In the above solution, substitute the 1310nm MUX/DEMUX with a 1550nmMUX/DEMUX that splits the 1550nm wavelength from the CWDM wavelengths.For additional information see Optics Central app notes:“The WDM Metro Access Solution”“Implementing DWDM on CWDM” 6 (650) 324-1283www.opticscentral.com