Upgrade to 500G with 40CH DWDM Mux/Demux System

Enterprise networks face a condition called fiber exhaust when the demand for backbone fiber exceeds the availability of installed fiber strands. The most obvious and expensive solution to fiber exhaust is to install more fiber. However, it’s a costly proposition. It is estimated at about $70,000 per mile, most of which is the cost of permits and construction rather than the fiber itself. There is another solution to solve fiber exhaust is to increase the bit rate of existing systems. Using TDM, data is now routinely transmitted at 2.5 Gbps and, increasingly, at 10 Gbps. Recent advances have resulted in speeds of 40 Gbps and 100 Gbps. The electronic circuitry that makes this possible, however, is complex and costly, both to purchase and to maintain.

DWDM Gives the Most Cost-effective Solution for Fiber Exhaust

Since two solutions mentioned above are not cost-effective enough, how to solve this problem? In fact, there is a third solution that is to increase the number of wavelengths on a fiber. In this approach, many wavelengths are combined onto a single fiber. Using dense wavelength division multiplexing (DWDM) technology, several wavelengths, or light colors, can simultaneously multiplex signals of 2.5 to 40 Gbps each over a strand of fiber. Without having to lay new fiber, the effective capacity of existing fiber plant can routinely be increased by a factor of 16 or 32. DWDM MUX/DEMUX systems with 40 and 96 wavelengths are in operation today, with higher density on the horizon.

How to Use DWDM MUX/DEMUX Systems to Achieve Higher Bandwidth?

In DWDM system, each lambda can carry its own independent signal, providing the same overall bandwidth per channel (approximately 2.4 Gbps with most of today’s fiber) that a single-color laser does. Thus, if you run DWDM with eight lambdas (eight channels), you increase the capacity of a fiber pair from 2.4 Gbps to 19.2 Gbps. This creates virtual dark fiber, which enterprise networks can use to run multiple higher-layer technologies such as ATM and Gigabit Ethernet simultaneously over the same physical fiber strands.

Upgrade to 500G with 40CH DWDM Mux/Demux System

At present, we usually use DWDM SFP+ transceivers with DWDM Mux/Demux system to expand our network. In this scenario, each wavelength can be transmitted at 10 Gbps. Therefore, if we use a 40 channels DWDM Mux/Demux system, we can achieve 400G over a fiber pair. Then how do we achieve 500G with 40 channels DWDM Mux/Demux system? In fact, there is a 1310 nm port integrated in a 40 channels DWDM Mux/Demux system. The 1310nm added port is a Wide Band Optic port (WBO) added to other specific DWDM wavelengths in a module. When we run out of all channels in a DWDM Mux/Demux system, we can add the extra optics via this 1310nm port.

You should note that your added optics must be working in 1310nm, for example 40G LR4 1310nm QSFP transceivers, 40G ER4 1310nm QSFP transceivers and 100G LR4 1310nm CFP2 transceivers etc. In above solution, we only need to plug 100G LR4 1310nm CFP2 fiber optic transceiver into the terminal equipment (Ethernet switch, router etc.) , then use the patch cable to connect it to your existing DWDM network via a 1310nm band pass port on the DWDM multiplexer. Then this set-up allows the transport of up to 40 x10Gbps plus 100Gbps over one fiber pair, in total 500Gbps! Similarly, if you use the 40G LR4 1310nm QSFP transceivers, you can then achieve 40 x10Gbps plus 40Gbps over one fiber pair, in total 440Gbps.

Item Number	ID#	FS Part Number	Item Description
1	35887	40MDD-1RU-A1-FSDWDM	40 Ch 1RU Duplex DWDM MUX DEMUX C21 to C60 with 1310nm Port and Monitor Port
2	14491	DWDM-SFP10G-40	10GBASE 100GHz DWDM SFP+ 40km, LC Duplex Interface, C21 to C60
	31533	DWDM-SFP10G-80	10GBASE 100GHz DWDM SFP+ 80km, LC Duplex Interface, C21 to C60
	14599	DWDM-XFP10G-40	10GBASE 100GHz DWDM XFP 40km, LC Duplex Interface, C21 to C60
	14650	DWDM-XFP10G-80	10GBASE 100GHz DWDM XFP 80km, LC Duplex Interface, C21 to C60
3	35208	QSFP-LR4-40G	40G QSFP+ LR4 1310nm 10km, LC Duplex Interface
	35210	QSFP-ER4-40G	40G QSFP+ ER4 1310nm 40km, LC Duplex Interface
	35014	CFP2-LR4-100G	100G CFP2 LR4 1310nm 10km, LC Duplex Interface

Source: http://www.fs.com/upgrade-to-500g-with-40ch-dwdm-mux-demux-system-aid-493.html