Faced with the multifaceted challenges of increased service needs, fiber exhaust, and layered bandwidth management, the main challenge for service providers is to provide more and cheaper bandwidth and integrated services using different methods. Today, this article is to introduce a method that upgrades your network to 500G with DWDM (dense wavelength division multiplexing) technology.
As we have known, network operators are facing pressure to increase bandwidth in an economical way. In order to release this pressure, there are three available methods to solve this problem. The first one is to lay more fibers directly. The second one is to increase the bit rate using TDM (time division multiplexing). The last to deploy DWDM technology. However, compared with the last one, the former two ways are either too costly or will cause other problems. While using 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.
In a 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.
Generally speaking, we use DWDM SFP+ transceivers with DWDM Mux/Demux system to expand our network. Under this condition, each wavelength can be transmitted at 10 Gbps. Therefore, if we deploy a 40 channels DWDMMux/Demux system, we can achieve 400G over a fiber pair. Then, How about another 100G? Actually, there is a 1310nm port integrated into a 40 channels DWDM Mux/Demux system. The 1310nm added port is a Wide Band Optic (WBO) port 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 extra optics via this 1310nm port.
You should note that the optical components you added 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 the 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 bandpass 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. Here is a simple graphical representation.
This article represents a way to upgrade to 500G with DWDM Mux/Demux system. However, the benefits of deploying DWDM are not confined to that. By using DWDM technology, the distance between network elements can be extended. And service providers also can expand capacity in any portion of their networks flexibly, which other technology cannot offer.