Can the Hybrid CWDM-DWDM System Work for Higher Capacity?

When facing the capacity-hungry issue, have you ever hesitated over which WDM system should be choose? As the CWDM system is a more economical solution for limited expanding capacity while the expensive DWDM solution enables much higher capacity, which one should be chose is really a tough decision. In order to solve the issue, can we deploy a Hybrid CWDM-DWDM system, for not choosing a wrong solution to increase the network capacity? Thereby, both the bandwidth shortage with CWDM solution or the potential bankruptcy with DWDM solution can be avoided. Let’s seeking the answer.

Can the Hybrid CWDM-DWDM System Work?

Can the Hybrid CWDM-DWDM system work for higher network capacity? The answer is yes. In fact, it is an ideal solution for boosting the network capacity, which is designed with merging DWDM and CWDM traffic seamlessly at the optical layer, taking full use of the WDM technology. In a hybrid CWDM-DWDM system, more channels can be added to deal with the limited capacity and reach in a CWDM system. That’s to say, the hybrid CWDM-DWDM system utilizes the DWDM technology to empower CWDM system, by integrating CWDM and DWDM equipment, which offers true pay-as-you-grow capacity growth and investment protection.

In short, the hybrid CWDM-DWDM system is a simple, plug-and-play option that enables more DWDM channels interleaved with the existing CWDM channels, for transmitting more data signals. It gets the utmost out of CWDM and DWDM technologies in a single system that greatly reduces the cost, simplifies the installation and keeps the system flexibility for bigger network capacity.

How to Build a Hybrid CWDM-DWDM System?

In general, a normal complete optical connection can be simply done by using a length of fiber patch cable to connect two fiber transceivers and then separately inserting the two transceivers into the ports of two switches. While in a hybrid CWDM-DWDM system, both the CWDM Mux Demux and DWDM Mux Demux should be added offering multiple channels to multiplex and demultiplex the signals. Here offers a typical 44 channel hybrid CWDM-DWDM system information for your reference.

From the figure, we can learn that the original CWDM system uses two 8 channel CWDM Mux Demux with wavelengths from 1470 nm to 1610 nm (20nm channel spacing). In order to add more channels for transmitting larger data signals, two pairs of DWDM multi-channel Mux/Demux are deployed separately under the pass band of the existing CWDM filters. In principle, deploying the DWDM multi-channel Mux/Demux in the 1530nm channel can create 25 100 GHz spaced DWDM channels. However, only 19 DWDM channels circled in the following figure are suitable to be added in the hybrid CWDM-DWDM system. It is also the same to the 1550 channel. Hence, this hybrid CWDM-DWDM system totally offers 6 CWDM channels and 38 DWDM channels with less deployment cost but easier installation.

Conclusion

If you come across the capacity-hungry issue and can’t make the decision about which WDM system should be choose for increasing your network capacity, you are highly recommended to deploy a hybrid CWDM-DWDM system. As an economical and future-proofing solution, the hybrid CWDM-DWDM system can completely deal with the issue of bandwidth shortage when building a CWDM system and avoid the potential bankruptcy for a DWDM system. You can just deploy a CWDM system first. Once the capacity the CWDM system offers can’t meet your requirement, you can add DWDM equipment in for more channels to transmit signals. All in all, the hybrid CWDM-DWDM system is an ideal choice that not only costs less for deployment but keeps the flexibility to increase the network capacity.

Dual-Fiber vs. Single-Fiber CWDM Mux Demux

What would you do if your network capacity can not meet your requirement? Will you put more fibers or update your system? In fact, these two methods are not very recommendable. Why? As your fiber cabling infrastructure is limited for adding fibers and high cost is required for upgrading system, these two methods are unworkable or too expensive. Under this condition, using a pair of CWDM Mux Demux to build a CWDM system with higher capacity is highly recommended. The CWDM Mux Demux is regarded as a key component for a CWDM system, as shown below. It can be simply divided into two types, dual-fiber and single-fiber CWDM Mux Demux. To meet the higher capacity need of your system, this post will mainly introduce the basic knowledge of the dual-fiber and single-fiber CWDM Mux Demux and guide you find a more suitable fiber optic Mux Demux for building your CWDM system.

Dual-Fiber CWDM Mux Demux

Dual-Fiber CWDM Mux Demux is a passive device multiplexing and demultiplexing the wavelengths for expanding network capacity, which must work in pairs for bidirectional transmission over dual fiber. It enables up to 18 channels for transmitting and receiving 18 kinds of signals, with the wavelengths from 1270 nm to 1610 nm. The CWDM transceiver inserted into the fiber optic Mux port should have the same wavelength as that of Mux port to finish the signal transmission. For instance, the two reliable 4 channel CWDM Mux Demux showed below use four wavelengths, 1510 nm, 1530 nm, 1550 nm and 1570 nm, their corresponding CWDM transceivers also features the same wavelengths.

When the connection above works, the left 4 channel dual-fiber CWDM Mux Demux uses 1510 nm, 1530 nm, 1550 nm and 1570 nm for transmitting 4 kinds of signals through the first fiber, while the right 4 channel dual-fiber CWDM Mux Demux features 1510 nm, 1530 nm, 1550 nm and 1570 nm for receiving the signals. On the other hand, the transmission from the right to left use the same wavelengths to carry another 4 signals through the second fiber, finally achieving the bidirectional signal transmission.

Single-Fiber CWDM Mux Demux

Single-fiber CWDM Mux Demux should be also used in pairs. One multiplexes the several signals, transmits them through a single fiber together, while another one at the opposite side of the fiber demultiplexes the integrated signals. Considering that the single-fiber CWDM Mux Demux transmitting and receiving the integrated signals through the same fiber, the wavelengths for RX and TX of the same port on the Single-fiber CWDM Mux Demux should be different. Hence, if the 4 channel single-fiber CWDM Mux Demux is used for CWDM system, 8 wavelengths are required, the twice time as that of the dual-fiber one.

The working principle of single-fiber CWDM Mux Demux is more complicated, compared to the dual-fiber one. As shown in the figure above, the transmission from the left to right uses 1470 nm, 1510 nm, 1550 nm and 1590 nm to multiplex the signals, transmit them through the single fiber, and using the same four wavelengths to demultiplex the signals, while the opposite transmission carries signals with 1490 nm, 1530 nm, 1570 nm and 1610 nm over the same fiber. As for the wavelength of the transceiver, it should use the same wavelength as TX of the port on the CWDM Mux Demux. For example, when the port of a single-fiber CWDM Mux Demux has 1470 nm for TX and 1490 nm for RX, then a 1470nm CWDM transceiver should be inserted.

Dual-Fiber or Single-Fiber CWDM Mux Demux for Higher Capacity Need?

We always consider whether an item is worth buying according to its performance and cost. In view of the performance, the single-fiber CWDM Mux Demux can carry signals through only one fiber supporting fast speed transmission and saving the fiber resource, while the dual-fiber one requires two fibers for transmission with a higher reliability. Besides, using single-fiber CWDM Mux Demux can be easier to install. In view of the cost, the single-fiber CWDM Mux Demux is much more expensive than the dual-fiber. And the simplex fiber cable also costs higher than duplex fiber cable. Thereby, the whole cost for building single-fiber CWDM system must be much more higher. Like the two sides of the same coin, both the dual-fiber and single-fiber CWDM Mux Demux have their own advantages and disadvantages. Which one should be used just depends on your network needs and your budget for building the CWDM system.