Overview of BiDi Transceiver Modules

During optical transmission process, it’s no wonder that using one fiber to receive data from networking equipment, and another one to transmit data to the networking equipment. This kind of transmission mode will increase investment cost certainly. Luckily, here is a type of transceiver can solve this problem. It’s bi-directional transceiver. Today, this article will take you to make sense why BiDi transceiver can make it possible to transmit data over one fiber.

Basics of BiDi Transceiver

BiDi is short for bidirectional. BiDi transceiver is a type of fiber optic transceiver which is used WDM (Wavelength Division Multiplexing) bi-directional transmission technology so that it can achieve the transmission of optical channels on a fiber propagating simultaneously in both directions. BiDi transceiver is only with one port which uses an integral bidirectional coupler to transmit and receive signals over a single fiber optical cable. Thus, it must be employed in pairs.

How Does BiDi Transceiver Work?

The obvious difference between BiDi transceivers and traditional two-fiber fiber optic transceivers is that BiDi transceivers are fitted with Wavelength Division Multiplexing (WDM) couplers, also known as diplexers, which combine and separate data transmitted over a single fiber based on the wavelengths of the light. For this reason, BiDi transceivers are also referred to as WDM transceivers.

To work effectively, BiDi transceivers must be deployed in matched pairs, with their diplexers tuned to match the expected wavelength of the transmitter and receiver that they will be transmitting data from or to.

For example, if paired BiDi transceivers are being used to connect Device A (Upstream) and Device B (Downstream), as shown in the figure below, then:

  • Transceiver A’s diplexer must have a receiving wavelength of 1550nm and a transmit wavelength of 1310nm
  • Transceiver B’s diplexer must have a receiving wavelength of 1310nm and a transmit wavelength of 1550nm

bidi transceiver diagram

Common Types of BiDi Transceiver

BiDi SFP Transceiver

BiDi SFP transceiver is typically applied for the high-performance integrated duplex data link over a single optical fiber. It interfaces a network device mother board (for a switch, router or similar device) to a fiber optic or unshielded twisted pair networking cable. And the most typical wavelength combination is 1310/1490 nm, 1310/1550 nm, 1490/1550 nm and 1510/1570 nm. This BiDi SFP transceiver is used in optical communication for both telecommunication and data bidirectional communications applications.

BiDi SFP+ Transceiver

BiDi SFP+ transceiver is an enhanced SFP transceiver. It is designed for bi-directional 10G serial optical data communications such as IEEE 802.3ae 10GBASE-BX by using 1330/1270nm transmitter and 1270/1330nm receiver. And its transmission distance is up to 20 km.

SFP+ BX

Advantages of BiDi Transceiver

The obvious advantage of utilizing BiDi transceivers, such as BiDi SFP+ and BiDi SFP transceivers, is the reduction in fiber cabling infrastructure costs by reducing the number of fiber patch panel ports, reducing the amount of tray space dedicated to fiber management, and requiring less fiber cable.

While BiDi transceivers (a.k.a. WDM transceivers) cost more to initially purchase than traditional two-fiber transceivers, they utilize half the amount of fiber per unit of distance. For many networks, the cost savings of utilizing less fiber is enough to more than offset the higher purchase price of BiDi transceivers.

Conclusion

In summary, BiDi transceivers can combine and separate data transmitted over a single fiber based on the wavelengths of the light. That is to say, to achieve the same transmitting result, it needs less money. Except for above SFP & SFP+ BiDi transceivers, FS.COM also provides 40G BiDi transceiver. This BiDi transceiver has two 20 Gbps channels, each transmitted and received simultaneously on two wavelengths over a single MMF strand (OM3 or OM4). Any one of the transceivers would meet your different application requirements with high performance.

Related ArticleA Brief Introduction of BiDi SFP Transceiver

BiDi Transceiver Overview

For several years ago, when talked about fiber optic transceiver, almost most of people engaged in telecommunication industry would tell that a transceiver is a device comprising both a transmitter and a receiver which are combined and share common circuitry. Almost all fiber optic transceivers uses two fibers to transmit data between routers and switches. One fiber is devoted to transmitting data to the networking equipment, while the other one is devoted to receiving data from the networking equipment. For recent years, a new kind of fiber optic transceiver has been available — Bi-Directional transceiver (BiDi transceiver).

BiDi Transceiver Basis

BiDi transceiver is a type of fiber optic transceiver which uses WDM (wavelength division multiplexing) bi-directional transmission technology so that it can achieve the transmission of optical channels on a fiber propagating simultaneously in both directions. BiDi transceiver is only with one port which uses an integral bidirectional coupler to transmit and receive signals over a single optical fiber (see the following picture). BiDi transceivers are specifically designed for the high-performance integrated duplex data link over a single optical fiber and used in bi-directional communication applications. The BiDi transceivers interface a network device mother board (for a switch, router or similar device) to a fiber optic or unshielded twisted pair networking cable.

BiDi transceiver

Working Principle of BiDi Transceiver

The difference between BiDi transceivers and the two-fiber optical transceiver mainly lies in that BiDi transceivers are fitted with WDM couplers, also known as diplexers, which help to combine and separate data transmitted over a single fiber based on the wavelengths of the light. So BiDi transceivers are also called WDM transceivers. BiDi transceivers are usually deployed in matched pairs to get the work most efficiently. And the diplexers of BiDi transceivers are tuned to match the expected wavelength of the transmitter and receiver that they will be transmitting data from or to.

As can be seen from the following diagram, the paired BiDi transceivers are being used to connect two devices. Device A is used to get upstream data, and Device B is used to get downstream data. Tx means transmit. Rx means receive. The diplexer in one transceiver (Device A) should have a transmitting wavelength of 1310 nm and have a receiving wavelength of 1550 nm. The diplexer in the other transceiver (Device B) should have a transmitting wavelength of 1550 nm and have a receiving wavelength of 1310 nm.

BiDi transceiver

Advantages of BiDi Transceiver

The decisive advantage of using BiDi transceiver is that it helps to reduce the cost of fiber cabling infrastructure. This is caused by reducing the number of fiber path panel ports as well as reducing the amount of tray space dedicated to fiber management. The deployment of BiDi transceiver enables the bandwidth capacity of the optical fiber to be doubled.

FS.COM BiDi Transceiver Solution

FS.COM supplies a series of BiDi transceivers with different types such as BiDi SFP. These BiDi Gigabit SFP transceivers support Fast Ethernet, Gigabit Ethernet, and Fibre Channel, etc. And they can be available for simplex SC or LC connector interface, which is used for data transmitting and receiving. Also, the BiDi SFPs are able to support a wide range of physical media from copper to long-wave single-mode optical fiber with transmission distance up to hundreds of kilometers. The most typical Tx and Rx wavelength combinations are 1310/1490 nm, 1310/1550 nm and 1490/1550 nm. FS.COM has a large selection of BiDi transceivers in stock. Choosing a FS.COM BiDi transceiver can help your fiber optic network to be most economical and efficient.

Related Article: A Brief Introduction of BiDi SFP Transceiver