Understanding Bi-Directional Optical Transceiver Technology: BiDi Transceivers

Understanding BiDi | FluxLight Optical Transceivers

Almost all modern optical transceivers utilize two fibers to transmit data between switches, firewalls, servers, routers, etc. The first fiber is dedicated to receiving data from networking equipment, and the second fiber is dedicating to transmitting data to the networking equipment.

A new optical transceiver technology is now available that allows transceivers to both transmit and receive data to/from interconnected equipment through a single optical fiber. This technology first emerged about 5 years ago and has led to the development of Bi-Directional transceivers, or BiDi transceivers for short.

How BiDi Transceivers Work:

The primary 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 1490nm and a transmit wavelength of 1310nm
  • Transceiver B’s diplexer must have a receiving wavelength of 1310nm and a transmit wavelength of 1490nm
Diplexers at Work in BiDi Optical Ethernet Transceivers | FLuxLight
Diplexers at Work in BiDi Optical Ethernet Transceivers

Economic Advantages of BiDi Transceivers:

The obvious advantage of utilizing BiDi transceivers, such as SFP+- BiDi and SFP-BiDi 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.

Want to learn more about the advantages of utilizing BiDi transceivers? Give the optical network professionals at FluxLight a call: 888-874-7574

We carry a large selection of BiDi transceivers in stock and can help you determine which transceiver will be the most economical and efficient for your fiber optic network.

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