WHAT IS A BIDI MODULE?

 

Bidirectional transmission (BiDi) is a perfect solution for data centers and IT infrastructure and for maximizing the fiber usage. The development of the WDM technique enables reception and transmission of optical signals of different wavelengths over one fiber. BiDi modules take advantage of that feature.

 

HOW DOES A BIDI MODULE WORK?

 

BiDi modules also known as BX modules can transmit the signal in both directions over a single optical fiber. This is possible because BiDi modules are equipped with diplexers that can split the signal intro two different wavelengths. You can see how a BiDi module works in wavelengths 1310/1550 on the picture below:

Wkładki Bidi budowa.jpg

 

For comparison, the following diagram shows how signal transmission works in duplex SFP, SFP+ and XFP modules.

 

wkładki duplex sygnał

 

WHICH PATCH CABLE GOES WITH BIDI MODULES?

 

SFP BiDi modules can be connected with an LC/UPC or SC/UPC connector, however SFP+ BiDi modules and XFP BiDi modules can be connected only with LC/UPC connectors (they never occur with an SC-type socket).

 

SFP BX.jpg



How to match BiDi modules?

 

For 1J (single fiber) connection, the transceivers should be cross connected, so that the TX transceiver on the one side corresponds to the RX receiver on the other side, as shown on the picture below. For your convenience, the clasps/latches of the module are color-coded, depending on the manufacturer. Some of the combinations are blue and green, blue and yellow, blue and purple.

 

łączenie wkładek BiDi

The process of linking BX SFP-type modules over one fiber using

LO-SF-1G-3S5-20L and LO-SF-1G-5S3-20L

 

The raise of capacity significantly complicates the process of connection between the receptive and transmitting modules. To learn more about how the 40Gbs and 100Gbs modules work, please visit other articles at our website (link below).

 

What are the advantages and disadvantages of BiDi modules?

 

  • Save the number of fibers (thanks to duplex-type connection with only one fiber instead of two)
  • Reduce by half the number of patch cables necessary in data centers

 

BiDi modules occur in SFP, SFP+ and XFP cases. In the following table you can compare data rates, range and connector types of given models:

 


  Model
  

  Form Factor
  

  BitRate
  

  Range
  
Connector
  TX(nm)
  

  RX(nm)
  
LO-SF-1G-3S5-03LSFP 1 Gbps3 kmLC 13101550
LO-SF-1G-5S3-03LSFP 1 Gbps3 kmLC15501310
LO-SF-1G-3S5-03SSFP1 Gbps3 kmSC13101310
LO-SF-1G-5S3-03SSFP1 Gbps3 kmSC15501550
LO-SF-1G-3S5-20LSFP1 Gbps20 kmLC13101310
LO-SF-1G-5S3-20LSFP1 Gbps20 kmLC15501550
LO-SF-1G-3S5-20SSFP1 Gbps20 kmSC13101310
LO-SF-1G-5S3-20SSFP1 Gbps20 kmSC15501550
LO-SF-1G-3S5-40LSFP1 Gbps40 kmLC13101310
LO-SF-1G-5S3-40LSFP1 Gbps40 kmLC15501550
LO-SF-1G-5S4-80LSFP1 Gbps80 kmLC14901550
LO-SF-1G-4S5-80LSFP1 Gbps80 kmLC15501490
LO-SP-10G-3S2-10SFP+10 Gbps10 kmLC13301270
LO-SP-10G-2S3-10SFP+10 Gbps10 kmLC12701330
LO-SP-10G-3S2-20SFP+10 Gbps20 kmLC13301270
LO-SP-10G-2S3-20SFP+10 Gbps20 kmLC12701330
LO-SP-10G-3S2-40SFP+10 Gbps40 kmLC13301270
LO-SP-10G-2S3-40SFP+10 Gbps40 kmLC12701330
LO-SP-10G-3S2-60SFP+10 Gbps60 kmLC13301270
LO-SP-10G-2S3-60SFP+10 Gbsp60 kmLC12701330
LO-XP-10G-2S3-20XFP10 Gbps20 kmLC12701330
LO-XP-10G-3S2-20XFP10 Gbps20 kmLC13301270
LO-XP-10G-3S2-40XFP10 Gbps40 kmLC13301270
LO-XP-10G-2S3-40XFP10 Gbps40 kmLC12701330

 



BiDi modules- application

 

The most common application is point-to-point connection. Typically, a pair of modules is connected to two active devices such as switches, servers, media converters.

BiDi modules significantly reduce the cost of fiber leases. Especially the LightOptics module is a cost-effective solution compliant with such manufacturers as CISCO, HP and others. It is not only affordable but also reliable and high quality.