100G QSFP28 SINGLE-LAMBDA VS. TRADITIONAL 100G QSFP28 WITH 4-CHANNELS
2022-09-07 17:39:56
WHAT IS "SINGLE-LAMBDA" AND WHY SHOULD I USE IT?
100G transmission is common in today's networks. Typically these transceivers are based on 4 parallel lanes that operate at speed of 25G each and modulated with NRZ (Non Return to Zero). For single mode fibre each lane has its assigned wavelength (like CWDM4 or LR4) as well as one of the four lasers and receivers.
Standardised by the 100G Lambda MSA, 100G single lambda transceivers process these 4 x 25G electrical signals from the host side via a built-in discrete DSP (Digital Signal Processor) using PAM4 (4 level Pulse Amplitude Modulation) - instead of NRZ - and feed the new modulated signal into one single laser at the speed of 100G. That reduces the cost for optical components, etc.
Specified for up to 500m, single-lambda started with 100GBASE-DR; followed by 100GBASE-FR for up to 2km and 100GBASE-LR for distances up to 10km.
Model |
3C-QSFP28-LR1 |
3C-QSFP28-LR4 |
Spec
|
QSFP28 LR Single-lambda (10km) |
QSFP28 LR4 (10KM)
|
Working Mode
|
Modulation scheme PAM4
|
NRZ with integrated 4-ch Mux/Demux
|
Wavelength
|
1311nm
|
1295.56nm
1300.05nm
1304.58nm
1309.14nm
|
FEC
Requirement
|
BER 5E-5: FEC in Host required for BER 1E-12
|
no additional FEC needed
|
Power Consumption
|
~ 4W
|
~ 3.5W
|
Receiver
|
APD ROSA
|
PIN ROSA
|
PDF |
|
|
3C-LINK 100G QSFP28 LR1 optical transceiver modules are designed to support 100G Ethernet, suitable for data center links up to 10km or 20km over single mode fiber. The 100G QSFP28 LR1 modules are compatible with the 100G-LR1-20 specification of 100G Lambda MSA and IEEE 802.3cu 100GBASE-LR1. The transmission side converts 4x 25G NRZ electrical signals into 1x 100G PAM4 optical signal. Reversely the receiving side converts 1x 100G PAM4 optical signal into 4x 25G NRZ electrical signals.