Auto-Tuning for 25G Tunable DWDM Transceiver Technical Guide


As 5G is coming, the increased bandwidth consumption is forcing network operators to make continuous changes to their fronthaul infrastructure to increase network capacity. HiSilicon Optoelectronics developed auto-tuning technology to SFP28 tunable DWDM optics to boost the capacity of fronthaul networks without significant changes to existing hardware equipment and fiber resources. What’s more, with automated tuning capabilities it also reduces inventory and provisioning efforts to a minimum.

HiSilicon Optoelectronics' auto-tuning solution is shown in the following system schematic, a low frequency auto-tuning signal is over-layed on top of the normal signal as a kind of out-band pilot tone modulation information channel, the transmitter/receiver’s wavelength related information are carried in the information channel to let both HEE (head-end-equipment) and TEE (tail-end-equipment) automatically match each other. HEE and TEE play the same role in auto-tuning procedure, which is more intelligent than G.698.4 (known as G.metro), where auto-negotiation mechanism is based on master/slave mode. The wavelength negotiation is started from channel 1 up to the matched channel, and adjustment time is less than 8 seconds between two neighbor channels.

Furthermore, the sensitivity loss (0.5~1 dB) caused by pilot tone modulation is within the link margin scope, which does not compromise fiber transmission performance. This solution significantly improves network O&M efficiency at lower costs without complex circuits.


Figure 1 Auto-Tuning Principle