The difference between GPON ONU optical module and GPON OLT optical module

Nowadays, with the continuous optimization and upgrading of optical fiber modules, PON (passive optical fiber network) has become an important way to carry broadband access network services. PON is divided into GPON and EPON. GPON can be said to be an upgraded version of EPON. This article, ETU-LINK, will take you to understand GPON optical modules.

Let's first look at GPON technology. Compared with many aspects such as bandwidth utilization, cost, multi-service support, and OAM function, GPON is superior to EPON. GPON uses the scrambling code as the line code, only changes the code without adding the code, so there is no bandwidth loss; it has a high rate of gigabit, and the cost is low in terms of single-bit cost; due to its unique packaging form, it can well support ATM Business and IP business; OAM information is rich, including bandwidth authorization allocation, dynamic bandwidth allocation (DBA), link monitoring, protection switching, key exchange and various alarm functions.

The requirements of the optical module of the GPON system are divided into three levels: A, B, and C, and the optical indicators of each level are different. At present, it is mainly divided into Class B+ and Class C+. The received optical power range of the ONU side is generally about 1-2dbm less than that of the OLT side. The difference between the two is as follows:

The main function of the GPON ONU optical module is to receive and transmit light, which is realized by the laser, converts the modulated electrical signal into an optical signal, and inputs it into the optical fiber network for transmission. The receiver completes the light receiving, amplifies and converts the received light into an electrical signal and transmits it to the system for signal processing to obtain useful information. Its package type is SFP, SC interface, the transmission rate is 1.25G/2.5G, the transmission distance can reach 20km, the emission wavelength is 1310nm, the reception wavelength is 1490nm, it supports DDM digital diagnosis function, commercial grade (0℃-70℃) and industrial grade (-40℃-+85℃) The working temperature is optional.

GPON OLT optical module package type is SFP, SC interface, transmission rate is 2.5G/1.25G, transmission distance can reach 20km, emission wavelength 1490nm, receiving wavelength 1310nm, support DDM digital diagnosis function, commercial grade (0℃-70℃) And industrial grade (-40℃-+85℃) working temperature is optional, suitable for optical line terminal.