Nowadays, with the continuous optimization and upgrading of fiber optic modules, PON (Passive Fiber Optic Network) has become an important way of carrying broadband access network services. PON is divided into two types: GPON and EPON, and GPON can be said to be an upgraded version of EPON.
Looking at GPON technology first, in terms of bandwidth utilization, cost, multi service support, OAM functionality, and other aspects, GPON is superior to EPON. GPON uses scrambling code as line code, and only changes code without adding code, so there is no bandwidth loss; Having a gigabit high-speed rate, the cost is relatively low in terms of single bit cost; Due to its unique packaging form, it can effectively support ATM and IP services; OAM is rich in information, including bandwidth authorization allocation, dynamic Bandwidth allocation (DBA), link monitoring, protection switching, key exchange and various alarm functions.
The requirements of optical module of GPON system are divided into three levels: A, B and C. The optical indicators of each level are different. At present, it is mainly divided into Class B+and Class C+, and the optical power range on the ONU side is generally 1-2 dbm less than that on the OLT side.
The main function of GPON ONU optical fiber module is to receive and emit light, which is realized by the laser, to convert the modulated electrical signal into optical signal and input it into the optical network for transmission. The receiver completes the reception of light, amplifies and converts the received light into electrical signals, which are transmitted to the system for signal processing to obtain useful information. Its packaging type is SFP module , SC interface, with a transmission rate of 1.25G/2.5G, a transmission distance of up to 20km, a transmission wavelength of 1310nm, a reception wavelength of 1490nm, support for DDM digital diagnosis function, and optional operating temperatures for commercial grade (0 ℃ -70 ℃) and industrial grade (-40 ℃ -+85 ℃).
The packaging type of GPON OLT optical module is SFP, SC interface, the transmission rate is 2.5G/1.25G, the transmission distance can reach 20km, the transmission wavelength is 1490nm, and the reception wavelength is 1310nm. It supports the DDM digital diagnosis function, and the operating temperature of commercial grade (0 ℃ - 70 ℃) and industrial grade (- 40 ℃ -+85 ℃) is optional. It is suitable for optical line terminals.