Hi, Gerard.
Five specifications for the power budget of the optical GPON port include CLASS A, CLASS B, CLASS B+, CLASS C, and CLASS C+. CLASS B+ is used most frequently. CLASS C+ is used for long-distance transmission in some scenarios. The power budget of CLASS B+ can reach 28.5 dB, while that of CLASS C+ is higher, reaching 32 dB.
The following lists the GPON-related recommendations:
ITU-T G.984.1: General characteristics, describing the basic GPON features and main protection modes.
ITU-T G.984.2: Physical Media Dependent layer specification, describing physical-layer GPON parameters such as physical parameters of optical modules, including the transmit optical power, receive sensitivity, and overload power. In addition, various levels of optical power budgets such as CLASS B+ are defined in this recommendation.
ITU-T G.984.3: Transmission convergence layer specification, describing TC-layer GPON protocols, including the upstream and downstream frame structures and GPON working principles.
ITU-T G.984.4: ONT management and control interface specification, describing the GPON management and maintenance protocols, including OAM, PLOAM, and OMCI protocols.
ITU-T G.984.5: Enhancement band, describing GPON wavelength planning, especially the reserved wavelength bands reserved for the next-generation PON.
ITU-T G.984.6: Reach extension, describing several long reaches PON solutions for prolonging the GPON transmission distance.
TR-156: using GPON access in the context of TR-101, describing the basic standards and implementation of GPON access technology.
GPON Optical Port Power Budget Attenuation Range
CLASS A 5 dB – 20 dB
CLASS B 10 dB – 25 dB
CLASS B+ 13 dB – 28 dB
CLASS C 15 dB – 30 dB
CLASS C+ 17 dB – 32 dB
Thanks.
