Today, I'd like to share with you a knowledge point. The details are as follows:
ODN: Optical distribution network provides the optical channel between the OLT and the ONT. The drop cable section is the most arduous in an ODN project.
Split ratio: Currently, in a GPON system, the largest split ration is 1:64 but in an EPON system, the largest split ratio is 1:32. In addition , in an ODN project, only 1-level or 2-level splitting is adopted, and 3-level or multi-level splitting is not recommended.
Case Study: Xiaojie is an ODN planning engineer in W site, China. in this site, the 1-level splitting for the GPON port is 1:18, and the 2-level splitting is 1:8,1:8 and 1:16 respectively on three links, as shown in the below figure.
Sol: The split ratio is not determined by the number of connected devices because optical attenuation is generated as soon as the optical splitter is connected. For the figure above, the split ratio is (1:8 * 1:16) = 1:128, which goes beyond the largest split ratio of 1:64. Therefore, this ODN network is unacceptable.
I hope it will be helpful for you. Thank you!
