In the application of PON technology, OLT equipment is an important bureau-end equipment. Its functions are as follows: 1. Connecting with the front-end (convergence layer) switch by network wire, converting into optical signal, and connecting with the splitter at the user end by a single optical fiber. 2. Realize the functions of control, management and ranging of ONU. 3. OLT equipment, like ONU equipment, is also a photoelectric integrated equipment.
EPON network consists of OLT, ODN and ONU. OLT belongs to the service node side equipment of access network. It connects with the corresponding service node equipment through SNI interface to complete the service access of access network.
It mainly completes the upstream access of PON network and connects with ONU equipment through the PON port through the ODN network (composed of optical fiber and passive splitter), generally using 1:32 or 1:64 to form the whole PON network. Generally, PON ports are connected by a single optical fiber and ODN network. The splitter is 1:n (n = 2, 4, 8, 16, 32, 64, etc.). The ONU downlink adopts broadcasting mode, and the ONU device receives selectively. The upstream is shared. The development of PON technology has gone through the process of APON/BPON, EPON and GPON, and is evolving towards 10G PON and WDM PON. PON technology has been widely used because of its flexible deployment and low cost, and has become the main mode of fixed broadband access.
If the optical signal on OLT is too strong (sometimes because the loss of short distance optical signal is small), an attenuator is needed. OLT connects ONU downward and splitter between them.