The basic working principle of the GPBD board is as follows:
* The control module loads the board software, controls the running of the board, and manages the board.
* The switching module aggregates the signals from eight GPON ports.
* The interface module converts between GPON signals and Ethernet packets.
* The power module supplies power to other functional modules of the board.
* The clock module provides the working clock for other functional modules of the board.