(IDLE) -> | Beacon > -> < Central beacon ? > < Central beacon ? > -yes-> |NTB \n compute Frequency error| -tick offset, rho-> < Tracked beacon ? > < Central beacon ? > -no-> |Callback upper layer| < Tracked beacon ? > -no-> |Callback upper layer| < Tracked beacon ? > -yes-> |Compute schedules\nand update ACLF| -schedules-> |Program CA| -tick offset, rho, bpsd[4]-> |Callback upper layer| |Callback upper layer| -> (IDLE)