Optical repeater device and relay method

An optical repeater system, comprising:

• a first optical repeater device connected to a first plurality of base stations of a mobile communication network and a first plurality of remote units for wireless communication with user terminals;
• and
• a second optical repeater device connected to a second plurality of base stations of a mobile communication network and a second plurality of remote units for wireless communication with user terminals, wherein
• the first optical repeater device includes:
• a plurality of signal processors each configured to connect to one of the first plurality of base stations and detect a switching time between uplink and downlink signals of the connected base station;
• a multiplexer/demultiplexer unit connected to the plurality of signal processors and configured to connect to the first plurality of remote units;
• a timing comparator configured to:
• acquire detected switching times from the plurality of signal processors for the first plurality of base stations,
• calculate adjustments for synchronizing the switching times to an internal switching time target for transmission of a downlink signal to a remote unit of the first plurality from the multiplexer/demultiplexer unit,
• acquire an external switching time target from the second optical repeater device for the second plurality of base stations, and
• calculate adjustments for synchronizing the switching times to a switching time target set according to the internal switching time target and the external switching time target;
• and
• a monitoring controller configured to:
• acquire detected delay amounts for transmissions to the first plurality of remote units from the plurality of signal processors,
• calculate an internal target delay amount from the acquired detected delay amounts,
• acquire external target delay information from the second optical repeater device for the second plurality of remote units, and
• calculate timing adjustments for synchronizing transmissions from the first and second plurality of remote units based on the detected delay amounts and the external target delay information.

A method for an optical repeater systems, the method comprising:

• acquire detected switching times from a plurality of signal processors for a first plurality of base stations connected to a first optical repeater device;
• calculate adjustments for synchronizing the switching times to an internal switching time target for transmission of a downlink signal from the multiplexer/demultiplexer unit to a remote unit of a first plurality of remote units connected to the first optical repeater device;
• acquire an external switching time target from a second optical repeater device for a second plurality of base stations connected to the second optical repeater device;
• calculate adjustments for synchronizing the switching times to a switching time target set according to the internal switching time target and the external switching time target from the second optical repeater device;
• acquire detected delay amounts for transmissions to the first plurality of remote units from the plurality of signal processors;
• calculate an internal target delay amount from the acquired detected delay amounts;
• acquire external target delay information from the second optical repeater device for a second plurality of remote units connected to the second optical repeater device;
• and
• calculate timing adjustments for synchronizing transmissions from the first and second plurality of remote units based on the detected delay amounts and the external target delay information.