Systems and methods of optical path protection for distributed antenna systems

A method comprising:

• transmitting a downlink optical signal to a downlink fiber of one of a first fiber path and a second fiber path;
• combining any downlink optical signal received on the downlink fiber of the first fiber path and any downlink optical signal received on the downlink fiber of the second fiber path in order to output the downlink optical signal;
• splitting an uplink optical signal for transmission on an uplink fiber of the first fiber path and an uplink fiber of the second fiber path;
• determining a signal quality of the downlink optical signal as received at a first unit;
• determining a signal quality of the uplink optical signal as received at a second unit;
• switching at the second unit between a normal state and backup state based on one or both of the signal quality of the uplink optical signal and the signal quality of the downlink optical signal;
• wherein the first unit communicates the signal quality of the downlink optical signal to the second unit.

A distributed antenna system, the system comprising:

• means for combining an optical signal received on a downlink fiber of a first fiber path with an optical signal received on a downlink fiber of a second fiber path in order to output a downlink optical signal;
• means for splitting an uplink optical signal for transmission on an uplink fiber of the first fiber path and an uplink fiber of the second fiber path;
• means for determining an attribute of the downlink optical signal indicative of the signal quality of the downlink optical signal as received at a first unit;
• means for determining an attribute of the uplink optical signal indicative of the signal quality of the uplink optical signal as received at a second unit;
• and
• means for switching between a normal alignment state and a backup alignment state based on one or both of the attribute of the downlink optical signal and the attribute of the uplink optical signal
• wherein the first unit communicates the attribute of the downlink optical signal to the second unit.