received by the International Bureau on 26 May 2015 (26.05.2015)

1 , A distributed antenna system (DAS) configured to determine a slope efficiency of an optical signal source, comprising:

at least one optica! fiber;

head end equipment (HEE), comprising:

a downlink transmitter comprising a downlink laser diode; arid an uplink receiver configured to receive signals from a plurality of remote units (RUs);

a plurality of RUs, each RU comprising:

one or more antennas configured to communicate wireless!y with one or more remote clients;

a downlink receiver communicatively coupled to the downlink transmitter through the at least one optical fiber;

an uplink transmitter communicatively coupled to the uplink receiver through the at least one optical fiber, wherein the uplink transmitter comprises an uplink laser diode; and

a control system associated with one of the HEE or one of the plurality of RUs, the control system configured to:

determine a slope efficiency of the respective downlink or uplink laser diode; and

provide slope efficiency information related to the slope efficiency to the receiver communicatively coupled to the respective uplink or downlink laser diode.

2. The DAS of claim 1, wherein the control system configured to provide information related to the slope efficiency to the receiver is .configured to send a management signal to a controller associated with the receiver.

3. The DAS any of claims 1 or2, further comprising a temperature sensor associated with the control system.

4. The DAS of claim 3, wherein the control system configured to determine the slope efficiency .initiates such determination based on a change in temperature reflected by output from the temperature sensor,

.5. The DAS any of claims 3 or 4, wherein the control system is further configured, to poll the temperature sensor periodically.

6. The DAS any of claims I to 5, wherein the control system configured to determine the slope efficiency is configured to measure a sample of optical power from the respective laser diode at a first, current setting and measure a second sample of optical power from the respective laser diode at a second current setting.

7. The DAS of any of claims 1, 2 or 6, wherein the control system configured to determine the slope efficiency is configured to determine the slope efficiency periodically,

8. The DAS any of claims 1 to 7, wherein the control system is associated with the H EE, the respective laser diode is the downlink laser diode, and the receiver associated with the respective laser diode is the downlink receiver.

9. The DAS .any of claims I to 8, wherein the control system is associated with the one of the plurality of RUs, the respective laser diode is the uplink laser diode, and the receiver associated with the respective laser diode is the uplink receiver.

10. A distributed communication system, comprising:

head end. equipment (HEE), comprising:

a downlink transmitter comprising a downlink laser diode;

an uplink receiver configured to receive signals from a. plurality of remote units (RUs); and

a control system configured to:

determine a slope efficiency of the downlink laser diode; and provide Information related to the slope efficiency to a receiver in one of the plurality of RUs, the receiver communicatively coupled to the downlink transmitter.

11 . A distributed communication system, comprising:

a remote unit (RU) comprising;

one or more antennas configured to communicate wirelessly with one or more remote clients;

a downlink receiver configured to receive signals from head end equipment (HEE) through at least one optica! fiber;

an uplink transmitter communicatively coupled to an uplink receiver tlirougli the at least one optical fiber, wherein the uplink, transmitter comprises an uplink laser diode; and

a control system configured to;

determine a slope efficiency of the uplink laser diode; and

provide information related to the slope efficiency to a receiver in the HEE, the receiver communicatively coupled to the uplink transmitter,

32. A method of compensating for variations in laser diode performance in a distributed communication system, the method comprising:

determining a slope efficiency of a transmitter^'s laser diode;

providing information relating to the slope efficiency to a receiver in the distributed communication system communicatively coupled to the transmitter^'s laser diode; and

adjusting a link gain at the receiver based on the information relating to the slope efficiency,

13. The method of claim 12, wherein adjusting the link gain occurs in substantially real time during active communication by the distributed communication system.

14. The method of any of claims 12 or 13, wherein determining the slope efficiency comprises periodically determining the slope efficiency.

15. The method of claim 12, wherein determining the slope efficiency comprises measuring a temperature at the laser diode and determining the slope efficiency if the temperature has changed more than a threshold amount compared to a previously recorded temperature.

16. The method of any of claims 12 to 15, wherein adjusting the link gain at the recei ver comprises adjusting the link gain in a radio frequency (RF) amplifier.

17. The method of any of claims 12 to 16, wherein determining the slope efficiency comprises:

measuring a first current level;

^'measuring a first output power from the laser diode at the first current level;

adjusting a current source to a second current level; and

measuring a second output power from the laser diode at the second current level.

18. The method of any of claims .12 to 17, wherein providing information relating to the slope efficiency to the receiver in the distributed communication system comprises sending the information in a management signal.

19. The method of claim 12, wherein the laser diode is in head end equipment (HEE).

20. The method of claim 12, wherein the laser diode is in a remote unit (RU).

21. A non -transitory computer readable medium comprising software with instructions to: determine a slope efficiency of a transmitter's laser diode;

provide information relating to the slope efficiency to a receiver in the distributed communication system communicatively coupled to the transmitter's laser diode; and

adjust a link gain at the receiver based on the information relating to the slope efficiency.