Systems and methods for optimization of transmission signal quality in point-to-multipoint networks

1 . A method of determining an achievable receive signal quality of a subcarrier group of an optical signal, comprising:

receiving, by a hub node, an optical signal comprising a plurality of subcarrier groups each transmitted at a transmission output power from one or more leaf nodes;

continuously running, by the hub node, a signal optimization cycle configured to iteratively adjust a receive signal quality of each of the plurality of subcarrier groups to be within a required receive signal quality margin, while staying within a transmission output power margin for each of the plurality of subcarrier groups, the signal optimization cycle comprising:

determining, by the hub node, the receive signal quality of each subcarrier group of the plurality of subcarrier groups;

determining, by the hub node, that one or more of the plurality of subcarrier groups is outside of the required receive signal quality margin by comparing the receive signal quality of each subcarrier group of the plurality of subcarrier groups to the required receive signal quality margin for each of the plurality of subcarrier groups;

determining, by the hub node, a power adjustment to bring the receive signal quality of the one or more of the plurality of subcarrier groups that is outside of the required receive signal quality margin to within the required receive signal quality margin; and

adjusting, by each leaf node, a transmission output power of each of the plurality of subcarrier groups based on the power adjustment necessary to bring the receive signal quality of one or more of the plurality of subcarrier groups within the required receive signal quality margin while staying within the transmission output power margin;

determining, by the hub node, that each of the plurality of subcarrier groups is currently being transmitted within the required receive signal quality margin by comparing the receive signal quality of each subcarrier group of the plurality of subcarrier groups to the required receive signal quality margin;

sending, by the hub node, a first signal to leaf nodes transmitting the plurality of subcarrier groups, the first signal configured to cause the leaf nodes to report a current transmission output power of each of the plurality of subcarrier groups when each of the plurality of subcarrier groups is being transmitted within the required receive signal quality margin as a first transmission output power to the hub node;

sending, by the hub node, a second signal to a new leaf node in the one or more leaf nodes, the second signal configured to cause the new leaf node to begin transmitting a new subcarrier group that is combined in the optical signal and received by the hub node;

running, by the hub node and the new leaf node, the signal optimization cycle configured to bring a receive signal quality of the new subcarrier group up to within the required receive signal quality margin by gradually increasing a transmission output power of the new subcarrier group until the receive signal quality of the new subcarrier group is within the required receive signal quality margin;

sending, by the hub node, a third signal to the new leaf node, the third signal configured to cause the new leaf node to report a current transmission output power of the new subcarrier group when the receive signal quality of the new subcarrier group is within the required receive signal quality margin as a second transmission output power to the hub node;

sending, by the hub node, a fourth signal to each of the leaf nodes transmitting the plurality of subcarrier groups and the new leaf node, the fourth signal configured to cause the new leaf node to gradually increase transmission output power of the new subcarrier group and cause the leaf nodes transmitting the plurality of subcarrier groups to continuously run the signal optimization cycle and adjust to receive signal quality changes caused by the increase of the transmission output power of the new leaf node;

monitoring, by the hub node, the plurality of subcarrier groups and the new subcarrier group to determine if any of the plurality of subcarrier groups and the new subcarrier group has reached a maximum transmission output power;

monitoring, by the hub node, a signal quality of each of the plurality of subcarrier groups to determine if the receive signal quality of any of the plurality of subcarrier groups and the new subcarrier group begins to degrade;

determining, by the hub node, that one or more of the plurality of subcarrier groups and the new subcarrier group has reached the maximum transmission output power or that the signal quality of one or more of the plurality of subcarrier groups and the new subcarrier group has begun to degrade; and

determining, by the hub node, a current receive signal quality of the new subcarrier group when one or more of the plurality of subcarrier groups and the new subcarrier group has reached the maximum transmission output power or the receive signal quality of one or more of the plurality of subcarrier groups and the new subcarrier group has begun to degrade, the current receive signal quality of the new subcarrier group being the achievable received signal quality of the new subcarrier group without degrading the signal quality of the plurality of subcarrier groups.

2 . The method of claim 1 , wherein after determining the achievable receive signal quality of the new subcarrier group, the hub node sends a fifth signal to each of the leaf nodes transmitting the plurality of subcarrier groups and the new leaf node, the fifth signal configured to cause the leaf nodes transmitting the plurality of subcarrier groups to return the transmission output power of each of the plurality of subcarrier groups to the first transmission output power and the new leaf node to return the new subcarrier group to the second transmission output power.

3 . The method of claim 1 , wherein after determining the achievable receive signal quality of the new subcarrier group, the hub node sends a fifth signal to the new leaf node, the fifth signal configured to cause the new leaf node to return the new subcarrier group to the second transmission output power and the leaf nodes transmitting the plurality of subcarrier groups adjusts the transmission output powers of the plurality of subcarrier groups to within the required receive signal quality margin by continuously running the signal optimization cycle.

4 . The method of claim 1 , wherein after determining that one or more of the plurality of subcarrier groups and the new subcarrier group has reached the maximum transmission output power or the receive signal quality of one or more of the plurality of subcarrier groups and the new subcarrier group has begun to degrade, the hub node sends a fifth signal to the new leaf node, the fifth signal configured to cause the new leaf node to determine a current transmission output power of the new subcarrier group and save the current transmission output power as an achievable transmission output power of the new subcarrier group without degrading the signal quality of the plurality of subcarrier groups.

5 . The method of claim 4 , wherein the hub node subtracts the second transmission output power of the new subcarrier group from the achievable transmission output power of the new subcarrier group to determine a transmission output power margin of the new subcarrier group.

6 . The method of claim 1 , wherein each of the receive signal quality is quantified as one of a signal to noise ratio, a bit error rate, a quality factor, mutual information, an error vector magnitude, and combinations thereof.

7 . The method of claim 1 , wherein each of the receive signal quality is quantified as a signal to noise ratio and each of the required receive signal quality margin is a target signal to noise ratio comprising a transmit signal to noise ratio of the leaf node transmitting a particular subcarrier group of the plurality of subcarrier groups plus a margin.

8 . The method of claim 1 , wherein monitoring the plurality of subcarrier groups and the new subcarrier group includes receiving, by the hub node, a current transmission output power for each of the plurality of subcarrier groups and the new subcarrier group each time the transmission output power is increased and saving a previous transmission output power of each of the plurality of subcarrier groups and the new subcarrier group as a last transmission output power; and

wherein determining if any of the plurality of subcarrier groups and the new subcarrier group has reached a maximum transmission output power comprises one or more of:

comparing the current transmission output power for each of the plurality of subcarrier groups and the new subcarrier group to a maximum transmission output power of each of the plurality of subcarrier groups and the new subcarrier group reported by each of the leaf nodes transmitting the plurality of subcarrier groups and the new leaf node;

determining, by the hub node, that the current transmission output power of one or more of the plurality of subcarrier groups and the new subcarrier group is the same as the last transmission output power; and

combinations thereof.

9 . A method of determining an achievable receive signal quality of each subcarrier group of a plurality of subcarrier groups of an optical signal, comprising:

receiving, by a hub node, the optical signal comprising a plurality of subcarrier groups each transmitted at a transmission output power;

determining, by the hub node, a receive signal quality of each of the plurality of subcarrier groups;

determining, by the hub node, that each of the plurality of subcarrier groups is currently being transmitted at a required receive signal quality margin by comparing the receive signal quality of each of the plurality of subcarrier groups to the required receive signal quality margin;

sending, by the hub node, a first signal to leaf nodes transmitting the plurality of subcarrier groups, the first signal configured to cause the leaf nodes to report a first transmission output power of each of the plurality of subcarrier groups when each of the plurality of subcarrier groups is being transmitted at the required receive signal quality margin to the hub node;

sending, by the hub node, a second signal to each of the leaf nodes transmitting the plurality of subcarrier groups, the second signal configured to cause the leaf nodes to gradually increase the transmission output power of each of the plurality of subcarrier groups;

monitoring, by the hub node, the plurality of subcarrier groups to determine if any of the plurality of subcarrier groups has reached a maximum transmission output power;

monitoring, by the hub node, a signal quality of each of the plurality of subcarrier groups to determine if the receive signal quality of any of the plurality of subcarrier groups begins to degrade;

determining, by the hub node, that one or more of the plurality of subcarrier groups has reached the maximum transmission output power or the receive signal quality of one or more of the plurality of subcarrier groups has begun to degrade; and

determining, by the hub node, a current receive signal quality of each of the plurality of subcarrier groups when one or more of the plurality of subcarrier groups has reached the maximum transmission output power or the receive signal quality of one or more of the plurality of subcarrier groups has begun to degrade, the current receive signal quality of each of the plurality of subcarrier groups being an achievable receive signal quality of each of the plurality of subcarrier groups without degrading the receive signal quality of any other one of the plurality of subcarrier groups.

10 . The method of claim 9 , wherein after determining the achievable receive signal quality of each of the plurality of subcarrier groups, the hub node sends a third signal to each of the leaf nodes transmitting the plurality of subcarrier groups, the third signal configured to cause the leaf nodes transmitting the plurality of subcarrier groups to return the transmission output power of each of the plurality of subcarrier groups to the first transmission output power.

11 . The method of claim 9 , wherein after determining that one or more of the plurality of subcarrier groups has reached the maximum transmission output power or the receive signal quality of one or more of the plurality of subcarrier groups has begun to degrade, the hub node sends a third signal to each of the leaf nodes transmitting the plurality of subcarrier groups, the third signal configured to cause each of the leaf nodes transmitting the plurality of subcarrier groups to determine a current transmission output power of each of the plurality of subcarrier groups and save the current transmission output power as an achievable transmission output power of each of the plurality of subcarrier groups without degrading the signal quality of any other one of the plurality of subcarrier groups.

12 . The method of claim 11 , wherein the hub node subtracts the first transmission output power of each of the plurality of subcarrier groups from the achievable transmission output power of each of the plurality of subcarrier groups to determine a transmission output power margin of each of the plurality of subcarrier groups.

13 . The method of claim 9 , wherein each of the receive signal quality is quantified as one of a signal to noise ratio, a bit error rate, a quality factor, mutual information, an error vector magnitude, and combinations thereof.

14 . The method of claim 9 , wherein each of the receive signal quality is quantified as a signal to noise ratio and each of the required receive signal quality margin is a target signal to noise ratio comprising a transmit signal to noise ratio of the leaf node transmitting a particular subcarrier group of the plurality of subcarrier groups plus a margin.

15 . The method of claim 9 , wherein monitoring the plurality of subcarrier groups to determine if any of the plurality of subcarrier groups has reached a maximum transmission output power comprises receiving, by the hub node, a current transmission output power for each of the plurality of subcarrier groups each time the transmission output power is increased, and saving a previous transmission output power of each of the plurality of subcarrier groups as a last transmission output power; and

wherein determining if any of the plurality of subcarrier groups has reached the maximum transmission output power comprises one or more of:

comparing the current transmission output power for each of the plurality of subcarrier groups to a maximum transmission output power of each of the plurality of subcarrier groups reported by each of the leaf nodes transmitting the plurality of subcarrier groups;

determining, by the hub node, that the current transmission output power of one or more of the plurality of subcarrier groups is the same as the last transmission output power; and

combinations thereof.

16 . An optical network system, comprising:

one or more existing leaf nodes each transmitting an optical signal having an existing subcarrier group transmitted at a transmission output power over an optical network;

a new leaf node connected to the optical network and configured to transmit a new optical signal having a new subcarrier group transmitted at a new transmission output power over the optical network;

an optical combiner configured to combine the optical signals transmitted from the one or more existing leaf nodes and the new optical signal transmitted from the new leaf node into a combined optical signal; and

a hub node configured to receive the combined optical signal from the one or more existing leaf nodes and the new leaf node, the hub node having a processor and memory storing processor executable code that, when executed, causes the processor to:

continuously run a signal optimization cycle configured to iteratively adjust a receive signal quality of each of the existing subcarrier groups to be within a required receive signal quality margin, while staying within a transmission output power margin for each of the existing subcarrier groups, the signal optimization cycle comprising:

determining, by the processor, the receive signal quality of each existing subcarrier group;

determining, by the processor, that one or more of the existing subcarrier groups is outside of the required receive signal quality margin by comparing the receive signal quality of each existing subcarrier group to the required receive signal quality margin for each of the existing subcarrier groups;

determining, by the processor, a power adjustment to bring the receive signal quality of the one or more existing subcarrier groups that is outside of the required receive signal quality margin to within the required receive signal quality margin; and

adjusting, by each leaf node, the transmission output power of each of the existing subcarrier groups based on the power adjustment necessary to bring the receive signal quality of one or more of the existing subcarrier groups within the required receive signal quality margin while staying within the transmission output power margin;

determining, by the processor, that each of the existing subcarrier groups is currently being transmitted within the required receive signal quality margin by comparing the receive signal quality of each existing subcarrier group to the required receive signal quality margin;

sending, by the hub node, a first signal to the one or more existing leaf nodes transmitting the existing subcarrier groups, the first signal configured to cause the existing leaf nodes to report a current transmission output power of each of the existing subcarrier groups when each of the existing subcarrier groups is being transmitted within the required receive signal quality margin as a first transmission output power to the hub node;

sending, by the hub node, a second signal to the new leaf node, the second signal configured to cause the new leaf node to begin transmitting the new subcarrier group that is combined into the combined optical signal and received by the hub node;

running, by the hub node and the new leaf node, the signal optimization cycle configured to bring a receive signal quality of the new subcarrier group up to within the required receive signal quality margin by gradually increasing the new transmission output power of the new subcarrier group until the receive signal quality of the new subcarrier group is within the required receive signal quality margin;

sending, by the hub node, a third signal to the new leaf node, the third signal configured to cause the new leaf node to report a current transmission output power of the new subcarrier group when the receive signal quality of the new subcarrier group is within the required receive signal quality margin as a second transmission output power to the hub node;

sending, by the hub node, a fourth signal to each of the existing leaf nodes transmitting the existing subcarrier groups and the new leaf node transmitting the new subcarrier group, the fourth signal configured to cause the new leaf node to gradually increase the new transmission output power of the new subcarrier group and cause the existing leaf nodes transmitting the existing subcarrier groups to continuously run the signal optimization cycle and adjust to receive signal quality changes caused by the increase of the new transmission output power of the new leaf node;

monitoring, by the hub node, the existing subcarrier groups and the new subcarrier group to determine if any of the existing subcarrier groups and the new subcarrier group has reached a maximum transmission output power;

monitoring, by the hub node, a signal quality of each of the existing subcarrier groups and the new subcarrier group to determine if the receive signal quality of any of the existing subcarrier groups and the new subcarrier group begins to degrade;

determining, by the hub node, that one or more of the existing subcarrier groups and the new subcarrier group has reached the maximum transmission output power or that the signal quality of one or more of the existing subcarrier groups and the new subcarrier group has begun to degrade; and

determining, by the hub node, a current receive signal quality of the new subcarrier group when one or more of the existing subcarrier groups and the new subcarrier group has reached the maximum transmission output power or the receive signal quality of one or more of the existing subcarrier groups and the new subcarrier group has begun to degrade, the current receive signal quality of the new subcarrier group being an achievable received signal quality of the new subcarrier group without degrading the signal quality of the existing subcarrier groups.

17 . The optical network system of claim 16 , wherein after determining the achievable receive signal quality of the new subcarrier group, the processor executable code causes the hub node to send a fifth signal to each of the existing leaf nodes transmitting the existing subcarrier groups and the new leaf node, the fifth signal configured to cause the existing leaf nodes transmitting the existing subcarrier groups to return the transmission output power of each of the existing subcarrier groups to the first transmission output power and the new leaf node to return the new subcarrier group to the second transmission output power.

18 . The optical network system of claim 16 , wherein after determining the achievable receive signal quality of the new subcarrier group, the processor executable code causes the hub node to send a fifth signal to the new leaf node, the fifth signal configured to cause the new leaf node to return the new subcarrier group to the second transmission output power; and wherein the existing leaf nodes transmitting the existing subcarrier groups continuously run the signal optimization cycle to adjust the transmission output powers of the existing subcarrier groups to within the required receive signal quality margin.

19 . The optical network system of claim 16 , wherein after determining that one or more of the existing subcarrier groups and the new subcarrier group has reached the maximum transmission output power or the receive signal quality of one or more of the existing subcarrier groups and the new subcarrier group has begun to degrade, the processor executable code causes the hub node to send a fifth signal to the new leaf node, the fifth signal configured to cause the new leaf node to determine a current transmission output power of the new subcarrier group and save the current transmission output power as an achievable transmission output power of the new subcarrier group without degrading the signal quality of the existing subcarrier groups.

20 . The optical network system of claim 19 , wherein the processor executable code causes the hub node to subtract the second transmission output power of the new subcarrier group from the achievable transmission output power of the new subcarrier group to determine a transmission output power margin of the new subcarrier group.