Out-of-band communication channel for subcarrier-based optical communication systems
In an example method, an edge transceiver receives a first message from a hub transceiver over a first communications channel of an optical communications network, including an indication of available network resources on the optical communications network. The edge transceiver transmits, over a second communications channel of the optical communications network, a second message to the hub transceiver, including an indication of a subset of the available network resources selected by the edge transceiver. The edge transceiver receives, from the hub transceiver, a third message acknowledging receipt of a selection by the edge transceiver and a fourth message confirming an assignment of the selected subset of the available network resources to the edge transceiver. The edge transceiver transmits, using the selected subset of the available network resources, data via the hub transceiver.
1. A method comprising:
receiving, by an edge transceiver communicatively coupled to a first network node and to an optical communications network, a first message from a hub transceiver over a first communications channel of the optical communications network, wherein the first message comprises an indication of available network resources on the optical communications network,
transmitting, by the edge transceiver over a second communications channel of the optical communications network, a second message to the hub transceiver, wherein the second message comprises an indication of a subset of the available network resources selected by the edge transceiver for use in communicating over the optical communications network,
receiving, by the edge transceiver from the hub transceiver, a third message acknowledging receipt of a selection by the edge transceiver,
receiving, by the edge transceiver from the hub transceiver, a fourth message confirming an assignment of the selected subset of the available network resources to the edge transceiver for use in communicating over the optical communications network, and
transmitting, by the edge transceiver using the selected subset of the available network resources, data from the first network node to a second network node via the hub transceiver.
2. The method of claim 1 , wherein the indication of the available network resources on the optical communications network comprises:
an indication of a plurality of optical subcarriers of the optical communications network, and
an identity of one or more of the optical subcarriers that are not currently assigned to the edge transceiver or any other edge transceivers of the optical communications network.
3. The method of claim 2 , wherein the first communications channel comprises first signals that have been amplitude modulated with respect to each of the plurality of optical subcarriers.
4. The method of claim 3 , wherein the second communications channel comprises second signals transmitted according to one or more frequencies that do not coincide with the plurality of optical subcarriers.
5. The method of claim 2 , wherein the first message further comprises:
instructions for requesting assignment of the one or more of the optical subcarriers that are not currently assigned to the edge transceiver or any other edge transceivers of the optical communications network.
6. The method of claim 1 , further comprising:
transmitting, by the edge transceiver, the second message to the hub transceiver periodically until the third message is received by the edge transceiver from the hub transceiver.
7. The method of claim 1 , further comprising:
receiving, by the edge transceiver, a fifth message from the hub transceiver, wherein the fifth message comprises a command to modify an assignment of network resources to the edge transceiver, and
responsive to receiving the fifth message, transmitting, by the edge transceiver, data from the first network node to the second network node via the hub transceiver according to the modified assignment of network resources.
8. The method of claim 1 , further comprising:
receiving, by the edge transceiver, a fifth message from the hub transceiver, wherein the fifth message comprises a command to relinquish the subset of network resources that had been assigned to the edge transceiver, and
responsive to receiving the fifth message, refraining from transmitting, by the edge transceiver, data to the hub transceiver using the subset of network resources that had been assigned to the edge transceiver.
9. The method of claim 1 , further comprising:
receiving, by the edge transceiver, a fifth message from the hub transceiver, wherein the fifth message comprises a request for a status of the edge transceiver, and
responsive to receiving the fifth message, transmitting, by the edge transceiver, the status of the edge transceiver to the hub transceiver.
10. The method of claim 1 , further comprising transmitting, by the edge transceiver, a status of the edge transceiver to the hub transceiver periodically.
11. The method of claim 1 , further comprising:
receiving, by the edge transceiver, a fifth message from the hub transceiver, wherein the fifth message comprises a command to modify a transmit power of the edge transceiver, and
responsive to receiving the fifth message, transmitting, by the edge transceiver, data from the first network node to a second network node via the hub transceiver according to the modified transmit power.
12. The method of claim 1 , further comprising:
receiving, by the edge transceiver, a fifth message from another edge transceiver or the hub transceiver, wherein the fifth message comprises a command to forward data from the edge transceiver to a further transceiver communicatively coupled to the optical communications network, and
responsive to receiving the fifth message, forwarding, by the edge transceiver, the data to the further transceiver according to the fifth message.
13. The method of claim 2 , wherein the further transceiver is another edge transceiver of the optical communications network.
14. The method of claim 1 , further comprising determining, by the edge transceiver, a carrier frequency associated with the hub transceiver.
15. The method of claim 14 , wherein determining a carrier frequency associated with the hub transceiver comprises:
receiving a signal from the hub transceiver via the optical communications network, wherein receiving the signal comprises scanning a frequency range using a local oscillator of the edge transceiver, the frequency range including a plurality of frequency subsets,
determining a plurality of power values of the optical signal, each of the plurality of power values being associated with a corresponding one of the plurality of frequency subsets, and
determining, based on the plurality of power values, a carrier frequency associated with the hub transceiver.
16. The method of claim 15 , wherein the power level corresponding to the carrier frequency is greater than the power values corresponding to the frequency ranges that do not coincide with the carrier frequency.
17. The method of claim 1 , further comprising:
receiving, by the edge transceiver from the hub transceiver, one or more quality metrics regarding a signal transmitted from the edge transceiver to the hub transceiver, and
modifying, by the edge transceiver, one or more control parameters for transmitting data based on the one or more quality metrics.
18. The method of claim 17 , wherein the one or more control parameters comprise a transmit power of the first edge transceiver.
19. The method of claim 1 , wherein at least one of the first communications channel or the second communications channel corresponds to a respective optical subcarrier.
20. The method of claim 1 , further comprising physically coupling the edge transceiver to an external connection interface of the first network node.
21. An apparatus comprising:
a hub transceiver configured to be communicatively coupled to a first network node and to an optical communications network, wherein the hub transceiver is operable to:
transmit, over a first communications channel of the optical communications network, a first message to each of a plurality of edge transceivers concurrently, wherein the first message comprises an indication of available network resources on the optical communications network, and wherein each of the edge transceivers is configured to be communicatively coupled to a respective second network node and to the optical communications network,
receive, from a first edge transceiver of the plurality of edge transceivers, a second message over a second communications channel of the optical communications network, wherein the second message comprises an indication of a subset of the available network resources selected by the first edge transceiver for use in communicating over the optical communications network,
transmit, to the first edge transceiver, a third message acknowledging receipt of a selection by the first edge transceiver,
assigning the selected subset of the available network resources to the first edge transceiver for use in communicating over the optical communications network, and
transmit a fourth message confirming an assignment of the selected subset of the available network resources to the first edge transceiver.
22. The apparatus of claim 21 , wherein the hub transceiver is configured to transmit the first message periodically to each of the edge transceivers.
23. The apparatus of claim 21 , wherein the indication of the available network resources on the optical communications network comprises:
an indication of a plurality of optical subcarriers of the optical communications network, and
an identity of one or more of the optical subcarriers that are not currently assigned to any of the edge transceivers.
24. The apparatus of claim 23 , wherein the first communications channel comprises first signals that have been amplitude modulated with respect to each of the plurality of optical sub carriers.
25. The apparatus of claim 24 , wherein the second communications channel comprises second signals transmitted according to one or more frequencies that do not coincide with the plurality of optical subcarriers.
26. The apparatus of claim 23 , wherein the first message further comprises:
instructions for requesting assignment of the one or more of the optical subcarriers that are not currently assigned to any of the edge transceivers.
27. The apparatus of claim 21 ,
wherein the hub transceiver is operable to:
transmit a fifth message to the first edge transceiver, wherein the fifth message comprises a command to modify an assignment of network resources to the first edge transceiver.
28. The apparatus of claim 21 ,
wherein the hub transceiver is operable to:
transmit a fifth message to the first edge transceiver, wherein the fifth message comprises a command to relinquish the subset of network resources that had been assigned to the first edge transceiver.
29. The apparatus of claim 21 ,
wherein the hub transceiver is operable to:
transmit a fifth message to the first edge transceiver, wherein the fifth message comprises a request for a status of the first edge transceiver.
30. The apparatus of claim 21 ,
wherein the hub transceiver is operable to:
transmit a fifth message to the first edge transceiver, wherein the fourth message comprises a command to modify a transmit power of the first edge transceiver.
31. The apparatus of claim 21 , wherein the hub transceiver is operable to:
receive, from each of the edge transceivers, a respective signal,
determine, for each received signal, a respective power of the received signal,
determine a modification to a transmit power of one or more of the edge transceivers to reduce a difference in power between the received signals, and
transmit, to the one more of edge transceivers, an indication of the modification to a transmit power.
32. The apparatus of claim 21 ,
wherein the hub transceiver is operable to:
receive a signal from the first edge transceiver,
determine, one or more quality metrics regarding the received signal, and
transmit the one or more quality metrics to the first edge transceiver.
33. The apparatus of claim 32 , wherein the one or more control parameters comprise a transmit power of the first edge transceiver.
34. The apparatus of claim 21 , wherein at least one of the first communications channel or the second communications channel corresponds to a respective optical subcarrier.
35. The apparatus of claim 21 , wherein the hub transceiver is configured to be physically coupled to an external connection interface of the first network node.
36. The apparatus of claim 21 , wherein the first network node and the second network nodes are computing devices.