Managing multi-mode communications between nodes in a network

1. A method comprising:

initiating a carrier sense multiple access with collision avoidance (CSMA/CA) session at a first node while in a first mode, wherein the CSMA/CA session is associated with a request to transmit a data message to a second node;

switching from the first mode to a second mode;

in response to switching to the second mode, suspending the CSMA/CA session at the first node by suspending one or more operations for assessing availability of a channel for transmitting the data message to the second node in the first mode;

switching back to the first mode; and

in response to switching back to the first mode, resuming the CSMA/CA session at the first node.

2. The method of claim 1 , wherein initiating the CSMA/CA session at the first node comprises determining availability of a first channel associated with a channel schedule of the second node for the first mode.

3. The method of claim 2 , further comprising:

determining that the first channel is unavailable; and

in response to determining that the first channel is unavailable, initiating a backoff timer.

4. The method of claim 3 , further comprising pausing the backoff timer while the CSMA/CA session is suspended.

5. The method of claim 4 , further comprising resuming the backoff timer when the CSMA/CA session is resumed.

6. The method of claim 2 , further comprising, after resuming the CSMA/CA session, determining availability of a second channel associated with the channel schedule of the second node for the first mode.

7. The method of claim 6 , wherein the second channel is different from the first channel.

8. The method of claim 1 , wherein the first mode is a unicast mode and the second mode is a broadcast mode.

9. The method of claim 1 , wherein the first mode is a broadcast mode and the second mode is a unicast mode.

10. One or more non-transitory computer-readable media storing program instructions that, when executed by one or more processors, cause the one or more processors to perform the steps of:

initiating a carrier sense multiple access with collision avoidance (CSMA/CA) session at a first node while in a first mode, wherein the CSMA/CA session is associated with a request to transmit a data message to a second node;

switching from the first mode to a second mode;

in response to switching to the second mode, suspending the CSMA/CA session at the first node by suspending one or more operations for assessing availability of a channel for transmitting the data message to the second node in the first mode;

switching back to the first mode; and

in response to switching back to the first mode, resuming the CSMA/CA session at the first node.

11. The one or more computer-readable storage media of claim 10 , further comprising pausing a backoff timer associated with the CSMA/CA session while the CSMA/CA session is suspended.

12. The one or more computer-readable storage media of claim 11 , further comprising resuming the backoff timer when the CSMA/CA session is resumed.

13. The one or more computer-readable storage media of claim 10 , wherein the switching from the first mode to the second mode is based on a channel schedule associated with the second mode.

14. The one or more computer-readable storage media of claim 10 , wherein:

the first mode is a unicast mode and the second mode is a broadcast mode; or

the first mode is a broadcast mode and the second mode is a unicast mode.

15. The one or more computer-readable storage media of claim 14 , wherein, when the first mode is the unicast mode and the second mode is the broadcast mode, the steps further comprise:

switching from the unicast mode to the broadcast mode at a start of a broadcast time slot included in a broadcast channel schedule; and

switching from the broadcast mode to the unicast mode at an end of the broadcast time slot.

16. A system, comprising:

a plurality of nodes included in a wireless mesh network;

a first node included in the plurality of nodes; and

a second node included in the plurality of nodes, the second node configured to perform the steps of:

initiating a carrier sense multiple access with collision avoidance (CSMA/CA) session, wherein the CSMA/CA session is associated with a request to transmit a data message to the first node in a first mode;

switching from the first mode to a second mode;

in response to switching to the second mode, suspending the CSMA/CA session by suspending one or more operations for assessing availability of a channel for transmitting the data message to the second node in the first mode;

switching back to the first mode; and

in response to switching back to the first mode, resuming the CSMA/CA session.

17. The system of claim 16 , wherein the second node is configured to perform the steps of:

determining availability of a first channel associated with a channel schedule of the first node for the first mode;

determining that the first channel is unavailable; and

in response to determining that the first channel is unavailable, initiating a backoff timer.

18. The system of claim 16 , wherein the switching from the first mode to the second mode comprises switching to the second mode in accordance with a start of a time slot included in a channel schedule associated with the second mode.

19. The method of claim 1 , wherein the one or more operations for assessing availability of a channel for transmitting the data message to the second node in the first mode include listening to the channel.

20. The method of claim 1 , wherein the one or more operations for assessing availability of a channel for transmitting the data message to the second node in the first mode include performing a clear channel assessment.