Systems and methods for acknowledging broadcast messages in a wireless lighting control network
Embodiments of the present disclosure decrease conflicts between individual lighting devices in a wireless network when responding to a broadcast/multicast message sent to a group of devices. In some embodiments the devices delay sending their acknowledgment to commands until after a specific time period. Some embodiments limit the number of time delays to one of a predetermined number of time delays, where the number of time delays are assigned by an external source, such as the gateway. Still other embodiments include assigning each device one of a limited number of preset time delays, where the total number of preset time delays are less than the number of devices, for example, ten (10) percent of the number of devices (here some devices will have the same time delays as other devices). Still other embodiments use bitmaps to designating which one or more individual devices the message is intended for.
1. A lighting control system, comprising:
a plurality of devices forming a wireless mesh network, each of the plurality of devices controlling at least one lighting fixture, and each of the plurality of devices configured as a repeater or an end-device; and
a gateway configured to operate as a coordinator of the wireless mesh network, the gateway further configured to send a message to the plurality of devices, and
wherein each plurality of devices:
receives the message,
delays for a period of time equal to one of a predetermined set of delay times after receiving the message, and
sends a response message to the gateway after delaying for the period of time.
2. The lighting control system of claim 1 , wherein the gateway communicates the predetermined set of time delays to the devices in the network.
3. The lighting control system of claim 2 , wherein the gateway communicates the predetermined set of time delays to the devices in the network during the commissioning process.
4. The lighting control system of claim 2 , wherein the gateway communicates the predetermined set of time delays to the devices in the network after the commissioning process.
5. The lighting control system of claim 4 , wherein the gateway communicates the predetermined set of time delays to the devices with a directed message to one or more specific devices.
6. The lighting control system of claim 4 , wherein the gateway communicates the predetermined set of time delays to the devices with a broadcast message to all devices in the network.
7. The lighting control system of claim 1 , wherein the number of delay times comprising the predetermined set of delay times is less than the number of devices comprising the plurality of devices.
8. The lighting control system of claim 7 , wherein the number of delay times comprising the predetermined set of delay times is ten (10) percent of the number of devices forming the wireless mesh network.
9. The lighting control system of claim 7 , wherein the delay time is preset for each of the plurality of devices.
10. The lighting control system of claim 7 , wherein the delay times for each of the plurality of devices are randomly selected from the predetermined set of delay times.
11. The lighting control system of claim 1 , wherein the message includes a bitmap designating which of the plurality of devices are to respond and which of the plurality of devices are to not respond to the message.
12. A method, comprising:
transmitting a message from a network coordinator to a plurality of devices in a wireless network with information related to a predetermined number of time delays for devices responding to messages from the network coordinator;
receiving the message from a mesh network coordinator with one or more of the plurality of devices;
determining the individual time delay from the predetermined number of time delays for each of the one or more of the plurality of devices;
transmitting a lighting command from the mesh network coordinator;
receiving the lighting command from the mesh network coordinator with the one or more of the plurality of devices; and
transmitting a response message from each of the one or more of the plurality of devices after waiting a time period equal to the individual time delay for each of the plurality of devices.
13. The method of claim 12 , wherein said transmitting a message includes transmitting a predetermined number of time delays equal to less than the total number of devices in the wireless network.
14. The method of claim 13 , wherein said transmitting a message includes transmitting a predetermined number of time delays equal to ten (10) percent of the total number of devices in the wireless network.
15. The method of claim 12 , wherein said receiving the message from a mesh network coordinator occurs during the commissioning of each of the one or more devices in the wireless network.
16. The method of claim 12 , wherein said receiving the message from a mesh network coordinator occurs after the commissioning of each of the one or more devices in the wireless network.
17. The method of claim 12 , wherein said transmitting a message includes transmitting a message with a bitmap identifying less than the total number of devices in the wireless network, and wherein said receiving the message includes determining by each of the one or more devices whether the bitmap identifies the device receiving the message.
18. The method of claim 12 , wherein the message is a broadcast message to all devices in the network.
19. The method of claim 12 , wherein the message is a directed message to one or more specific devices.