Wake-up packet based coordination of broadcasting device responses

1 . A method of controlling broadcasting devices, the method comprising:

sending, from a wireless-local area network access point, a wake-up packet which is receivable by broadcasting devices in vicinity of the wireless-local area network access point and which has the purpose of activating a subset of the broadcasting devices, wherein the subset includes multiple broadcasting devices; and

in response to the wake-up packet, receiving, by the wireless-local area network access point, responses from the broadcasting devices in the subset, each response comprising an identifier of the broadcasting device sending the response;

wherein the wake-up packet coordinates the sending of the responses by the broadcasting devices with respect to each other; and

wherein the wake-up packet comprises a data mask configured to select the multiple broadcasting devices in the subset that are to send a response to the wake-up packet, wherein the data mask is to be combined, by an XOR operation, with an identifier of a broadcasting device for enabling the broadcasting device to determine whether the broadcasting device is allowed to send a response, wherein the data mask is a binary sequence of the same length as used for representing identifiers of the broadcasting devices, wherein the data mask has a value of one in one or more positions of the binary sequence, and wherein the subset of broadcasting devices includes any broadcasting devices whose identifiers have a value of one in those same one or more positions.

2 . The method according to claim 1 , wherein the wake-up packet indicates information for controlling the sending of a response by a respective broadcasting device.

3 . The method according to claim 1 , wherein the wake-up packet indicates a frequency channel to be used for sending of a response by a respective broadcasting device.

4 . The method according to claim 1 , wherein the wake-up packet comprises timing information for controlling a timing of sending of a response by a respective broadcasting device, wherein the timing information comprises a target time after which the broadcasting device is allowed to send the response or comprises a contention window for controlling a random backoff applied by the broadcasting device before sending the response.

5 . The method according to claim 1 , comprising sending, by the wireless-local area network access point, multiple wake-up packets for activating broadcasting devices in vicinity of the wireless-local area network access point, wherein the multiple wake-up packets are sent with different transmit powers to coordinate the sending of the responses by the broadcasting devices.

6 . The method according to claim 5 , comprising:

using a first transmit power, sending, by the wireless-local area network access point, a first wake-up packet for activating broadcasting devices in vicinity of the wireless-local area network access point;

in response to detecting a congestion of a channel used by the broadcasting devices for sending responses to the first wake-up packet, sending, by the wireless-local area network access point, using a second transmit power that is lower than the first transmit power, a second wake-up packet for activating broadcasting devices in vicinity of the wireless-local area network access point; and

in response to the second wake-up packet, receiving, by the wireless-local area network access point, one or more responses from one or more of the broadcasting devices, each response comprising an identifier of the broadcasting device sending the response.

7 . The method according to claim 1 , comprising:

sending, by the wireless-local area network access point, a first wake-up packet for activating broadcasting devices in vicinity of the wireless-local area network access point;

in response to the first wake-up packet, receiving, by the wireless-local area network access point, one or more responses from one or more of the broadcasting devices, each response comprising an identifier of the broadcasting device sending the response;

de-selecting, by the wireless-local area network access point, one or more broadcasting devices corresponding to one or more identifiers received in the one or more responses;

sending, by the wireless-local area network access point, a second wake-up packet for activating broadcasting devices in vicinity of the wireless-local area network access point, the second wake-up packet identifying the one or more de-selected broadcasting devices and indicating that the one or more de-selected broadcasting devices are not allowed to send a response to the second wake-up packet.

8 . The method according to claim 1 , wherein the broadcasting devices do not support performing a listen-before-talk procedure for before sending the response.

9 . A method of controlling a broadcasting device, the method comprising:

receiving, by the broadcasting device, a wake-up packet from a wireless-local area network access point, wherein the wake-up packet is receivable by broadcasting devices in vicinity of the wireless-local area network access point and has the purpose of activating a subset of the broadcasting devices, wherein the subset includes multiple broadcasting devices, wherein the wake-up packet coordinates the sending of the response by the broadcasting device with respect to sending of responses to the wake-up packet by the other broadcasting devices in the vicinity of the wireless-local area network access point, and wherein the wake-up packet comprises a data mask configured to select the multiple broadcasting devices in the subset that are to send a response to the wake-up packet, wherein the data mask is a binary sequence of the same length as used for representing respective identifiers of the broadcasting devices, wherein the data mask has a value of one in one or more positions of the binary sequence, and wherein the subset of broadcasting devices includes any broadcasting devices whose identifiers have a value of one in those same one or more positions;

determining whether the broadcasting device is allowed to send a response to the wake-up packet, by using an XOR operation to combine the data mask with the identifier of the broadcasting device; and

based on determining that the broadcasting device is allowed to send a response to the wake-up packet, in response to the wake-up packet, sending, by the broadcasting device, a response comprising the identifier of the broadcasting device.

10 . The method according to claim 9 , wherein the wake-up packet indicates information for controlling the sending of the response by the broadcasting device.

11 . The method according to claim 9 , wherein the wake-up packet indicates a radio channel to be used for sending of the response by the broadcasting device.

12 . The method according to claim 9 , wherein the wake-up packet comprises timing information for controlling a timing of sending of the response by the broadcasting device, wherein the timing information comprises a target time after which the broadcasting device is allowed to send the response or comprises a contention window for controlling a random backoff applied by the broadcasting device before sending the response.

13 . The method according to claim 9 , comprising receiving, by the broadcasting device, multiple wake-up packets sent with different transmit powers.

14 . The method according to claim 9 , comprising:

receiving, by the broadcasting device, a first wake-up packet from the wireless-local area network access point;

in response to the first wake-up packet, sending, by the broadcasting device, the response comprising the identifier of the broadcasting device; and

receiving, by the broadcasting device, a second wake-up packet from the wireless-local area network access point, the second wake-up packet identifying the broadcasting device as being de-selected and indicating that the broadcasting device is not allowed to send a response to the second wake-up packet.

15 . The method according to claim 9 , wherein the broadcasting device does not support performing a listen-before-talk procedure for before sending the response.

16 . The method according to claim 9 , wherein said determining comprises:

determining a result of the XOR operation by, only for each bit of the data mask that has a value of one, XORing the bit of the data mask with a respective bit of the identifier of the broadcasting device; and

determining whether the broadcasting device is allowed to send the response, based on whether the result of the XOR operation is zero.

17 . A wireless-local area network access point comprising:

at least one processor; and

a memory, the memory containing instructions executable by the at least one processor whereby the wireless-local area network access point is configured to:

send a wake-up packet which is receivable by broadcasting devices in vicinity of the wireless-local area network access point and which has the purpose of activating a subset of the broadcasting devices, wherein the subset includes multiple broadcasting devices; and

in response to the wake-up packet, receive responses from the broadcasting devices in the subset, each response comprising an identifier of the broadcasting device sending the response;

wherein the wake-up packet coordinates the sending of the responses by the broadcasting devices with respect to each other; and

wherein the wake-up packet comprises a data mask configured to select the multiple broadcasting devices in the subset that are to send a response to the wake-up packet, wherein the data mask is to be combined, by an XOR operation, with an identifier of a broadcasting device for enabling the broadcasting device to determine whether the broadcasting device is allowed to send a response, wherein the data mask is a binary sequence of the same length as used for representing identifiers of the broadcasting devices, wherein the data mask has a value of one in one or more positions of the binary sequence, and wherein the subset of broadcasting devices includes any broadcasting devices whose identifiers have a value of one in those same one or more positions.

18 . The wireless-local area network access point according to claim 17 , wherein the wake-up packet indicates information for controlling the sending of a response by a respective broadcasting device.

19 . The wireless-local area network access point according to claim 17 , wherein the wake-up packet indicates a frequency channel to be used for sending of a response by a respective broadcasting device.

20 . The wireless-local area network access point according to claim 17 , wherein the wake-up packet comprises timing information for controlling a timing of sending of a response by a respective broadcasting device, wherein the timing information comprises a target time after which the broadcasting device is allowed to send the response or comprises a contention window for controlling a random backoff applied by the broadcasting device before sending the response.

21 . The wireless-local area network access point according to claim 17 , the memory containing instructions executable by the at least one processor whereby the wireless-local area network access point is configured to send multiple wake-up packets for activating broadcasting devices in vicinity of the wireless-local area network access point, wherein the multiple wake-up packets are sent with different transmit powers to coordinate the sending of the responses by the broadcasting devices.

22 . The wireless-local area network access point according to claim 17 , the memory containing instructions executable by the at least one processor whereby the wireless-local area network access point is configured to:

using a first transmit power, send a first wake-up packet for activating broadcasting devices in vicinity of the wireless-local area network access point;

in response to detecting a congestion of a channel used by the broadcasting devices for sending responses to the first wake-up packet, send, using a second transmit power that is lower than the first transmit power, a second wake-up packet for activating broadcasting devices in vicinity of the wireless-local area network access point; and

in response to the second wake-up packet, receive one or more responses from one or more of the broadcasting devices, each response comprising an identifier of the broadcasting device sending the response.

23 . The wireless-local area network access point according to claim 17 , the memory containing instructions executable by the at least one processor whereby the wireless-local area network access point is configured to:

send a first wake-up packet for activating broadcasting devices in vicinity of the wireless-local area network access point;

in response to the first wake-up packet, receive one or more responses from one or more of the broadcasting devices, each response comprising an identifier of the broadcasting device sending the response;

de-select one or more broadcasting devices corresponding to one or more identifiers received in the one or more responses; and

send a second wake-up packet for activating broadcasting devices in vicinity of the wireless-local area network access point, the second wake-up packet identifying the one or more de-selected broadcasting devices and indicating that the one or more de-selected broadcasting devices are not allowed to send a response to the second wake-up packet.

24 . The wireless-local area network access point according to claim 17 , wherein the broadcasting devices do not support performing a listen-before-talk procedure for before sending the response.

25 . The wireless-local area network access point according to claim 17 , the memory containing instructions executable by the at least one processor whereby the wireless-local area network access point is configured to generate the data mask as a function of a maximum number of broadcasting devices that are allowed to send a response to the wake-up packet.

26 . The wireless-local area network access point according to claim 17 , the memory containing instructions executable by the at least one processor whereby the wireless-local area network access point is configured to generate the data mask to select a random subset of the broadcasting devices as being allowed to send a response to the wake-up packet.

27 . A broadcasting device comprising:

at least one processor; and

a memory, the memory containing instructions executable by the at least one processor whereby the broadcasting device is configured to:

receive a wake-up packet from a wireless-local area network access point, wherein the wake-up packet is receivable by broadcasting devices in vicinity of the wireless-local area network access point and has the purpose of activating a subset of the broadcasting devices, wherein the subset includes multiple broadcasting devices, wherein the wake-up packet coordinates the sending of the response by the broadcasting device with respect to sending of responses to the wake-up packet by the other broadcasting devices in the vicinity of the wireless-local area network access point, and wherein the wake-up packet comprises a data mask configured to select the multiple broadcasting devices in the subset that are to send a response to the wake-up packet, wherein the data mask is a binary sequence of the same length as used for representing respective identifiers of the broadcasting devices, wherein the data mask has a value of one in one or more positions of the binary sequence, and wherein the subset of broadcasting devices includes any broadcasting devices whose identifiers have a value of one in those same one or more positions;

determine whether the broadcasting device is allowed to send a response to the wake-up packet, by using an XOR operation to combine the data mask with the identifier of the broadcasting device; and

based on determining that the broadcasting device is allowed to send a response to the wake-up packet, in response to the wake-up packet, send a response comprising the identifier of the broadcasting device.

28 . The broadcasting device according to claim 27 , wherein the wake-up packet indicates information for controlling the sending of the response by the broadcasting device.

29 . The broadcasting device according to claim 27 , wherein the wake-up packet indicates a radio channel to be used for sending of the response by the broadcasting device.

30 . The broadcasting device according to claim 27 , the memory containing instructions executable by the at least one processor whereby the broadcasting device is configured to:

determine a result of the XOR operation by, only for each bit of the data mask that has a value of one, XORing the bit of the data mask with a respective bit of the identifier of the broadcasting device; and

determine whether the broadcasting device is allowed to send the response, based on whether the result of the XOR operation is zero.