Communicating in a second channel while ceasing transmission in a first channel
In some examples, a wireless device receives, from an access point (AP), information indicating that the wireless device is to cease transmission in a first channel. In response to the information, the wireless device communicates with the AP in a second channel that is a subset of the first channel, during a time interval in which the wireless device is to cease transmission in the first channel.
1. A method of a wireless device, comprising:
receiving, by the wireless device from an access point (AP), a Quiet Element comprising information indicating that the wireless device is to cease transmission in a wideband channel, wherein the Quiet Element is received in a message that includes a flag set to a specified value indicating that narrowband communication is supported;
in response to the information, communicating, by the wireless device with the AP in a narrowband channel that is a subset of the wideband channel, during a time interval in which the wireless device is to cease transmission in the wideband channel;
receiving, by the wireless device from the AP, a further information element;
deciding, by the wireless device based on the information in the further information element, to switch to a narrowband communication mode to communicate in the narrowband channel;
responsive to the flag set to the specified value, sending, by the wireless device to the AP, a query for narrowband communication information; and
receiving, by the wireless device from the AP in response to the query, the narrowband communication information.
2. The method of claim 1 , further comprising:
communicating, by the wireless device with the AP outside the time interval, in the wideband channel.
3. The method of claim 1 , wherein the narrowband channel has a frequency range less than a frequency range of the wideband channel.
4. The method of claim 1 , wherein the Quiet Element is an Extended Quiet Element that includes information of a legacy Quiet Element and information relating to communication using the narrowband channel.
5. The method of claim 4 , wherein the information relating to communication using the narrowband channel in the Extended Quiet Element includes one or more selected from among:
an indication of an operation to be performed during a Quiet Period,
a range of a narrowband network,
a schedule relating to future Quiet Periods,
a time duration within a Quiet Period to be used for narrowband communication,
an indication of a maximum transmit power of the narrowband network,
a set of supported communication rates of the narrowband network,
an indication relating to a power save mode when communicating with the narrowband network, and
a location of the narrowband channel within the wideband channel.
6. The method of claim 1 , further comprising receiving, by the wireless device from the AP, a preamble to silence the wireless device, wherein the preamble is received after receipt of the information indicating that the wireless device is to cease transmission in the wideband channel, and prior to the wireless device performing an operation during the time interval.
7. The method of claim 1 , wherein narrowband beacons are transmitted in the narrowband channel less frequently than wideband beacons in the wideband channel.
8. The method of claim 1 , further comprising:
receiving, by the wireless device with the AP in the narrowband channel during the time interval in which the wireless device is to cease transmission in the wideband channel, a trigger for uplink data; and
in response to the trigger, sending, by the wireless device, the uplink data.
9. An access point (AP) comprising:
a communication interface to communicate wirelessly with a wireless device; and
at least one processor configured to:
send, to the wireless device, information indicating that the wireless device is to cease transmission in a first channel;
determine whether the AP is associated with any wireless device that is capable of communication in a second channel that is a subset of the first channel;
determine whether the AP is associated with any wireless device that is a legacy wireless device capable of communication in the first channel but not in the second channel; and
send, to the wireless device, further information relating to communication in the second channel, to cause the wireless device to communicate in the second channel during a time interval in which the wireless device is to cease transmission in the first channel, and wherein the sending of the further information occurs in an Extended Quiet Element in response to determining that one or more wireless devices associated with the AP are capable of communicating in the second channel and determining that no wireless device associated with the AP is the legacy wireless device, and
wherein the sending of the further information occurs in a narrowband network information element separate from a legacy Quiet Element in response to determining that one or more wireless devices associated with the AP are capable of communicating in the second channel and determining that at least one wireless device associated with the AP is the legacy wireless device.
10. The AP of claim 9 , wherein the at least one processor is configured to send further information to set an indicator of a time period during which wireless transmission by the wireless device is not initiated, to protect communication in the second channel from interference.
11. The AP of claim 10 , wherein the further information is in a legacy preamble or a clear to send (CTS)-to-self message, and wherein the indicator comprises a network allocation vector (NAV).
12. The AP of claim 9 , wherein the at least one processor is configured to cause the AP to communicate in the second channel but not the first channel during the time interval.
13. An access point (AP) comprising:
a communication interface; and
at least one processor coupled to the communication interface and configured to:
cause transmission of a wideband beacon in a wideband channel;
determine whether the AP is associated with a wireless device that is able to perform narrowband communication in a narrowband channel that is a subset of the wideband channel;
in response to determining that the AP is associated with the wireless device that is able to perform narrowband communication:
send, to the wireless device, information indicating that the wireless device is to cease transmission in the wideband channel,
send, to the wireless device, further information relating to communication in the narrowband channel, to cause the wireless device to communicate in the narrowband channel during a time interval in which the wireless device is to cease transmission in the wideband channel; and
send a narrowband beacon in the narrowband channel to the wireless device during the time interval; and
in response to determining that the AP is not associated with any wireless device that is able to perform narrowband communication, decline to send the further information.
14. The AP of claim 13 , wherein the further information is included in:
an Extended Quiet Element that includes information of a legacy Quiet Element and the further information, or
a narrowband network information element that is distinct from the legacy Quiet Element.
15. The AP of claim 13 , wherein the narrowband beacon comprises information for discovery of the narrowband channel.