Method and apparatus for dynamic frequency selection in wireless local area network system
A method of dynamic frequency selection by an access point (AP) in a basic service set (BSS) in a wireless local area network is provided. The access point configured to communicate over a primary subchannel and a secondary subchannel. The method includes: transmitting a frame including a quiet element and a quiet channel element; and performing channel measurements in the quiet interval. The quiet element defines an quiet interval during which no transmission occurs, the quiet channel element indicates that the secondary subchannel is to be quieted during the quiet interval, and the quiet channel element indicates a condition under which the primary subchannel may be used during the quiet interval.
1. A method of dynamic frequency selection by an access point (AP) in a wireless local area network, the AP configured to communicate over a primary subchannel and a secondary subchannel with a plurality of stations of a basic service set (BSS), the method comprising:
transmitting a frame including a quiet channel element to at least one station of the plurality of stations,
wherein the quiet channel element indicates that the secondary subchannel is to be quieted during a quiet interval in which the AP tests the secondary subchannel for a presence of radar transmissions and the mobile station does not send any frame to the AP, and
wherein the quiet channel element includes an AP quiet mode field having a single bit and indicating whether a communication to the AP is allowed within the primary subchannel during the quiet interval; and
quieting the secondary subchannel during the quiet interval and communicating with the at least one station of the plurality of stations via the primary subchannel during the quiet interval, if the AP quiet mode field indicates the communication to the AP is allowed with the primary subchannel during the quiet interval,
wherein the primary subchannel and the secondary subchannel each have a bandwidth of 80 MHz,
wherein the primary 80 MHz subchannel is used to transmit an 80 MHz physical layer protocol data unit (PPDU) in the BSS having a bandwidth of 160 MHz and includes a primary 20 MHz subchannel that is a common channel of operation for all of the plurality of stations,
wherein the secondary 80 MHz subchannel is used to form a 160 MHz channel together with the primary 80 MHz subchannel and does not include the primary 20 MHz subchannel, and
wherein the quiet channel element further includes information about the quiet interval for the secondary 80 MHz subchannel only if the AP quiet mode field indicates that the communication to the AP is allowed within the primary 80 MHz subchannel during the quiet interval.
2. The method of claim 1 ,
wherein the value of the AP quiet mode field is set to 1 to indicate the communication to the AP is allowed within the primary 80 MHz subchannel, and
wherein the value of the AP quiet mode field is set to 0 to indicate the communication to the AP is not allowed within the primary 80 MHz subchannel.
3. The method of claim 2 , wherein the quiet channel element includes a quiet count field, a quiet period field, a quiet duration field, and a quiet offset field if the AP quiet mode field indicates the communication to the AP is allowed within the secondary 80 MHz subchannel.
4. The method of claim 3 , wherein the quiet count field, the quiet period field, the quiet duration field, and the quiet offset field in the quiet channel element establish the quiet interval.
5. The method of claim 1 , wherein the primary 80 MHz subchannel and the secondary 80 MHz subchannel are non-contiguous.
6. An access point (AP) in a wireless local area network, the AP configured to perform dynamic frequency selection in one of a primary subchannel and a secondary subchannel with a plurality of stations of a basic service set (BSS), the AP comprising:
a transceiver; and
a controller operatively connected to the transceiver and configured to:
instruct the transceiver to transmit a frame including a quiet channel element to at least one station of the plurality of stations,
wherein the quiet channel element indicates that the secondary subchannel is to be quieted during a quiet interval in which the AP tests the secondary subchannel for a presence of radar transmissions and the mobile station does not send any frame to the AP, and
wherein the quiet channel element includes an AP quiet mode field having a single bit and indicating whether a communication to the AP is allowed within the primary subchannel during the quiet interval; and
instruct the transceiver to quiet the secondary subchannel during the quiet interval and communicate with the at least one station of the plurality of stations via the primary subchannel during the quiet interval, if the AP quiet mode field indicates the communication to the AP is allowed within the primary subchannel during the quiet interval,
wherein the primary subchannel and the secondary subchannel each have a bandwidth of 80 MHz,
wherein the primary subchannel is used to transmit an 80 MHz physical layer protocol data unit (PPDU) in the BSS having a bandwidth of 160 MHz and includes a primary 20 MHz subchannel that is a common channel of operation for all of the plurality of stations,
wherein the secondary 80 MHz subchannel is used to form a 160 MHz channel together with the primary 80 MHz subchannel and does not include the primary 20 MHz subchannel, and
wherein the quiet channel element further includes information about the quiet interval for the secondary 80 MHz subchannel only if the AP quiet mode field indicates that the communication to the AP is allowed within the primary 80 MHz subchannel during the quiet interval.
7. The AP of claim 6 ,
wherein the value of the AP quiet mode field is set to 1 to indicate the communication to the AP is allowed within the primary 80 MHz subchannel, and
wherein the value of the AP quiet mode field is set to 0 to indicate the communication to the AP is not allowed within the primary 80 MHz subchannel.
8. The AP of claim 7 , wherein the quiet channel element includes a quiet count field, a quiet period field, a quiet duration field, and a quiet offset field if the AP quiet mode field indicates the communication to the AP is allowed within the secondary 80 MHz subchannel.
9. The AP of claim 8 , wherein the quiet count field, the quiet period field, the quiet duration field, and the quiet offset field in the quiet channel element establish the quiet interval.
10. The AP of claim 6 , wherein the primary 80 MHz subchannel and the secondary 80 MHz subchannel are non-contiguous.
11. The method of claim 1 , wherein the quiet channel element does not include any information about the quiet interval for the secondary 80 MHz subchannel if the AP quiet mode field indicates that the communication to the AP is not allowed within the primary 80 MHz subchannel during the quiet interval.
12. The AP of claim 6 , wherein the quiet channel element does not include any information about the quiet interval for the secondary 80 MHz subchannel if the AP quiet mode field indicates that the communication to the AP is not allowed within the primary 80 MHz subchannel during the quiet interval.