Method and device for transmitting and receiving PPDU on basis of FDD in wireless LAN system
A method and a device for transmitting and receiving a PPDU on the basis of an FDD in a wireless LAN system are presented. Particularly, an AP transmits a trigger frame to a first STA and a second STA. The AP transmits a first downlink (DL) PPDU to the first STA on the basis of the trigger frame. The AP transmits a second DL PPDU to the second STA on the basis of the trigger frame. The AP receives a first uplink (UL) PPDU from the second STA on the basis of the trigger frame. The trigger frame includes bandwidth information of a primary channel and a secondary channel. The first DL PPDU is transmitted through the primary channel. The second DL PPDU and the first UL PPDU are transmitted through the secondary channel. The first and second DL PPDU are simultaneously transmitted. The first UL PPDU is received after a preset period after the second DL PPDU is transmitted.
1. A method in a wireless local area network (WLAN) system, the method comprising:
receiving, by a non-access point multi-link device (non-AP MLD), a first data from an AP MLD; and
transmitting, by the non-AP MLD, a second data to the AP MLD,
wherein the non-AP MLD includes a first non-AP station (STA) and a second non-AP STA,
wherein the AP MLD includes a first AP and a second AP,
wherein the AP MLD sets up first and second links with the non-AP MLD, and
wherein the second AP receives the second data from the second non-AP STA through the second link, while the first AP transmits the first data to the first non-AP STA through the first link.
2. The method of claim 1 ,
wherein a third data is transmitted from the second AP to the second non-AP STA,
wherein the first data comprises a first preamble and a first data field,
wherein the third data comprises only a second preamble or comprises the second preamble and a quality of service (QoS) null frame, and
wherein the second preamble is a preamble obtained by duplicating the first preamble.
3. The method of claim 2 ,
wherein the second preamble comprises a legacy-short training field (L-STF), a legacy-long training field (L-LTF), a legacy-signal (L-SIG), and an FDD-signal (FDD-SIG), and
wherein the FDD-SIG comprises bandwidth information of the first link and the second link.
4. The method of claim 1 ,
wherein the pre-set duration is set to a first duration or a second duration,
wherein the first duration is a short inter-frame space (SIFS), and
wherein the second duration is a duration having a value greater than the SIFS and less than a point coordination function inter-frame space (PIFS).
5. The method of claim 1 ,
wherein the second data comprises only a second data field, or comprises only an ACK frame for the first data, or comprises a frame obtained by aggregating the second data field and the ACK frame, and
wherein the ACK frame comprises a block Ack (BA) frame.
6. The method of claim 5 ,
wherein the second data does not include an ACK frame for the third data, and
wherein the ACK frame for the third data is not required.
7. The method of claim 3 ,
wherein a transmission end time of the second data is equal or prior to a transmission end time of the first data, and
wherein the L-SIG comprises information on the transmission end time of the first data.
8. The method of claim 1 , further comprising:
wherein a trigger frame is transmitted from the AP MLD to the non-AP MLD,
wherein the trigger frame comprises bandwidth information of the first link and the second link, information on a center frame, a channel number of the first link and the second link, indication information of DL and UL PPDUs, duration information of the DL and UL PPDUs, and transmission opportunity (TXOP) information of the DL and UL PPDUs, and
wherein the trigger frame further comprises a first trigger frame transmitted in the first link and a second trigger frame transmitted in the second link.
9. The method of claim 8 , wherein the second trigger frame is obtained by duplicating the first trigger frame.
10. The method of claim 8 , wherein if the second trigger frame is aggregated with a physical layer service data unit (PSDU) comprised in the third data, the second data is received when an SIFS elapses after the trigger frame is transmitted.
11. A non-access point multi-link device (non-AP MLD) in a wireless local area network (WLAN) system, the non-AP MLD comprising:
a memory;
a transceiver; and
a processor operatively coupled to the memory and the transceiver, wherein the processor is configured to:
receive a first data from an AP MLD; and
transmit a second data to the AP MLD,
wherein the non-AP MLD includes a first non-AP station (STA) and a second non-AP STA,
wherein the AP MLD includes a first AP and a second AP,
wherein the AP MLD sets up first and second links with the non-AP MLD, and
wherein the second AP receives the second data from the second non-AP STA through the second link, while the first AP transmits the first data to the first non-AP STA through the first link.
12. The method of claim 11 ,
wherein a third data is transmitted from the second AP to the second non-AP STA,
wherein the first data comprises a first preamble and a first data field,
wherein the third data comprises only a second preamble or comprises the second preamble and a quality of service (QoS) null frame, and
wherein the second preamble is a preamble obtained by duplicating the first preamble.
13. The method of claim 12 ,
wherein the second preamble comprises a legacy-short training field (L-STF), a legacy-long training field (L-LTF), a legacy-signal (L-SIG), and an FDD-signal (FDD-SIG), and
wherein the FDD-SIG comprises bandwidth information of the first link and the second link.
14. The method of claim 11 ,
wherein the pre-set duration is set to a first duration or a second duration,
wherein the first duration is a short inter-frame space (SIFS), and
wherein the second duration is a duration having a value greater than the SIFS and less than a point coordination function inter-frame space (PIFS).
15. The method of claim 11 ,
wherein the second data comprises only a second data field, or comprises only an ACK frame for the first data, or comprises a frame obtained by aggregating the second data field and the ACK frame, and
wherein the ACK frame comprises a block Ack (BA) frame.
16. The method of claim 15 ,
wherein the second data does not include an ACK frame for the third data, and
wherein the ACK frame for the third data is not required.
17. The method of claim 13 ,
wherein a transmission end time of the second data is equal or prior to a transmission end time of the first data, and
wherein the L-SIG comprises information on the transmission end time of the first data.
18. The method of claim 11 , further comprising:
wherein a trigger frame is transmitted from the AP MLD to the non-AP MLD,
wherein the trigger frame comprises bandwidth information of the first link and the second link, information on a center frame, a channel number of the first link and the second link, indication information of DL and UL PPDUs, duration information of the DL and UL PPDUs, and transmission opportunity (TXOP) information of the DL and UL PPDUs, and
wherein the trigger frame further comprises a first trigger frame transmitted in the first link and a second trigger frame transmitted in the second link.
19. The method of claim 18 , wherein the second trigger frame is obtained by duplicating the first trigger frame.
20. A method in a wireless local area network (WLAN) system, the method comprising:
transmitting, by an access point multi-link device (AP MLD), a first data to a non-AP MLD; and
receiving, by the AP MLD, a second data from the non-AP MLD,
wherein the non-AP MLD includes a first non-AP station (STA) and a second non-AP STA,
wherein the AP MLD includes a first AP and a second AP,
wherein the AP MLD sets up first and second links with the non-AP MLD, and
wherein the second AP receives the second data from the second non-AP STA through the second link, while the first AP transmits the first data to the first non-AP STA through the first link.