Sector level sweep method and apparatus

1. A sector level sweep method, comprising:

generating, by a local end, a first sector sweep packet at a local end sector sweep stage; and

sending, by the local end, the first sector sweep packet to a peer end by using a first beam, wherein

a quantity of bytes of the first sector sweep packet is 27; and

the first sector sweep packet comprises beam indication information of the first beam, the beam indication information comprises antenna identification information of the beam.

2. The method according to claim 1 , wherein the beam indication information further comprises beam identification information of the beam; and

a maximum quantity of beams indicated by the beam identification information of the beam is at least 2048.

3. The method according to claim 1 , wherein the beam indication information further comprises countdown identification information corresponding to the beam at the local end sector sweep stage; and

a maximum quantity of beams indicated by the countdown identification information of the beam is at least 16384.

4. The method according to claim 1 , wherein before the generating, by a local end, a first sector sweep packet, the method further comprises:

receiving, by the local end, a second sector sweep packet by using a second beam at a previous peer end sector sweep stage adjacent to the local end sector sweep stage, wherein the second sector sweep packet comprises beam indication information of the second beam, and a quantity of bytes of the second sector sweep packet is not greater than 27; and

the generating, by a local end, a first sector sweep packet comprises:

selecting, by the local end, to-be-fed-back beam indication information of each of at least one first to-be-fed-back beam from the second sector sweep packet received at the previous peer end sector sweep stage adjacent to the local end sector sweep stage; and

generating, by the local end, the first sector sweep packet based on the to-be-fed-back beam indication information of each of the at least one first to-be-fed-back beam and the beam indication information of the first beam, wherein

the to-be-fed-back beam indication information comprises beam identification information of the to-be-fed-back beam, and a maximum quantity of beams indicated by the beam identification information of the to-be-fed-back beam is at least 2048.

5. The method according to claim 4 , wherein the to-be-fed-back beam indication information further comprises antenna identification information of the to-be-fed-back beam; and

a maximum quantity of antennas indicated by the antenna identification information of the to-be-fed-back beam is at least 8.

6. The method according to claim 5 , wherein the local end selects at least two first to-be-fed-back beams from the sector sweep packet received at the previous peer end sector sweep stage adjacent to the local end sector sweep stage.

7. The method according to claim 1 , after the sending, by the local end, the first sector sweep packet to a peer end by using a first beam, further comprising:

sending, by the local end, a sector sweep feedback frame to the peer end, and receiving, by the local end, a sector sweep acknowledgement frame sent by the peer end; or

receiving, by the local end, a sector sweep feedback frame sent by the peer end, and sending, by the local end, the sector sweep acknowledgement frame to the peer end, wherein

for each of the sector sweep feedback frame and the sector sweep acknowledgement frame, a quantity of occupied bytes is not greater than 48, and a quantity of occupied Low-Density Parity-check Code (LDPC) code blocks is not greater than 3.

8. The method according to claim 7 , wherein each of the sector sweep feedback frame and the sector sweep acknowledgement frame comprises at least two sector sweep feedback fields; and

each of the at least two sector sweep feedback fields comprises:

to-be-fed-back beam indication information of at least two third to-be-fed-back beams corresponding to a same antenna.

9. The method according to claim 4 , after the sending, by the local end, the first sector sweep packet to a peer end by using the first beam, further comprising:

receiving, by the local end, a third sector sweep packet by using a third beam at a subsequent peer end sector sweep stage adjacent to the local end sector sweep stage, wherein

the third sector sweep packet comprises to-be-fed-back beam indication information that is of a second to-be-fed-back beam and that is selected by the peer end from the sector sweep packet received at the local end sector sweep stage.

10. The method according to claim 9 , wherein the first sector sweep packet further comprises:

indication information used to indicate whether a local end sector sweep stage next to the local end sector sweep stage exists.

11. The method according to claim 1 , wherein when the sector sweep packet is a short SSW packet, information about a physical layer service data unit length field in the short Sector Sweep (SSW) packet is 6 bytes; and

the local end adds beam indication information at the local end sector sweep stage to the sector sweep packet at the local end sector sweep stage, comprising:

adding, by the local end, the beam indication information at the local end sector sweep stage to a beam indication information field that is at the local end sector sweep stage and that is in the sector sweep packet at the local end sector sweep stage, wherein

the beam indication information field at the local end sector sweep stage comprises the beam indication information field at the local end sector sweep stage, a beam indication information field obtained after extension at the local end sector sweep stage, and a second indication information field; and

the second indication information field is used to define any one or more of a frame check sequence field, a packet type field, and a reserved bit field in the short SSW packet as the beam information indication field obtained after the extension at the local end sector sweep stage.

12. A sector level sweep apparatus, comprising:

a processor, configured to generate a first sector sweep packet at the local end sector sweep stage; and

a transceiver, configured to send the first sector sweep packet to a peer end by using a first beam, wherein

a quantity of bytes of the first sector sweep packet is 27; and

the first sector sweep packet comprises beam indication information of the first beam, the beam indication information comprises antenna identification information of the beam.

13. The apparatus according to claim 12 , wherein the beam indication information further comprises beam identification information of the beam; and

a maximum quantity of beams indicated by the beam identification information of the beam is at least 2048.

14. The apparatus according to claim 12 , wherein the beam indication information further comprises countdown identification information corresponding to the beam at the local end sector sweep stage; and

a maximum quantity of beams indicated by the countdown identification information of the beam is at least 16384.

15. The apparatus according to claim 12 , wherein the transceiver is further configured to:

receive a second sector sweep packet by using a second beam at a previous peer end sector sweep stage adjacent to the local end sector sweep stage, wherein the second sector sweep packet comprises beam indication information of the second beam, and a quantity of bytes of the second sector sweep packet is not greater than 27; and

the processor is configured to:

select to-be-fed-back beam indication information of each of at least one first to-be-fed- back beam from the sector sweep packet received at the previous peer end sector sweep stage adjacent to the local end sector sweep stage; and

generate the first sector sweep packet based on the to-be-fed-back beam indication information of each of the at least one first to-be-fed-back beam and the beam indication information of the first beam, wherein

the to-be-fed-back beam indication information comprises beam identification information of the to-be-fed-back beam, and a maximum quantity of beams indicated by the beam identification information of the to-be-fed-back beam is at least 2048.

16. The apparatus according to claim 15 , wherein the to-be-fed-back beam indication information further comprises antenna identification information of the to-be-fed-back beam; and

a maximum quantity of antennas indicated by the antenna identification information of the to-be-fed-back beam is at least 8.

17. The apparatus according to claim 15 , wherein the first sector sweep packet comprises 27 bytes; and

at least two first to-be-fed-back beams are selected from the sector sweep packet received at the previous peer end sector sweep stage adjacent to the local end sector sweep stage.

18. The apparatus according to claim 12 , wherein the transceiver is further configured to:

send a sector sweep feedback frame to the peer end, and receive a sector sweep acknowledgement frame sent by the peer end; or

receive a sector sweep feedback frame sent by the peer end, and send the sector sweep acknowledgement frame to the peer end, wherein

for each of the sector sweep feedback frame and the sector sweep acknowledgement frame, a quantity of occupied bytes is not greater than 48, and a quantity of occupied Low-Density Parity-check Code (LDPC) code blocks is not greater than 3.

19. The apparatus according to claim 18 , wherein each of the sector sweep feedback frame and the sector sweep acknowledgement frame comprises at least two sector sweep feedback fields; and

each of the at least two sector sweep feedback fields comprises:

to-be-fed-back beam indication information of at least two third to-be-fed-back beams corresponding to a same antenna.

20. The apparatus according to claim 15 , wherein the transceiver is further configured to:

receive a third sector sweep packet by using a third beam at a subsequent peer end sector sweep stage adjacent to the local end sector sweep stage, wherein

the third sector sweep packet comprises to-be-fed-back beam indication information that is of a second to-be-fed-back beam and that is selected by the peer end from the sector sweep packet received at the local end sector sweep stage.