Frame transmission method and apparatus for wireless local area network
Embodiments of the present invention disclose a frame transmission method and an apparatus for a wireless local area network, which relate to the field of communications technologies. In the present invention, in a WLAN frame transmission process, a frame sent by a wireless local area network WLAN device is received, and identification of frames of different standards is completed by detecting a format indication field included in the frame, so as to implement backward compatibility of the WLAN device, so that hybrid networking of WLAN devices of different standards can be supported, flexibility of network deployment is improved, and networking complexity is reduced.
1. A frame transmission method for a wireless local area network, wherein the method comprises:
receiving a frame sent by a wireless local area network (WLAN) device, wherein the frame comprises a format indication field, the format indication field comprises N symbols, and N is a positive integer greater than or equal to 3; and
determining a standard of the frame according to modulation schemes used by the N symbols comprised in the format indication field;
determining the frame is a frame of a first standard when the first symbol of the N symbols is a symbol of a preset modulation scheme, wherein the preset modulation scheme is quadrature binary phase shift keying (QBPSK);
determining energy of an in-phase component and energy of a quadrature component, wherein the in-phase component and the quadrature component are of a M th symbol of the N symbols, and M is a positive integer less than or equal to N; and
determining the M th symbol is a QBPSK symbol when a difference obtained by subtracting the energy of the in-phase component from the energy of the quadrature component is greater than a preset threshold.
2. The method according to claim 1 , wherein the determining a standard of the frame according to modulation schemes used by the N symbols comprised in the format indication field comprises:
determining the frame is a frame of a (K+1) th standard when none of first K symbols of the N symbols is a symbol of a preset modulation scheme and the (K+1) th symbol is a symbol of the preset modulation scheme, wherein K is a positive integer less than N.
3. The method according to claim 2 , wherein when N is equal to 3, the method comprises: determining the first standard is 802.11n; when K is equal to 1, determing the (K+1) th standard is 802.11ac; when K is equal to 2, determining the (K+1) th standard is 802.11ax; and determining an (N+1) th standard is 802.11a.
4. The method according to claim 1 , wherein the determining a standard of the frame according to modulation schemes used by the N symbols comprised in the format indication field comprises:
determining the frame is a frame of an (N+1) th standard when none of the N symbols is a symbol of a preset modulation scheme.
5. A frame transmission method for a wireless local area network, wherein the method comprises:
receiving a frame sent by a wireless local area network (WLAN) device, wherein the frame comprises a format indication field, the format indication field comprises N symbols, and N is a positive integer greater than or equal to 2;
determining a standard of the frame according to a preset check rule and modulation schemes used by the N symbols comprised in the format indication field;
determining the frame is a frame of a first standard when the first symbol of the N symbols is a symbol of a preset modulation scheme, wherein the preset modulation scheme is quadrature binary phase shift keying (QBPSK);
determining energy of an in-phase component and energy of a quadrature component, wherein the in-phase component and the quadrature component are of a M th symbol of the N symbols, and M is a positive integer less than or equal to N; and
determining the M th symbol is a QBPSK symbol when a difference obtained by subtracting the energy of the in-phase component from the energy of the quadrature component is greater than a preset threshold.
6. A frame transmission method for a wireless local area network, wherein the method comprises:
modulating, according to a preset rule, N symbols comprised in a format indication field of a frame, wherein N is a positive integer greater than or equal to 3, and the format indication field is used to indicate a standard of the frame; and
sending the frame to a wireless local area network (WLAN) device;
determining, by the device, the frame as a frame of a first standard if the first symbol of the N symbols is a symbol of a preset modulation scheme wherein the preset modulation scheme is quadrature binary phase shift keying QBPSK;
determining, by the device, energy of an in-phase component and energy of a quadrature component, wherein the in-phase component and the quadrature component are of a M th symbol of the N symbols, and M is a positive integer less than or equal to N; and
determining, by the device, the M th symbol as a QBPSK symbol if a difference obtained by subtracting the energy of the in-phase component from the energy of the quadrature component is greater than a preset threshold TH.
7. The method according to claim 6 , wherein when N is equal to 3, the preset rule comprises:
first two symbols of the format indication field do not use a preset modulation scheme, and the third symbol of the format indication field uses the preset modulation scheme.
8. An apparatus for a wireless local area network, wherein the apparatus comprises a processor and a non-transitory computer-readable storage medium including computer-executable instructions executed by the processor to perform operations comprising:
receiving by a receiver, a frame sent by a wireless local area network (WLAN) device, wherein the frame comprises a format indication field, the format indication field comprises N symbols, and N is a positive integer greater than or equal to 3; and
determining a standard of the frame according to modulation schemes used by the N symbols comprised in the format indication field received by the receiver;
determining the frame as a frame of a first standard if the first symbol of the N symbols is a symbol of a preset modulation scheme, wherein the preset modulation scheme is quadrature binary phase shift keying QBPSK;
determining energy of an in-phase component and energy of a quadrature component, wherein the in-phase component and the quadrature component are of a M th symbol of the N symbols, and M is a positive integer less than or equal to N; and
determining the M th symbol as a QBPSK symbol if a difference obtained by subtracting the energy of the in-phase component from the energy of the quadrature component is greater than a preset threshold TH.
9. The apparatus according to claim 8 , wherein the operations further comprise:
determining the frame is a frame of a (K+1) th standard if none of first K symbols of the N symbols is a symbol of a preset modulation scheme and the (K+1) th symbol is a symbol of the preset modulation scheme, wherein K is a positive integer less than N.
10. The apparatus according to claim 9 , wherein when N is equal to 3, the operations further comprise:
determining the first standard as 802.11n; when K is equal to 1, determining the (K+1) th standard is 802.11ac; when K is equal to 2, determining the (K+1) th standard is 802.11ax; and determining an (N+1) th standard is 802.11a.
11. The apparatus according to claim 8 , wherein the operations further comprise:
determining the frame is a frame of an (N+1) th standard if none of the N symbols is a symbol of a preset modulation scheme.
12. An apparatus for a wireless local area network, wherein the apparatus comprises a processor and a non-transitory computer-readable storage medium including computer-executable instructions executed by the processor to perform operations comprising:
receiving a frame sent by a wireless local area network (WLAN) device, wherein the frame comprises a format indication field, the format indication field comprises N symbols, and N is a positive integer greater than or equal to 2; and
determining a standard of the frame according to a preset check rule and modulation schemes used by the N symbols comprised in the format indication field received by the receiver;
wherein the frame is received by a receiver having a processor and a non-transitory computer-readable storage medium including computer-executable instructions executed by the processor to perform operations comprising:
determining the frame as a frame of a first standard if the first symbol of the N symbols is a symbol of a preset modulation scheme, wherein the preset modulation scheme is quadrature binary phase shift keying QBPSK;
determining energy of an in-phase component and energy of a quadrature component, wherein the in-phase component and the quadrature component are of a M th symbol of the N symbols, and M is a positive integer less than or equal to N; and
determining the M th symbol as a QBPSK symbol if a difference obtained by subtracting the energy of the in-phase component from the energy of the quadrature component is greater than a preset threshold TH.
13. An apparatus for a wireless local area network, wherein the apparatus comprises a processor and a non-transitory computer-readable storage medium including computer-executable instructions executed by the processor to perform operations comprising:
modulating, according to a preset rule, N symbols comprised in a format indication field of a frame, wherein N is a positive integer greater than or equal to 3, and the format indication field is used to indicate a standard of the frame; and
sending, to a wireless local area network (WLAN) device, the frame determined by the processor;
wherein the frame is received by a receiver having a processor and a non-transitory computer-readable storage medium including computer-executable instructions executed by the processor to perform operations comprising:
determining the frame as a frame of a first standard if the first symbol of the N symbols is a symbol of a preset modulation scheme, wherein the preset modulation scheme is quadrature binary phase shift keying QBPSK;
determining energy of an in-phase component and energy of a quadrature component, wherein the in-phase component and the quadrature component are of a M th symbol of the N symbols, and M is a positive integer less than or equal to N; and
determining the M th symbol as a QBPSK symbol if a difference obtained by subtracting the energy of the in-phase component from the energy of the quadrature component is greater than a preset threshold TH.