Technique for configuring preamble in wireless local area network system
An example according to the present specification relates to a technique relating to a configuration of a preamble in a wireless LAN (WLAN) system. A reception STA can receive a PPDU. The reception STA can perform a modulo operation with respect to whether or not an L-SIG field is repeated and a value of a length field. The reception STA can determine the received PPDU as an EHT PPDU on the basis of the modulo operation with respect to whether or not the L-SIG field is repeated and the value of the length field.
1. A method performed by a receiving station (STA) in a wireless local area network system, the method comprising:
receiving a physical protocol data unit (PPDU) comprising a legacy-signal (L-SIG) field; and
determining whether the PPDU is an extreme high throughput (EHT) PPDU based on whether the L-SIG field is repeated and a “modulo 3 operation” with respect to a value of a length field of the L-SIG field,
wherein the PPDU is determined as the EHT PPDU based on that a result of the “modulo 3 operation” is “0”,
wherein the EHT PPDU further comprises a repeated L-SIG (RL-SIG) field in which the L-SIG field is repeated,
wherein the PPDU further comprises a control signal field which is contiguous to the RL-SIG field,
wherein the control signal field comprises a bandwidth field related to the PPDU, a physical version field having a length of 3 bits, a Basic Service Set (BSS) color field having a length of 6 bits and related to an identifier of a BSS, a cyclic redundancy check (CRC) field having a length of 4 bits, and a tail field having a length of 6 bits,
wherein a value of the physical version field is used to identify a physical version starting with EHT.
2. A method performed by a station (STA) in a wireless local area network system, the method comprising:
receiving a physical protocol data unit (PPDU) comprising a legacy-signal (L-SIG) field;
determining whether the PPDU comprises a repeated L-SIG (RL-SIG) field which is a repeat of the L-SIG field, wherein the RL-SIG is contiguous to the L-SIG field; and
after determining that the PPDU comprises the RL-SIG field, determining whether a length field included in the L-SIG field is set to a value satisfying a condition that a remainder is zero when a value of the length field is divided by three (3), wherein the remainder is used to differentiate an extreme high throughput (EHT) PPDU from a high efficiency (HE) PPDU, and
wherein the PPDU is determined as the EHT PPDU based on the remainder having a value of zero (0),
wherein the PPDU further comprises a control signal field which is contiguous to the RL-SIG field,
wherein the control signal field comprises a bandwidth field related to the PPDU, a physical version field having a length of 3 bits, a Basic Service Set (BSS) color field having a length of 6 bits and related to an identifier of a BSS, a cyclic redundancy check (CRC) field having a length of 4 bits, and a tail field having a length of 6 bits,
wherein a value of the physical version field is used to identify a physical version starting with EHT.
3. The method of claim 2 , wherein the PPDU is determined as the HE PPDU based on the remainder having a non-zero value.
4. A method performed by a receiving station (STA) in a wireless local area network system, the method comprising:
receiving a physical protocol data unit (PPDU) comprising a legacy signal (L-SIG) field, a repeated L-SIG (RL-SIG) field in which the L-SIG field is repeated, and a control field,
wherein the RL-SIG field is contiguous to the L-SIG field, and the control field is contiguous to the RL-SIG field,
wherein the control field comprises information related to a Basic Service Set (BSS) color related to the PPDU and three-bit information;
determining a type of the PPDU based on whether the L-SIG field is repeated, a “modulo 3 operation” with respect to a value of a length field included in the L-SIG field, and the three-bit information,
wherein the PPDU is determined as an extremely high throughput (EHT) type based on the L-SIG field being repeated, a result of the “modulo 3 operation” being set to zero, and the three-bit information,
wherein the three-bit information identifies a physical version starting with EHT,
wherein the three-bit information is related to a physical version field,
wherein the information related to the BSS color has a length of six bits,
wherein the control signal field further comprises a bandwidth field related to the PPDU, a cyclic redundancy check (CRC) field having a length of four bits, and a tail field having a length of six bits; and
decoding the PPDU.
5. A method performed by a receiving station (STA) in a wireless local area network (WLAN) system, the method comprising:
receiving a physical protocol data unit (PPDU) comprising a legacy-signal (L-SIG) field, a repeated L-SIG (RL-SIG) field, and at least one indication symbol, wherein the RL-SIG field is contiguous to the L-SIG field, and the at least one indication symbol is contiguous to the RL-SIG field;
determining a type of the PPDU based on the L-SIG field, a “modulo 3 operation” with respect to a value of a length field of the L-SIG field, and packet indication information having a length of 3 bits, wherein the packet indication information is included in the at least one indication symbol,
wherein the type of the PPDU is determined as an extremely high throughput (EHT) type based on the L-SIG field being repeated in the RL-SIG field, a result of the “modulo 3 operation” being “0”, and the packet indication information,
wherein the at least one indication symbol includes a bandwidth field related to the PPDU, a Basic Service Set (BSS) color field having a length of 6 bits and related to an identifier of a BSS, a cyclic redundancy check (CRC) field having a length of 4 bits, and a tail field having a length of 6 bits,
wherein a value of the packet indication information is used to identify a physical version starting with EHT; and
decoding the PPDU.