Wireless communication method using OFDMA random access and wireless communication terminal using same
Provided is a wireless communication terminal that wirelessly communicates with a base wireless communication terminal. The wireless communication terminal includes a transceiver, and a processor. The processor is configured to set an integer selected from a range of 0 to a value equal to or smaller than an OFDMA Contention Window (OCW) as a counter for random access, receive a trigger frame for triggering random access using one or more resource units (RUs) allocated for the random access from the base wireless communication terminal using the transceiver, decrement a value of the counter based on the one or more RUs allocated for the random access, randomly select one RU based on the one or more RUs allocated for the random access when the value of the counter is 0 or reaches 0, and attempt transmission to the base wireless communication terminal using the selected RU.
1. A wireless communication terminal that wirelessly communicates with a base wireless communication terminal, the wireless communication terminal comprising:
a transceiver; and
a processor,
wherein the processor is configured to:
set an integer selected from a range of 0 to a value equal to or smaller than an OFDMA Contention Window (OCW) as a counter for random access,
receive a trigger frame for triggering random access using one or more resource units (RUs) allocated for the random access from the base wireless communication terminal using the transceiver,
decrement a value of the counter based on the one or more RUs allocated for the random access and a capability of the wireless communication terminal,
randomly select any one of RUs through which the wireless communication terminal is capable of transmitting a trigger based (TB) PPDU according to the capability of the wireless communication terminal among the one or more RUs allocated for the random access when the value of the counter is 0 or reaches 0, and
attempt transmission to the base wireless communication terminal using the selected RU,
wherein the RU is a group of a plurality of subcarriers usable for uplink transmission and downlink transmission.
2. The wireless communication terminal of claim 1 , wherein the processor is configured to decrement the value of the counter by the number of RUs through which the wireless communication terminal is capable of transmitting a TB PPDU according to the capability of the wireless communication terminal among the one or more RUs allocated for the random access.
3. The wireless communication terminal of claim 1 , wherein the capability of the wireless communication terminal comprises a capability related to a bandwidth through which the wireless communication terminal is capable of performing transmission.
4. The wireless communication terminal of claim 1 , wherein the capability of the wireless communication terminal comprises a capability related to a length of a padding field included in the TB PPDU.
5. The wireless communication terminal of claim 1 , wherein the capability of the wireless communication terminal comprises a capability related to a modulation and coding scheme with which the wireless communication terminal is capable of performing transmission.
6. The wireless communication terminal of claim 1 , wherein when the wireless communication terminal is a wireless communication terminal unassociated with the base wireless communication terminal,
the processor is configured to:
set an OCW minimum value, which is a parameter indicating a minimum value of an OCW, to a value predetermined as a default value of the OCW minimum value, and
set an OCW maximum value, which is a parameter indicating a maximum value of an OCW, to a value predetermined as a default value of the OCW maximum value,
wherein the value predetermined as the default value of the OCW minimum value and the value predetermined as the default value of the OCW maximum value are not values designated by the base wireless communication terminal.
7. The wireless communication terminal of claim 1 , wherein when the wireless communication terminal is a wireless communication terminal unassociated with the base wireless communication terminal and the wireless communication terminal communicates with a different base wireless communication terminal different from the base wireless communication terminal, the processor is configured to initialize a parameter for random access to the different base wireless communication terminal,
wherein the parameter for the random access comprises the counter, an OCW minimum value, which is a parameter indicating a minimum value of the OCW, and an OCW maximum value, which is a parameter indicating a maximum value of the OCW.
8. The wireless communication terminal of claim 7 , wherein when the wireless communication terminal is a wireless communication terminal unassociated with the base wireless communication terminal, the processor is configured to:
set the OCW minimum value and the OCW maximum value according to information received from the base wireless communication terminal when the wireless communication terminal communicates with the base wireless communication terminal, and
set the OCW minimum value and the OCW maximum value according to information received from the different base wireless communication terminal when the wireless communication terminal communicates with the different base wireless communication terminal.
9. The wireless communication terminal of claim 1 , wherein when the wireless communication terminal is associated to a BSS corresponding to a nontransmitted Basic Service Set Identification (BSSID) of a multiple BSSID set, the processor is configured to set an OCW minimum value, which is a parameter indicating the minimum value of the OCW, and an OCW maximum value, which is a parameter indicating the maximum value of the OCW, according to UL OFDMA-based Random Access (UORA) parameter set element from a BSS corresponding to a transmitted BSSID of the multiple BSSID set,
wherein the UORA parameter set includes a parameter related to the counter.
10. The wireless communication terminal of claim 9 , wherein the processor is configured not to decrement the value of the counter based on a trigger frame transmitted from the BSS corresponding to the transmitted BSSID of the multiple BSSID set.
11. The wireless communication terminal of claim 9 , wherein the UORA parameter set received from the BSS corresponding to the transmitted BSSID is not a UORA parameter set indicated in a signaling field allocated for a BSS including the wireless communication terminal.
12. The wireless communication terminal of claim 1 , wherein when the trigger frame schedules an uplink transmission of the wireless communication terminal, the processor is configured not to decrement the value of the counter based on the trigger frame.
13. A method of operating a wireless communication terminal wirelessly communicating with a base wireless communication terminal, the method comprising:
setting an integer selected from a range of 0 to a value equal to or smaller than an OFDMA Contention Window (OCW) as a counter for random access,
receiving a trigger frame for triggering random access using one or more resource units (RUs) allocated for random access from the base wireless communication terminal,
decrementing a value of the counter based on the one or more RUs allocated for the random access and a capability of the wireless communication terminal,
randomly selecting any one of RUs through which the wireless communication terminal is capable of transmitting a trigger based (TB) PPDU according to the capability of the wireless communication terminal among the one or more RUs allocated for the random access when the value of the counter is 0 or reaches 0, and
attempting transmission to the base wireless communication terminal using the selected RU,
wherein the RU is a group of a plurality of subcarriers useable for OFDM communication.
14. The method of claim 13 , wherein the decrementing the value of the counter based on the one or more RUs allocated for the random access and the capability of the wireless communication terminal comprises decrementing the value of the counter by the number of RUs that the wireless communication terminal is capable of transmitting the TB PPDU according to the capability of the wireless communication terminal among the one or more RUs allocated for the random access.
15. The method of claim 13 , wherein when the wireless communication terminal is a wireless communication terminal unassociated with the base wireless communication terminal, the method further comprises:
setting an OCW minimum value, which is a parameter indicating a minimum value of the OCW, to a value predetermined as a default value of the OCW minimum value, and
setting an OCW maximum value, which is a parameter indicating a maximum value of the OCW, to a value predetermined as a default value of the OCW maximum value,
wherein the value predetermined as the default value of the OCW minimum value and the value predetermined as the default value of the OCW maximum value are not values designated by the base wireless communication terminal.