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EP-4521816-B1 - WIRELESS COMMUNICATION METHOD USING ENHANCED DISTRIBUTED CHANNEL ACCESS, AND WIRELESS COMMUNICATION TERMINAL USING SAME

EP4521816B1EP 4521816 B1EP4521816 B1EP 4521816B1EP-4521816-B1

Inventors

  • AHN, WOOJIN
  • SON, JUHYUNG
  • KO, Geonjung
  • KWAK, JINSAM

Dates

Publication Date
20260513
Application Date
20170907

Claims (10)

  1. A wireless communication terminal (100) that wirelessly communicates with a base wireless communication terminal, the wireless communication terminal comprising: a transceiver (120); and a processor (110) for processing a radio signal received through the transceiver (120) or a radio signal to be transmitted through the transceiver (120), wherein the processor (110) is configured to: receive, from the base wireless communication terminal, a trigger frame using the transceiver (120), wherein the trigger frame triggers an orthogonal frequency division multiple access, OFDMA, uplink transmission for a multi-user uplink transmission participation of the wireless communication terminal (100), and transmit, to the base wireless communication terminal (200), a trigger-based physical layer protocol data unit, PPDU, in response to the trigger frame, using the transceiver (120), characterized by the processor further being configured to switch an enhanced distributed channel access, EDCA, parameter set, which is a set of parameters used for the channel access, from a first EDCA parameter set to a second EDCA parameter set based on whether the base wireless communication terminal (200) triggers the multi-user uplink transmission participation of the wireless communication terminal (100), set a second EDCA parameter set timer based on whether an immediate response is requested by a MAC protocol data unit, MPDU, included in the trigger-based PPDU, wherein when the MPDU included in the trigger-based PPDU requests an immediate response, the processor (110) is configured to set the second EDCA parameter set timer when a reception of the immediate response ends, and when the MPDU included in the trigger-based PPDU does not request an immediate response, the processor (110) is configured to set the second EDCA parameter set timer when a transmission of the trigger-based PPDU ends, terminate an application of the second EDCA parameter set when the second EDCA parameter set timer expires, calculate a random integer value within a contention window, CW, wherein the CW is determined according to a priority of data to be transmitted to the base wireless communication terminal, set a backoff timer based on the random integer value, and access a channel based on the back off timer and a predetermined slot time, wherein the first and second EDCA parameter sets each comprises a minimum value, CWmin, of the CW and a maximum value, CWmax, of the CW, wherein the immediate response is an ACK, and wherein the MPDU included in the trigger-based PPDU is a QoS data frame.
  2. The wireless communication terminal (100) of claim 1, wherein the processor (110) is configured to set the second EDCA parameter set timer for an access category of an MPDU for which the immediate response is received.
  3. The wireless communication terminal (100) of claim 1, wherein the processor is configured to receive a beacon frame from the base wireless communication terminal and obtain information indicating a period of the second EDCA parameter set timer from the beacon frame.
  4. The wireless communication terminal (100) of claim 1, wherein when switching the EDCA parameter set from the first EDCA parameter set to the second EDCA parameter set, the processor (110) is configured to set the second EDCA parameter set timer.
  5. The wireless communication terminal (100) of claim 1, wherein when the application of the second EDCA parameter set is terminated, the processor is configured to, switch the EDCA parameter set from the second EDCA parameter set to the first EDCA parameter set and if a value of the CW, is greater than the CWmax of the first EDCA parameter set, set the value of the CW to the CWmax of the first EDCA parameter set.
  6. The wireless communication terminal (100) of claim 1, wherein the processor (110) is configured to operate a plurality of queues that are classified according to an access category of data stored in a queue and perform backoff procedure of accessing a channel based on a time corresponding to a backoff timer in each of the plurality of queues, and when there is no data stored in the queue and the backoff timer corresponding to the queue is 0, perform no operation at a slot boundary of the backoff timer, wherein the backoff timer is set based on a random integer value calculated in the CW, and is reduced when the channel is idle for a predetermined slot time.
  7. The wireless communication terminal of claim 6, wherein when there is no data stored in the queue and the backoff timer corresponding to the queue is 0, the processor is configured to maintain the backoff timer to be 0.
  8. An operation method of a wireless communication terminal (100) that wirelessly communicates with a base wireless communication terminal, the method comprising: receiving, from the base wireless communication terminal, a trigger frame, wherein the trigger frame triggers an orthogonal frequency division multiple access, OFDMA, uplink transmission for a multi-user uplink transmission participation of the wireless communication terminal (100), transmitting a trigger-based physical layer protocol data unit, PPDU in response to the trigger frame, to the base wireless communication terminal; characterized in that the method further comprises switching an enhanced distributed channel access, EDCA, parameter set, which is a set of parameters used for the channel access, from a first EDCA parameter set to a second EDCA parameter set based on whether the base wireless communication terminal triggers the multi-user uplink transmission participation of the wireless communication terminal; setting a second EDCA parameter set timer based on whether an immediate response is requested by a MAC protocol data unit, MPDU, included in the trigger-based PPDU, wherein when the MPDU included in the trigger-based PPDU requests an immediate response, the method comprises setting the second EDCA parameter set timer when a reception of the immediate response ends, and when the MPDU included in the trigger-based PPDU does not request an immediate response, the method comprises setting the second EDCA parameter set timer when a transmission of the trigger-based PPDU ends; terminating an application of the second EDCA parameter set when the second EDCA parameter set timer expires; calculating a random integer value within a contention window, CW, wherein the CW is determined according to a priority of data to be transmitted to the base wireless communication terminal; setting a backoff timer based on the random integer value; accessing a channel based on the backoff timer and a predetermined slot time; and transmitting a data through the channel, wherein the first and second EDCA parameter sets each comprises a minimum value, CWmin, of the CW and a maximum value, CWmax, of the CW, wherein the immediate response is an ACK, and wherein the MPDU included in the trigger-based PPDU is a QoS data frame.
  9. The method of claim 8, further comprising when the application of the second EDCA parameter set is terminated, switching the EDCA parameter set from the second EDCA parameter set to the first EDCA parameter set and if a value of the CW, which is determined according to a priority of the data to be transmitted, is greater than the CWmax of the first EDCA parameter set, setting the value of the CW to the CWmax of the first EDCA parameter set.
  10. The method of claim 8, wherein the setting of the second EDCA parameter set timer comprises setting the second EDCA parameter set timer for an access category of an MPDU for which the immediate response is received.

Description

[Technical Field] The present invention relates to wireless communication method and a wireless communication terminal using enhanced distributed channel access. [Background Art] In recent years, with supply expansion of mobile apparatuses, a wireless communication technology that can provide a rapid wireless Internet service to the mobile apparatuses has been significantly spotlighted. The wireless communication technology allows mobile apparatuses including a smart phone, a smart pad, a laptop computer, a portable multimedia player, an embedded apparatus, and the like to wirelessly access the Internet in home or a company or a specific service providing area. One of most famous wireless communication technology is wireless LAN technology. Institute of Electrical and Electronics Engineers (IEEE) 802.11 has commercialized or developed various technological standards since an initial wireless LAN technology is supported using frequencies of 2.4 GHz. First, the IEEE 802.11b supports a communication speed of a maximum of 11 Mbps while using frequencies of a 2.4 GHz band. IEEE 802.11a which is commercialized after the IEEE 802.11b uses frequencies of not the 2.4 GHz band but a 5 GHz band to reduce an influence by interference as compared with the frequencies of the 2.4 GHz band which are significantly congested and improves the communication speed up to a maximum of 54 Mbps by using an Orthogonal Frequency Division Multiplexing (OFDM) technology. However, the IEEE 802.11a has a disadvantage in that a communication distance is shorter than the IEEE 802.11b. In addition, IEEE 802.11g uses the frequencies of the 2.4 GHz band similarly to the IEEE 802.11b to implement the communication speed of a maximum of 54 Mbps and satisfies backward compatibility to significantly come into the spotlight and further, is superior to the IEEE 802.11a in terms of the communication distance. Moreover, as a technology standard established to overcome a limitation of the communication speed which is pointed out as a weak point in a wireless LAN, IEEE 802.11n has been provided. The IEEE 802.11n aims at increasing the speed and reliability of a network and extending an operating distance of a wireless network. In more detail, the IEEE 802.11n supports a high throughput (HT) in which a data processing speed is a maximum of 540 Mbps or more and further, is based on a multiple inputs and multiple outputs (MIMO) technology in which multiple antennas are used at both sides of a transmitting unit and a receiving unit in order to minimize a transmission error and optimize a data speed. Further, the standard can use a coding scheme that transmits multiple copies which overlap with each other in order to increase data reliability. As the supply of the wireless LAN is activated and further, applications using the wireless LAN are diversified, the need for new wireless LAN systems for supporting a higher throughput (very high throughput (VHT)) than the data processing speed supported by the IEEE 802.11n has come into the spotlight. Among them, IEEE 802.11ac supports a wide bandwidth (80 to 160 MHz) in the 5 GHz frequencies. The IEEE 802.11ac standard is defined only in the 5 GHz band, but initial 11ac chipsets will support even operations in the 2.4 GHz band for the backward compatibility with the existing 2.4 GHz band products. Theoretically, according to the standard, wireless LAN speeds of multiple stations are enabled up to a minimum of 1 Gbps and a maximum single link speed is enabled up to a minimum of 500 Mbps. This is achieved by extending concepts of a wireless interface accepted by 802.11n, such as a wider wireless frequency bandwidth (a maximum of 160 MHz), more MIMO spatial streams (a maximum of 8), multi-user MIMO, and high-density modulation (a maximum of 256 QAM). Further, as a scheme that transmits data by using a 60 GHz band instead of the existing 2.4 GHz/5 GHz, IEEE 802.11ad has been provided. The IEEE 802.11ad is a transmission standard that provides a speed of a maximum of 7 Gbps by using a beamforming technology and is suitable for high bit rate moving picture streaming such as massive data or non-compression HD video. However, since it is difficult for the 60 GHz frequency band to pass through an obstacle, it is disadvantageous in that the 60 GHz frequency band can be used only among devices in a short-distance space. Meanwhile, in recent years, as next-generation wireless communication technology standards after the 802.11ac and 802.11ad, discussion for providing a high-efficiency and high-performance wireless communication technology in a high-density environment is continuously performed. That is, in a next-generation wireless communication technology environment, communication having high frequency efficiency needs to be provided indoors/outdoors under the presence of high-density terminals and base terminals and various technologies for implementing the communication are required. Especially, as the number of devices u