AX PERFORMANCE EVALUATION

During 802.1 lax standard formulation, system-level simulation verifies that various technologies with this standard improve WLAN performance. Uplink multiuser transmission is used as an example to verify improvements in 802.1 lax compared with 802.1 lac.

The simulation uses a typical indoor scenario where one AP is deployed and multiple STAs are positioned at random distances around the AP. Table 2.9 lists specifications for the simulation environment. It is worth noting that 802.1 lac uses EDCA contention-based transmission, and

802.1 lax uses AP-triggered transmission. The MU EDCA mechanism allows STAs to disable EDCA contention-based transmission, and perform transmission using a trigger frame sent from the AP.

The 802.11 standard defines reference channel model D, which is suitable for indoor work scenarios, such as typical offices, large conference rooms, or open office spaces with partitions.

Impact of Different Transmission Modes on Uplink Throughput

The AP has a fixed coverage radius of 10 m, with the number of STAs increasing from 5 to 15, 50, 100, 200, and 500. Uplink throughput has been measured, as the results in Figure 2.77 indicate.

TABLE 2.9 802.1 lax Performance Simulation Environment

Simulation Environment Item

Specifications

Scenario

Indoor

Channel model

Reference model D

Frequency band

5 GHz

Bandwidth

20 MHz

Number of antennas

AP: 4 antennas STA: 1 antenna

Transmit power

AP: 20 dBm STA: 15 dBm

Traffic model

Full traffic, only uplink data

Packet size

1460 bytes

Impact of different transmission modes on uplink throughput

FIGURE 2.77 Impact of different transmission modes on uplink throughput.

  • • Uplink throughput: The 802.1 lax standard supports uplink MU- MIMO, and therefore an AP can receive data from four STAs simultaneously. In this example, five STAs are used, and uplink throughput in 802.1 lax is fourfold that in 802.1 lac, as illustrated in the figure.
  • • Transmission efficiency: The 802.1 lax standard uses trigger-based transmission. Therefore, the AP schedules STAs to send data, reducing loss caused by STA contention for channel resources. As the number of STAs increases, uplink throughput in 802.1 lac decreases; however, this does not occur in 802.1 lax. Specifically, as the number of STAs approaches 500, 802.1 lax delivers uplink throughput that is over eightfold that in 802.1 lac.

Test on Uplink Throughput Improvement Using the AP Scheduling Algorithms

15 STAs were used, and the coverage radius of the AP increased from 10 to 20, 30,40, and 50 m. The AP uses different algorithms for uplink transmission, and uplink throughput has been measured.

Random scheduling algorithm

After contending a channel for use, the AP randomly selects four STAs and triggers data transmission. Figure 2.78 displays the measurement results. When the AP coverage radius is relatively small, uplink throughput in 802.11ax is fourfold that in 802.11ac. However, as the AP coverage radius increases, gain decreases gradually.

Impact of the AP scheduling algorithm on uplink throughput (random scheduling algorithm)

FIGURE 2.78 Impact of the AP scheduling algorithm on uplink throughput (random scheduling algorithm).

• Nearest-STA scheduling algorithm

Four STAs with optimal channel conditions are always selected for uplink MU-MIMO transmission. Figure 2.79 displays the measurement results. This scheduling algorithm sacrifices fairness for the highest possible uplink throughput.

• K-best-STA scheduling algorithm

Four STAs are randomly selected from К STAs with optimal channel conditions for uplink MU-MIMO transmission equals 8 in this simulation). Figure 2.79 displays the measurement results. This scheduling algorithm prioritizes fairness at the expense of throughput. However, total throughput is about four times higher than that in 802.11ac.

Impact of the AP scheduling algorithm on uplink throughput

FIGURE 2.79 Impact of the AP scheduling algorithm on uplink throughput.

Test on Throughput Improvement Using Various Technologies

In addition to the preceding simulations, various system-level simulations can be used to verify performance improvement in the 802.1 lax standard.

. OFDMA

In the non-line-of-sight (NLOS) environment, the 802.1 lax throughput is 5.9-13 times the 802.11ac throughput. A larger number of STAs indicates a more significant improvement.

• Spatial reuse

Spatial reuse increases throughput by 30%-60% in an OBSS environment.

AX STANDARD ACCELERATES INDUSTRY DEVELOPMENT

Enterprise WLANs provide fast and secure wireless Internet access services. Furthermore, with increasingly diverse applications, especially AR/VR, 4K/8K video, and automated guided vehicles (AGVs), wireless networks are transforming into infrastructure for delivering existing and emerging enterprise services. These services require higher bandwidth, lower latency, and larger connectivity capabilities. The next-generation

  • 802.1 lax-compliant wireless delivers these capabilities, promoting the application of new technologies and accelerating digital transformation across various industries.
  • 802.1 lax (Wi-Fi 6) provides wireless networks with the same level of reliability previously available only on wired networks, thereby enabling a wider range of applications for various industries. For example, a wireless network can be built to replace a wired network to transmit enterprises’ production data. Through wireless networks, numerous IoT devices in the manufacturing industry, as well as unmanned robots, can be operated and controlled. While WLAN has been extensively used in scenarios such as enterprise offices, education, healthcare, finance, airports, and manufacturing, 802.1 lax will revolutionize these industries.
 
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