Allion Labs | Alvin Tsai & Chris Wu
In the previous article, we briefly introduced the background information of the TR-398 Wi-Fi In-Premises Performance Testing (the “TR-398 Standard”) and the significance of the launch of this test standard. We also introduced the environment setup and requirements in a more in-depth manner starting from the scope of impact of the TR-398 Standard. In this article, we will continue from where we ended in the last article and explain the test items (bandwidth) of the TR-398 Standard.
Forgot where we left last time? Click here to go back to Part I of TR-398
Category 2: Baseline Performance
2-1. Maximum Connection Test: Mandatory Test
This test verifies if the Wi-Fi AP can support 32 devices simultaneously connected with minimal packet loss.
- For each test configuration, the packet error rate (PER) for each station shall achieve less than 1%.
- For each test configuration, the overall throughput of all connected stations shall achieve:
- For 32 connected stations (802.11n), both downlink and uplink total throughput shall be not less than 64 Mbps * 99%.
- For 32 connected stations (802.11ac), both downlink and uplink total throughput shall be not less than 256 Mbps * 99%.
2-2. Maximum Throughput Test: Mandatory Test
To measure the maximum throughput performance of the device under test in short distance. This is an indicator of the ability of a device to transmit data.
The measured average throughput shall satisfy the performance requirements of the following table according to the GI used in the test.
Implementing a maximum throughput test for different APs can reveal the significant differences between each company’s products under the same conditions.
2-3. Airtime Fairness Test: Mandatory Test
Airtime fairness is a feature that improves overall network performance by sacrificing airtime of the slowest devices. Long-distance to travel or obstacle penetration leads to larger attenuation, which makes the data rate in a low level. When air interface has run out, occupying excessive air time of stations with small MCS will be unfair to the stations with large MCS.
Here, the average performance of multiple stations connected to the AP simultaneously is tested. Each station’s maximum connection value has significantly deviated from the average range that it should have.
Average performance expectations pass criteria:
- STA1_throughput_1 shall be within plus or minus 5% of the average value (STA2_throughput_1 and STA1_throughput_1).
- STA2_throughput_1 shall be within plus or minus 5% of the average value (STA2_throughput_1 and STA1_throughput_1).
- STA1_throughput_2 shall be within plus or minus 15% of the average value (STA2_throughput_1 and STA1_throughput_1).
- STA1_throughput_3 shall be within plus or minus 15% of the average value (STA2_throughput_1 and STA1_throughput_1).
Here, the maximum performance of multiple stations connected to the AP simultaneously is tested. The connection performance is significantly lower than the expected bandwidth value.
Maximum performance expectations pass criteria:
- STA1_throughput_1 + STA2_throughput_1 shall be greater than the expected bandwidth speed (2.4G: 80 Mbps, 5G: 475Mbps)
- STA1_throughput_2 + STA2_throughput_2 shall be greater than the expected bandwidth speed (2.4G: 54 Mbps, 5G: 280Mbps)
- STA1_throughput_3 + STA3_throughput_3 shall be greater than the expected bandwidth speed(2.4G: 50 Mbps, 5G: 230Mbps)
In this article, we introduced three test items for the throughput framework of the TR-398 Standard. These three test cases, maximum connection test, maximum throughput test, and airtime fairness test are mandatory tests. This article tries to give readers a deep understanding of the pass/fail criteria. In the following articles, Allion will continue to lead you in understanding the test framework: For the many test cases and conditions of coverage and multi-user support, stay tuned to our technical articles!
Meanwhile, you might want to get back to Part I to review Category 1: Receiver Sensitivity Test (RF Performance), please click the link below.