Wireless Performance

I tested the Vision using our wireless test procedures, which use both open-air testing and Azimuth's ACE 400NB Channel Emulator.

I used a Belkin N1 Wireless Notebook Card (F5D8011) Version 3000, which, as noted earlier, is the only model Wi-Fi Certified for Draft 2.0 802.11n. The card was inserted into a Fujitsu P7120 Lifebook (1.2 GHz Intel Pentium M, 504 MB) notebook running WinXP Pro SP2 with all the latest updates. I used the 1.0.2.0 driver with Windows Wireless Zero Config.

The router had F5D8232-4_WW_1.00.11 firmware and I left all factory default settings in place, except as noted.

Maximum Throughput

To start, I ran some close range open-air IxChariot tests to look at maximum performance and throughput variation. This also provides baselines to check the Azimuth results against. Testing was done with the router and notebook about 10 feet apart in open air sitting in my lab with no other networks in range.

Figure 9 shows a composite IxChariot plot of wireless uplink, downlink and simultaneous up and downlink tests. Tests were made with router defaults, which as I noted, properly used the 20 MHz Channel mode. The best speed of 69 Mbps was found running uplink. Throughput is generally stable, but with some large dropouts in downlink, which depressed the average throughput result.

Figure 9: Up and downlink throughput - 2.4 GHz band, 20 MHz bandwidth

Figure 10 shows a composite of test runs with the 20 MHz+40 MHz auto mode forced. The best-case 98 Mbps throughput was again found running uplink.

Figure 10: Up and downlink throughput - 40 MHz bandwidth