Wireless Performance

Testing and analysis by Tim Higgins

I used the open air test method described here to test the 685's wireless performance. Testing was done using the SNB standard wireless test client, an Intel Wi-Fi Link 5300 AGN mini-PCIe card and 12.2.0.11 driver in a Dell Mini 12 running WinXP Home SP3. I left all client-side defaults in place except for enabling throughput enhancement (packet bursting) and changing the 802.11n Channel Width (2.4 GHz) setting from its 20 MHz default to Auto, so that the adapter would support 40 MHz channel bonding mode.

The router had the latest 1.01NA firmware and all factory default settings in place, except setting channel 1.

Figure 17 shows a composite of up and downlink throughput tests made at the six test locations with both 20 and 40 MHz channel width modes. Each column represents the average throughput from a one minute test. Best case throughput of 111.4 Mbps was measured running downlink with a 40 MHz channel bandwidth at Location A.

Unfortunately, the 685's range performance isn't a match for its peak speed. Unlike most other 2.4 GHz draft 11n routers that I have tested lately, the 685 was unable to run the throughput tests in the most difficult Location F and barely made it through the tests in Location E. So if you're looking for long range in a draft 11n router, the 685 probably isn't a good choice.

Figure 17: Six location wireless throughput summary

The good news, however is that the IxChariot plot in Figure 18 shows much lower throughput variation than I am accustomed to seeing from draft 802.11n routers.

Figure 18: Six location wireless throughput - 2.4 GHz, 20 MHz channel, downlink

If you'd like to see the other IxChariot plots just click the links: 20 MHz uplink, 40 MHz downlink, 40 MHz uplink.

Wireless Security

Figure 19 shows that the 685 properly (as per draft 802.11n standard requirements) limits performance to 11g speeds with WEP and WPA/TKIP enabled. And selecting WPA2/AES security has no significant effect on throughput.

Figure 19: Security mode comparison - 2.4 GHz, 20 MHz channel, downlink