Since the Belkin F5D8233-4 doesn't have the connectors required to attach it to the Azimuth test system, I had to use a combination of my previous open-air test method and my current sealed RF chamber Azimuth test system method.
The first open-air results are from a "best case" test with the router and client card in the same room about 10 ft. apart with no other RF sources or wireless networks in operation. The results are at the bottom of the wireless summary table. I have marked the best results for each test in green and the worst in red.
The obvious overall winner for highest open-air best case throughput in all tests is the Belkin F5D8233-4, which uses a Ralink chipset. The 80 Mbps throughput using the 20 MHz bandwidth mode is 20 Mbps better than the next closest competitors and is quite surprising. Just as surprising was that the throughput didn't change when the 40 Mbps bandwidth mode was selected! I verified that the product was actually using the specified bandwidth during each test using a Cognio Spectrum Expert Wi-Fi spectrum analyzer.
The prize for lowest open-air best case throughput goes to the D-Link DIR-615, which averaged only 34 Mbps during a one-minute uplink test in 20 MHz bandwidth mode.
Since I couldn't attach the Belkin to the Azimuth system, I couldn't see whether this surprisingly good throughput holds up as signal levels are attenuated in a controlled setting. So instead, I started a long IxChariot simultaneous up and downlink test in 20 MHz mode and walked a notebook around to my five test locations.
I was again surprised to find that the Belkin router and card not only stayed connected at my troublesome test Locations 4 and 5, but maintained 4 - 5 Mbps of throughput, both up and downlink!
I ran the same walk-around test on all products and gathered the results into Table 3. They show that the only other product to produce useful throughput in my worst-case open-air test locations was the Trendnet TEW-632BRP.
|Product||Walk-Around Test Result|
|Stayed connected @ locations 4 & 5 w/ ~ 4-5 Mbps throughput.|
|Disconnected at Locations 4, 5.|
|Stayed connected at Locations 4 and 5, but w/ very low, unstable throughput.|
|Disconnected at Location 4. Intermittently connected
Location 5 with very low throughput.
|Stayed connected at Locations 4 and 5 with 1 - 2 Mbps throughput.|
|Stayed connected at Locations 4 and 5. 6 Mbps down @ Location 4, 1 - 2 Mbps @ Location 5. Uplink 1 - 2 Mbps @ both Locations 4 and 5.|
Table 3: Open Air Walk-around results
Turning to the Wireless Charts, let's see how the products (except for the Belkin, unfortunately) behave as signal levels are attenuated in the Azimuth system's controlled RF environment.
Figures 3 and 4 show down and uplink results using 20 MHz bandwidth mode. The products tend to cluster together in downlink throughput most of their signal range. The exception is the D-Link DIR-615, which falls off earlier and disconnects earlier than the other products in both up and downlink. The prize for staying connected the longest, in both up and downlink, goes to the Atheros-based Trendnet TEW-632BRP.
Figure 3: Wireless downlink throughput comparison - 20 MHz bandwidth mode
The uplink results are an odd mix. There are three distinct groupings up to around 88 dB of path loss; the two Linksyses, the DIR-615 and TEW-632BRP and then the DIR-625. As the products go over the "waterfall" (the descending part of the curve) the Linksyses stay together. But the two D-Links swap groups with the DIR-615 joining the Trendnet TEW-632BRP for the rest of the ride and the DIR-615 again ending earliest.
Figure 4: Wireless uplink throughput comparison - 20 MHz bandwidth mode
Figures 5 and 6 contain the results for the 40 MHz bandwidth mode tests. The downlink curves show a pattern similar to the 20 MHz curves; tight clustering, DIR-615 ending earliest and TEW-632BRP ending last.
Figure 5: Wireless downlink throughput comparison - 40 MHz bandwidth mode
The 40 MHz mode uplink curves are again similar to the 20 MHz. The main differences are that the groupings are closer together and the DIR-615 jumps up to join the Linksyses from 55 to 73 dB of path loss. The DIR-625 once again turns in the lowest uplink throughput performance of around 60 Mbps before hitting the "waterfall". And the DIR-615 again ends its curve at 100 dB of path loss.