The TL-WPA4220 is not Wi-Fi Certified. It defaults to Auto channel, 11bgn mixed mode and Auto channel width by default. As noted, WiFi Protected Setup (WPS) is not supported. So I manually enabled WPA2/AES encryption for testing.
Since TP-LINK positions the TL-WPA4220KIT as a wireless extender, I didn't test it as an AP and run standard throughput vs. attenuation plots on it. But I also could not use our new wireless extender test process, because it is designed for conventional extenders that connect wirelessly to the home network.
So I used a four-step approach for testing:
1) Test powerline performance using our standard process
2) Test best-case wireless open-air performance
3) Determine a wireless dead-zone
4) Test wireless extended performance
Here are the IxChariot plots for the downlink powerline tests. This measures throughput between two computers plugged into the 10/100 Ethernet ports on the TL-PA4010 AV500 adapter and TL-WPA4220 AP.
Powerline throughput - downlink
These results are similar to what I have found with other HomePlug AV 500 adapters, if not a bit on the low side for the Location A tests, which represent maximum throughput.
Powerline throughput - uplink
I have not entered these results into the Powerline Chart database, because the test standard is to use two of the same adapter. TP-LINK is sending another TL-PA4010 adapter so that I retest and get the product into the charts.
For step two in my four-step process, I parked the AP in my downstairs office and ran an open-air up and downlink tests using my old open-air standard client, a Lenovo x220i notebook with Intel Centrino Ultimate N 6300 AGN adapter in the same room about 10 feet away. This represents best-case wireless throughput. I then walked the Lenovo upstairs to my old open-air Location E and ran another set of tests, which represent throughput at my "dead zone".
Finally for the fourth step measurement, I moved the AP to the same outlet used for the Location E powerline test. This put the TL-WPA4220 AP about four feet from the Lenovo notebook. The TL-WPA4220 AP was connected via powerline to the TL-PA4010, which was in the powerline Location A outlet, right outside my office. Its Ethernet port was connected back to my base network. The whole setup is illustrated below in my crudely edited version of TP-LINK's Unified Home Network diagram found at the top of this review.
TP-LINK TL-WPA4220KIT Extender test setup
The IxChariot plot below summarizes downlink test results. The loce_wireless_direct bottom trace represents unextended wireless throughput directly from the Lenovo back to the AP located in the downstairs office. The top loca_wireless trace is the best-case wireles throughput measured with notebook and AP about 10 feet apart in the same room. Finally the loce_wireless_repeat trace represents extended wireless throughput as per the diagram above.
The extended connection yielded 39 Mbps vs. direct 3.9 Mbps for a 10X throughput gain. This isn't as high as the 70 Mbps throughput measured at the Location E powerline location, but still a significant gain.
TP-LINK TL-WPA4220KIT extended wireless performance comparison - downlink
Uplink results are shown in the composite plot below. This time the 57 Mbps, loce_wireless_repeat repeated throughput is actually slightly higher than best case loca_wireless throughput and much closer to the 62 Mbps measured bandwidth of the powerline connection. With direct wireless throughput of about 3 Mbps, this is an almost 20X throughput gain through the extended wireless connection.
TP-LINK TL-WPA4220KIT extended wireless performance comparison - uplink
The TL-WPA4220KIT's performance results can't be directly compared to those of conventional repeater-style N300 extenders we have tested because the test conditions are not exactly the same. Still, it is interesting to compare the two results. The Wireless Extender Chart downlink screenshot below is filtered to show N300 and N300HPAV (a new class I added) class extenders only.
Since the throughput available (via powerline) to the TL-WPA4220 is 70 Mbps and since the AP is not repeating, I'd expect throughput to be closer to 70 Mbps.
N300 Wireless Extender performance - 2.4 GHz downlink
The uplink comparison is more favorable to the TP-LINK, showing roughly twice the throughput of the all-wireless extenders.
N300 Wireless Extender performance - 2.4 GHz uplink
I'll confess that I am a fan of HomePlug enabled mini APs and am glad to see them getting slowly better. But progress is slower than it could be, most likely because manufacturers still see HomePlug products as slow sellers in the U.S. While HomePlug has long been popular outside the U.S., here we are so in love with doing everything wirelessly, we balk at even trying other methods. Most people would rather spend $200+ on a new router in hope of slightly improving wireless performance, rather than spend much less trying a powerline approach.
With the TL-WPA4220KIT priced at only $60, TP-LINK is trying to make an offer you really can't refuse. For relatively little money, you not only get a surprisingly decently performing wall-pluggable HomePlug AV500 enabled N300 class access point with two-port 10/100 switch, but a HomePlug AV500 adapter to hook it up. If you don't like HomePlug, you can connect the AP via Ethernet. And if your AP extension doesn't work out the way you hoped, you still have a pair of HomePlug AV 500 adapters.
I hope TP-LINK has enough success with the product to continue to evolve it and prove that the product concept has merit. Maybe someday we'll have even smaller wall-plugged 802.11ac APs with 1000 Mbps HomePlug AV2 MIMO built-in and enough smarts to self-configure into self-managed plug-and-play multiple AP wireless LANs. In the meantime, if you have been looking for a cheap and easy way to light up a location that has refused to yield to standard full-wireless extenders, give the TL-WPA4220KIT a shot.