|At a Glance|
|Product||TRENDnet 500 Mbps Powerline AV Adapter Kit (TPL-401E2K)|
|Summary||HomePlug AV compatible, IEEE 1901-compliant powerline adapter kit with Gigabit Ethernet LAN port and higher maximum throughput than HomePlug AV|
|Pros||• 70 Mbps maximum throughput
• HomePlug AV certified and interoperable
|Cons||• 70 Mbps maximum throughput
• Throughput drops with distance
"Gigabit" powerline networking may have vanished with Gigle's absorption into Broadcom. But TRENDnet has come to the aid of those looking for more than the mid-40 Mbps throughput obtained from the latest crop of HomePlug AV adapters. TRENDnet's TPL-401E has managed to beat NETGEAR's XAVB5001 to market with the first powerline products based on Atheros' "500 Mbps" chipset. TRENDnet ships the adapter singly and in a kit of two (TPL-401E2K), which was submitted for review.
How It Works
Like Gigle, Atheros' AR1500 / AR7400 chipset achieves its higher bandwidth primarily by using a wider spectrum (2 to 68 MHz) than the 2 to 30 MHz spectrum that standard HomePlug AV uses (Figure 2).
Figure 1: HomePlug AV Frequency Use
At any rate, as we've all learned the hard way, maximum link rates touted by networking product manufacturers bear little resemblance to actual usable throughput. And to cut to the chase, Atheros' "500 Mbps" technology is no exception, at least as embodied in TRENDnet's adapters.
Figure 2: Atheros AR7400/AR1500 block diagram
Atheros claims that the AR4700 / AR1500 chipset will even achieve a 700 Mbps maximum PHY rate when connected to coax instead of home wiring. But that would be another product, not what I'm reviewing today.
The board photo in Figure 3 shows a layout typical of powerline products with numerous large components handling powerline interface. The AR7400 chip is under the heatsink, and the AR1500 to its upper right. The device to the left of the AR7400 is an Atheros AR8021 Gigabit Ethernet PHY. The EtronTech EM6A9160TSA provides 16 MB of RAM and I couldn't find the flash, which may be on the bottom of the board.
Figure 3: TPL-401E board
Setup And Administration
HomePlug adapters are factory set to just plug in and go, and the pair of TPL-401E's did just that. I sometimes had to replug an adapter to get the Powerline link light to come on, but otherwise setup was uneventful.
Figure 4 shows a summary of the adapter's lights. Note that the three color signal quality light seen on some of the HomePlug AV roundup adapters is incorporated into this product.
Figure 4: TRENDnet TPL-401E lights
Like all HomePlug adapters, the TPL-401E's data stream is secured with 128 bit AES encryption and the adapters come set with a default key set to "HomePlugAV". So installation consists of plugging the adapter into a wall outlet and running a cable from the adapter's 10/100/1000 Ethernet port to the device being networked.
The adapter auto-negotiates the Ethernet link speed and connects to another adapter within seconds of it being plugged in. If you want to change the security code, you use the Sync pushbutton on the bottom of the adapter.
I briefly checked the utility that came on the CD shipped in the adapter kit, which first installs WinPCap 4.1.1, which is a Windows packet capture and network monitoring library. The utility (Figure 5) is essentially the same as TRENDnet ships with TPL-303E2K 200Mbps Powerline AV Adapter. Aside from upgrading firmware and changing an adapter password, there are no other settings you can play with.
Figure 5: TRENDnet TPL-401E utility
It's worth mentioning that the link rate you see in Figure 5 was with obtained with both adapters plugged into the same outlet.