My apartment is a Wifi nightmare. It has three floors and although every floor has phone and TV antenna outlets in at least one room, installing a fast and reliable network is a real problem.

I've been trying to solve this for three years and I finally had to do something after switching from a DSL internet connection to a much much faster cable modem. Instead of a measly 5 MBit downstream I now have 100 MBit downstream and 7 MBit upstream - and it really is that fast. The problem is that all of this speed is lost when I want to use any networking device which is not in the same room as the cable modem.

I'd like to have the cable modem on floor A, where my office is. Since I can't open up the (massive) walls and put network cable in, I always tried to bridge the network into floors B and C (livingroom) using Wifi. I should mention that the floors/ceilings are 30 cm of steel-reinforced concrete. With a 2.4 Ghz Wifi signal, straight at a 90 degree angle through one floor already reduces the signal to about 50%. Two floors means I barely can get a signal at all on most devices and I'm certainly not streaming any HD video from the NAS in my office to the TV in my livingroom. Forget about 5 Ghz, it barely makes it through one floor.

After trying various access points, bridges, repeaters, etc. I now turned to Powerline communication. The house is about 20 years old and built to whatever standards Switzerland had at that time. Floors A and B are connected to one fuse in the box, floor C to another one. (Yeah, that's really great if you have lots of electrical devices NOT in your livingroom, which computer people of course never have.)

Last time I heard about Powerline it came with plenty of caveats, it wasn't working well apparently. Things have changed but I'm still clueless about the technology. So I got three different starter kits each containing two Powerline/Ethernet adapters (the CHF is almost the same as the USD):

• Netgear XAVB1004 Powerline, CHF 114,-
• Devolo dLAN 200 Avsmart+, CHF 163,-
• Belkin Gigabit Powerline HD, CHF 141,-

I don't know if any of these adapters will work at all or what their performance is going to be like, so I'll test all of them thoroughly. I need at least 25 megabit/s reliable to stream video.

Netgear XAVB1004

The first kit I'm testing is the Netgear XAVB1004 Powerline Starterkit, which comes with an adapter connected through a cable but also offering a 4 port 100 MBit switch, and a simple adapter with a single ethernet port which plugs right into a power point. It does however not pass through the power outlet, so that point will not be usable for any other device. The manual says to not plug the adapter into an extension powerstrip. This already got me thinking: You need two outlets on your wall next to each other, or you'll have cables in the room.

Negative: There is no user manual for the Netgear device. There is a leaflet with quickstart instructions included which states that a user manual is available on the CD or online on the Netgear website. I haven't found it on the website and if you open the CD you find an HTML page which... hold your breath, links to the website and you'll get a 404. On the plus side there is a (rather crude) GUI administration software for OS X included which you use to set encryption keys, configure VLANs and so on.

Setting up encryption keys does not work on the Netgear devices. The instructions say to press the security button on each device for two seconds within two minutes, then supposedly the LED would start blinking and they would exchange keys. I managed to get one of them to blink after a few attempts but never the other one. I set an encryption key with the Netgear OS X utility I've mentioned earlier, although I'm sure my 60 year old uncle wouldn't be able to do that. The adapters worked immediately with or without encryption, no problems there.

Devolo dLAN 200 Avsmart+

The Devolo adapters offer a power outlet passthrough, so you can connect your other devices to the powerline adapter without losing the outlet (and it's actually recommended because the adapters filter the signal). This is a major feature and a good reason why I already like the Devolo adapters better than the Netgear.

Installation was no problem, even the encryption setup with the buttons on the adapters worked immediately. Included is an installation wizard for OS X for the same purpose, which also worked great. The manual PDF is on the CD and it explains everything well. Having a display on each adapter that shows the status is nice but probably not necessary after the setup has been completed.

Belkin Gigabit Powerline HD

Again, there were problems with the encryption key setup with the button on the adapters. The installation leaflet says to press the button for one second, then the LEDs would blink and the button on the next adapter is to be pressed. Well, no LED flashed but after five seconds pressing the button they flashed alright. I don't know what that affected but the connection was gone after this procedure.

The installation leaflet is wrong. I've opened the included CD and found no OS X software - but curiously some pretty useless icons in OS X icon format made it into the root folder. The manual PDF on the CD explains how to set up encryption keys: Hold the button for 10 seconds on each adapter to generate a key, then press it again for one second (but not longer than three!) to exchange the keys. I call that failed quality assurance.

The Belkin adapters don't offer power passthrough, in fact, they are rather bulky black boxes which also get quite warm. There is a sticker on the packaging that says this is normal though. I've read in another review that Belkin is still updating the firmware. I do not touch Windows machines, so I can't udpate.

Performance comparison

For each test run I transfered a large compressed file over HTTP, from one gigabit-connected machine to another and from and to RAM. No harddisk access was involved, so this is pretty much raw TCP speed. The adapters were connected to power outlets on the respective floors, note that floor C is on a different breaker circuit.

	A only	A to B	A to C
Netgear XAVB1004	6.4 MiB/s (3.379 ms)	4.8 MiB/s (3.768 ms)	2.8 MiB/s (3.608 ms)
Devolo dLAN 200 Avsmart+	7.0 MiB/s (3.331 ms)	5.1 MiB/s (3.424 ms)	4.1 MiB/s (3.463 ms)
Belkin Gigabit Powerline HD	13.9 MiB/s (1.222 ms)	3.4 MiB/s (2.648 ms)	2.5 MiB/s (4.510 ms)

What you don't see from these numbers is that the Netgear and Devolo adapters had a very stable sustained transfer rate, while the Belkin adapters were fluctuating up to 30%! This is also reflected in the round-trip times, as some pings would take 10 milliseconds while the next would go through in 3. All in all, I'd say that the Belkin is very fast when used in the same room or floor but that it really has problems with distance and crossing curcuit boundaries.

I'm going to permanently install the Devolo adapters now which are obviously the best in my comparison, and from a practical point of view. If anything changes in the future I'll update this blog entry.