If you want to have network access in multiple rooms of your house or flat without installing new twisted pair cables everywhere, the obvious choice is WiFi. That's what I used here for the last 2 years.
Even though 802.11g can achieve speeds up to 54Mbit/s those are rarely reached and depend heavily on the building structure and interfering other networks. In my case I had about 20 Mbit/s in our home office and just about 5 Mbit/s in the living room.
Time to look for an alternative. One is called PowerLAN (or Power Line Communication). It allows you to create a network using the usual electric power cables that are already in your home.
I bought the Devolo dLAN 200 Avplus Network Kit which contains three PowerLAN adapters. Devolo advertises them with up to 200 MBit/s but like with WiFi these speeds are never reached in the real world. However my measurements with iperf showed at least some improvements over the WiFi speeds.
Then I read the manual (which comes on CD only). The Avplus adapters do not only have a power socket for providing power but they also filter interferences other electrical devices might cause. That's why the manual recommends to never plug the adapter in a multi socket but always directly into a wall socket, with additional devices following “on top”.
After reconnecting the adapters as recommended, transfer speeds doubled! Here's a graphic of my measurements:
So PowerLAN is here to stay and this is what my home network looks like now1):
I'm still thinking about a few changes. I like to move the B3 into the office and connect it directly to the gigabit switch we have there. And maybe I add another switch in the living room to connect the Playstation and TV set2) to the PowerLAN as well.
What does your home network look like? Got a network diagram to share? Please do so in the comments, I love these things3).