I’ve used various powerline adapters for several years. They now can go up to 500 megabits per second, but 85 or 200 will be cheaper. I currently use TrendNet Powerline routers.
Why not use wifi? The bands are becoming crowded. You can try to use 5Ghz N routers, and they help, but if all your other devices – your phone, iPod, Kindle all have to use the 2.4GHz wifi, it can get congested. Wireless USB peripherals and Bluetooth also use the same band. Not everything supports the 5GHz band, so your laptop might not
work, or you will need a special card or adapter for your desktop. Then there’s securing things and getting the network password right. And in apartments, every one of your neighbors is using the same band.
Powerline adapters need passwords, but they are between the adapters and you only have to use the setup utility once. They are basically ethernet bridges. I have my cable router plugged in where the cable comes in and the signal is best, then have my wifi and powerline adapters plugged into that router (it has 4 ports). I’ve not had any problem streaming or even sending files between computers. I have several 200Mb/s refurbished models and they work well for that, but I have gigabit switches at my central computer “nerve center”. The powerline adapters also make printers a lot easier to setup. I have a Brother printer that is finicky about Wifi: it can attach USB, Ethernet, or Wifi, but even after typing in the correct information when attached with one of these other methods it often “fails to associate”. Instead, I just use the powerline adapter, and instantly it is on ethernet with no headaches.
Well, there is one. A powerline adapter uses up an electrical socket, which is where the “Liberator” comes in. Basically, a 3 pronged pass-through extension cord. The short plug-depth seems to play well with the powerline adapter, and the extension is hefty enough for my laser printer. The Liberators also work well with power strips or even to go sideways when space is at a premium.
There are a few rare cases where powerline adapters have problems. One is if there is something extremely electrically noisy on the same branch (and if it isn’t noisy you need the passwords to prevent your neighbors from snooping). This usually involves some huge motor, arc welding, or other industrial process involving intermittent high current. Another thing is if there are any ground loops or ifhot and ground get swapped by adapters or bad wiring. Also it helps to avoid circuits with dimmers and microwaves, though I’ve only had the problem when some part of the house wiring was wrong enough to show bars on my old CRT TV when the microwave was on. The powerline signal cannot pass through the large (utility pole) transformers. There is a length limit, but I haven’t been in a position to see how fast the signal goes at hundreds or thousands of feet.
If wifi works and the total cost of adapters and such is low, it might be a be a better solution, but for reasonable distances where there is lots of interference or if you only have ethernet, nothing beats powerline adapters.
This illustration demonstrates how the powerline can be used to extend the range of a home’s ethernet without additional wiring or the use of WiFi.