Saturday, 11 July 2009

Extending Your Network - Homeplugs and Powerline Adapters


There may come a time when you want to link additional devices to your home network. Another computer, a games console, media player or even an HD TV perhaps. If you are lucky, the layout of your home and phone connection will allow you to do this simply using ethernet (wired) of WiFi (wireless) connections to your HomeHub or other router. However, your home may have thick walls, or walls fitted with metal-foil coated insulation, and the Wifi signal may not reach to all parts of it. If you want to use your computer in the garden, the WiFi signal may not reach that far. You may even want to use your computer in an outbuilding, but again the WiFi signal won't reach that outside your home.

You could reach for a drill and start putting holes through walls, ceilings and floors and threading ethernet cable through the house and even under the garden to achieve what you want. However, there is an easier way that will work in most domestic circumstances - using Homeplugs or Powerline adapters.

These devices, like the Netgear HDX101 shown at the top of the article, transmit data over the domestic power supply. One device is wired into your router by ethernet cable and the second device (or more than one if you like) can be placed in a convenient wall socket, close to where you want to use it, and connected by ethernet cable to whatever device you want to use. Some Homeplugs/Powerline adapters are WiFi enabled and so can act as a remote access point (AP) for your home network. Alternatively, you can connect a WiFi router to the remote adapter, to give you both wired connectivity and another AP. This last option is a little more complex to set up and beyond the scope of this blog, but the following diagram shows a simplified version of what can be achieved.



The problem here was to extend the network to a summer-house, allowing an Xbox to be installed and also to allow for occasional use of a laptop in the garden and summerhouse. The layout of the house and thick internal and external walls prevented this from being done by WiFi and I really didn't fancy the amount of digging and drilling that would have been required to install ethernet cable.

The primary router is a Netgear DG834PN, although I have used the same network configuration with HomeHub 1.0, HomeHub 1.5, HomeHub 2.0 and a 2-Wire 2700HGV BT Business Hub as the primary router. This links by ethernet to the main PC and to the first of the Netgear HDX101 powerline adapters. It also provides the primary WiFi access point. The second Netgear HDX101 is plugged into a power socket in the summer-house and is linked by ethernet to the LAN side of an old Linksys WRT54G router which acts as a secondary AP. A second ethernet link connects the Linksys router to an Xbox, but if the Linksys router isn't needed for a while, the Xbox can be plugged directly into the Netgear HDX101 without any network reconfiguaration.

OK, What do you need to know if you want to set up a simple network extension using Homeplug/Powerline adapters?

The first thing is to choose a pair of Homeplug/Powerline adapters. Several companies offer them for sale: Netgear, Devolo, Linksys, Billion, Draytek, et, etc. They also come in three speed ratings: 14mbps, 85mbps and 200mbps with prices to match the speed ratings. To be honest, it probably isn't worth getting anything other than a pair of 200mbps models - the slower ones may just be too slow to allow you to do everything you might want to do with them - especially if you are considering streaming HD video, or have an ardent gaming fan in the house. In theory, adapters with different speed ratings could coexist on the same power supply, but you cannot connect them together - so not a lot of point mentioning that, other than by way of a warning! Similarly, don't be tempted to try and mix adapters from more than one manufacturer, that almost certainly won't work either.

Most Homeplug/Powerline adapters now come with built-in signal encryption. Please use it, or otherwise anyone with access to an adapter from the correct manufacturer and to a power socket in your house, outbuilding or garden, could gain a way in to your network. You have been warned.

Installation is simple and almost plug and play, but ensure you read the instructions and follow them to the letter. This will usually involve loading a bit of software on to a PC linked by ethernet to your router, and then connecting each adapter in turn to the router to set it up. When you have done this, and before you plug the adapter into its remote location to test it, switch everything off - Your PC, the router, your shiny new adapter - everything! Go and have a cup of tea.

OK, now you are ready to try out your Homeplug/Powerline adapters. Wire up whatever device you want to use in the remote location (eg a PC or Xbox), but DO NOT switch it or the adapter on at this stage.

Now go and switch on the router and let it connect and stabilise. Secondly, power up your PC and check that it is behaving normally. Once you are happy, switch on the Homeplug/Powerline adapter that is connected by ethernet cable to the router and once it has settled down, go and switch on the remote Homeplug/Powerline adapter. Lastly, you can switch on the remote device - and if you have followed all the instructions correctly, that should be it - connected!

It has to be said that Homeplug/Powerline adapters won't work in every situation. The electrical sockets you plug the adapters into all need to lie on the consumer side of a single electricity meter. Even then, problems have been reported where an outbuilding has a separate fuse-box to the rest of the house. My outbuildings have independent residual current circuitbreakers (RCCBs) rather than fuse-boxes and the system works just fine.

You also need to plug the adapter into a wall socket. Whatever you do, don't plug them into extensions fitted with surge protectors, etc., else they may not work at all.

Homeplug/Powerline adapters can also pick-up RF interference from the mains power supply and couple this back into the LAN - which can have some dire effects on other parts of your system, but I have never experienced this myself.

Finally, you are unlikely to be able to have the two Homeplug/Powerline adapters separated by more than 200 metres of power cable and still get them to work.

You should always try and buy them on a sale-or-return basis!

Good luck and have fun - they really are a useful idea.

1 comment:

Anonymous said...

I'd like to post that this article was simply superb. I consider myself a fairly decent computing guru but not much on the side of network engineer and came across a problem for a dear friend with an ancient house. I'd heard of the technology but needed somewhere to start and after a spot of googling came across this article. Armed with this I'll be able to turn the rustic old house into wifi heaven. Many thanks from a fellow blogger.

Having had some major problems with my own broadband service, I understand how others struggle to get help from BT.

There is a lot of good information out there, but it can be hard to find. So this blog is an attempt to pull some of it together, in one place.

It's a blog that really shouldn't be needed - if only BT and possibly other ISP's in the UK, provided useful customer support.