Introduction to the HOWTO Pages
These pages are intended to help people construct their own wireless distribution networks. If your broadband connection to the telephone exchange goes over more than 1km of copper, then you are probably better off with a wireless link. If it’s more than 5km, the chances are that broadband will be miserably slow or not work at all; in which case wireless is definitely better. Of course, it would be better still if someone would replace the copper with fibre, but that is expensive and fraught with bureaucratic obstacles. In the next few years, wireless networks are going to be the only viable option for many rural communities. Moreover they are cheap to build; and the technology is rapidly improving and delivering faster speeds.
The first thing to say is that how you deploy wireless depends on all sorts of factors, there is no standard solution; but for people who are new to wireless networks we thought to start with the simplest possible scenario – just to illustrate how simple it is.
You live in an idyllic cottage at the head of Glenbogle. Perfect peace; a beautiful garden; spectacular views; but no broadband. The telephone line is very old and comes all the way up the glen from Inverbogle by a rather circuitous route. Inverbogle is a prosperous town, and the exchange has been upgraded to ADSL2+. There’s even talk of deploying fibre through the town. Your friend Fiona, who has a house in Inverbogle reports that she is reliably getting 17Mb/s on a connection that her service provider – as is their habit – advertised at 20Mb/s. At any rate, it’s more than enough for Fiona, and since her children have all left home, she is quite happy to share her connection with you.
On a clear day, you get out your telescope and find that you can see – all the way down Glenbogle to Fiona’s house – about 5 miles away, What do you do? You buy two of these small box-like antennae or maybe two of these small dishes if you want to use the extra speed when Fiona gets a super-fast connection. There are other competitive products on the market too. You mount them on your and Fiona’s roof tops pointing at each other. You connect the one on Fiona’s roof with a thin cable to Fiona’s ADSL modem. You connect the one on your roof directly to your computer (or maybe to a wireless router in your house). You configure the two boxes (it’s very easy) through a simple Web interface, and that’s it!
The total cost if you do this yourself is probably about £200, a bit more if you employ a sparky to make the cables and climb around on your roof. Given that you are now sharing the cost of Fiona’s broadband connection, and paying her £100 a year - half the cost of her connection, the equipment has paid for itself in two years; and Fiona is also saving money.
There are certainly people for whom this is the answer. However, for most of us it’s more complicated. The major issues are:
You cannot see Fiona’s house, and it’s 20 miles away so you need to build one or more intermediate relays.
You are not alone in Glebogle, but live in a small village, and while Fiona is happy to put a small transmitter on her roof, she’s not sharing her internet connection with 50 people.
Note that we have not listed “you don’t have a friend such as Fiona” as an obstacle. In our experience, there is always a “Fiona”, though sometimes it is a helpful institution or company rather than an individual, the only question is whether they have good enough internet access to help you out.
The following pages take you through the details of building a more sophisticated wireless network.
- Network planning
- Fresnel zones
- Relay construction
- Power supplies
- EMF Safety for Community Networks
- 5.8GHz spectrum, power output and licensing