how wireless networks work

So what's so great about a wireless network?

Well, basically, it gives you the ability to work on your computer anywhere in your house. No more sitting in the basement next to the water tank while paying your bills. Tuck that laptop under your arm and go out on the deck; play World of Warcraft or chess on Yahoo while listening to the neighbors dogs bark.

What does a wireless network consist of?

First you will need to get with an Internet Service Provider (ISP). Some of the big ones are Earthlink, Bellsouth, Comcast and AOL (Note: mentioning them does not imply endorsement. And no, I'm NOT going to tell you that I use Earthlink, so don't even bother to....oops.). The ISP will give you an account to connect to the Internet.

Then you will need some equipment. The first thing you need is a MODEM. This is actually an abbreviation for MOdulation/DEModulation. Back before high speed Internet, when we were still using dial up connections over a regular phone line, the stream of data from your computer had to be altered - modulated - to be sent over the phone line, then at the other end the process had to be reversed - demodulated - so that another computer could decipher it. This is because computers use a digital format and your voice uses analog. We don't do this transformation anymore, but the name has stuck. Your ISP will give you your modem, and you will either connect it to a cable line (if you're using cable) or the phone line (if you're using a Digital Subscriber Line, or DSL).

What is DSL? The reason we don't have to modulate and demodulate from digital to analog anymore is because science has discovered an unused range of frequencies on your phone line that can be used to transmit data (there's no telling what was being transmitted over these undiscovered frequencies before computers were invented!). Now, digital computer signals can travel over the very same phone line as your analog voice. Your voice will use it's own frequency range (0 to 3400 cycles per second, also called a HERTZ) and your computer will use another range (4 KiloHertz - Kilo is thousand - and above), and never the two shall meet. You will still need DSL filters to put on all your phone jacks; your ISP will supply these as well.

At this point, you could plug in your computer to the modem with an ETHERNET cable (basically like a fat phone cable....but don't call it that to it's face....) and be ready to go.

So here's how the setup would work:
Your phone jack would connect to a DSL filter with a regular phone cord
Your DSL filter would connect to your modem with a regular phone cord
Your modem would be plugged into an electrical outlet for power
Your modem would be plugged into your computer with an Ethernet cable

At this point you would have a traditional wired network, even though you're really using only 1 computer so it can't really be called a network (please forget that I just called it that). In order to make it a wireless network, you need to add a wireless ROUTER. A router is a device that allows multiple computers to connect and talk to each other. In the past, routers simply were connected to computers by Ethernet cables (and they still can be) but wireless routers have a radio signal beamed out that allows computers with a wireless card to connect to them and transmit data as though they were connected with an old-school Ethernet cable.

Even though you could stop there, there's one other component that is VERY important: a FIREWALL. This prevents unauthorized access to your computer from the Internet. You should not get on the Internet without a good firewall. The Windows Operating System comes with a firewall that is regarded by many experts as having too many vulnerabilities to be your only firewall. Firewalls are available as software (programs) or hardware (things you can touch, or throw). Most routers have at least 1 firewall included.

So here's how the wireless setup would work:
Your phone jack would connect to a DSL filter with a regular phone cord
Your DSL filter would connect to your modem with a regular phone cord
Your modem would be plugged into an electrical outlet for power
Your modem would be plugged into your wireless router with an Ethernet cable
The wireless router would beam out a radio signal for any computer in range with a wireless card

In a subsequent post we'll talk about SECURING your wireless network (very important!).