[CS-FSLUG] Bigger antenna

[Nathan T.]

Here's a question for you ham radio operators in the list, dad's not
home so I can't ask him right now and I'm impatient :-)

Anyway, my router has a line of sight range of approximately 400
metres according to D-Link, I have been doing some reading and while
it didn't all make sense I know I have an invaluable resource just an
e-mail away I can get information from. So, here goes...

Why is the length of the antenna half the wavelength? How does
shortening or lengthening it affect it? Does the length of the antenna
allow the router to pick up computers further away or does that
require those computers to have better antennas?

I've heard of wireless amplifiers, obviously they increase the range
of the router, but if a computer was further away, would that also
increase the router's ability to pick up on that signal?

How many computers, or traffic do you think my router, a 4-port +
802.11a/b/g D-Link DI-524 could handle?

Is there some kind of regulation that would limit the size of the
antenna I can use? Obviously I'm not talking about a 60 foot antenna
here, more likely something no bigger than 5 metres high on the roof
of a house, maybe even smaller if I can get reasonable range .

How about regulations on how much power I can use in the antenna
without requiring any kind of licenses or permits (in Canada)?

Obviously you know I'm going to be messing around with this stuff
sooner or later. But not for a few years yet. I'm now thinking of
getting into some networking related technical courses after high
school and then I'll have my fun.