Internet Hotspots and Distances

  I am looking for confirmation about my understanding of wireless networks. I have always been told that two devices communicating via wireless with each other is like playing a game of catch. Each device must be capable of throwing the ball all the way to the other device before it will work. Correct?

   I am king of questioning how internet hotspots work. I can put up a 100 megawatt antenna capable of sending a signal to the moon but if the dude on the moon is using a notebook computer with a standard PCMCIA NIC it wouldn't even come close to sending back to earth.

   To bring it down to earth level San Francisco and Google are teaming up to give the entire city Wi-FI. Same senario. People using weak antennas are only going to be able to throw the ball maybe 100ft. So does google need to put access points 100 feet apart across the entire city? Am I confusing access points and hotspots?

What am I not getting? Thanks!
LVL 11
jimbecherAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

gkumaranCommented:
Your understanding is partially correct. Both equipment should be capable of throwing the signal so that it reached each other.

However you are more concerned about the Transmission (Tx) power. However there is something called Receiver (Rx) Sensitivity, means how much signal power required by an equipment to understand it to make data out of it.

Assume that a normal PCMCIA Card on a Laptop Tx at the 100mW, this power would wade in due course of distance. So at 100ft if this is say 13mW, a normal Access Point can sense and make the communication to happen. However at 200ft it this drops as low as 8mw, then receiver should be sensible enough for this, or else the communication would not happen.

So, Hotspots not only has good Tx power to transmit, but also have good Receiving sensitivity.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Broadband

From novice to tech pro — start learning today.