Communication: How Wireless Internet Works

From mobile phones to hand-held organizers to your own home computer network, wireless internet is everywhere, and spreading faster each month.

Wireless Internet takes two dominant forms today, in the guise of two protocols: WAP and WiFi (also known as 802.11 networking). WAP is used primarily in cellular and PCS applications, such as mobile phones and PDAs (Personal Digital Assistants, like Palm Pilots). WiFi, or 802.11, is used for networking multiple computers together without using physical cable connections.

First, let's talk WAP, which stands for Wireless Application Protocol. This is the technology that drives our mobile devices. You've heard of HTML (Hyper-Text Markup Language), right? WAP speaks a slightly different language than our home computers, which use HTML; WAP uses something called WML, or Wireless Markup Language. The reason for this different language is to allow mobile devices to access the Internet with greater speed, despite having far slower connection speeds. If a WAP device used the same language as our home computers, it would take a very, very long to view Internet data. A standard dial-up modem on a home computer reaches speeds of 56k, while a mobile WAP device can rarely get more than 14.4k. Since such speeds are completely unacceptable to most consumers, an entirely new language (WML) was devised that would be able to take shortcuts, allowing more information to end up on your device even though the data moved through the air is far less.

WAP also provides a way to navigate the Internet without a mouse, which is critical for obvious reasons. Here is a quick rundown of how WAP is able to get that Internet site to your mobile device:

1. You turn on the mobile device and activate its mini-browser

2. A radio signal from your device searches for service

3. The device connects to your Internet Service Provider

4. You pick the website you want to see

5. Using WAP, a signal is sent to the gateway server with your request

6. The gateway finds your information using HTTP

7. The gateway translates HTML into WML

8. WML information is sent to your mobile device

9. You see a wireless version of the website you chose

So how about WiFi, or 802.11? WiFi has a simplicity that can't be ignored, especially when you set up a WiFi network. The freedom it allows, coupled with the lack of extra cables, makes it an attractive option. To imagine how it works, think CB radio. Each radio can send and receive a signal, just like two WiFi enabled devices can send and receive a signal.

The difference is that a CB radio is on a much lower frequency -- and lower frequencies are not acceptable if you need to transfer high amounts of data. WiFi uses very high frequencies, to make data transfer faster, as well as using special encoding techniques to squeeze more information into fewer radio waves. These techniques are called orthogonal frequency-division multiplexing (OFDM) for 802.11a and 802.11g, or Complementary Code Keying (CCK) for 802.11b.

WiFi devices are able to frequency-hop, allowing them to have several separate "channels" available, and quickly switch between them. This allows multiple WiFi devices to operate without interfering with each other. WiFi may sound like a complicated technology, but it is actually one of the easiest to use and setup.

© High Speed Ventures 2011