How Wireless Works
A wireless phone is really a radio – a very sophisticated and versatile radio. Much like a walkie-talkie, a wireless phone receives and sends radio waves. But, wireless phones offer much more – the ability to call any telephone anywhere in the world, Internet access, media and games, and business services.WHAT'S INSIDE
Inside your wireless phone, there is a compact speaker, a microphone, a keyboard, a display screen, and a powerful circuit board with microprocessors that make each phone a miniature computer. When connected to a wireless network, this bundle of technologies allows you to make phone calls or exchange data with other phones and computers around the world. The components operate so efficiently that a lightweight battery can power your phone for days.
Today, wireless phones fit in the palm of your hand, weigh only a few ounces, and offer features such as Web browsing, streaming video, GPS location services, and office applications. Only a few years ago, the electronics in this sleek device would have filled a large briefcase.
THE NUTS AND BOLTS
Wireless networks operate on a grid that divides cities or regions into smaller cells. One cell might cover a few city blocks or up to 250 square miles. Every cell uses a set of radio frequencies or channels to provide service in its specific area. The power of these radios is controlled in order to limit the signal’s geographic range. Because of this, the same frequencies can be re-used in nearby cells. So, many people can hold conversations simultaneously in different cells throughout the city or region, even though they are on the same channel.
In each cell, there is a base station consisting of a wireless antenna and other radio equipment. The wireless antenna in each cell links callers into the local telephone network, the Internet or to another wireless network.
No longer just big radio towers, wireless antennas can be mounted in church steeples, on trees and flagpoles, and on top of tall buildings. Many are no larger than stereo speakers. In rural areas, taller antennas send signals further distances to better serve users who are more spread out.
Wireless antennas transmit signals just like your local radio station. And just like your car radio, these radio signals can be obstructed by trees, tall buildings and even weather.
CONNECTING TO THE WIRELESS NETWORK
When you turn on your wireless phone, it searches for a signal to confirm that service is available. Then the phone transmits certain identification numbers, so the network can verify your customer information – such as your wireless provider and phone number.
If you are calling from a wireless phone to a wired phone, your call travels through a nearby wireless antenna and is switched by your wireless carrier to the traditional landline phone system. The call then becomes like any other phone call and is directed over the traditional phone network, and to the person you are calling.
If you are calling another wireless phone, your call may go through the landline network to the recipient’s wireless carrier, or it might be routed within the wireless network to the cell site nearest the person you called.
If you’re calling someone further away, your call will be routed to a long distance switching center, which relays the call across the country or around the world through fiber-optic cables.
All of this takes place in a few seconds – before you say “hello.”
HOW YOUR VOICE MOVES WIRELESSLY
Most wireless phones use digital technology, which converts your voice into the binary digits 0 and 1 – much like a music CD. These small packets of data are relayed through wireless networks to the receiving phone. On the other end, the conversion process is reversed and the person you are calling hears your voice.
But what makes your phone mobile? Say you’re talking on your wireless phone while walking down the street. The wireless network senses when your signal is getting weaker and hands off your call to an antenna with a stronger signal. Using smaller cells enables your phone to use less power and keep a clearer signal as you move. Even when you’re not talking, your wireless phone communicates with the wireless antenna nearest to you. So, it’s ready to connect your call at any time.
If you travel outside your home area and make a call, another wireless carrier may provide service for your wireless phone. That provider sends a signal back to your home network, so you can send and receive calls as you travel. This is called roaming. Roaming is key to mobile communications, as wireless providers cooperate to provide callers service wherever they go.
Because the shape and size of cells vary, there may also be empty spaces between the coverage areas of two or more cells. These gaps or dead spots can also be caused by trees, tall buildings or other obstructions that block your wireless signal from reaching a nearby antenna. If a local government or landowner won’t allow placement of a wireless antenna, that too creates a dead spot.
DOING MORE WITH DATA
A wireless phone is actually a computer connected to a radio. So, it works much like your personal computer to send and receive information. Digital technology is used to convert data, such as short messages, e-mail or digital pictures, into small packets. These packets are transmitted securely over wireless systems as a series of 0’s and 1’s. Because of its efficiency, digital wireless technology supports more callers per cell site, while offering better sound quality, greater security, longer battery life and faster data services.
As the wireless industry converts to packet-based networks, using the same technology as the Internet, wireless data services continue to expand. Today wireless networks operate at data speeds five to ten times greater than dial-up telephone or earlier wireless networks. Upgraded networks will offer even greater speeds, equivalent to DSL and beyond.
These faster networks mean that Internet services formerly available only on desktop computers will become available anywhere, in the palm of your hand, as a result of digital wireless technology.
