The Way Things Work Now by David Macaulay & Neil Ardley

Author:David Macaulay & Neil Ardley
Language: eng
Format: epub
Published: 2016-05-30T06:59:24+00:00

WORKING WITH WAVES

TELEPHONE NETWORK

TELEPHONE

The global telephone network enables us to speak to people anywhere in the world. Using metal cables, radio links and fibre-optic cables, a call HANDSET

from a fixed telephone goes through a series of local and main exchanges that route it to another telephone. A mobile phone connects by radio to a nearby base station, which provides coverage over a hexagonal area known as a cell. Each cell has a base station and varies in size depending on the number of callers in the cell. As a mobile phone moves from one cell to another, it automatically connects to the base station in the next cell so that the call can continue. Each base station routes the call to a mobile exchange, which connects to the main exchange in the network. A telephone’s mouthpiece and earpiece work in the same way as a microphone (see p.228) and earphone (see p.233). Mobile networks also support text messaging and picture messaging, and allow users to

PHONE SOCKET

connect to the Internet.

LOCAL EXCHANGE

All the telephones in a small

FIBRE-OPTIC

area are connected to a local

PUBLIC PHONE BOX

CABLE LINK

exchange.

MAIN

C

E

ELL

XCHANGE

BASE

STATION

RADIO LINK

BASE

STATION

BASE

MOBILE

S

E

M

TATION

XCHANGE

OBILE PHONE

PHONE MOVES

CELL

TO ANOTHER

CELL

CELL

BASE

S

B

TATION

ASE

STATION

RADIO LINK

BASE STATION

SMARTPHONE

OR TABLET

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25/01/2016 16:58

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