With
the trend towards working from home, there is an increase in communication
equipment in the home such as telephones, fax machines, computers and modems to
access the internet. Multi-function machines are now available which offer fax,
copier, printer, PC-fax, scanner and e-mail from one unit. |
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Internet, Modem and Interactive
Services
A modem is a device which allows a computer or Digital Set
Top Box (STB) to send and receive information over a telephone line. It can be
an internal device built into the desktop, laptop, or STB, a separate external
box that connects to a computer’s serial port, or a PC card that plugs
into the PC card slot found on most laptops. |
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Telephone There
are basically four types of telephone:
1. Analogue Corded The
traditional telephone with a fixed cord from the phone base to the
handset.
2. Analogue Cordless The first system of cordless
technology with limited operating distances.
3. New Frequency
Analogue Cordless
An enhanced system which uses eight channel
technology, a new frequency range of 31-39MHz and gives clearer call and larger
operating distance approx. 100m away from the base station.
4.
DECT-Digital Enhanced Cordless Telephony DECT phones that use digital
cordless technology operate on 1.8GHz and allow multiple handsets to be used
from a single base station, offering significantly greater range than analogue
models, improved reception and clearer speech.
Combined mobile/DECT
cordless phones provide mobile and DECT features in one smart handset, which
can accept or make calls on both mobile and land line networks. These use DECT
protocol close to the home and automatically switch to mobile use outside a
certain range.
Fax Machines
Fax machines plug into a
telephone socket and have built-in software to enable the user to transmit data
for instance, a letter, which can be received normally by another fax machine.
Early fax machines used thermal paper but more modern machines print directly
onto standard A4 paper.
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Modems are available in a
variety of speeds. The faster the modem, the quicker the data can be
transferred and hence the shorter and cheaper the phone call will be. This is
provided the telephone line and other end of the line can support the modem
speed and protocol.
To connect a modem to a telephone line, the socket
will need to be a BT style socket. See following section on BT style sockets
and installing extensions. Faster access speeds are possible using ISDN digital
phone lines, or services such as BT Highway which adds a digital line alongside
your existing phone line. To connect your computer to the digital line you need
an ISDN adapter rather than a modem, and the Internet Service Provider you
choose must offer ISDN support.
An alternative to the PC-modem-phone
line or PC-ISDN approach is to connect through the mobile phone networks,
either by linking a laptop to a mobile phone through a data card or an
infra-red link. Cable modems and STB modems are often used as the return path
for the interactive services offered by the terrestrial, satellite or cable
operators. These modems may also offer internet access via the STB.
Telephone Extensions
Before
installing a telephone extension, it is important to note the Ring Equivalent
Number (REN). Telephone lines have a REN of 4- they can operate up to 4
telephone accessories (e.g. phones, fax, answerphone), each with a REN of 1.
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