One piece of equipment
controlling the operation of
equipment by sending to it.
Equipment is usually
Personal
communication
systems
Fibre optic cable
Works by transmitting
data as a series of
pulses along a thin glass
fibre. One bundle of
fibres is used to send
messages and a second
bundle carries messages
in the opposite direction
Are good at
transferring data
because they are fast
and do not suffer
from interference
like metal cables.
Broadband
Very high
speed
digital lines
A router is a special
piece of hardware
which co-ordinates
the switching of
messages between
the computers and
the rest of the
internet
Broadband
allows you to
be on the
phone whilst
on the internet
Wireless
media /
Radiowaves
Microwaves
Mobile phones use
microwaves. Ideal for
linking computers in
two separate buildings
fairly near each other.
Satellite systems also
make use of
microwaves.
Infra-red
Short range
communications
Key freatures are
Robustness
Low cost
Low power
Examples
Wireless
mouse /
Keyboard
Link from a
laptop
computer
to a printer
Wireless
hands
free for
mobile
phones
in cars
Bluetooth
Can only travel
short distances and
line of sight and this
limits their use
TV
remote
control
Mobile
phones
Disadvantages
Signal
cannot
be
recieved
Limit
calls
Low
battery
Low
credits
Microwave
radiation that
comes from
the phone can
affect health
Users can build
up large phone
bills using
internet service
Can be a
nuisance is
they ring at
inconvenient
times