DTMF
One of the frequencies is from the upper frequency band and the other from the
lower band. All frequencies are inside the voice frequency band (300–3,400 Hz).
This signaling principle is known as dual-tone multi-frequency (DTMF) signaling.
Other services of Tone dialing.
• Supplementary services enable subscribers to influence the routing of their
telephone calls.
• Value-added services are services that we can use via the telephone
network (One example of value added services is telebanking)
The worst disadvantage is the subscribers still have to memorize command
sequences to use the new services offered by a modern telephone network.
Subscriber Loop Systems
• Every subscriber has two dedicated lines connecting to the nearest
switching exchange, which are called the Loop lines of that subscriber.
• The laying of lines to the subscriber premises from the exchange office is
called Cabling.
• As it is difficult to run cables from each subscriber’s premises to the
exchange, large cables are used through which the drop wires (subscriber
lines) are taken to a distribution point.
One of the frequencies is from the upper frequency band and the other from the
lower band. All frequencies are inside the voice frequency band (300–3,400 Hz).
This signaling principle is known as dual-tone multi-frequency (DTMF) signaling.
Other services of Tone dialing.
• Supplementary services enable subscribers to influence the routing of their
telephone calls.
• Value-added services are services that we can use via the telephone
network (One example of value added services is telebanking)
The worst disadvantage is the subscribers still have to memorize command
sequences to use the new services offered by a modern telephone network.
Subscriber Loop Systems
• Every subscriber has two dedicated lines connecting to the nearest
switching exchange, which are called the Loop lines of that subscriber.
• The laying of lines to the subscriber premises from the exchange office is
called Cabling.
• As it is difficult to run cables from each subscriber’s premises to the
exchange, large cables are used through which the drop wires (subscriber
lines) are taken to a distribution point.
