This is the summary notes of the important terms and concepts in Chapter 16 of the book "Electronic Communications System" by Wayne Tomasi. The notes are properly synchronized and concise for much better understanding of the book. Make sure to familiarize this review notes to increase the chance of passing the ECE Board Exam.
Process of conveying information from one place to another.
Is a long-distance communications
One of the most remarkable devices ever invented.
Anyone who uses a telephone or a data modem on a telephone
circuit is part of a global communications network.
Public Telephone Network
The PTN is comprised of several very large corporations and
hundreds of smaller independent companies jointly.
The telephone system as we know it today began as an unlikely
collaboration of two men with widely disparate personalities:
Alexander Graham Bell and Thomas A. Watson
The simplest and most straightforward form of telephone
Plain Old Telephone Service
Most fundamental component of a telephone circuit.
Subscriber Loop or Local Loop
An unshielded twisted-pair transmission line consisting of two
insulated conductors twisted together
Comes from the Greek word "tele" meaning from afar
and phone, meaning sound, voice, or voiced sound.
The first telephone set that combined a transmitter and
receiver into a single handheld unit was introduced in 1878
Helps prevent the speaker from talking too loudly
Sidetone or Talkback
The pair of wores connecting.
A series of telephone connection interfaces that are
registered with the U.S. Federal Communications Commission.
RJ or Registered Jacks
The most common telephone jack in use today and can have up to
An apparatus that creates an exact likeness of sound waves
with an electric current.
Is originally an electromagnetic bell, placed directly across
the tip of the ring of the local loop.
Purpose of a Ringer.
Alert the destination party of incoming
Sometimes called a Switch Hook.
On/Off Hook Circuit
Helps solve an important transmission problem in telephone set
It is the transmitter of the telephone.
Converts acoustical signals in the form of sound pressure
waves from the caller to electrical signals that are transmitted into the
Enables the subscriber to output signals representing digits.
Signaling messages can be subdivided further into one or four
Indicate a request for service.
Provide call status information.
Provide information in the form of announcements.
Provide the routing information.
Is strictly for signaling between a subscriber’s location and
the nearest telephone office or message switching center.
Are used to transfer digits and control signals between
Are combinations of two frequencies that fall within the
normal speech bandwidth so they can be propagated over the same circuits as
Equipment Busy Signal is sometimes.
Congestion Tone or No-Circuit-Available
Occurs whenever the system is overloaded and more calls are
being placed than can be completed.
Is sent from a central office to a subscriber whenever there
is an incoming call.
Telephones that operate without the cords attached to the
Relay radio signals and messages from wire line and cellular
telephones to subscribers carrying portable receivers.