This is the summary notes of the important terms and concepts in Chapter 19 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.
The term for mobile telephone services which began in 1940s
and are sometimes called Manual telephone systems.
Mobile Telephone Manual System (MTSs)
The frequency used by MTSs.
Switch that was used by MTS to activate the transceiver.
It was introduced in 1964 which used several carrier
frequencies and could, therefore, handle several simultaneous mobile
conversations at the same time.
Improved Mobile Telephone System
The term suggested any radio transmitter, receiver, or
transceiver that could be moved while operation.
The term that described a relatively small radio unit that was
handled, battery powered, and easily carried by a person moving at walking
It is similar to two-way mobile radio in that most
communications occurs between base stations and mobile units.
It operates on half duplex and use PTT transceivers.
Examples of two-way radio:
land mobile radio
A one to one system that permits two-way simultaneous
transmissions and operates the same way as the standard wire line telephone
Hinted of a cellular telephone scheme that he referred to as
simply a small-zone radio telephone system in the July 28, 1945.
On June 17, 1946, they introduced the first American
commercial mobile radio-telephone service to private customers.
AT&T and Southwestern Bell
A radio telephone service introduced by AT&T in 1947.
Unveiled the most famous mobile telephone to date: the fully
mobile shoe phone in 1966 in a television show called Get Smart.
The year when FCC granted AT&T the first license to
operate a developmental cellular telephone service in Chicago.
A satellite-based wireless personal communications satellite
Another term for cellular telephone.
A large geographic market area.
It is employed to increase the capacity of a mobile telephone
The shape that was used because it provides the most effective
transmission by approximating a circular pattern while eliminating the gaps
present between adjacent circles.
Large cells that typically has 1 mile and 15 miles radius with
base station transmit power 1W and 6 W.
The smallest cells that typically has radius of 1500 feet or
less with base station transmit powers between 0.1 W and 1 W.
The process in which the same set of frequencies can be
allocated to more than one cell, provided the cells are separated by
A geographic cellular radio coverage area containing three
groups of cells.
Typically equal to 3,7, or 12.
The process of finding the tier with the nearest co-channel
Two cells using the same set of frequencies.
The interference between the co-channels cells.
Adding radio channels to a system:
the transmit power per cell
vacated coverage areas with new cells
The ratio of the cell radius and distance from the nearest
The ratio of the cell radius and distance
from the nearest co-channel cell
Channel next to one another in the frequency domain.
It results from imperfect filters in receivers that allow
nearby frequencies to enter the receiver.
Most prevalent when a mobile unit is receiving a weak signal
from the base station.
The area of a cell, or independent component coverage areas of
cellular system is further subdivided thus creating more areas.
Occurs when number of the number of subscriber wishing to
place a call at any given time equals the number of channels in the cell.
Maximum Traffic Load
A condition occurs when a new call is initiated in an area
where all the channels are in use.
Smaller areas when a single omnidirectional antenna is
replaced by several directional antennas, each radiating within smaller area.
Using directional antennas.
Placing two receive antennas one above the other.
A means of avoiding full-cell splitting where the entire area
would otherwise need to be segmented into smaller cells.
A means of avoiding co-channel interference, although it
lowers the capacity of a cell by enabling reuse inside the reuse distance
which is normally prohibited.
The locations of radio-frequency transceivers. It serves are
central control for all users within that cell.
It handles all cell-site control and switching functions.
Occurs when a mobile unit moves from one cell to another
It controls channel assignment, call processing, call setup
and call termination.
Mobile Exchange (EMX)- Bell Lab.
Mobile Telephone Switching Office
The transfer of a mobile unit from one base station’s control
to another base station’s control.
A connection that is momentarily broken during the
cell-to-cell transfer. It is a break before-make process.
A flawless hand off with no perceivable interruption of
It is used by computers that is based on variations in signal
strength and signal quality.
Either the mobile unit or the network determines the need for
a handoff and initiates the necessary network procedures.
Appropriate network procedures reserve the resources needed to
support the handoff.
The actual transfer of control from one base station to
another base station takes place.
Execution Unnecessary network resources are relinquish and
made available to other mobile units.
Roaming from one company’s calling area into another company’s
Stands for Electronics Industries
Association/Telecommunications Industry Association, developed the IS-41
It aligns with a subprotocol of the SS7 protocol stack that
facilitates communications among database other network entities.
Stands for Cellular Telecommunication Industry Association.
The process where a mobile unit notifies a serving MTSO of its
presence and location through a base station controller.
Components of Cellular Telephone System:
A digital telephone exchange located in the MTSO that is the
heart of a cellular telephone system.
Electronic Switching Center
A datalink protocol at a transmission rate of 9.6 kbps.
Another name for cell-site controller.
Base Station Controller
It manages each of the radio channels at each site supervises
calls, turns the radio transmitter and receiver on and off, injects data onto
the control and voice channels, and performs diagnostic tests in the
Stands for Base transceiver station.
A part of base station subsystem that can be either narrowband
FM analog system or either PSK or QAM for digital systems with effective
The radio receiver that detects the strongest signal.
It governs the way telephone calls are established and
Examples of Protocol:
The actual voice channel where mobile users communicate
directly with either mobile or wireline subscribers through a base station.
It is used for transferring control and diagnostic information
between mobile users and a central cellular telephone switch through a base
Transmit on base station:
Receive on base stations:
Types of calls: