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Chapter 26: Satellite Multiple Accessing Arrangements – Review Notes

Chapter 26: Satellite Multiple Accessing Arrangements

This is the summary notes of the important terms and concepts in Chapter 26 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.


CHAPTER 26

SATELLITE MULTIPLE
ACCESSING ARRANGEMENTS


Items

Definitions

Terms

1

Also called as Multiple Destination, It implies that more than
one user has access to one or more radio channels within a satellite
communications channel.
Multiple Accessing Arrangement:
·        
Frequency-division
multiple accessing (FDMA)
·        
Time-division
multiple accessing (TDMA)
·        
Code-division
multiple accessing (CDMA)

Multiple Accessing

2

A given number of the available voice-band channels from each
earth station are assigned a dedicated destination.

Pre-assignment (dedicated)

3

Voice channels are assigned on an as-needed basis.

Demand Assignment

4

The method of assigning adjacent channels different
electromagnetic polarizations and is possible by using orthogonal
polarization and spacing adjacent channels 20 MHz apart.

Frequency Reuse

5

Eskimo word meaning “little brother”.

Anik

6

Domestic Satellites operated by Telsat Canada.

Anik-E communications Satellite

7

A method of multiple accessing where a given RF bandwidth is
divided into smaller frequency bands.

FDMA

8

Multiple channels per carrier formats assigned and remain
fixed for a long Period of time.

Fixed-Assignment, Multiple
Access (FAMA)

9

Assigning carrier frequency on temporary basis using a
statistical assignment process.

Demand-Assignment
Multiple Access

10

An acronym for Single-channel-per-carrier PCM multiple Access
Demand-assignment Equipment.

SPADE

11

Stands for Single-Carrier-Per-Channel.

SCPC

12

A time division-multiplexed transmission that is frequency
division multiplexed.

Common Signaling Channel
(CSC)

13

The predominant Multiple-access method of time division
multiplexing digitally modulated carriers between participating earth
stations within a satellite network through a common satellite transponder.

TDMA

14

An RF-to-RF repeater that simply receives the earth station
transmissions, amplifies them, and then retransmits them in a downlink beam
that is received by all other participating station.

Transponder

15

It is where transmissions from all earth stations are
synchronized.

Reference Burst

16

It is where all receiving stations recover a frequency and
phase coherent carrier for PSK demodulation.

Carrier Recovery Sequence
(CRS)

17

An acronym for, Conference of European Postal and
Telecommunications Administrations, is commonly used TDMA frame format for
digital satellite system.

CEPT

18

Sometimes referred to as Spread-Spectrum Multiple entire
allocated bandwidth Access, the transmissions can spread throughout.

Code-Division Multiple Access
CDMA)

19

A unique binary word that each earth station’s transmissions
are encoded.

Chip Code

20

It compares two signals and recover the original data.

Correlator

21

It assigns an individual terrestrial channel (TC) to a
particular satellite channel (SC) for the duration of the call.

Digital non interpolated Interface

22

It assigns a terrestrial channel to a satellite channel only
when speech energy is present on the TC.

Digital Speech Interpolated Interface

23

A form of analog channel compression that has been used for
sub oceanic cables for many years.

Time-Assignment Speech Interpolation
(TASI)

24

The art or science of plotting, ascertaining or directing the
course of movements, in other words, knowing where you are and being able to
find your way around.

Navigation

25

It is the most ancient and rudimentary method of navigation
and simply continuing to travel about until you reach your destination,
assuming of course that you have one.

Wandering

26

Earliest effective means of navigation wherein direction and
distance are determined from precisely timed sightings of celestial bodies,
including the stars and moon.

Celestial Navigation

27

Method of navigation by means of fixing a position and
direction with respect to familiar, significant landmarks such as railroad
tracks, water towers, barns, mountains and bodies of water.

Piloting

28

A navigation technique that determines position by
extrapolating a series of measured velocity increments.

Dead Reckoning

29

The term derived from the word “deduced” and not necessarily
from the fate of the people who used the technique.

Dead

30

He used dead reckoning successfully in 1927 during his
historic 33-hour transatlantic journey.

Charles Lindbergh

31

She attempted to make the first around-the-world in 1937 using
the dead reckoning technique.

Amelia Earhart

32

Navigation technique wherein the position is determined by
measuring the travel time of an electromagnetic wave as it moves from a
transmitter to a receiver.

Radio Navigation

33

A radio Navigation system for terrestrial surface broadcast.

Decca

34

Radio Navigation system that provides global coverage and
terrestrial surface broadcast.

Omega

35

Also a terrestrial surface broadcast.

LORAN

36

Low-orbit satellite broadcast that provides global coverage.

Navy Transit GPS

37

Medium-orbit satellite broadcast also provides global
coverage.

Navstar GPS

38

Means of radio navigation in which receivers acquire Coded
signals from two pairs of high-powered, land based transmitters whose
locations are precisely known.

LORAN

39

An acronym for Navigation System with Time and Ranging.

Navstar

40

An abbreviation for Global Positioning System.
Two levels of service or accuracy:
·        
Standard
Positioning Service
·        
Precise
Positioning Service

GPS

41

A satellite-based open navigation system which simply means
that it is available to anyone equipped with a GPS receiver.
Consists of three segments:
·        
a
space segment
·        
a
ground control segment
·        
user
segment

Navstar GPS

42

It was when the Navstar declared as fully operational by the
U.S. Air Force Space Command.

April 27, 1995

43

It was completed in 1994 and is maintained by the United
States Air Force.

Navstar Satellite System

44

A positioning and timing service that is available to all GPS
users on a continuous, worldwide basis with no direct change.

Standard Positioning
Service

45

Sometimes called Space Segment, consists of 24operational
satellites revolving around Earth in six orbital planes approximately 60°
apart with four satellites in each plane.

Satellite Segment

46

It produces highly accurate timing signals for satellites.

Cesium Atomic Clock

47

A unique integer number that is used to encrypt the signal
from that satellite.

Pseudorandom Noise
(PRN)
Code Number

48

A term associated with a table showing the position of a
heavenly body on a number dates in a regular sequence, in essence, an
astronomical almanac.

Ephemeris

49

Error in the receiver’s clock which affects the accuracy of
the time-difference measurement.

Clock Bias Error

50

The Navstar control segment.
It consists of :
·        
Fixed-location
ground based monitor stations
·        
Master
Control Station
·        
uplink
transmitter

Operational Control
System

51

It makes standard GPS more accurate. It works by cancelling
out most of the natural and man-made errors that creep into normal GPS
measurements.

Differential GPS

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