Too add to PA/SAQ:
LAST
UPDATE: 11/11/99
This will probably always under reconstruction!
This is
the most current version of Learning Module II; however, the study guide
needs to be written (for the independent learner) and
some of
the content sections, links, and assessment tools need to be fine-tuned.
(Nothing is wrong, just imperfect!)
Note that
the blinking text designates things that I need to work on; the material
is not wrong, but can be improved.
(Don't
worry, I don't like blinking text, either, so there will not be any in
the finished product!)
LEARNING MODULE
II: REVIEW/OVERVIEW OF
COMMUNICATIONS
& NETWORKING
This learning module summarizes concepts, hardware, and software that is
involved with communications and networking in general. Because Cyberspace,
by definition, involves computer networks, everything in this learning
module applies to Cyberspace and consequently to the Internet; however,
on the otherhand, the content of this module is perfectly general, applying
to all data communications and to any kind of network. before
proceeding consult the Study Guide for this learning moduleIf you
haven't already done so, read the Introduction
to the Study Guide.
The Objectives of this learning module are:
-
To survey the fundamentals of Computer Hardware
and Software necessary to understand the concepts of this course.
-
To relate online access to the concept of protocols
which will be amplified in Learning Module IV.
-
To survey the basic types of networks and introduce
network terminology.
TPQ
OC.1: Rewrite the preceding objectives in terms of personal accomplishments
to be attained after finishing the study of this learning module.
The sequence of
presentations is:
-
DATA COMMUNICATIONS, AN OVERVIEW
-
TRANSMISSION CHARACTERISTICS
-
COMMUNICATIONS HARDWARE
-
COMMUNICATIONS MEDIA
-
COMMUNICATIONS SOFTWARE
-
COMMUNICATIONS PROTOCOLS
-
NETWORK ARCHITECUTRE
-
NETWORK
TECHNOLOGIES
-
INTERNET
CONNCECTIONS
-
SUMMARY
In technological
terms "Communications" is a general word for the transmission of
signals between two or more points. When these signals constitute computer
data, we refer to "data communications". "Telecommunications"
pertains to transmissions over a distance in one of two forms: (1) electronic
transmission (via electrons) occurs through physical media such as
wires and (2) electromagnetic wave transmission (via laser, radio,
TV, microwave, etc.) requires no media (thus information can be sent through
space); however, an exception to this wirless transmission is fiber optics
in which light carries data through cables. Networking is the linking
of computers (not necessarily over large distances) so they can communicate,
sharing hardware and software, thus uniting processing power. The goal
of distributed computing is the optimum spread of computing resources
among users; obviously, telecommunications and networking are critical
features of such systems. The combination of large databases, communications,
and distributed computing is having a dramatic impact on all areas
of human interaction; it will have a profound effect on education
and learning.
1.
DATA COMMUNICATIONS, AN OVERVIEW:
-
An oversimplified generic
model of communications (See) would have a signal from a
source encoded (i.e. the ________(1)
signal is __________(2)) for
transmission over a communications channel after which it is decoded
for the receiver. Four types of transmissions involving different signal/channel
combinations are shown in Figure
C&N-2
-
the signal must be protected
from corruption by "noise" (interference from the environment)
-
Processing in a distributed
environment is based on the client-server model
-
In general, a telecommunication
network is a particular arrangement of resources including:
-
computer hardware (host
computers, servers, workstations, peripheral devices, etc.)
-
communication hardware
(modems, codecs, transmitters, receivers, repeaters, & switching devices)
(See section 3, below.)
-
communication media (telephone
lines, cables, etc.) (See section 4, below.), and
-
communication software
that coordinates the nework components. (See section 5,
below.)
-
Types
of transmission signals (See Figure
C&N-3.):
-
An
