Managing Information Technology

Chapter 3 • Telecommunications and Networking 63

revolution, managers need to have a rudimentary under-
standing of the various telecommunications and network-
ing options available to their organizations.
The prefix tele-simply means operating at a distance.
Thereforetelecommunicationsis communications at a
distance. There are a number of other terms or abbrevia-
tions that are used almost interchangeably with telecommu-
nications:data communications,datacom,teleprocessing,
telecom, and networking. We prefer telecommunications
because it is the broadest of these similar terms. It includes
both voice (telephone) and data communications (including
text and image). Teleprocessing means the computer
processing is taking place at a distance from where the data
originate, which obviously requires telecommunications.
Networking is the electronic linking required to accomplish
telecommunications.
One might think that only a wire or a wireless sig-
nal is needed for telecommunications, but it is much
more complex than that! To begin a detailed considera-
tion of telecommunications, first consider the primary
functions performed by a telecommunications network,
as listed in Table 3.1. The most obvious of these func-
tions is the transmissionof voice or data, or both, using
the network and the underlying media. The processing
involves making sure that an error-free message or data
packet gets to the right destination. Subfunctions of
processing include editorial, conversion, and routing.

Editorial involves checking for errors and putting

the communication into a standardized format, and

conversionincludes any necessary changes in the coding

system or the transmission speed when moving from one

device on the network to another. In networks where al-

ternative paths are possible between the source and the

destination of a communication (particularly WANs and

the Internet), routing—choosing the most efficient

path—is an important task. Closely related to the pro-

cessing function is network control, which includes

keeping track of the status of various elements of the

system (e.g., which elements are busy or out of service)

and, for some types of networks, checking each worksta-

tion periodically to see if it has a communication to

send. A not-so-obvious but critical function is the provi-

sion of an interfacebetween the network and the user;

hopefully this interface will make it easy and efficient

for a manager or any other network user to send a com-

munication. The next major section explores the variety

of ways in which the functions listed in Table 3.1 can

be delivered.

Key Elements of Telecommunications and Networking

We believe that you as a business manager need to

understand certain key elements about telecommunica-

tions and networking to participate effectively in the

communications revolution—to know what the options

are for the business systems you need. These key ele-

ments include certain underlying basic ideas, such as

analog versus digital signals and switched versus pri-

vate lines; the variety of transmission media available;

the topology (or possible arrangements) of networks;

the various types of networks, including LANs and

WANs; and the network protocols employed on these

networks. This section will be somewhat technical, but

we will do our best to make it understandable. Above all

the details, we want you to keep sight of the big picture

of telecommunications.

Analog and Digital Signals

Perhaps the most basic idea about telecommunications is

that the electronic signals sent on a network may be either

analog or digital, depending on the type of network.

Historically, the telephone network has been an analog

network, with voice messages sent over the network by

having some physical quantity (e.g., voltage) continuously

vary as a function of time. This analog signal worked fine

for voice transmission because it required the significant

variations provided by an analog signal (corresponding to

TABLE 3.1 Functions of a Telecommunications

Network

Function Brief Description

Transmission Movement of voice and/or data

using network and underlying media

Processing Ensuring that error-free communication

gets to right destination

Editorial Checking for errors and putting

communication into standardized

format

Conversion Changing coding system or speed

when moving from one device to

another

Routing Choosing most efficient path when

multiple paths are available

Network control Keeping track of status of network

elements and checking to see if

communications are ready to be sent

Interface Handling interactions between users

and the network