Voice-based wireless devices may have started out as new
and exciting technology but their success was partially due
to their ability to connect to the old dull technology of landline
telephones. Imagine what would have happened if early cellular
phones were only able to call other cellular phones. Who
would these early users have been able to call? Perhaps the
only other users would have been a very small and exclusive
club of executives with a habit of traveling in remote places. It’s
clear that cellular devices and service would not have been very
useful to mainstream society. (Unless you consider the value
generated by keeping the boss entertained while out in the
boondocks—useful for some, I’m sure.)
The CB radio is a good example of a device that is limited
to communicating only with other CB radios. CB’s are relatively
cheap to buy and free to talk on—no roaming or per
minute usage fees. But they don’t offer the best value because
you can’t reach everyone you wish to speak with, those you do
try to reach aren’t always on, and privacy doesn’t exist. This
points out the need for interconnections and the ability to convert
from one protocol or system to another.
It’s relatively easy to create concepts for cool new devices
and services but regardless of how cool and unique a device or
service, the value comes from the ability to connect and communicate
to others.
Metcalfe’s law is the theory that the value of the network
increases exponentially. If you double the size of the network
(let’s say from a network that serves 1,000 users to one that
reaches 2,000 users) you more than double the value—you
actually quadruple the value of the network.
Imagine if someone were to approach you and offer to
switch your Internet service to one that was half the cost. The
only difference would be that this cheaper service could only
reach half of your current network. Would you be willing to
switch? Most likely you would not.
This is why both the telephony system and the Internet
continue to grow in both users and value—the greater the size
of the network the greater the value.
Dr. Robert M. Metcalfe, inventor of Ethernet, founder of
3Com Corp. and columnist for Infoworld. Dr. Metcalfe together
with D.R.Boggs invented Ethernet back in 1973 while working
for Xerox Corporation in their Palo Alto Research Center
(PARC). PARC was also involved in the invention of the PC
and Graphical User interface; however, it was not the place
where these innovations were developed into successful commercial
products. Ethernet, the name for Local Area
Networking (LAN) technology turned PC’s into communication
tools by linking them together into a common network.
In 1979, Metcalfe left Xerox and founded 3Com Corp. (so
named for three words—computer, communication and compatibility)
for the purpose of promoting PC LAN’s and
Ethernet as the standard. Metcalfe was successful in bringing
together companies such as Digital Equipment, Intel and
Xerox and made Ethernet the most widely used LAN.
Metcalfe retired from 3Com in 1990 and embarked on a
career in journalism that led to his writing a weekly column on
networking, “From the Ether,” for Infoworld. It was in this
forum that he published “From the Ether: A network becomes
more valuable as it reaches more users;” Infoworld Magazine,
October 2, 1995. This article set forth the principles now
known as Metcalfe’s Law.
This law is very important to the growth and adoption of
wireless Internet. The premise that the network value grows by
the square of the size of the network does not discriminate by
device or access method. The number of network users can be
a combination of various access devices using various access
technologies, each with their own network speeds. The sheer
number of wireless Internet mobile devices forecasted to be in
use in the future creates the yet another source of network
growth and source of value for all users of the network. 178
IT Certification CCIE,CCNP,CCIP,CCNA,CCSP,Cisco Network Optimization and Security Tips
SECURITY VIDEO MONITORING
SECURITY VIDEO MONITORING
Security video monitoring applications help to visually assure
that valuable assets are not eroded or destroyed by unauthorized
users. Traditionally, security video monitoring was limited
to on-site video monitors that security personnel viewed as
either videotapes or as real-time images. The introduction of
low-cost digital video cameras and data connections allow for
the remote location of video cameras. When these cameras are
connected through the Internet, they are called Web cameras
(WebCams.)
At the end of 2000, there were already in excess of 100,000
public WebCams in operation throughout the world* and private
video monitoring systems have millions of privately
installed video cameras. Although many of these video cameras
are connected by wire, some are connected by wireless links.
The key applications for wireless security monitoring
included traffic management (traffic cams), public access
monitoring (public safety), law enforcement (cameras on
police cars), and other applications that require a camera at
remote locations where wired connections are not practical or
where mobility (video monitoring while moving) is important.
Figure 4-12 shows the video camera that is normally
mounted in police cars. Using high-speed wireless systems,
images from police cars can be monitored at a central facility.
This may dramatically increase the safety for police officers. 176
Security video monitoring applications help to visually assure
that valuable assets are not eroded or destroyed by unauthorized
users. Traditionally, security video monitoring was limited
to on-site video monitors that security personnel viewed as
either videotapes or as real-time images. The introduction of
low-cost digital video cameras and data connections allow for
the remote location of video cameras. When these cameras are
connected through the Internet, they are called Web cameras
(WebCams.)
At the end of 2000, there were already in excess of 100,000
public WebCams in operation throughout the world* and private
video monitoring systems have millions of privately
installed video cameras. Although many of these video cameras
are connected by wire, some are connected by wireless links.
The key applications for wireless security monitoring
included traffic management (traffic cams), public access
monitoring (public safety), law enforcement (cameras on
police cars), and other applications that require a camera at
remote locations where wired connections are not practical or
where mobility (video monitoring while moving) is important.
Figure 4-12 shows the video camera that is normally
mounted in police cars. Using high-speed wireless systems,
images from police cars can be monitored at a central facility.
This may dramatically increase the safety for police officers. 176
GOVERNMENT
GOVERNMENT. Providing education for government workers
is necessary to ensure that information-intensive systems (such
as tax collection) can operate effectively. In the United States
in 1999, there were more than 3 million government workers.
The average government worker receives 1 to 2 weeks of training
per year to learn software and technology systems, standard
processes, and to develop leadership skills. This results in a
requirement of over 5 million weeks of training. To minimize
the costs of travel and lost time, many government agencies
use distance learning programs to reduce training costs.
is necessary to ensure that information-intensive systems (such
as tax collection) can operate effectively. In the United States
in 1999, there were more than 3 million government workers.
The average government worker receives 1 to 2 weeks of training
per year to learn software and technology systems, standard
processes, and to develop leadership skills. This results in a
requirement of over 5 million weeks of training. To minimize
the costs of travel and lost time, many government agencies
use distance learning programs to reduce training costs.
PROFESSIONAL
PROFESSIONAL. Because technology and business processes
are constantly changing, professional education is developed and
provided by companies to keep their employees competitive.
Training budgets range from 1 to 5 percent of a company’s gross
sales, and a growing percentage of these funds are used for distance
learning courses.
are constantly changing, professional education is developed and
provided by companies to keep their employees competitive.
Training budgets range from 1 to 5 percent of a company’s gross
sales, and a growing percentage of these funds are used for distance
learning courses.
COLLEGE AND UNIVERSITY EDUCATION
COLLEGE AND UNIVERSITY EDUCATION. Since the Internet
was pioneered at universities to facilitate information sharing,
it’s not surprising that an increasing number of them are
creating Web-based universities. By 2002, 85 percent of two-year
colleges (in 1999 there were 847 two-year colleges in the
United States) are expected to be offering distance learning
courses, up from 58 percent in 1998. It is projected that over
80 percent of the four-year colleges (in 1999 there were 1,472
four-year colleges and universities in the United States) will be
offering distance learning courses in 2002, up from 62 percent
in 1998. Many of these will be Web-based. To put this into perspective,
there are 15 million full- and part-time college students
in the United States, of which an estimated 90 percent
are online, representing by far the most active single group on
the Net. Moreover, in 1998, 21 percent of these students purchased
$900 million in goods and services online.
It is estimated that 93 percent of distance learning programs
in American colleges and universities use email and
almost 60 percent use email in conjunction with the Web.†
When distance education is offered, campus visits are not
required for most programs. Learners register online each
semester and may take single courses for personal enrichment
or opt to enter a degree program. Textbooks and class syllabi
can be mailed to learners. Online classes run typically on a 16-
week semester schedule, beginning and ending at the same
time as on-campus classes. Students read their textbooks and
visit online message boards weekly, posting class comments or
questions whenever it is convenient for them. The back-andforth
commentary on the message boards simulates a classroom
discussion. Midterm and final exams are usually taken
under the watchful eye of an approved proctor at a local college,
library, or human resources training center. 173
was pioneered at universities to facilitate information sharing,
it’s not surprising that an increasing number of them are
creating Web-based universities. By 2002, 85 percent of two-year
colleges (in 1999 there were 847 two-year colleges in the
United States) are expected to be offering distance learning
courses, up from 58 percent in 1998. It is projected that over
80 percent of the four-year colleges (in 1999 there were 1,472
four-year colleges and universities in the United States) will be
offering distance learning courses in 2002, up from 62 percent
in 1998. Many of these will be Web-based. To put this into perspective,
there are 15 million full- and part-time college students
in the United States, of which an estimated 90 percent
are online, representing by far the most active single group on
the Net. Moreover, in 1998, 21 percent of these students purchased
$900 million in goods and services online.
It is estimated that 93 percent of distance learning programs
in American colleges and universities use email and
almost 60 percent use email in conjunction with the Web.†
When distance education is offered, campus visits are not
required for most programs. Learners register online each
semester and may take single courses for personal enrichment
or opt to enter a degree program. Textbooks and class syllabi
can be mailed to learners. Online classes run typically on a 16-
week semester schedule, beginning and ending at the same
time as on-campus classes. Students read their textbooks and
visit online message boards weekly, posting class comments or
questions whenever it is convenient for them. The back-andforth
commentary on the message boards simulates a classroom
discussion. Midterm and final exams are usually taken
under the watchful eye of an approved proctor at a local college,
library, or human resources training center. 173
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