http://www.agc.gov.my/Akta/Vol.%207/Act%20332.pdf
Tuesday, 12 June 2012
Web Searching
What
is web browser???
This is the answer...
1.
A web browser is a software application that enables a user
to
display and interact with text, images, and other
information
typically
located on a web page at a website on
the
World Wide Web or a local area network.
2.
Software that displays web pages
3.
Software that gives a user access to the World Wide Web.
Web
browsers often provide a graphical interface that lets
users
click buttons, icons, and menu options to view and
navigate
Web pages..
answer from the wikipedia...
Although browsers are primarily intended to access the World Wide Web, they can also be used to access information provided by web servers in private networks or files in file systems. The major web browsers are Firefox, Google Chrome, Internet Explorer, Opera, and Safari.
Monday, 14 May 2012
Introduction to HTML Programming
what is HTML..?
- An acronym for HyperText Markup Language,
HTML is the language used to tag various
parts of a Web document so browsing
software will know how to display that
document's link, text., graphics, and attached media.
Monday, 26 March 2012
Electromagnetic spectrum
The
electromagnetic (EM) spectrum is the range of all possible electromagnetic radiation. The
"electromagnetic spectrum" (or just spectrum) of an object is
the characteristic distribution of electromagnetic radiation from that object.
The
electromagnetic spectrum, shown in the chart, extends from just below the
frequencies used for modern radio (at the long-wavelength end) to gamma
radiation (at the short-wavelength end), covering wavelengths from thousands of
kilometers
down to fractions of the size of an atom. In
our universe, the short wavelength limit is likely to be the Planck length, and
the long wavelength limit is the size of the universe itself, though in
principle the spectrum is infinite.
The
most familiar part of the electromagnetic spectrum is the visible region, which
spans the colors of the rainbow
(wavelength range of 400-700 nanometers (nm)). We are able to see things
because our eyes are sensitive to this region of the spectrum. A variety of
applications have been found for the different parts of the spectrum. For
instance, radio waves are used for the transmission of data for television,
mobile phones, and wireless networking. X-rays
and gamma rays are used in medicine.
cellular network
A cellular network is a radio network distributed over land areas called cells, each served by at least one
fixed-location transceiver known as a cell site or base station . When joined together these cells
provide radio coverage over a wide geographic area. This enables a large number
of portable transceivers (e.g., mobile phones, pagers,
etc.) to communicate with each other and with fixed transceivers and telephones
anywhere in the network, via base stations, even if some of the transceivers
are moving through more than one cell during transmission.
Cellular networks offer a number of
advantages over alternative solutions:
- increased capacity
- reduced power use
- larger coverage area
- reduced interference from other signals
An example of a simple non-telephone
cellular system is an old taxi driver's radio system
where the taxi company has several transmitters based around a city that can
communicate directly with each taxi.
Example of frequency reuse factor or
pattern 1/4
In a cellular radio system, a land area to be supplied
with radio service is divided into regular shaped cells, which can be
hexagonal, square, circular or some other irregular shapes, although hexagonal
cells are conventional. Each of these cells is assigned multiple frequencies (f1
- f6) which have corresponding radio base stations.
The group of frequencies can be reused in other cells, provided that the same
frequencies are not reused in adjacent neighboring cells as that would cause co-channel
interference.
The increased capacity in a cellular network, compared with a
network with a single transmitter, comes from the fact that the same radio
frequency can be reused in a different area for a completely different
transmission. If there is a single plain transmitter, only one transmission can
be used on any given frequency. Unfortunately, there is inevitably some level
of interference
from the signal from the other cells which use the same frequency. This means
that, in a standard FDMA system, there must be at least a one cell gap between
cells which reuse the same frequency.
In the simple case of the taxi
company, each radio had a manually operated channel selector knob to tune to
different frequencies. As the drivers moved around, they would change from
channel to channel. The drivers knew which frequency covered approximately what area. When
they did not receive a signal from the transmitter, they would try other
channels until they found one that worked. The taxi drivers would only speak
one at a time, when invited by the base station operator (in a sense TDMA).
What is a Protocol?
What is a Protocol?
• A protocol is a set of rules that governs the
communications between computers on a network.
communications between computers on a network.
Protocol
These rules include guidelines that regulate the
following characteristics of a network:
– access method,
– allowed physical topologies,
– types of cabling, and
– speed of data transfer.
following characteristics of a network:
– access method,
– allowed physical topologies,
– types of cabling, and
– speed of data transfer.
Protocol
• Protocol (communications protocol)=
standards that specifically address how the
devices on a network communicate, i.e
– How the data is packaged for transmission
– How receiving devices acknowledge signals from
sending devices
– How errors are detected and handled
• Protocol (communications protocol)=
standards that specifically address how the
devices on a network communicate, i.e
– How the data is packaged for transmission
– How receiving devices acknowledge signals from
sending devices
– How errors are detected and handled
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