. noktah hidup

Tuesday, 12 June 2012

http://www.agc.gov.my/Akta/Vol.%207/Act%20332.pdf

web Seaching....

some knowledge to share...

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... 
 
A web browser is a software application for retrieving, presenting, and traversing information resources on the World Wide Web. An information resource is identified by a Uniform Resource Identifier (URI) and may be a web page, image, video, or other piece of content.[1] Hyperlinks present in resources enable users easily to navigate their browsers to related resources. A web browser can also be defined as an application software or program designed to enable users to access, retrieve and view documents and other resources on the Internet.
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.

 The concept
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. 
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.

 


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