Sandeep Kumar

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Posts Tagged ‘IT’

What Is A 4G Network?

Posted by Sandeep Kumar on August 25, 2010

The fourth generation of the wireless networks is called a 4G network. Although it is still in its development stage, various cell phone and related technology companies are actively researching on this technology. The main aim of the research is to ensure that a secure and comprehensive Internet Protocol solution is developed which would have much faster speeds as compared to the older generation networks.

During the 1980s, the 1G network or the first wireless network was developed. In the early 1990s, the 2G network was introduced. The 2G network had the ability to allow more transmissions per communication channel. In the late 1990s, the 3G network was researched upon and developed and during early 21st century it had been implemented in various countries.

Providing higher quality of service is the main aim of the 4G network. The other priorities include information exchanges, better reception and less dropped data. The standards of the present networks are calculated by the ITU or International Telecommunications Union and it had stated that the present networks need to have an improved multimedia message service which includes video services also. A minimum of 100 megabits per second of data rate is recommended by the ITU if a user is moving at very high speeds and one gigabit per second of data rate if a user is stationary. Interactive roaming between various networks is also recommended by the UTI.

There has been an establishment of various groups who work on developing the 4G network. One of the options recommended by these groups is WiMax which is a much faster version of WiFi networks. The packet-based information exchange which is based upon standard IP technology is planned to be utilized too. So, this could be the fastest mobile communication method.

What is a 4G networkHowever, there should be development and implementation of smart antennas in order to make an efficient 4G network. A number of methods to transmit data were created with the advent of 2G and 3G networks. The 4G network can utilize these technologies. But standardized antennas are preferred by the ITU and other working groups. Spatial multiplexing is one of the techniques that have been recommended to order to achieve this. In this type of multiplexing, a single receiver and transmitter system is linked to a series of antennas. The space-time exchange rate of data can be speeded up as these antennas have the capability to work simultaneously.

It took a decade for the overall implementation of 3G around the world. However, a much more timely and effective rolling out of the 4G network is planned by the ITU. It is expected that the 4G network will revolutionize the wireless communication systems due to its improved video and technology and much faster speeds. The other factors that are being considered regarding the development of 4G are security and stability.

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How To Speed Up A Computer?

Posted by Sandeep Kumar on August 21, 2010

A computer is a machine which can be programmed. It receives input, stores data and processes it to give us an output in a useful format. Although, mechanical computers have existed for a long time – abacus and slide rule are good examples of this – electronic computers are a fairly recent phenomenon. This recent phenomenon has become so much an important part of our lives that nothing feels more annoying when computers don’t work or work at a snail’s pace! If your computer is also working slower, then here are a couple of tips you can try:

Booting:
If there are a lot of programs installed on your computer then it would take longer to boot up. It is certainly not advisable to delete some of them, because you may need them, but there is a little thing that we can do. We can identify programs that are least used and then, can load them only when a need arises.

(1) When your computer starts, all the programs that are installed on it are loaded and it takes longer than it would have if only those programs which are used most were to load during booting. So the first step is to click on the Start Menu, go to Run Type (Microsoft configurations). There among other options you will be presented with there two options: Normal Start Up and Selective Start Up. Just click on Selective Start Up tab and select the programs you use most of the time and unmark those, which are not-so-used.

(2) When you are in Microsoft Configurations(MS configuration) mode, you can look for BOOT.INI tab. Click on it and you will find a new box, which reads Timeout. It’s is normally set at 30 sec. which means a delay of half a minute. Change that to 3 sec., click on the tab OK and reboot your computer. After this, it is possible that your computer gives you a pop up saying you’re in selective boot mode; now just disable the window while saving your changes.

(3) There is a program called HijackThis, which can be downloaded from merijn.org. This program will analyze the processes that are running on your computer and will alert you about the things which are not needed.

How to speed up computer(4) If you can ascertain that Trojans and Ad Ware are not loading when you boot, it would enhance the performance of your computer.

(5)Once or twice a month, clear all your temporary Internet files, vacant your recycle bin and move files, which are not needed to back up drive. Go to My Computer, click on Properties followed by Tools and then select the tab defragment. It would take some time but improve the booting time of your computer.

(6)If you are leaving your computer for not a long time, say only a couple of hours, then instead of shutting down your computer you can leave it in a stand-by mode. A computer on a stand-by mode remembers everything you were doing but this memory is called volatile memory. You can also save everything; this would an insurance against a power cut.

(7)Hibernate mode is a better option than stand-by mode if you are not going to use your computer for a whole day or similarly for long intervals. Hibernation mode saves an image of your computer’s open application and documents on the hard drive. You can put your computer on hibernate mode by going into the computer’s Control Panel. Turn off your computer holding down the shift key and the Hibernate option will appear, just click on it and your computer will go into a snooze.

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How To Get Rid Of Computer Viruses?

Posted by Sandeep Kumar on August 19, 2010

Computer viruses are unwanted computer programs. They keep themselves hidden in your computer and then replicate themselves in their own way and multiply (spread). The Internet connects a lot of computers to each other and sometimes, while sharing data; sending emails etc, along with the files, computer viruses also get transmitted. A virus can do anything to a computer – it can delete files, it can corrupt data and it can also disable your computer’s security systems or can damage it irreversibly.

Viruses are sometime transmitted unknowingly but not always because there are people, who are known as hackers, who design these computer programs to break into others’ computers. Their reason could be any i.e. stealing data, personal animosity etc.

Common Types:

Resident Viruses: They remain hidden in your computer. They are in the RAM memory and control and intercept the operations which are carried out by the system. Their primary use is to capture secret information about the user i.e. passwords, credit card numbers etc.

Direct Action Viruses: They quickly replicate themselves and they are designed to fulfill a certain objective. They normally attach themselves to the files stored in the computer and when that file is made to run they get activated.

Overwrite Viruses: Their objective is straightforward – to destroy whatever information it can put its hands on. It deletes all the information contained in a file and copies itself on the files resulting in the files becoming useless.

Boot Virus: Boot system is that part of a computer which stores basic programs like how to start the computer etc. These viruses are after the boot sector of computers. The best ways to avoid them is to write-protect the floppy discs and never start you computer with an unknown floppy disc in the drive.

Macro Viruses: Programs like Microsoft Word, PowerPoint etc, have the ability to use small programs, known as ‘helper’ programs, to expand their functionality. These ‘helper’ programs are called ‘macros’. They remain stored in the document files of a computer. When that file is run, the virus gets activated.

How to get rid of computer virusesFile Infectors: Viruses falling in this category infect executable files (programs). Most of the viruses found today are of this category. Once the infected program is run, they get activated.

Solutions:
The best defense against any type of infection is a virus scanner that not only detects a threat, but eradicates it as well. Installing anti-virus software is the best solution and some of them are available for free:

Commercial:
There are some companies like McAfee Antivirus, the oldest antivirus development company in the world, which are experienced. And there is another of the Norton Antivirus kind, with really heavy antivirus systems. Other famous names include Quick Heal, ESET etc.

Free:
There are some companies which provide antivirus for free for home use. They include Avast Antivirus and AVG. Both are relatively new companies and provide you with an easy to install protection shield. There are other companies too, which make anti-virus software available for free under certain conditions – Avira AntiVirus Personal, Bit Defender etc.

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How Does Radar Work?

Posted by Sandeep Kumar on July 29, 2010

The concept of radar was introduced in 1902, but radar systems were implemented in late 1930s. The concept includes the radio waves which were used to detect objects. Many countries aided the inventors in their research and were successful in the development of a rudimentary warning system which could detect moving objects. During World War II, this system was used to guard the coastline of England against hostile German aircraft. Using high frequency radio waves, the system could detect enemy German planes during World War II and calculate the distance between the system and the planes. This application of the system lead to its being named radar, which stands for `radio detection and ranging’.

It might be confusing to understand the principle of the radar, but it can be explained with the help of a very simple experiment. We need two additional instruments: a “super hearing” device and an accurate stopwatch. Now imagine a place where we are facing the side of a mountain at some distance. In this experiment, a person can become a basic radar unit. We just have to scream as loudly as we can and at the same time we should start the timing mechanism of a stopwatch. We stop the watch when the first echo of our voice comes back to us. Now we have the time in which the voice rolls back to us, and we know the speed of sound, so we can easily calculate the distance between us and the mountain.

The above demonstrated principle is applied to the radar, in the way it works. A burst of powerful radio beams at a high frequency is sent out by the radar set. When this radio energy bounces off a solid object, a small portion of the energy will be reflected back to the transmitter end of the radar set. To detect this small part of the reflected energy, a sensitive electronic receiver is used, which amplifies that weak signal for further processing, just like the super hearing device used in the above example. The receiver and the transmitter are mounted close to each other in a basic radar unit.

RadarThus, the same formula is used by the radar operator to calculate the distance between him and the object by calculating the time taken by a signal to bounce back and also the speed of the radio waves. Multiple feedbacks are allowed by the moving transmitter/receiver which helps it to access different points. These points are combined to detect the motion of an object and its size.

Since World War II, the underlying principle is the same for all the radar systems but a number of improvements have been made in the radar technology. Data collected from the receiver and transmitter of the radar set is used to calculate the object’s direction and speed. A duplex (a two-way communication device) is used along with a radar antenna, so that while spinning, the antenna can send out thousands of signals as well as receive them simultaneously.

Unlike shortwave radio frequencies which were used by the British inventors, modern radar systems use radio frequencies which are largely in the microwave range. This is due to the fact that microwave frequencies are very difficult to jam, while the other frequencies can be confused with the matching frequencies of radar jammers.

Article is taken from:-thegeminigeek.com

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