How Do Wireless Networks Work?
by
John Maxim
Wireless networks work using radio waves instead of wires to transmit data between computers. That's the simple version. If you're curious to know what's going on in more detail, then it's all explained in this article.
Ones and Zeros.
I'm sure you know that computers transmit data digitally, using binary: ones and zeros. This is a way of communicating that translates very well to radio waves, since the computer can transmit ones and zeros as different kinds of beep. These beeps are so fast that they're outside a human's hearing range -- radio waves that you can't hear are, in fact, all around you all the time. That doesn't stop a computer from using them, though.
Morse Code.
The way it works is a lot like Morse code. You probably already know that Morse code is a way of representing the alphabet so that it can be transmitted over radio using a dot (short beep) and a dash (long dash). It was used manually for years, and became a great way of getting information from one place to another with the invention of the telegraph. More importantly for this example, though, it is a binary system, just like a computer's ones and zeros.
You might think of wireless networking, then, as being like Morse code for computers. You plug a combined radio receiver and transmitter in, and the computer is able to send out its equivalent of dots and dashes (bits, in computer-speak) to get your data from one place to another.
All About Frequencies.
You might wonder, though, how the computer could possibly transmit enough bits to send and receive data at the speed it does. After all, there must be a limit on how much can be sent in a second before it just becomes useless nonsense, right? Well, yes, but the key to wireless networking is that it gets around this problem.
First of all, wireless transmissions are sent at very high frequencies, meaning that more data can be sent per second. Most wireless connections use a frequency of 2.4 gigahertz (2.4 billion cycles per second) -- a similar frequency to mobile phones and microwave ovens. As you might know, though, a frequency this high means that the wavelength must be very short, which is why wireless networking only works over a limited area.
In addition, wireless networks make use of a technique known as 'frequency hopping'. They use dozens of frequencies in the range they are given, and constantly switch between them. This makes wireless networks more immune to interference from other radio signals than they would be if they only transmitted on one frequency.
Access Points.
The final step is when it comes to all the computers on a network sharing Internet access. This is done using a special piece of wireless equipment called an access point. Access points are more expensive than wireless cards for one computer, as they contain radios that are capable of talking to around 100 computers at the same time, and sharing out access to the Internet between them. Dedicated access points are only really essential for larger networks, though -- if you only have a few computers, it is possible to use one of them as the access point, or you could just get a wireless router.
They Understand Each Other.
That's all well and good, then, but how does wireless equipment made by entirely different companies manage to work together when this is all so complicated? Well, the answer is that there are standards that all wireless devices follow. These standards are technically called the 802.11 standards, and are set by the IEEE (Institute of Electrical and Electronics Engineers). It is thanks to people sticking to their standards that wireless networking is so easy and cheap to use today.
You Don't Need to Worry.
If all this talk of frequencies has you a little worried, you don't need to be -- wireless networking hardware and software handles all of this automatically, without you needing to do a thing. Don't think that you're going to have to tell one wireless device what frequency another is using, because it's just not going to happen, alright? Wireless networking, for all its complicated workings, is really far more simple to use than you'd ever expect.
John is a world recognized expert on wireless networking and network management. His blog can be found at http://www.wirelessinternetonline.com. |
Do It Yourself - 10 Different Hewlett Packard Printer Problems with 10 Different Printer Solutions
by Joseph Mercado
How many of you know that when you printing documents and running those reams of paper through your printer, one of them is going to get tangled up. If your print sessions are valuable to you, then you should check this article out.
Below are 10 HP LaserJet printer problems with 10 HP LaserJet printer solutions to help you with your printing nightmares.
1. Paper jams: (Don't you just love when your printer jams)
Among the most common problems with any make of printer are paper jams.
A printer will jam for any number of reasons: It's dirty, the wrong paper type is being used, or the rollers on the printer that feed the paper through its pathway are worn down.
While cleaning the printer periodically and using the correct paper type are easy fixes, roller replacement can be a difficult job depending on the model of HP printer.
For some HP printers, the rollers are easily accessible, but you'll need to completely tear down other models to remove the rollers.
Regardless of the cause, when removing a paper jam, always pull the paper in the direction of the paper path, because pulling it backwards can severely damage the printer. Certain HP printers are more susceptible to paper jams than others.
In my experience, any printer that holds the paper vertically and then pulls it down through the printer invariably ends up having paper jam problems.
These models aren't designed for heavy use, but many organizations make use of them on individual systems and should be aware of this flaw.
In addition, some people have trouble with the newer HP 4000 series printers' paper pickup rollers--which is odd, because the older 4000 and 5000 series HP printers are considered rock solid and don't seem to have any trouble with their pickup rollers.
2. Some or all of the printing on the page is faded:
A faded print image is normally the result of one of three conditions: The printer is getting low on toner, the print density is set too low, or Economode printing is turned on.
For the last two settings, a printer self-test (typically a separate button on the printer) will show what the current settings are.
If Economode is on, and users are complaining about how light the print is, turn it off and/or set the print density higher.
If the toner is low, simply removing the cartridge and shaking it to redistribute the toner more evenly can temporarily resolve the problem until you can replace the cartridge.
3. Ghosting:
Ghosting is a condition where the image prints properly, but a much lighter copy of the image also prints elsewhere. This can be due to a problem with the power outlet that is supplying power to the printer.
Check the power outlet by plugging in a different printer to see if the same results occur. Ghosting can also be caused when consumable printer parts (such as the drum or imaging kit) are near the end of their life.
All of the consumable parts in a printer are rated for a certain number of pages. Once a printer gets near that magic number, you'll need to replace those parts to eliminate ghosting.
4. Toner smears or does not stay on the paper
If words and images come off the paper when a hand is run across them, there are a few possible problems.
First, the fuser assembly may be damaged or at the end of its life. The solution is to replace the fuser assembly.
Repairing a fuser assembly is generally not recommended because the fuser is considered a consumable printer part and not worth the time or effort to fix.
Second, the toner cartridge may be defective and letting too much toner out at one time.
In a black-and-white laser printer, the solution is to replace the toner cartridge. In a colour laser printer, only replace the cartridge that is exhibiting the problem.
Third, some toner may have spilled in the printer. If so, you'll need to clean it out.
5. Printer is displaying a 50.4 error message:
A 50.4 error message on some of the newer HP LaserJet printers indicates a problem with the power supply.
If the printer is connected to a UPS, disconnect it, or disconnect it from a power strip and plug it directly into a wall outlet.
A laser printer should never be plugged into a UPS, because the UPS can be damaged by the surges of power required by a printer to keep the fuser assembly warm.
If that doesn't work, make sure that all of the components in the printer are seated properly.
6. Can't find a driver for a particular operating system:
As new operating systems are released, new drivers will need to be loaded for your existing printers. Not all printers have a driver for every OS (operating system).
In these cases, it's best to consult the printer manual and find out what printers the drivers will emulate. While not all of the functionality of the printer will be available under this emulation, at least basic printing will work.
For example, most HP printers will print with the HP LaserJet II driver installed, although specific options, such as duplexing, will not work.
7. Printer is not printing from the expected paper tray:
You can check in two places to correct this particular error.
First, look on the printing PC, and second, on the printer.
If the application is set to print to the wrong paper tray, correct it within the application by clicking on Printer Properties and finding the Tray Selection source.
On the printer, make sure that the paper sizes in the control panel match what is actually in the paper trays.
8. Printer picks up all the paper from the manual feed tray rather than one sheet:
The pad that is responsible for separating the paper has likely worn out and needs to be replaced. You can order and install a new pad without sending the printer out for repair.
It is also possible that the paper is wet due to humidity. Make sure the paper is properly stored and that it is fanned before putting it into the printer.
9. Printer is displaying a 79 error:
A 79 error can be the result of a problem with the network print server that services the printer. When troubleshooting a 79 error, first open the Printer folder from the Start menu on the Print server to make sure there are no jobs pending.
A 79 error can also indicate a failure of a printer add-on component, such as an MIO (modular input/output) card or a RAM (random access memory) module.
All add-ons should be removed and then added back to the printer one by one to determine which module may be at fault.
10. Trouble printing onto envelopes:
Envelopes can cause many problems for laser printers. Choose envelopes that are close to 20-lb paper in weight and thickness.
Also, make sure that the adhesive on the envelope is capable of withstanding the heat that the fuser puts out to keep the printing on the page. If you don't, the envelopes will come out of the printer already sealed.
If envelopes are coming out of the printer wrinkled, they may be too stiff for the paper path. Open the rear of the printer and let them exit at that location instead.
HP printers are considered to be among the most reliable in the industry. But just as any other piece of IT equipment, they're vulnerable to failure. And it seems the newer printers can't withstand the same amount of abuse that the older models could.
So if you work on newer-model HP printers in a paper-intensive environment, expect more troubleshooting calls involving the problems I've described.
No matter what the age of your HP printer, this guide to common printing problems will help you diagnose and fix the problem quickly.
As a result of this content of information, you are now geared for the next problem you encounter. This time you will have an answer, making you the best "Solution Provider" that you can possibly be.
In description of, Joseph Mercado is known as The Internet Marketing Tyrant. He specializes in the consumable market involving studies on inkjet cartridges.
Joseph is also a respected Marketing Innovator who seeks his own innovative mind to construct proven ink formulas designed to leave major impacts within this cartridge industry.
https://www.inksecrets.com
Allen Brown is a freelance writer for www.1888SoftwareDownloads.com , the premier website to find Free Software Downloads including free anti-virus software, free spyware detection software, free toolbars, free chat software and more. He also freelances for http://www.1888FreeOnlineGames.com .
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