Give Your Wireless Signal a Boost Add Some Power and Consistency to your WLAN Ron Pacchiano
The range of wireless networks can fluctuate dramatically depending on the environment you're in, but there is a simple way to add some power and consistency to your WLAN. Plus, what the heck is NAT?
Q.
In my home I have three PCs. My primary system is a Compaq EVO running Windows 2000. It's connected to a Linksys EtherFast AP Cable DSL Wireless Router, and Internet access is being provided via a Comcast cable modem. My other two computers are both equipped with D-Link DWL-650 wireless network adapters. The first one is a Dell Dimension desktop PC that resides about 25 feet away from my primary computer and is typically used to accesses the Internet and some shared files. According to the D-Link configuration utility, the wireless link quality and signal strength on this computer varies from 33 percent to 85 percent.
The problem I'm experiencing has to do with my third computer. This is a Toshiba laptop that's located one floor above my primary computer. For the last few weeks, this system has been having an increasingly difficult time maintaining its link to the wireless router. The link quality and signal strength for this machine has varied from a high of 55 percent all the way down to nothing.
When I use the laptop downstairs, the signal strength increases to about 60 percent — in spite of the fact that it's separated from the wireless router by about 30 feet and one wall. I'd like to be able to use the laptop on my deck, which is about 50 feet away. Unfortunately, the signal strength decreases to practically nothing as I get closer to the deck. I can't understand how a distance of barely 30 feet could cause such a dramatic change in the signal quality.
So my question is what could have happened to cause my signal strength to degrade so dramatically since the network was installed, and what can I do to improve the link quality or at least maintain my link while I'm working on my laptop? I checked D-Link's site for a new driver or firmware update, but I am already running the latest ones.
I really would like to be able to use the wireless network from anywhere in my home without having to worry about losing my high-speed Internet connection. Do you have any suggestions?
A.
There are a number of variables that could be causing your wireless network's signal quality to fluctuate so dramatically. For starters, you might be experiencing a problem with range. Theoretically, the operating range of an indoor wireless network at 11Mbps will be well over 100 feet — greater than that in an open area like a hall or auditorium. However, this range can significantly decrease depending on the environment you're in. Most homes constructed of wood and sheetrock aren't too restricting, but a building made of steel and concrete can cause considerable interference. Other external factors, such as cordless phones and microwaves, can also hinder performance. So, whereas your neighbor might be able to get over 150 feet from her wireless router, you may be able to go only 75 feet from your wireless router.
The fact that your transmission rate has a tendency to drop so significantly from time to time leads me to believe that something is creating interference and is consequently restricting the range and reliability of your wireless network — all of which means even though you're looking to travel only about 80 feet from the router, you can still be out of the router's operational range.
There are some things you can try that may possibly help you get around this problem. You might want to consider relocating the router to another part of the room or moving it to another floor altogether. One benefit of cable modems and DSL lines is that they give you a good deal of flexibility regarding where they can be located. In general, any room with a phone line or cable connection is useable. Additionally, placing the router in a higher location could also help compensate for a weaker signal. You could also monitor your signal strength with D-Link's diagnostic utility when the phone or microwave is in use to see if any fluctuations in link quality occur.
Honestly, though, I think the best way for you to get around this would be to simply purchase and install a repeater. You see, when you first broadcast a wireless signal it is very strong. As it continues to travel away from its source, the signal strength begins to grow weaker. The farther the signal travels, the weaker it becomes — until finally it completely loses its integrity. This is referred to as attenuation.
A repeater picks up this weakened signal, regenerates it, and then rebroadcasts it, thus extending the range of your network. This regeneration also strengthens the signal, making it possible to overcome some of the interference you might be encountering. After the repeater has been configured to work with your network, simply plug it in somewhere between the router and the wireless PC. This should be enough to increase the signal strength of your wireless network and hopefully resolve you problem.
After you configure the repeater to work with your network, simply plug it in somewhere between the router and your deck. This should easily extend the range of your wireless network to cover the balcony. If you place it on top of a wall unit, it might even help compensate for the fluctuating signal on the Dell machine upstairs as well. You can confirm the performance improvement using D-Link's wireless monitoring utility to measure the signal strength, both before and after the installation.
My personal recommendation for a wireless repeater is the D-Link AirPlus DWL-800AP+, an enhanced 802.11b Wireless Range Extender that can operate either as a Wireless Access Point or as a Wireless Repeater. The unit has a street price of about $65, so it's very affordable. Best of luck!
Q.
I don't have a very extensive computer background, but I would like to add a wireless router to my home office network. While researching for a router I keep coming across the term NAT. It seems to be important because all of the routers I've looked at list it as a feature, but I don't know what it is or what it does. Could you explain it to me? Thanks!
A.
No problem. NAT is an abbreviation for Network Address Translation. To put it simply, NAT is an Internet standard that enables a local-area network (LAN) to use one set of (Private) IP addresses for internal traffic and a second set of (Global) IP addresses for external traffic. The NAT device resides at the point where the LAN meets the Internet.
A NAT inside the router translates any incoming data on that Global address to the destination of the private IP address of the PC that requested it. When it's time to send that data back, the NAT strips away the private IP address information and replaces it with the Global IP address of its destination.
NAT has two primary purposes. First, it provides a type of security for your network by hiding all of your PCs behind a single IP address. Since only the NAT device knows what Internet traffic is going to what PC on the local network, it forces all data packets to be examined before granting them access to the internal network. This helps protect your PC from unauthorized access by an outside threat like a hacker or a Denial of Service (DoS) attack.
Secondly, NAT reduces the need for a large amount of publicly known IP addresses by creating a separation between publicly known and privately known IP addresses. This enables a company to use more internal IP addresses. Since the private IP addresses are only used internally, there's no possibility of conflict with IP addresses used by other companies and organizations. NAT also helps to reduce the IP address depletion problem because all of a company's communications can be routed through only a handful of — or as few as one — Global IP addresses.
NAT capability can be found in every router on the market today.
