Troubleshooting Q&A - February 28, 2005
Wireless Woes? Repeat, Rearrange or Replace?
Wireless networks must overcome steel beams, concrete, glass, sheer distance and other types of interference. To conquer these obstacles, you can try repeaters and rearranging your WLAN configuration. Or you could opt for a more stable, more secure and faster wired network.
By Ron Pacchiano
Q. In my office, I have a cable modem that provides high-speed Internet access for two computers. The cable modem is connected to a D-Link AirPlus Xtreme G DI-624 4-Port Wireless Router. One PC is connected to the router using an RJ-45 cable, the other is using a D-Link AirPlus Xtreme G DWL-G520 Wireless PCI Adapter and resides about 80 feet from the router.
On the computer using the RJ-45 connection, my Internet connection runs quite fast, yet the computer with the wireless connection suffers from extreme lag times. For example, when I am talking on AIM, I won't get any messages for about five minutes, and then suddenly, a bunch of messages will appear. Response time while browsing Web sites can also be painfully slow at times. The strange part is that, according to the diagnostic utility included with the D-Link wireless card, the signal strength is very good. The speed usually registers high, but at times, can fluctuate dramatically.
The only thing I could attribute this to is the fact that our office is in a 40-year old cinder block building. The wireless computer is also separated from the router by a few walls, which might be causing interference. So my question is, is there anything I can do to fix this or would I be better off running a line to the second PC and forgoing the wireless network? Thanks for all of your assistance.
A. Obviously, the most reliable thing you can do is to run a wired line to the second PC. If this is indeed an option for you, then it certainly bears consideration. Even with all of the advances made in wireless network technology over the last few years, wired networks still have many advantages going for it. For starters, it isn't prone to any of the interference issues that wireless networks suffer from and it is at least 10 times quicker than an 802.11g wireless connection. It is also far more secure, so there is no need to concern yourself with things like WEP encryption or SID broadcasting. The downside to a wired network is that it can sometimes be very difficult to run lines to the offices needing access particularly in a cinder block building like yours. This means bringing in qualified people to run the lines and check there integrity, or simply running long cables throughout the office in a somewhat haphazard manner.
However, I suspect that if you went through the time and trouble to invest in wireless equipment in the first place, then this isn't an option that could be implemented easily at your location. Lucky for you, there are numerous things you can do that might help alleviate some of the problems you're experiencing before having to make such a decision.
Normally, 80 feet between the router and the wireless computer shouldn't be a problem. The typical operating range of an indoor wireless network should be around 100 feet (maybe more in an open area like an auditorium). However, as you mentioned, there are numerous obstacles that could severely shorten that range. Steel beams within the building, concrete, even glass, can all contribute to a decrease in signal distance. Plus, as the distance between the router and the wireless card increases, the signal strength weakens and the speed drops.
The fact that your transmission rate has a tendency to drop significantly from time to time leads me to believe that something is generating interference on the same frequency as your wireless network. There are a number of things that could cause this: microwaves and wireless phones being two examples. So you might want to check to see if any of these are in use when problems occur. A while back Wi-Fi Planet (one of our sister sites) did a story on just this sort of. If you're curious, you can read it here.
If you share office space with other companies, there might be other wireless networks running there that might be causing you problems. One way to potentially alleviate this problem would be to try broadcasting on a different channel. Channels range from 1-11. Also, take a peek at the router settings and see if your SSID is being broadcast. If you're not using WEP encryption and didn't bother changing your default admin password, it's possible that somebody might be mooching off your bandwidth.
Other options might be to move the PC to a different part of the room to see if you can improve reception or place the router higher to try and compensate for the signal weakness. Also it's worth mentioning that the problems you're experiencing could be caused by a virus on the wireless PC. It might seem unlikely as I'm sure you're running anti-virus software, but it's worth checking.
If after trying all this you still have problems and feel that the distance is what's affecting your performance then I would think that the best way for you to attempt to get around this problem would be to purchase a Repeater. You see, when you first broadcast a digital 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 looses its integrity. This is referred to as Attenuation.
A Repeater picks up this weaken signal, regenerates it and then rebroadcast it, extending the range of your network. This regeneration also makes the signal strong, making it possible to overcome some of the interference you might be encountering from the concrete walls. 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 relieve you problem.
As a last resort you could always try contacting D-Link Tech Support for help in trying to resolve this issue. D-Link should be able to help you determine that everything is installed correctly and that you're using the most current firmware. They can be reached at http://support.dlink.com/contact. I hope this helps!
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