Troubleshooting Q&A - September 25, 2003
Troubleshooting Wireless Networking Performance Issues
Suffering from performance problems with your wireless network connection? This week's Q&A reveals some of the more common issues that can prevent you from getting top-notch speed out of your wireless connection.
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 Linksys Wireless Router (Model #BEFW11S4). One PC is connected to the router using an RJ-45 cable, while the other is using a Linksys Wireless PCI network adapter (Model #WMP11) and resides about 80 feet away 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 5 minutes, and then suddenly, a bunch of messages will appear. Response time while browsing websites can also be painfully slow at times.
The strange part is that according to the diagnostic utility included with the Linksys wireless card, the signal strength is very good. The speed usually clocks in at 11Mbps, but often drops down to 5.5, 2, or even 1. The only things I can attribute this to is the fact that our office resides in a forty-year-old cinder block building and the wireless computer is separated from the router by a few walls. So my question is this, is there anything I can do to fix the problem, 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 could do would be 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 them. For starters, they aren’t prone to any of the interference issues that wireless networks suffer from, and they’re at least 10x faster than 802.11b wireless connections. Wired networks are also far more secure, and there's no need to concern yourself with things like WEP encryption or SSID broadcasting.
The downside to wired networks is that it can sometimes be very difficult to run lines to the offices needing access, particularly in a cinder block building like yours. In your case, this would mean bringing in qualified people to run the lines and check their 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. Fortunately, there are a number of things you can do that might help alleviate some of the problems you’re experiencing before having to make such a drastic 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 at 11 Mbps would be at least 100 feet (and even more in an open area like an auditorium). As the distance between the router and the wireless card increases, the signal 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. You might want to check to see if any of these are in use when problems occur. An associate of mine at 802.11 Planet, Jim Geier, wrote a story on just this sort of thing a while back. If you’re curious, you can read it at http://www.80211-planet.com/tutorials/article.php/2191241.
If you share office space with other companies, there might be other wireless networks running nearby that could be causing problems. One way to potentially alleviate this problem would be to try broadcasting on a different channel. Channels range from 1-11, so experiment with several.
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 include moving the PC to a different part of the room to see if you can improve reception or placing the router higher to try to 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. While unlikely, as I’m sure you’re running anti-virus software, it’s worth checking into nonetheless.
Honestly, though, I think your best bet for getting around this issue would be to purchase a Repeater. When you first broadcast a digital signal, it is very strong, but as it continues to travel away from its source, the signal strength begins to diminish. The farther the signal travels, the weaker it becomes, until finally it completely loses its integrity. This process is referred to as Attenuation (Define).
A Repeater picks up weakened signals, regenerates them and then rebroadcasts them, thus extending the range of your network. This regeneration also keeps 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 your problem.
If all else fails, before you go through the expense of running another RJ-45 cable, you might want to consider switching from an 802.11b wireless network to a Powerline-based network. Powerline (or HomePlug) networks use the electrical cabling already running throughout your home or office to carry data between PCs. They have a throughput rating of 14Mbps and support 56-bit DES encryption for security and privacy. They also don’t use any device drivers, which makes them easy to install, and many of them can be purchased for about $100.
One of the best ones I’ve seen is the Siemens SpeedStream SS2502 Powerline Ethernet adapter. It’s roughly the size of a pack of cigarettes and plugs directly into one of your home’s standard power outlets. It connects to your PC’s Ethernet adapter via an RJ-45 cable. For more information about SpeedStream products, you can check out their web site at http://www.speedstream.com/products_powerline.html. A complete review of the SpeedStream SS2502 Powerline Ethernet adapter can be found at http://www.practicallynetworked.com/review.asp?pid=508.
As an absolute last resort, you could always try contacting Linksys' Tech Support for help in trying to resolve this issue. Linksys 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://www.linksys.com/contact/contact.asp.
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