WIFI – Stretching The Connection

This has been an interesting work week for me. Seem like everyone has wanted to either setup a new WIFI system or add to an existing one. And each installation had special problems to overcome.

One problem that they all had in common was- the remote computers were having trouble getting enough signal to make a good connection. Many people don’t realize that just because you’re receiving a signal from your wireless access point, you still may not be able to establish a connection.

Data is sent over WIFI systems in packets of binary bits. At the beginning of each packet is a special number called a “checksum.” A correction algorithm (CRC) uses the data in the packet to produce this checksum. Each packet transmitted across the WIFI network is constantly being checked for errors. If the number produced by the algorithm doesn’t match the number received, then there has been an error in the transmission, and the packet is resent. This is commonly referred to as CRC error correction. When you have a weak or noisy WIFI connection, re-sending flawed packets can slow things down considerable.

There are several ways you can improve the WIFI signal. The easiest is to move the transmitter. If possible, try to locate your “access point” near the center of the building. I’ve picked up WIFI signals from as far as several hundred yards away when there were no obstacles blocking the transmission. I’ve also had a hard time just getting it to go from one end of a house to the other. That’s especially true if the transmitter is upstairs and the signal has to pass through a floor and several walls.

If you can’t locate the access point near the center of the building, there are several other things you can try. First, try moving the receiving computer to a different location. Even turning it in a different direction may help. Laptops often have the antenna built into the LCD monitor so just facing it differently might be all you’ll need to do.

I’ve found that in general, external USB plug-in antennas work much better than most laptops with a built in antenna. These portable antennas come on a five foot cord and can be placed high in the air (on a wall for instance) away from metal obstacles that tend to block their reception. PCI devices seem to work the worst, most likely because the antenna is right against the back of the computer which may also be setting on the floor.

If all else fails, there are devices available that will boost the signal of the access point. There’s a maximum strength that the FCC allows so the gain won’t be more than is legally allowed, but at least you know you’re getting the maximum signal possible. I’ve used these boosters on several occasions and they’ve worked well. The one I’m most familiar with is made by Linksys. It connects easily to the duel antenna Linksys routers.

There are several protocols available for WIFI networks. I use the “G” protocol for most of my applications. It’s almost five times faster than the older “B” protocol, but it can interface with “B” as well. It’s also more powerful. It passes through walls easier so it can be picked up farther away. The “G” protocol transfers data at 54 MHz, compared to 11 MHz for the “B.” Most broadband Internet connections operate at less than 5 MHz so either will produce excellent results in your system. The “G” is just more powerful and faster. Reach me at randy@randybenjamin.com.