Wireless devices rarely achieve the stated range that vendors claim for them. These ranges assume that you have a clear line of sight without obstruction. However, the most useful wireless installations are those that allow you to avoid wiring between floors, walls or even buildings. Thus you may find that it is necessary to boost the range of your wireless devices, and by improving signal strength you also improve throughput.
Since wireless networking is a two-way system, each node's ability to transmit and receive can be improved. Most people begin by boosting the output power of their access points or routers by adding a higher gain antenna. Doing so can greatly extend the range of your wireless network's detection. However, since the traffic is both send and receive, you may find it necessary to replace the card in your laptop or PC with a better card, or replacing the antenna on that card if that is an option.
To create a wireless bridge you need to have two connected routers. Apple's Airport Extreme provides this connection and that connection can be improved through the addition of higher gain antennas. Once a wireless bridge is created you can use wireless access points at both locations to connect wireless clients to the network at both sites. PC users will find similar products from companies like Linksys and several others.
Barrie Sosinsky is president of consulting company Sosinsky and Associates (Medfield MA). He has written extensively on a variety of computer topics. His company specializes in custom software (database and Web related), training and technical documentation.