Speed

Wireless networking data throughput speeds depend on a few factors. Foremost is the standard that the wireless devices use. Depending on the standard used, wireless throughput speeds range from a measly 2 Mbps to a quick 300 Mbps. 802.11 topped out at 2 Mbps.

One of the other factors affecting speed is the distance between wireless nodes (or between wireless nodes and centralized access points). Wireless devices dynamically negotiate the top speed at which they can communicate without dropping too many data packets. Speed decreases as distance increases, so the maximum throughput speed is only achieved at extremely close range (less than 25 feet or so). At the outer reaches of a device's effective range, speed may decrease to around 1 Mbps before it drops out altogether.

Finally, speed is affected by interference from other wireless devices operating in the same frequency range-such as cordless phones or baby monitors-and by solid objects. So-called dead spots occur when something capable of blocking the radio signal comes between the wireless network nodes. Large electrical appliances, such as refrigerators, very effectively block a wireless network signal! Other culprits include electrical fuse boxes, metal plumbing, and air conditioning units.

Range

Wireless networking range is hard to define, and you'll see most descriptions listed with qualifiers such as "around 150 feet" and "about 300 feet." 802.11 networks fell into the former category. Like throughput speed, wireless range is greatly affected by environmental factors. Interference from other wireless devices and solid objects affect range.

The maximum ranges listed in the sections that follow are those presented by wireless manufacturers as the theoretical maximum ranges. In the real world, you'll see these ranges only under the most ideal circumstances. True effective range is probably about half of what you see listed.