Wireless Networks That Do More

Speed Matters, But...

For wireless gateways, the most important aspect of performance is not necessarily speed. Anyone who has used a Wi-Fi--equipped notebook knows that signal strength--your card's ability to receive Wi-Fi data under various conditions--is critical. Signal strength degrades as you move away from the gateway, and so does performance. The 802.11b standard specifies a nominal transfer rate of 11 mbps, which is plenty for most broadband connections. As you start to lose the signal, however, the standard's transfer rate drops dramatically--to 5.5 mbps, 2 mbps, and then 1 mbps. (Real-world throughput is about half these rates.)

The true measure of gateway performance is a combination of throughput and range, which is how far you can stray from the gateway and still get a good signal. Some of the fastest gateways in our tests had relatively poor range.

The test results show each gateway's maximum wireless throughput when it is placed right next to the client computer, where the signal is strongest. Here, the D-Link gateway was the star, thanks to its special 22-mbps Plus mode, a feature of the product's new Texas Instruments chip set. Expect other gateway vendors to adopt the TI chip set. To get the most out of 22-mbps mode, all client computers on the network need 22-mbps cards, though even 11-mbps clients will show somewhat improved throughput when used with the D-Link gateway.

As the performance chart shows, wireless speed drops a little when you turn on WEP encryption, though you should not let this deter you from using it. Throughput will drop dramatically when several users access the gateway simultaneously. The card in the gateway has a fixed bandwidth that all the client cards must share. Here, the D-Link has a decided advantage if all its clients use 22-mbps adapters.

We tested the gateways' range with an internal Mini-PCI card built into a Toshiba Portege notebook, and with an Orinoco Gold PC Card in the same Portege. We measured the signal strength from about 30 feet and through several walls. The Mini-PCI card exhibited much lower signal strength than the Orinoco card did. The Linksys and Zoom gateways established the strongest connections, while the Actiontec, D-Link, Proxim, and SMC devices were not far behind.

Combining these results with those for throughput and reliability of connection, we rated the D-Link, Linksys, Proxim, and SMC gateways highest in overall wireless performance. Despite some good numbers here and there, the Actiontec and Zoom units failed some file transfer tests, encountered problems establishing connections, and had other reliability issues. The Microsoft gateway had the second-slowest wireless performance in our download test. The NetGear MR814 was about average in all our wireless tests. The 3Com and Belkin units had the lowest overall performance scores.

In our wired ethernet performance tests, the D-Link and SMC gateways finished far ahead of the pack, with the Actiontec and Linksys products earning honorable mention. If you perform a lot of file transfers over your wired network (perhaps you have a Web server or you back up files from one hard disk to another), this feature should rate high in your decision making. If you rarely perform wired file transfers, a gateway's wireless performance will be more important.