MaximumPC 2007 11

58 MAXIMUMPC NOVEMBER 2007

We’re not exaggerating when we say we tortured these wire-

less routers and adapters: The offi ce environment in which we

tested them is much less friendly than most people’s homes. For

starters, our IT department runs two of its own 802.11g wireless

networks, with access points deployed throughout the building.

Shutting those networks down for a few days so we could test

ours wasn’t an option.

The structure is a typical midrise offi ce building, with concrete

fl oors and aluminum-stud and sheetrock partition walls. We set up

each router in the Lab on the shelf above our test bench, about

six feet from the fl oor. We installed each manufacturer’s match-

ing PC-card adapter in a generic laptop PC and measured TCP

throughput using Ixia’s Qcheck utility.

We set up the laptop in three locations: Environment 1 was

within the confi nes of the Lab, 15 feet from the router. Although

no walls separated the client from the host, there is a large

amount of metal inside the Lab, including exposed steel I-beams

that support the ceiling, the steel test benches, and other PCs

that weren’t part of the test.

Next, we moved to Environment 2, our employee lounge, 40

feet from the router and separated by two interior walls. This room

contains a refrigerator and two vending machines. Our fi nal test

location, Environment 3, was the employee kitchen—a large open

room 120 feet from the router, with eight interior walls in between.

We plugged the laptop into an AC outlet for the other two tests,

but left it running on battery power for this one.

We tested each router in mixed mode without security, in

mixed mode with WEP security, in mixed mode with WPA2 secu-

rity, and then—if the router supported it—running in 802.11n-only

mode with WPA2 security. We then tested backward compatibility

by repeating our fi rst scenario after bringing an 802.11g device

into the mix.

HOW WE TEST

A Wi-Fi network’s worst nightmare

BUYERS GUIDE

Don’t be put off by the marketing hype.

Here are the essential features to look

for in an 802.11n draft 2.0 router

CHANNEL BONDING: Wireless net-

works based on 802.11 standards can

use 20MHz channels to communicate.

Channel bonding combines two of these

20MHz channels to create a single chan-

nel with double the bandwidth (40MHz).

Networking gear based on the

802.11b, -g, and -n standards all oper-

ate in the 2.4GHz spectrum band, which

has only three non-overlapping 20MHz

channels. Operating your router in chan-

nel-bonding mode, therefore, has the

potential to disrupt your neighbor’s

wireless network. Some routers have

an auto feature that will turn off channel

bonding if they detect another wireless

network operating nearby; others give

you the option of toggling between the

two modes.

MIMO: The concept of multiple inputs,

multiple outputs forms the very heart of the

802.11n standard. Multipath distortion—

radio signals that bounce around objects

in the environment and create echoes that

arrive at their destination at different points

in time—used to be wireless networking’s

greatest weakness. MIMO turns that limi-

tation into a strength by combining the

echoes into a single, coherent stream

to signifi cantly increase the network’s

range and overall throughput.

MIXED MODE: All the routers we

tested allow you to connect 802.11b,

802.11g, and 802.11n gear to your

network, but some of them also allow

you to constrain your network to particu-

lar protocols. By running your network in

802.11g/n mode, for instance, you can

mix “g” and “n” gear while limiting your

network’s lowest data-transfer speed to

“g” speeds.

QUALITY OF SERVICE (QOS): Online

gaming, VoIP, and audio and video

streaming have very low tolerances for

dropped or delayed packets, packets

that are delivered out of order, and jitter

(packets arriving at their destination with

different delays). A router with QoS fea-

tures can assign different delivery priori-

ties to different classes of data so that all

applications enjoy optimal conditions on

the network.

SECURITY: In order to be Wi-Fi

Certifi ed, an 802.11n draft 2.0 router

must support WPA2 Personal (Wi-Fi

Protected Access) security. WPA2 uses

TKIP encryption to secure data transmit-

ted over the network, and it prevents

unauthorized access to the network

through the use of a preshared key. Most

routers that support WPA2 also give you

the choice of using stronger AES encryp-

tion instead of TKIP. A few routers offer

additional security in the form of WPA2

Enterprise, in which network users are

verifi ed through a separate authentica-

tion server.

Some older wireless products sup-

port only the first WPA standard. Even

older products might support only

the exceedingly weak WEP (Wired

Equivalent Privacy). We strongly discour-

age installing WEP-only products on

your network since they put your entire

network at risk.

WIRED CONNECTIONS: Don’t assume

your wireless network will never have hard-

wired connections. Each of the Wi-Fi rout-

ers in this roundup is equipped with a four-

port wired Ethernet switch. Some support

only Fast Ethernet (10/100Mb/s), but some

support Gigabit Ethernet (1Gb/s). Don’t

underestimate the value of support for the

faster standard.

An Ethernet switch is integrated into

each of these routers; some deliver

Gigabit Ethernet, others support only

Fast Ethernet.