Anybody who's used a wireless LAN (WLAN) for even a little while knows there's a big difference between the theoretical maximum speed of the WLAN, and the actual speed you get. Factors such as interference, congestion, transmission power, building materials, and even the weather can all play havoc with WLAN throughput in often unpredictable ways.
Aiming to improve the situation, WLAN vendors now offer both conventional equipment and MIMO (Multiple Input Multiple Output) gear, which combines several antennae to boost signal strength and equipment sensitivity. Vendors say MIMO delivers longer range, faster speeds and better penetration of objects -- but how much of a difference does it really make in practice? We decided to find out.The test set up
Using our test NEC Versa 4400 notebook PC with various combinations of MIMO (Netgear RangeMax WPN511 PC Card and RangeMAX WPN824 access point) and non-MIMO equipment (Netgear WG511 PC Card and Netgear WGR614 base station), we benchmarked a standard, unencrypted WLAN at different points around a standard-sized suburban Melbourne house. Base stations were connected directly to an Optus cable modem Internet service. Test sites included the back bedroom, where the WLAN access point was installed; the kitchen; the living room; the front bedroom; the front yard; the back yard; and the rear garage. Each location was a different distance from the WLAN base station, and required that the WLAN carrier pass through a different combination of building materials.
At each location, signal strength data was collected from the Netgear software's strength monitor; Windows XP's connection monitor; and Passmark Wirelessmon, which measures signal strength in dB and percentage of optimum. Real-world performance was tested by running three online bandwidth testers (CNET Bandwidth Meter Speed Test, Numion, and PCPitStop), three times each, then averaging the results.
Each set of tests was run four times at each location, allowing for four combinations of MIMO and non-MIMO base station and WLAN card. To simulate real-world activity, we timed the copying of a 6.36MB file from a hardwired network host to the WLAN-connected notebook.The results
While it's easy to dismiss hype, our testing confirmed that MIMO offers a significantly better WLAN signal. In every location, particularly those where walls significantly hampered non-MIMO communication, the introduction of MIMO gear boosted both reported connection speeds and real-world performance - in some cases, dramatically. MIMO gear delivered 54Mbps and 108Mbps connections from every location tested, turning in performance ratings that were consistently double or more the speed of non-MIMO equipment. It wasn't necessary to replace both base station and PC Card to get results: speed also increased even when just the PC Card or base station was upgraded.
Using a MIMO base station and PC Card brought a stable WLAN signal to the brick garage, front bedroom and front yard -- three places where the non-MIMO equipment had struggled to reach. In fact, only one equipment combination -- MIMO base station and PC Card -- was able to penetrate into the spare room inside the brick garage, lighting up that area for the first time ever.
Even your neighbours may benefit from MIMO, whether you want them to or not. Using the MIMO base station and PC Card, we got a usable WLAN signal from six houses up the street -- far short of the claimed 1km range, but much farther than was possible without MIMO.Click here for a full table of the results for each room.