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You are here: Central > Broadband Home Labs > Home Networking > Wi-Fi > Conclusions: Round One
Updated 3/9/2005

Wi-Fi Conclusions: Round One

We report our conclusions from completed tests of 802.11g access points with both 802.11g and 802.11b notebook adaptors, and partial tests of 802.11b and 802.11a access points. All tested 11g equipment was based on the Broadcom "54g" chip set with an early implementation of draft standards.

In summary:

  • Both 802.11g and 802.11b worked at all nineteen locations we tested, most of them obstructed by walls, floors and ducts, and one (location 19) quite far from the access point and through a wall. This is substantially improved from first-generation 802.11b equipment, which did not work at all at half of the locations.
  • The measured file transfer speed of 802.11g averaged a little more than twice as fast as 802.11b across all nineteen locations. 802.11g averaged 9.07 Mbps, while 802.11b averaged 4.34 Mbps.
  • 802.11g speeds varied considerably more than those of 802.11b. The average 802.11b speed (4.34 Mbps) was about 85% of the maximum of 5.14, while the average 802.11g speed (9.07 Mbps) was only about 50% of the maximum (18.09).
  • These early implementations of 11g would not provide satisfactory video networking even for standard-definition video in many houses.

These conclusions are based on tests in only one house, with one sample of each product. There is no way of knowing how well other products in other homes will perform. We expect that upcoming products based on the approved 11g standard will work better; we plan to test new products as they are available and update our reports and conclusions.

We were impressed with the dramatic improvement in 802.11b performance. Unlike the first generation of 11b products—which did not work at nearly half our test locations—we got very consistent 11b results from the current products, with reduced performance only at a few locations with substantial path loss.

We were pleased to see that the 802.11g devices worked well with their 802.11b counterparts, but were disappointed by the average measured speed when operating pairs of 11g devices. These promise "data rates 5 times faster than 11b" but delivered little better than two times faster on average in our house.

We were especially interested in examining the potential of using 11g—with a claimed data rate of 54 Mbps—for video networking. Today's "standard definition" video requires from 3 to 6 Mbps, depending on the source, with no interruptions. High definition currently requires about 20 Mbps.

While our tests showed six locations averaging 10 Mbps or better, we had five that averaged less than 6 Mbps and some combinations of equipment and location that measured less than 3 Mbps—all with no other wireless devices running. So we believe the current implementations of 11g would not provide satisfactory video networking even for standard-definition video in many houses with microwave ovens, cordless phones, other PCs and neighbors sharing the 2.4 GHz bandwidth, and with obstructions between the access point and wireless TVs.

Nevertheless, we believe 11g is a big step forward and that the participants have done an excellent job of moving the standard forward and bringing products to market. What remains to be done is similar to the process that improved 11b from its original form to the much more robust version we see today: iterative improvement in the key elements of the hardware and software implementation.


Next: Round Two Wi-Fi Baseline Tests