Aruba Networks Finds Wide Variability in 802.11N Wireless LAN Performance

Aruba Networks, Inc., a global leader in wireless LANs and secure unified mobility solutions, today announced the results of recent throughput tests conducted on four different 802.11n wireless LANs. The tests, using a variety of laptop computers containing wireless radio chip sets from Atheros, Broadcom, and Intel, revealed significant differences in the throughput performance of the same laptop with different wireless LANs. Overall the tests highlighted the importance of evaluating any 802.11n wireless LAN using a representative sample of different radio chip sets."The purpose of this test was to determine if the brand of 802.11n radio chip set affected packet throughput, but surprisingly the tests showed that the wireless LAN infrastructure itself had the biggest impact on throughput," said Vijay Raman, Aruba's head of technical marketing. "Some of the wireless LANs actually starved the laptops of airtime so that throughput dropped to almost zero. The wireless LAN that demonstrated the best airtime fairness also consistently achieved the highest throughput."

The laptop computers and 802.11n access points were situated on a table, and all antennas were aligned for best performance. Default configuration settings were used for both laptops and wireless LANs except where clearly noted, e.g., power saving mode was turned off in order to allow the tests to run uninterrupted. The test area was interference free, creating an ideal environment in which to run the wireless LANs. The test was designed to be easily reproducible, and all test parameters are described in the technical briefing paper.

"The tests highlighted the importance of evaluating 802.11n using clients that include all representative 802.11n chip sets," continued Raman. "The issues uncovered by the test are unrelated to the laptops or chip sets because at least one of the wireless LANs performed very well with all of the laptops. Rather the issues uncovered with the wireless LANs that performed poorly appear related to their architecture or implementation. That should provide comfort to end users that have purchased 802.11n based clients, and raise a flag for those considering any of the wireless LANs that exhibited poor throughout or client starvation."

The new technical brief, 802.11n Client Throughput Performance, can be downloaded directly from Aruba's Web site at http://www.arubanetworks.com/pdf/technology/TB_11NPERF.pdf.