Building a 802.11n Wi-Fi Network Today

by Yaroslav Lyssenko

[ 08/31/2006 | 09:38 PM ]

The popularity of Wi-Fi networks grows day by day, but some people stick to cable because of its much higher connection speeds. To address the need for higher transfer rates, members  of <%BANNER[article_nw]%>Institute of Electrical and Electronics Engineers (IEEE) designed a new standard for wireless local area network (WLAN) protocol. While the 802.11n standard for wireless connections hasn’t been yet finalized, some companies started to roll out products with the draft-802.11n  specification already.  

The proposed standard is known as 802.11n and is designed to eventually offer speeds up to 600Mb/s with average data transfer rates around 200Mb/s and ranges extending up to 200 feet indoors. The current shipping draft-802.11n products advertise speeds up to 300Mb/s with data transfer rates reaching 130Mb/s and indoor distances up to 150 feet. The current 802.11g standard offers speeds up to 54Mb/s with sustained transfer rates around 24Mb/s operating at distances up to 100 feet indoors.

With a number of draft-802.11n standard devices hitting the market, AnandTech has examined the performance level of several solutions, including Belkin N1, Linksys WRT300N, NetGear WNR834B routers. The products are based on the Broadcom Intensi-fi chipset for Linksys/NetGear offerings and Atheros XSpan chipset for Belkin router.

“With several network benchmarks available, we needed a consistent means of comparing the throughput of our test components in real world settings. We chose IXIA's IxChariot 6.30 test suite along with their Performance Endpoints software due to their industry wide acceptance as analysis tools. We install the Performance Endpoints software on each client to execute the transactions sent by the test script from the console program. This allows us to capture the performance metrics for test throughput, transaction rates, and response times. We use IxChariot's standard throughput script for our testing with TCP and UDP enabled,” explains the author.

As expected the “Draft N” products performed nowhere near their theoretical performance level. The author also reports that he had come across multiple problems with drivers and firmware as well.

“The Draft N routers we tested today had excellent maximum and very good average throughput in the same room tests and also at the 40 foot mark in a typical home setting without encryption enabled. We are concerned with the minimum throughput capability of the Belkin and Linksys routers in all distances along with their performance hits when enabling encryption. The NETGEAR Draft N router faired better in this area but none of our units could match the overall consistency of the NETGEAR RangeMax 240 based on the third generation Airgo chipset. During testing we found our Draft N routers to be particularly sensitive to antenna positioning and the wireless adaptor cards to be very sensitive to placement. If we placed our notebook next to a window at the 40 foot range we could expect our signal strength to drop upwards of 15% and watched minimal throughput scores almost hit zero several times,” concludes AnandTech.

“Even though we have not finished our testing, we have to strongly recommend that users wait if possible until 802.11n is ratified and approved,” underlines the author.

• AnandTech: Draft N Router Coverage: When the “n” in 802.11n Really Means “Not Yet”.