802.11n Copper bag hack to enhance MIMO at short distance

802.11n supports multiple radios on the same device transmitting at the same time. The thing that makes this theoretically possible is the fact that they will technically create different signals. In fact, the more diverse they are the better the receiver will be able to detangle a signal from each receiver.

You will typically be able to achieve this easily by just moving your AP far away from you. That's right -- move your AP far away. But if you're like me and you have to have it on your cube, you can come up with some interesting hacks.

This video is about one of those hacks -- I show a little concoction I made at work @ Atheros with some plastic bag and some copper tape. It took some experimenting to get it right but the effect is effective.

I show the iperf throughput over the air with some 2 stream 2x2 card we are testing over the air on a busy environment against a 3 stream AP configured to 2x2. The AP was configured in HT20 at 5 GHz. The STA lingered @ MCS15 LGI with and without the copper tape bag.

Driver running is ath9k

Note: for 3 stream support you will want to ensure your antenna configuration is one of the following:

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If you run an AP with 3 stream with this setup you will not get much benefit from MIMO:

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Category:

Science & Technology

Tags:

• 802.11n
• MIMO
• Atheros
• ath9k
• PB92
• Copper
• bag
• hack
• Linux
• iperf
• HT20
• MCS15
• 2x2
• stream

[mcgrof]

@endocine yes

[endocine]

did u make the copper bag out of copper tape?