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#1 2018-Nov-06 10:30:45

Yan Wang
Member
Registered: 2018-Oct-25
Posts: 21

802.11 Reference Design

Hello,

I am the beginner to learn the WARP board and I meet some problems when I run the experiment framework examples. 

The first problem I met was when I run the aggregate throughput example. I have configured nodes one as AP, and the other as STA. I set MCS=3 and the data rate is 26 Mbps. If the two nodes are very close, the throughput is about 15Mbps. And if I put the two nodes about 1 meter away, the throughput for both nodes drop down nearly to 0 Mbps. The experiment environment was in an office. Thus, can you please tell me why the throughputs have a sharp decline and it is correct?

The second problem happened when I run the Tx/Rx capture example. If I put the nodes very close, the number of packets is about 70000. If I put the nodes about 3 meters away, the number of packets also drop down to about hundreds. However, according to my calculation, the theoretical amount of packet number is about 140000 with MCS =3 and fully backlogged. Can you please tell me why this happened? 


Best regards,
Yan

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#2 2018-Nov-07 08:40:53

murphpo
Administrator
From: Mango Communications
Registered: 2006-Jul-03
Posts: 5159

Re: 802.11 Reference Design

Thus, can you please tell me why the throughputs have a sharp decline and it is correct?

We cannot diagnose this remotely - there are too many factors that affect performance of an over-the-air link. It could be any combination of interference, antenna properties, etc. I would suggest trying other channels, verifying the suitability of your antennas for the selected channel/orientation, etc. I would also suggest trying other MCS selections to test whether you observe the expected tradeoff in reliability/rate with increasing distance / decreasing SNR.

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