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Wi-Fi Combo Forum Discussions

Anonymous
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Hi,

We are team of researchers at MIT LIDS lab and we are extremely interested to have an answer to the following question: Does WICED, or any subsequent development build upon that, provide developers with access to the detailed WIFI physical layer information. Things such as channel state information (CSI),  beam-forming matrix, packet drop rate, time stamps, etc.?

Any feedback is highly appreciated.

Navid

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GauravS_31
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250 solutions authored 250 sign-ins First comment on KBA

Unfortunately there are no IOVARs internally for CSI and beamforming, so this information cannot be obtained.

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GauravS_31
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250 solutions authored 250 sign-ins First comment on KBA

You can refer to WL commands documented in "WL Tool for Embedded 802.11 Systems" and "Broadcom WLAN Client Utility Command Set" to access the PHY layer information. The documents are available in https://community.cypress.com/community/wiced-wifi/wiced-wifi-documentation/content.

Anonymous
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Thank you for the response. I already looked into this document. I think this is gonna be really helpful.

I am just not sure where to put together a bunch of these instructions to accomplish the task I have in mind (linux command line, a scripting language...?). I appreciate more insight if you have any experience using this wl package..

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GauravS_31
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250 solutions authored 250 sign-ins First comment on KBA

If you are using a platform that is supported in Wiced Studio, then you can consider using test.console application to run the WL commands. You need to set CONSOLE_ENABLE_WL ?= 1 in console.mk to enable WL commands and CONSOLE_USE_MFG_TEST_FW ?= 1 to enable manufacturing test. The list of supported commands in the particular chip can be found from wl cmds. The particular sequence of WL commands that you need to execute will depend on the specific test that you need to do. For instance, the wireless packet engine is used during manufacturing test of the WLAN device. The following sequence of commands are used:

wl mpc 0

wl up

wl isup

wl phy_watchdog 0

wl pkteng_start 10:20:30:40:50:60 tx 40 1000 0

wl pkteng_stop tx

wl pkteng_stats

The description of each of these commands have been provided in those documents. The pkteng_stats would display the RSSI, signal to noise ratio, lost frame count, etc. of the WLAN device. There is a document on RF Performance Measurements available here https://community.cypress.com/docs/DOC-2391 that provides the WL command sequences to test RF transmission and reception of BCM4339 for 802.11a/b/g/n/ac. But note that BCM4339 is not supported in Wiced so you cannot use test.console to evaluate this device. I referred you to this document only to give you an idea on how the WL commands can be used.

Anonymous
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Perfect clarifications! I have a final question: I found this "wl channel_qa" command in the instruction set which returns some report on the status of channel. While what I need in my work is a timely report on the detailed "channel state information", which should be a matrix of dozens of complex number (where real and imaginary parts in binary representation may be several bits each), I am suspecting that the above-mentioned command does not return that information. Indeed, I was looking for an answer and ran into a document somewhere reporting that this command return a number between [0,1,2,3]. Any further clarification on this front?

Thank you once again..

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GauravS_31
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250 solutions authored 250 sign-ins First comment on KBA

The "wl channel_qa" obtains the last channel quality measurement results that is basically the average of rssi samples of the last measured channel. It returns a quality metric (0-3) or -1 that is explained below:

3 - if rssi-average < -85

2 - if -85 < rssi-average < -75

1 - if -75 < rssi-average < -65

0 - if -65 < rssi-average

-1 -channel quality measurement is currently working

So yes, this command does not return CSI matrix. I will check internally to find out if there is indeed a function or command that obtains CSI matrix for a MIMO system.

Anonymous
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Great help!

Please let me know about the outcome of your investigations. Thank you very much for helping us on this.

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GauravS_31
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250 solutions authored 250 sign-ins First comment on KBA

Unfortunately there are no IOVARs internally for CSI and beamforming, so this information cannot be obtained.