Discuss EVDO PCMCIA Cards, ExpressCards, EVDO USB, PDAs, Phones, Coverage and Mobile Broadband Cards.
Discuss Sprint & Verizon Coverage. CradlePoint CTR350, CTR500, PHS300, MBR900, MBR1000, MBR1200, PHS300. Discuss Improving signal with 3Gstore Antennas and Amplifiers.
|
EVDOforums.com Discussion forum for EVDO users
|
Our sites Include:
EVDO Info :: EVDO Forums :: EVDO Maps :: EVDO Blog :: 3Gstore.com
To purchase your EVDO Card / Antenna / Amplifier / Router from the EVDO Experts, just contact us!
| View previous topic :: View next topic |
| Author |
Message |
timtech EVDO Newbie
Joined: 17 Jan 2007 Posts: 1
|
Posted: Wed Jan 17, 2007 11:30 am Post subject: Signal strength on Linux |
|
|
I haven't seen this any where and wanted to post for others.
If you have a communications program like minicom, you can point the modem to your device (in my case ttyACM0)
Then query the modem with
AT+CSQ
This will return two numbers xx,xx
The first number is the signal strength difference from the base of -109dBm
For example, if you get a return of 14,99
you take -109+14 which gives you -95dBm
You can also query the firmware revision with:
AT+GMR |
|
| Back to top |
|
 |
djmay EVDO Newbie
Joined: 22 Dec 2006 Posts: 2
|
Posted: Fri Jan 19, 2007 10:21 pm Post subject: |
|
|
I have been trying to find a way to do that, but this doesn't look right.
I have a 720S on a MB6000 router, which uses linux inside.
The MB6000 provides a AT Command interface.
AT+CSQ
74, 99
OK
So according to your formula that would mean I have a signal strength of
-109+74 = -35dBm
I could only wish...
You know that 74 looks about right for me.... could this be different for different cards?
MB6000 doesn't let me send AT commands while connected, but I would really like to find a way to monitor this while connected.
Also if I could determine the connection type, or check the signal strength for each EVDO Rev 0, EVDO Rev A, and 1xRTT, I would be really happy. |
|
| Back to top |
|
 |
glenozzy EVDO User
Joined: 03 Jan 2007 Posts: 53 Location: VA
|
Posted: Sat Jan 20, 2007 3:08 pm Post subject: |
|
|
first number is RSSI
second number is FER or SQE
99 means your not on a call or unsupported |
|
| Back to top |
|
 |
tamasrepus EVDO User
Joined: 30 Dec 2006 Posts: 37 Location: New York, NY, USA
|
Posted: Sat Jan 20, 2007 8:27 pm Post subject: |
|
|
| glenozzy wrote: | first number is RSSI
second number is FER or SQE
99 means your not on a call or unsupported |
For the non-electrical engineer or wireless-savvy here, what are FER and SQE? |
|
| Back to top |
|
 |
djmay EVDO Newbie
Joined: 22 Dec 2006 Posts: 2
|
Posted: Sat Jan 20, 2007 9:03 pm Post subject: |
|
|
I usually get somewhere between -72dBm to -85dBm
Since the numbers I got were 74, 99
I think it looks more like this particular card is reporting the abs(dBm)
I would think it is telling me I am currently measuring -74dBm
If this was RSSI then my understanding is that I would have -34dBm
according to this white paper
http://www.wildpackets.com/elements/whitepapers/Converting_Signal_Strength.pdf |
|
| Back to top |
|
 |
KriminalMinded EVDO Newbie
Joined: 01 Feb 2007 Posts: 5 Location: Little Rock
|
Posted: Wed Mar 07, 2007 2:57 am Post subject: |
|
|
Any possibility of getting this to work on a mac? _________________ Kriminal Minded |
|
| Back to top |
|
 |
timmerk15 EVDO Fledgling
Joined: 21 Jul 2007 Posts: 13
|
Posted: Mon Jul 30, 2007 5:05 pm Post subject: |
|
|
| KriminalMinded wrote: | | Any possibility of getting this to work on a mac? |
It already does with Apple's WWAN drivers. Hold option when clicking on the Signal Strength meter in the menu bar and it will show you the actual signal. |
|
| Back to top |
|
 |
plor EVDO Newbie
Joined: 09 Oct 2007 Posts: 5
|
Posted: Tue Oct 09, 2007 2:24 pm Post subject: |
|
|
| I also get measurements between 65 and 85, which would make the dBm make sense. I've seen lower numbers (<31) on other cards, which would probably use a different scale. Does anyone know of a place that would show the card and what the +CSQ command returns? |
|
| Back to top |
|
 |
|
|
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum
|
|
Buy from the 3G Experts @ 3Gstore.com
 MBR1200 + Free PHS300 $229.99
 Sprint MiFi FREE
 CTR500 $159.99
 MBR1000 + Free CTR350 $189.99
 CTR350 $84.99
 PHS300 $139.99
 Sprint 598U - Free
 CLEAR USB Modem
 Sprint U301 3G/4G USB, $19.99 - $50 Rebate
 Purchase an EVDO Booster Antenna
 Purchase an EVDO Amplifier
 Your Mac EVDO Experts
|
|