Hello all.
I am attempting to use osmocom-analog as an AMPS base station.
uhd_find_devices reports:
</> INFO] [UHD] linux; GNU C++ version 11.4.0; Boost_107400; UHD_4.6.0.0-141-g0f2007fc
– UHD Device 0
Device Address:
serial: 191796
name: MyB210
product: B210
type: b200
</>
I am using the following to start AMPS:
</> amps -v 1 --sdr-uhd -s 960000 -k 334 -p -d -F no --sysinfo sid=18 ,</>
There is a lot of output text. I think eveything is normal until here:
</> --------------------------------------±--------------------------------------
DSDR INFO sdr.c:135 Frequency 1 = 835.0200 MHz
DSDR INFO sdr.c:469 Total bandwidth (two side bands) for all RX Frequencies: 108000 Hz
DSDR INFO sdr.c:477 Using center frequency: RX 834.984000 MHz
DSDR DEBUG sdr.c:482 Frequency #0: RX offset: 0.036000 MHz
DSDR INFO sdr.c:492 Using gain: RX 0.0 dB
DSDR INFO sdr.c:525 Using local oscillator offseet: -1000000 Hz
DUHD INFO uhd.c:59 Using device args “”
DUHD INFO uhd.c:60 Using stream args “”
DUHD INFO uhd.c:61 Using tune args “”
DUHD INFO uhd.c:64 Creating USRP with args “”…
[INFO] [UHD] linux; GNU C++ version 11.2.0; Boost_107400; UHD_4.1.0.5-3
DUHD ERROR uhd.c:263 Given TX frequency 879984000 Hz is not supported, try 0 Hz
DUHD DEBUG uhd.c:521 Clean up UHD
DSDR DEBUG sdr.c:741 Close SDR device
DUHD DEBUG uhd.c:521 Clean up UHD
DSENDER ERROR sender.c:240 No device for transceiver!
DAMPS DEBUG amps.c:654 Destroying ‘AMPS’ instance for channel = 334.
DDSP DEBUG dsp.c:293 (chan 334) Cleanup DSP for treansceiver.
DSENDER DEBUG sender.c:276 (chan 334) Destroying ‘Sender’ instance
DJITTER INFO jitter.c:129 (334) Reset jitter buffer.
DJITTER INFO jitter.c:156 (334) Destroying jitter buffer.
DJITTER INFO jitter.c:129 (334) Reset jitter buffer.
DJITTER INFO jitter.c:156 (334) Destroying jitter buffer.
</>
Am I using an incorrect sample rate? Is there another argument I need to pass?
Any help of suggestions would be appreciated.
Thank you very much,
-Shawn
I looked the source amps.c file and other amps files for something obvious. But I can’t find what the problem is. I will also say that I do not understand what the problem is. There is an error. But is it the computation of transmit frequency? Sample rate?
I saw a YouTube video of a person running AMPS on a Ettus B205. So, the code works on at least one USRP.
The output looks correct until this line:
“DUHD ERROR uhd.c:263 Given TX frequency 879984000 Hz is not supported, try 0 Hz”
0 Hz? Why would I use a transmit frequency of 0 Hz? Also, my TX frequency should be 880.020 MHz (kanal 334). Why does the software think the frequency should be 879.984 MHz?
Below is the full output of what I see when I run the code.
Any help would be truly appreciated.
Thank you.
$ amps -v 1 --sdr-uhd -s 960000 -k 334 -p -d -F no --sysinfo sid=18
DOPTIONS INFO options.c:128 Config file ‘/home/shawn/.osmocom/analog/amps.conf’ seems not to exist, using command line options only.
DOPTIONS INFO options.c:280 Command line option ‘-v’ (‘–verbose’), parameter ‘1’
DOPTIONS INFO options.c:296 Command line option ‘–sdr-uhd’
DOPTIONS INFO options.c:280 Command line option ‘-s’ (‘–samplerate’), parameter ‘960000’
DOPTIONS INFO options.c:280 Command line option ‘-k’ (‘–kanal’), parameter ‘334’
DOPTIONS INFO options.c:282 Command line option ‘-p’ (‘–pre-emphasis’)
DOPTIONS INFO options.c:282 Command line option ‘-d’ (‘–de-emphasis’)
DOPTIONS INFO options.c:280 Command line option ‘-F’ (‘–flip-polarity’), parameter ‘no’
DOPTIONS INFO options.c:294 Command line option ‘–sysinfo’, parameter ‘sid=18’
Selected System ID (SID) 18 belongs to:
Alexandria, VA (Bell Atlantic Mobile)
Baltimore, MD (Bell Atlantic Mobile)
Frederick, MD (Bell Atlantic Mobile)
Silver Spring, MD (Bell Atlantic Mobile)
Washington, DC (Bell Atlantic Mobile)
DDSP DEBUG dsp.c:150 Generating sine table for SAT signal.
DAMPS NOTICE amps.c:583 You selected ‘combined control & paging & voice channel’. This is a hack, but the only way to use control channel and voice channel on one transceiver. Some phones may reject this, but all my phones don’t.
DAMPS DEBUG amps.c:597 Creating ‘AMPS’ instance for channel = 334 of band B (sample rate 960000).
DSENDER DEBUG sender.c:77 (chan 334) Creating ‘Sender’ instance
DJITTER INFO jitter.c:129 (334) Reset jitter buffer.
DJITTER INFO jitter.c:113 (334) Created jitter buffer. (samperate=8000, target_window=60ms, max_window=1000ms, flag:latency=true flag:repeat=true)
DJITTER INFO jitter.c:129 (334) Reset jitter buffer.
DJITTER INFO jitter.c:113 (334) Created jitter buffer. (samperate=960000, target_window=60ms, max_window=1000ms, flag:latency=true flag:repeat=true)
DDSP DEBUG dsp.c:202 (chan 334) Init DSP for transceiver.
DSENDER DEBUG sender.c:308 (chan 334) Maximum deviation: 8.0 kHz, Maximum modulation: 10.0 kHz
DSENDER DEBUG sender.c:309 (chan 334) Deviation at speech level: 2.9 kHz
DDSP DEBUG dsp.c:218 Use 96.0000 samples for full bit duration @ 960000.
DDSP DEBUG dsp.c:234 Bit window length: 96
DDSP DEBUG dsp.c:235 → Samples in window to analyse level left of edge: 24…47
DDSP DEBUG dsp.c:236 → Samples in window to analyse level right of edge: 48…71
DDSP DEBUG dsp.c:175 Generating smooth ramp table.
DDSP DEBUG dsp.c:259 Sat detection interval is 66 ms.
DDSP DEBUG dsp.c:927 (chan 334) SAT detector reset: Initial state.
DAMPS DEBUG amps.c:399 (chan 334) State change: (NULL) → IDLE
DAMPS INFO amps.c:685 (chan 334) Entering IDLE state, sending Overhead/Filler frames on combined control & paging & voice channel.
DDSP DEBUG dsp.c:927 (chan 334) SAT detector reset: Change to FOCC.
DDSP INFO dsp.c:944 (chan 334) Change mode to FOCC
DDSP DEBUG dsp.c:967 (chan 334) Reset FSK frame transmitter, due to setting dsp mode.
DAMPS NOTICE amps.c:638 Created channel #334 (System B) of type ‘CC/PC/VC’ = combined control & paging & voice channel
Base station on channel 334 ready (combined control & paging & voice channel), please tune transmitter to 880.020 MHz and receiver to 835.020 MHz. (-45.000 MHz offset)
DLCC DEBUG endpoint.c:1356 Creating new endpoint instance.
DLCC DEBUG endpoint.c:1207 setting automatic remote peer selection
DSDR DEBUG sdr.c:149 Open SDR device
DSDR INFO sdr.c:168 Require bandwidth of each channel is 2 * (8.0 deviation + 10.0 modulation) = 36.0 KHz
DSDR INFO sdr.c:307 We shift center frequency 18 KHz down (half bandwidth), to prevent channel from overlap with DC level.
DSDR INFO sdr.c:133 TX Spectrum:
1
---------------------------------------±--------------------------------------
DSDR INFO sdr.c:135 Frequency 1 = 880.0200 MHz
DSDR INFO sdr.c:357 Total bandwidth (two side bands) for all TX Frequencies: 108000 Hz
DSDR INFO sdr.c:365 Using center frequency: TX 879.984000 MHz
DSDR DEBUG sdr.c:370 Frequency #0: TX offset: 0.036000 MHz
DSDR INFO sdr.c:391 Using gain: TX 0.0 dB
DSDR INFO sdr.c:433 We shift center frequency 18 KHz down (half bandwidth), to prevent channel from overlap with DC level.
DSDR INFO sdr.c:133 RX Spectrum:
1
---------------------------------------±--------------------------------------
DSDR INFO sdr.c:135 Frequency 1 = 835.0200 MHz
DSDR INFO sdr.c:469 Total bandwidth (two side bands) for all RX Frequencies: 108000 Hz
DSDR INFO sdr.c:477 Using center frequency: RX 834.984000 MHz
DSDR DEBUG sdr.c:482 Frequency #0: RX offset: 0.036000 MHz
DSDR INFO sdr.c:492 Using gain: RX 0.0 dB
DSDR INFO sdr.c:525 Using local oscillator offseet: -1000000 Hz
DUHD INFO uhd.c:59 Using device args “”
DUHD INFO uhd.c:60 Using stream args “”
DUHD INFO uhd.c:61 Using tune args “”
DUHD INFO uhd.c:64 Creating USRP with args “”…
[INFO] [UHD] linux; GNU C++ version 11.2.0; Boost_107400; UHD_4.1.0.5-3
DUHD ERROR uhd.c:263 Given TX frequency 879984000 Hz is not supported, try 0 Hz
DUHD DEBUG uhd.c:521 Clean up UHD
DSDR DEBUG sdr.c:741 Close SDR device
DUHD DEBUG uhd.c:521 Clean up UHD
DSENDER ERROR sender.c:240 No device for transceiver!
DAMPS DEBUG amps.c:654 Destroying ‘AMPS’ instance for channel = 334.
DDSP DEBUG dsp.c:293 (chan 334) Cleanup DSP for treansceiver.
DSENDER DEBUG sender.c:276 (chan 334) Destroying ‘Sender’ instance
DJITTER INFO jitter.c:129 (334) Reset jitter buffer.
DJITTER INFO jitter.c:156 (334) Destroying jitter buffer.
DJITTER INFO jitter.c:129 (334) Reset jitter buffer.
DJITTER INFO jitter.c:156 (334) Destroying jitter buffer.