Re: Re: About sniff multi bursts in a frame, CCCH_CONF

Aegean Chou aegean2000 at 21cn.com
Mon Sep 26 09:28:57 UTC 2011


Hi, Sylvain Munaut

	It's china mobile, i can provide more information if you need.
	Thanks for pointing out the right way, i'll try to modify codes according to BCCH'.

	BTW, i modify TS (line l1s_rx_win_ctrl _ONLY_) from 0 to 2, 4 and 6, the TS2 and TS4 work well, but the TS6 crash very soon because FCCH error,
	for example, what's wrong? (high TS -> low TS)?

THIS FIRMWARE WAS COMPILED WITHOUT TX SUPPORT!!!
Assert DSP into Reset
Releasing DSP from Reset
Installing DSP sniff patch
Setting some dsp_api.ndb values
Setting API NDB parameters
DSP Download Status: 0x0001
DSP API Version: 0x0000 0x0000
Finishing download phase
DSP Download Status: 0x0002
DSP API Version: 0x3606 0x0000
LOST 1831!
L1CTL_FBSB_REQ (arfcn=70, flags=0x7)
Starting FCCH RecognitionFB0 (11:6): TOA= 7200, Power= -69dBm, Angle= 3691Hz
FB1 (21:8): TOA= 9651, Power= -69dBm, Angle=  103Hz
  fn_offset=20 (fn=21 + attempt=8 + ntdma = 7)
  delay=9 (fn_offset=20 + 11 - fn=21 - 1
  scheduling next FB/SB detection task with delay 9
=>FB @ FNR 20 fn_offset=20 qbits=3420
Synchronize_TDMA
LOST 3186!
SB1 (46:1): TOA=   29, Power= -69dBm, Angle=  217Hz
=> SB 0x00c12184: BSIC=33 fn=89118(67/16/21) qbits=24
Synchronize_TDMA
=>FB @ FNR 45 fn_offset=89118 qbits=4932
LOST 1912!
TOA AVG is not 16 qbits, correcting (got 20)
L1CTL_DM_EST_REQ (arfcn=4866, chan_nr=0x41, tsc=1)
LOST 2110!
L1CTL_DM_REL_REQL1CTL_FBSB_REQ (arfcn=70, flags=0x7)
Starting FCCH RecognitionLOST 3515!
FB0 (91861:3): TOA= 2544, Power= -67dBm, Angle= 3754Hz
FB1 (91871:8): TOA= 8751, Power= -67dBm, Angle=   40Hz
  fn_offset=91869 (fn=91871 + attempt=8 + ntdma = 6)
  delay=8 (fn_offset=91869 + 11 - fn=91871 - 1
  scheduling next FB/SB detection task with delay 8
=>FB @ FNR 91869 fn_offset=91869 qbits=4820
Synchronize_TDMA
LOST 3711!
SB1 (183745:1): TOA=   29, Power= -67dBm, Angle=  160Hz
=> SB 0x01e12284: BSIC=33 fn=91882(69/24/31) qbits=24
Synchronize_TDMA
=>FB @ FNR 183744 fn_offset=91882 qbits=4932
LOST 1912!
L1CTL_DM_EST_REQ (arfcn=4866, chan_nr=0x69, tsc=1)
LOST 2109!
L1CTL_DM_REL_REQL1CTL_FBSB_REQ (arfcn=70, flags=0x7)
Starting FCCH RecognitionLOST 3516!
FB0 (92514:8): TOA= 8784, Power= -67dBm, Angle= 3696Hz
FB1 (92524:8): TOA= 8755, Power= -67dBm, Angle=   69Hz
  fn_offset=92522 (fn=92524 + attempt=8 + ntdma = 6)
  delay=8 (fn_offset=92522 + 11 - fn=92524 - 1
  scheduling next FB/SB detection task with delay 8
=>FB @ FNR 92522 fn_offset=92522 qbits=4836
Synchronize_TDMA
LOST 3717!
SB1 (185051:1): TOA=   27, Power= -66dBm, Angle=   47Hz
=> SB 0x00852284: BSIC=33 fn=92535(69/ 1/21) qbits=16
Synchronize_TDMA
=>FB @ FNR 185050 fn_offset=92535 qbits=4924
LOST 1909!
TOA AVG is not 16 qbits, correcting (got 19)
L1CTL_DM_EST_REQ (arfcn=4866, chan_nr=0x73, tsc=1)
LOST 2578!
L1CTL_DM_REL_REQL1CTL_FBSB_REQ (arfcn=70, flags=0x7)
Starting FCCH RecognitionLOST 3047!
FB0 (93574:9): TOA=10032, Power= -72dBm, Angle= 3770Hz
FB1 (93585:9): TOA=10003, Power= -72dBm, Angle=  -11Hz
  fn_offset=93583 (fn=93585 + attempt=9 + ntdma = 7)
  delay=8 (fn_offset=93583 + 11 - fn=93585 - 1
  scheduling next FB/SB detection task with delay 8
=>FB @ FNR 93583 fn_offset=93583 qbits=4828
Synchronize_TDMA
LOST 3713!
SB1 (187172:1): TOA=   27, Power= -72dBm, Angle=  132Hz
=> SB 0x01582384: BSIC=33 fn=93596(70/22/11) qbits=16
Synchronize_TDMA
=>FB @ FNR 187171 fn_offset=93596 qbits=4924
LOST 1910!
L1CTL_DM_EST_REQ (arfcn=4866, chan_nr=0x43, tsc=1)
LOST 2578!
L1CTL_DM_REL_REQL1CTL_FBSB_REQ (arfcn=70, flags=0x7)
Starting FCCH RecognitionLOST 3047!
FB0 (94186:1): TOA=   48, Power= -68dBm, Angle= 3743Hz
FB1 (94197:9): TOA=10007, Power= -68dBm, Angle= 3738Hz
  fn_offset=94195 (fn=94197 + attempt=9 + ntdma = 7)
  delay=8 (fn_offset=94195 + 11 - fn=94197 - 1
  scheduling next FB/SB detection task with delay 8
FB1 (94217:11): TOA=12507, Power= -68dBm, Angle= 3783Hz
  fn_offset=94215 (fn=94217 + attempt=11 + ntdma = 9)
  delay=8 (fn_offset=94215 + 11 - fn=94217 - 1
  scheduling next FB/SB detection task with delay 8
FB1 (94237:11): TOA=12507, Power= -69dBm, Angle= 3743Hz
  fn_offset=94235 (fn=94237 + attempt=11 + ntdma = 9)
  delay=8 (fn_offset=94235 + 11 - fn=94237 - 1
  scheduling next FB/SB detection task with delay 8
FB1 (94248:2): TOA= 1259, Power= -69dBm, Angle= 3689Hz
  fn_offset=94246 (fn=94248 + attempt=2 + ntdma = 0)
  delay=8 (fn_offset=94246 + 11 - fn=94248 - 1
  scheduling next FB/SB detection task with delay 8
... ...

======= 2011-09-26 14:10:17 =======

>>        the bts arround me uses MultiCCCH, it's CCCH_CONF = 110 (6), so it uses TS0, TS2, TS4 and TS6 in a frame for PCH/AGCH.
>
>Mmm ,interesting, I had never seen that option being used before. What
>network is this.
>
>>        but the burst_ind only CCCH-CONF 0 & 1 are supported, it can sniff TS0 only, so only catch 1/4 IMM ASS for me.
>>        my OWN phone, it's just not in TS0 (i use nokia netmonitor to check it), so i can't catch it at all (phones use IMSI to decide page group).
>
>Well, it's your own phone (or any known target phone), you know the
>IMSI, hence the paging group ...
>
>
>>        i think the bottleneck is the DSP, as the DSP task (ALLC_DSP_TASK) can only process one TS of a frame (it's enough for phone),
>>        i think maybe backup/restore the DSP task variable patch needed, i'm new to the DSP disassemble and patch, anyone can help? thanks
>
>That's gonna be _very_ hard, the DSP uses _plenty_ of global variables ...
>
>But OTOH, instead of using the normal 'RX task', you can use the sniff
>task to listen to the CCCH. The sniff task will _not_ do the channel
>decoding (i.e. you'll have to call xcch_decode to get the actual 23
>bytes L2 frame), but it can sniff up to 4 bursts in a frame. just look
>at how sdcch sniffing is done, it currently sniff 2 timeslot 0 & 3 (to
>get DL & UL).
>
>This way you won't need any hard DSP patching, just a minor patch on
>the firmware to convert CCCH listening to burst_ind (leave the BCCH
>task as-it is, just mod the CCCH). And then a patch in the host app to
>call xcch_decode appropriately and feed the results 'as if' it cames
>from the phone directly.
>
>Cheers,
>
>    Sylvain

= = = = = = = = = = = = = = = = = = = =
			

Best regards
Steve				 



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