Nokia Site family » History » Revision 17

Revision 16 (csaba, 02/19/2016 10:47 PM) → Revision 17/23 (csaba, 02/19/2016 10:48 PM)

[[OpenBSC]] OpenBSC is currently supporting the Site family of Nokia BTSes. 

 *Things '''Things that work:* work:''' 

  - Nokia [[InSite]] InSite ,MetroSite and [[UltraSite]] UltraSite units are proven to be working, please see the detailed infos below 
  - Full Rate and Enhanced Full Rate voice calls (MO & MT) 
  - SMS (MO & MT) 
  - Cell reselection 
  - Handover (please see this patch: ") [] ) 
  - Multiple BTS: two [[InSite]] InSite and one [[MetroSite]] MetroSite units are connected to [[OpenBSC]] OpenBSC on the same E1 line, everything worked as it should 
  - Multi TRX: two or more TRX can be configured to add extra SDCCH or TCH capacity. Note that only one sector can be created at the moment. 
  - Hopping: baseband and RF hopping works on [[MetroSite]], MetroSite, RF hopping works on [[UltraSite]]. UltraSite. Tested with two TRXes, probably more TRX can be configured, but not tested. 

 *Things '''Things that do not work:* work:''' 

  - HR calls (the TRAU framer for E1 is only implementing 16kbit channels, HR needs 8kbit) 
  - GPRS, EDGE (no E1 based PCU implementation, probably never will) 

 *Handover:* '''Handover:''' 

 The [[OpenBSC]] OpenBSC side of the handover logic works quiet well. But at the moment, there is a slight problem with the Nokia units. The handover decision is made correctly, the GSM phone is commanded to switch to the new channel on the new BTS, which the phone does. But despite the channel release is sent, the old channel never get released, and this leads to a Radio Link Failure. 

 Update: it seems that the root cause of the previous handover failure is that the [[InSite]] InSite BTSes (probably others too) are not sending the channel release ACK to the BSC after the old channel release is requested by the BSC. Andreas Eversberg added a patch which overcomes this problem by implicating the missing ACK, so the BSC can continue and finish the handover process. This can be enbaled by adding the next line to the BTS part of the config file: 

 nokia_site no-local-rel-conf 1 


 This fix is tested on Nokia [[InSite]] InSite and [[MetroSite]] MetroSite units, all of them are performing handovers normally. 

 For more info, please see this patch: [":] [] 

 *E1 cards:* '''E1 cards:''' 

 The original Nokia support was written for HFC-E1 and mISDN. The Site can only be interfaced via traditional E1 lines (no IP ABIS support for these old units). It is also possible to use a DAHDI card to interface with the BTS. For this you have to use the following configuration in /etc/dahdi/system.conf: 



 Unlike in traditional E1 communication, we are using CCS signalling. For every signalling and traffic channel between the BTS and the BSC, we are using dedicated timeslots. Because of that, we are no longer need any shared signalling channel on the E1 line (e.g. D channel on timeslot 16. 

 *Example '''Example config file for an 1800MHz Nokia [[InSite]] unit:* InSite unit:''' 

 ! OpenBSC configuration saved from vty 
 !     ! 
 password foo 
 line vty 
  no login 
  e1_line 0 driver dahdi 
  # e1_line 0 port 0 
  log file /root/900_nokia.log 
  logging filter all 1 
  logging color 1 
  logging timestamp 1 
  network country code 1 
  mobile network code 1 
  short name [[OpenBSC]] OpenBSC 
  long name [[OpenBSC]] OpenBSC  
  neci 0 
  rrlp mode none 
  mm info 1 
  handover 0 
  handover window rxlev averaging 5 
  handover window rxqual averaging 1 
  handover window rxlev neighbor averaging 5 
  handover power budget interval 6 
  handover power budget hysteresis 3 
  handover maximum distance 9999 
  timer t3101 3 
  timer t3103 5 
  timer t3105 20 
  timer t3107 10 
  timer t3109 15 
  timer t3111 2 
  timer t3113 10 
  timer t3115 0 
  timer t3117 0 
  timer t3119 0 
  timer t3141 0 
  timer t3122 10 

  bts 0 
   type nokia_site 
   band GSM1800 
   cell_identity 1 
   location_area_code 1 
   base_station_id_code 63 
   training_sequence_code 7 
   ms max power 12 
   cell reselection hysteresis 4 
   periodic location update 10 
   nokia_site skip-reset 0 
   nokia_site no-local-rel-conf 1 
   oml e1 line 0 timeslot 8 sub-slot full 
   oml e1 tei 1 
   trx 0 
    arfcn 885 
    nominal power 18 
    max_power_red 10 
    rsl e1 line 0 timeslot 7 sub-slot full 
    rsl e1 tei 1 

     timeslot 0 
      phys_chan_config CCCH+SDCCH4 
      e1 line 0 timeslot 5 sub-slot 0 

     timeslot 1 
      phys_chan_config SDCCH8 
      e1 line 0 timeslot 5 sub-slot 1 

     timeslot 2 
      phys_chan_config TCH/F 
      e1 line 0 timeslot 5 sub-slot 2 

     timeslot 3 
      phys_chan_config TCH/F 
      e1 line 0 timeslot 5 sub-slot 3 

     timeslot 4 
      phys_chan_config TCH/F 
      e1 line 0 timeslot 6 sub-slot 0 

     timeslot 5 
      phys_chan_config TCH/F 
      e1 line 0 timeslot 6 sub-slot 1 

     timeslot 6 
      phys_chan_config TCH/F 
      e1 line 0 timeslot 6 sub-slot 2 

     timeslot 7 
      phys_chan_config TCH/F 
      e1 line 0 timeslot 6 sub-slot 3 


 *LMP }}} 

 '''LMP cable pinout for [[InSite]] units:* InSite units:''' 

 *LMP '''LMP cable pinout for [[MetroSite]] units:* MetroSite units:''' 


 *Tips '''Tips and tricks for Site family and [[OpenBSC]]:* OpenBSC:''' 

 *RESET Timer:* '''RESET Timer:''' 

 Every time you start a BTS, [[OpenBSC]] OpenBSC first resets (actually restarts) the unit, and only configures and starts the BTS after that. The reason behind this, is if you change the radio parameters of the BTS (ARFCN, CID, BSIC, TSC, TX power etc.), these parameters are not going to change on the BTS if this resets is skipped. 

 The default 15 seconds is working well in general, but in some cases you need to raise this parameter (eg. to force [[OpenBSC]] OpenBSC to wait more for the BTS to restart). For example: if you use more than one unit on the same E1 (InSite units daisy chained via the internal HDSL interface), or [[MetroSite]] MetroSite units daisy chained via the E1 cross connector TRE unit. 

 This parameter can be modified by adding the following to your [[OpenBSC]] OpenBSC config file: 

 nokia_site bts-reset-timer 15 


 Try 20 or 23 instead of 15. Example: for a HDSL cascaded two BTS [[InSite]] InSite setup, I needed to raise this parameter to 20 seconds. For 2 TRX [[MetroSite]] MetroSite it needs at least 25 seconds. For [[UltraSIte]] UltraSIte setups it needs 60 seconds. 

 Sometimes even the reset itself can cause problems (multi-BTS setup, [[MetroSite]] MetroSite setup). You can disable this RESET by adding the following line to the BTS part of the [[OpenBSC]] OpenBSC config file: 

 nokia_site skip-reset 1 


 Do not forget, that if you use the above parameter, every time you change the radio parameters of the BTS, you need to restart the BTS by powercycling    it, wait for it to start up, then start [[OpenBSC]]! OpenBSC! 

 *Segfault '''Segfault crash during BTS init:* init:''' 

 This problem is brought to daylight, but not caused by the following patch: 

 The easy solution (but not fixing!) of this problem is to simply comment out the part which was added by this patch: 

 	 /* free history buffer list */ 
	 dl->tx_hist = NULL;    <-- comment out this line! 


 After commenting out the above line, you need to recompile libosmocore, libosmo-abis and [[OpenBSC]]! OpenBSC! 

 *Running [[OpenBSC]] '''Running OpenBSC with Nokia [[UltraSite]]:* UltraSite:''' 

 In order to run an [[UltraSIte]] UltraSIte BTS with [[OpenBSC]], OpenBSC, you need to set the ".n201" parameter to 260 for both isdn, abis and sat in libosmo-abis/src/input/lapd.c: 

 const struct lapd_profile lapd_profile_isdn = { 
         .k                = LAPD_SET_K(7,7), 
         .n200             = 3, 
         .n201             = 260,                        <-- Modify this parameters to 260! 
         .n202             = 3, 
         .t200_sec         = 1,      .t200_usec        = 0, 
         .t201_sec         = 1,      .t201_usec        = 0, 
         .t202_sec         = 2,      .t202_usec        = 0, 
         .t203_sec         = 10,     .t203_usec        = 0, 
         .short_address    = 0 

 const struct lapd_profile lapd_profile_abis = { 
         .k                = LAPD_SET_K(2,1), 
         .n200             = 3, 
         .n201             = 260,                         <-- Modify this parameters to 260! 
         .n202             = 0, /* infinite */ 
         .t200_sec         = 0,      .t200_usec        = 240000, 
         .t201_sec         = 1,      .t201_usec        = 0, 
         .t202_sec         = 2,      .t202_usec        = 0, 
         .t203_sec         = 10,     .t203_usec        = 0, 
         .short_address    = 0 

 const struct lapd_profile lapd_profile_sat = { 
         .k                = LAPD_SET_K(15,15), 
         .n200             = 5, 
         .n201             = 260,        <-- Modify this parameters to 260! 
         .n202             = 5, 
         .t200_sec         = 2,      .t200_usec        = 400000, 
         .t201_sec         = 2,      .t201_usec        = 400000, 
         .t202_sec         = 2,      .t202_usec        = 400000, 
         .t203_sec         = 20,     .t203_usec        = 0, 
         .short_address    = 1 



 After the modification, you need to recompile Libosmocore, Libosmo-Abis and [[OpenBSC]]! OpenBSC! Note that with the above modification the support for other Site BTS-es (Insite, [[MetroSite]]) MetroSite) are not affected. 

 This is necessary because after [[OpenBSC]] OpenBSC issued the reset, during the BTS is restarting, actually the TRX software is not loaded. After the reset [[OpenBSC]] OpenBSC issues a "Use current version" command to the BTS which indicates to use the software from the local flash storge on the BOI card. The problem is that [[InSite]] InSite and [[MetroSite]] MetroSite units already load the TRX software when this command is being issued, but the [[UltrsSite]] UltrsSite only starts to load the TRX software when the "Use current version" is being issued to it. Because [[OpenBSC]] OpenBSC expects this to happens instantly, but with [[UltraSite]] UltraSite the TRX software load can take another 60 seconds, the LAPD link will time out until the TRX software is being loaded, and [[OpenBSC]] OpenBSC will never bootstrap the TRX. With "n201" set to 260, this gives enough time to the LAPD link to not fail during that extra 60 seconds it takes to load the TRX software. 

 Of corse this is a nasty hack, and it is not the proper way to handle this situation. The Nokia related part should be aware that an [[UltraSite]] UltraSite works like this by default, and it should wait with the first RSL lapd link activation another 60 seconds after the reset timer is expired and the "Use current version" command is sent. Maybe this will be implemented in the future, but until then, the above modification does work. 

 [[OpenBSC]] OpenBSC support for [[UltraSite]] UltraSite tested with one TRX, TCH fullrate and TCH enhanced fullrate, MO and MT voice calls and SMS works as it should.
Add picture from clipboard (Maximum size: 48.8 MB)