This part moves control channel message primitives from osmo-bts-sysmo to
common part.
In order to control ciphering fo BTS model, CIPHER (MPH_INFO) messages are
used.
The original code handled both the fact where a TIME indication would be
missed (and thus the frame number be higher than previous + 1), as well
as the two cases for combined / non-combined CCCH.
The L1SAP code removed some of those bits, which I'm re-introducing
here.
This is a regression of the code compared to the existing
sysmoBTS code, where the L1 tells us whether its AGCH or
PCH. However, it was not used even in the old code, so
we can afford to simply put a #warning here.
This first part moves BCCH message primitives from osmo-bts-sysmo to common
part. A new file "common/l1sap.c" is introduced to implement handling of
layer 1 messages from/to BTS model.
Use the new libosmo-abis API to query the session for the
statistics and then send it as a TLV element to the BSC.
This can be used to do post processing about the call. E.g
to figure out if no audio arrived at all.
The RSL_IE_MEAS_RES_NR is mandatory element with a minimum
of 5 octets (two for TL and three for the value). When we
establish a new channel we might not have had enough time
in a TDMA frame to calculate the average. The issue is not
easy to reproduce. At the point we receive the measurement
report we have two uplink measurements queued. As it is not
easy to reproduce and only occurs when a channel is new
I have decided to drop the message instead of sending made
up uplink measurement reports.
As of now lchan_build_rsl_ul_meas will always return 3 and
the condition will never be false.
Avoids: SYS#1781
Use the standard RSL commands to order a logical channel
to use a fixed power level.
The code is not fully verified and there was a last minute
change to invoke bts_model_adjst_ms_pwr.
Currently the DSP is instructed to achieve a given uplink
power target but there are circumstances (e.g. EMV testing)
where we need more control over it. The "manual/software/osmo"
power control can only be implemented per TRX and not per
lchan. Add a very very basic control that checks the MS Power
used by the phone, the actual receive level and then adjust
the power.
The code doesn't take the history into account, if the phone
can not reach the requested power level the code will be stuck
(e.g. no timeout based on multiframes). It has a mode for a
fixed power control but no way to set it yet.
The change of the mode requires a restart of the software.
This should handle OML channel combinations with CBCH and activate the
CBCH SAPI towards the DSP correspondingly. What is still missing is
sending any actual information over the CBCH in respons to the
PH-RTS.ind coming up from L1.
libosmo-abis doesn't make it easy to have these parameters
as const.. just declare it non-const in the api. We pass
a static string but we know it will not be modified.
We use the completion call-back from L1 to compare the instructed
TRX board output power with the actual value as reported back from
L1.
Right now we only print an error message in case the values disagree.
In the future we might want to either use that value as part of our
calculation or send an OML alarm report to the BSC.
We do not have the vty test script to do roundtrip testing. There
is no max-initinal-pout, then there was a typo inside 'initial' and
for the relative step size the unit is dB/mdB. Fix both of that.
Back in March 2013, some structures and defines related to decoded
measurement reports have been moved from openbsc to libosmocore
(libosmocore e128f4663104ed64e33e362cff2566f36d65e658) so that they can
be used also from osmo-bts. This finally follows up on that.
You need openbsc 7ff4f0e0fc692bfab829da50edb104e58b271e7e or later.
Using this control interface, an external program can request
attentuation of the transmitter for thermal management reasons. The
external application doesn't have to know anthing about the actual
transmit power, but it can just configure a certian value of milli-dB
(1/10000 bel) and update (increase/decrease) that value depending on
the thermal environment.
In order to support transmit power reduction by thermal management
as well as the variety of new internal / external PA configurations
of BTSs, we need a slightly more complex system.
Also, as at high power a single dB can be quite a big difference,
we are now doing all computations in milli-dB(m), i.e. 1/10000 bel.
Ramping is now used both for up and down ramping, as that is useful in
cases where you want to gracefully shut down a cell by shrinking its
radius, gradually handing over subscribers to neighboring cells.
Furthermore, this code is becoming part of the 'common' codebase, as it
is not really specific to how sysmobts is working.
The user can specify a single aggregate value for external system
gain/attenuation. Let's say you have 1dB loss of antenna cable, so you
can put that as 'user-gain -1' into the config, which means that a
'transmit power of 20dBm' will be compensatet for that and the TRX is
instructed to output 21dBm to compensate the cable loss. Similarly,
external PAs can be described by a positive user-gain.
One of the next steps will be to communicate those values and the
nominal power capability of the specific BTS to the BSC, so the BSC will
automatically show correct signal levels in the VTY and log files.
The code includes provisions for future extensions regarding
* an external and an internal PA with calibration tables
* a thermal attenuation setting to be controlled by the site manager
Extend the router to verify that the message received is
properly encoded. The code can deal with the basic structure
of ETSI OML and vendor specific messages for ip.access and
the osmocom project.
For LCR and other systems without out-of-band information we need
to indicate the CMR. Not every air message will include the mode
and we sent a stream that had the CMR set and not-set. This lead
to the AudioCodes MGW only playing every second frame.
Remember the last used mode and initialize it to _NONE when we
receive the multirate config. In case of a real error we will
still use AMR_CMR_NONE.
The initial patch is from Harald. I have added the initialization
and moving of the defines to amr.h.
Manually verified by enabling AMR5.9 and looking at two RTP
packages in sequence. In both cases the CMR was 2. I have looked
at "amr.nb.cmr != 2" in wireshark and only found the MGCP dummy
packet.
Limit the range from 0 to (_MAX_SYSINFO_TYPE - 1) instead of
0 to 31. This way we will never access the lchan->si.buf[] out
of bounds. This is only a theoretical issue though as the code
filling the lchan->si.buf for the SACCH will not have valid
>= _MAX_SYSINFO_TYPE. Add a small regression test to check we
still schedule all SIs.
Fixes: CID 1040765
Andreas Eversberg
Harald Welte