Commit Graph

248 Commits

Author SHA1 Message Date
Neels Hofmeyr 9f14174440 drop obsolete comment
Change-Id: I7cc79e368512483ff4e1e56b49ad2b950f627c2f
2021-10-05 08:29:15 +02:00
Keith Whyte 2262245209 Implement MS Uplink Power Control Loop
* Adds vty option dyn-bsc for ms-power-control -> mode
* Imports power_control.c from osmo-bts project
  [at commit 2f3cd4b697972d8484f9a9d3b7ef634086f65fa5]
* Removes unused C/I code from osmo-bts's power_control.c

This patch then calls the power loop on receipt of measurement
reports and updates the MS Power Level accordingly.

Change-Id: Ibc307e758697eb5ca3fb86622f35709d6077db9e
2021-10-05 04:32:33 +00:00
Neels Hofmeyr 62c4097dcf fix TSC / TSC Set used for Handover
From the nature of the lchan_activate_info.tsc_set and .tsc, it is easy
to forget to set tsc_set,tsc = -1 to use default TSC Set and TSC values.
Handover code is one such instance that forgets to set -1.

Change the semantics of tsc_set and tsc so that this kind of error can
not happen again as easily: use a separate bool to flag whether to use
the default config or explicit values.

Implicitly fix the lchan_activate_infos "launched" in handover_fsm.c as
well as abis_rsl_chan_rqd_queue_poll().

Related: OS#5244 SYS#4895
Related: I1ed6f068c85b01e5a2d7b5f2651498a1521f89af (osmo-ttcn3-hacks)
Change-Id: Iae20df4387c3d75752301bd5daeeea7508966393
2021-10-04 11:04:21 +00:00
Pau Espin 464227d071 MS Power Control Loop: Allow Turn off/on C/I independent from value setting
Improve the current VTY support to allow enabling/disabling C/I logic
independent from value setting. This way C/I support can be quickly
disabled & enabled.

Reminder: changing power parameters still require VTY Command "bts NR
resend-power-control-defaults" to be excuted prior to new parameters
being applied on the BTS.

Related: SYS#4917
Change-Id: Id1224c2d9a52db2ed805c49e048d3086ed0167f5
2021-09-29 15:39:17 +02:00
Pau Espin 54283ba626 MS Power Control Loop: Support set up of C/I parameters for osmo-bts
This commit extends existing VTY and RSL infrastructure to configure and
manage MS Power Parameters used in MS Power Control loop, by adding
support to set up Carrier-to-Interference (CI) parameters.

Using C/I instead of existing RxQual is preferred due to extended
granularity of C/I (bigger range than RxQual's 0-7).
Furthermore, existing literature (such as "GSM/EDGE: Evolution and Performance"
Table 10.3) provides detailed information about expected target values,
even different values for different channel types. Hence, it was decided
to support setting different MS Power Parameters for different channel
types.

These MS Power Parameters are Osmocom specific, ie. supported only by
newish versions of osmo-bts. Older versions of osmo-bts should ignore
the new IEs added just fine. The new IEs containing the MS POwer
Parameters are not send for non osmo-bts BTSs, hence this commit is
secure with regards to running  osmo-bsc against an ip.access BTS such
as nanoBTS.

Related: SYS#4917
Depends: libosmocore.git Change-Id Iffef0611430ad6c90606149c398d80158633bbca
Change-Id: I7e76ec47b323d469f777624b74b08752d1f5584f
2021-09-06 12:07:20 +02:00
Philipp Maier 8d22e68706 osmo_bsc_main: integrate MGW pooling into osmo-bsc
Since the libosmo-mgcp-client now supports MGW pooling, lets use this
feature in osmo-bsc. Large RAN installations may benefit from
distributing the RTP voice stream load on multiple media gateways.

Depends: osmo-mgw Icaaba0e470e916eefddfee750b83f5f65291a6b0
Change-Id: I8f33ab2cea04b545c403a6fe479aa963a0fc0d0d
Related: SYS#5091
2021-09-03 15:03:38 +00:00
Neels Hofmeyr a5d3c9d0f2 move BSC level stats and rate counters to new bsc_stats.[hc]
Instead of having static const structs in header files (which end up
duplicated in each and every compile unit!), have one .c file with the
rate_ctr and stat_item descriptions.

Related: SYS#5542
Change-Id: I8fd6380b5ae8ed2d3347e7cfbf674c30b6841ed9
2021-08-30 16:18:52 +00:00
Neels Hofmeyr c746509d3c early IMM ASS 3/n: implement 'pre-ts-ack'
Add experimental 'pre-ts-ack' to the 'immediate-assignment' options:
send the IMM ASS even before a dynamic timeslot is switched. This
possibly saves an Abis roundtrip, but may be racy.

When pre-ts-ack is chosen, already do the IMM ASS before the dyn TS
pchan switch is ACKed.

In Immediate Assignment, in case the dyn TS is not ready yet, get the
pchan kind from lchan->type, which already reflects the target type, and
not from ts->pchan_is, which still reflects the previous pchan type.

Related test is in I2ae28cd92910d4bc341a88571599347a64a18fe5

Related: SYS#5559
Change-Id: I19e6a3d614aa5ae24d64eed96caf53e6f0e8bb74
2021-08-16 02:13:17 +02:00
Neels Hofmeyr eec43fa532 early IMM ASS 2/n: implement 'pre-chan-ack'
When 'immediate-assignment pre-chan-ack' is set, send the Immediate
Assignment directly after the Channel Activation, not waiting for the
Activation ACK, to save an Abis roundtrip.

Related test is in If71f4562d532b6c5faf55f5fd073449a8a137ebf

Related: SYS#5559
Change-Id: I56c25cde152040fb66bdba44399bd37671ae3df2
2021-08-16 02:13:17 +02:00
Neels Hofmeyr 225af37f48 early IMM ASS 1/n: add vty config option
This patch adds only the VTY config option without any effect, to ease
patch review.
The implementation follows in I56c25cde152040fb66bdba44399bd37671ae3df2

The new config option is written so that further variants of Immediate
Assignment sequencing may be added easily.
See also I19e6a3d614aa5ae24d64eed96caf53e6f0e8bb74.

Related: SYS#5559
Change-Id: I710343d1728153faf3db9758ff5a1ef26bb8d3d4
2021-08-16 02:13:17 +02:00
Neels Hofmeyr 57af76cdcf introduce gsm48_lchan_and_pchan2chan_desc()
The function gsm48_lchan2chan_desc_as_configured() dups
gsm48_lchan2chan_desc() with merely a different pchan type
(ts->pchan_from_config instead of ts->pchan_is).

In an upcoming patch, I would like to do the same, just with yet another
pchan value (derived from lchan->type, because that reflects the channel
type even before a dynamic timeslot switched its pchan type).

So replace gsm48_lchan2chan_desc_as_configured() by
gsm48_lchan_and_pchan2chan_desc() with explicit pchan arg;
also call this from gsm48_lchan2chan_desc(), reducing code dup.

gsm48_lchan2chan_desc_as_configured() had more concise error logging.
Absorb that into the new gsm48_lchan_and_pchan2chan_desc().

Add gsm_lchan_and_pchan2chan_nr(), like gsm_lchan2chan_nr() just with
explicit pchan arg, to be able to pass the pchan down from the new
functions mentioned above.

Related: SYS#5559
Change-Id: I67f178c8160cdda1f2ab5513ac4f65c027d4012f
2021-08-16 00:12:12 +00:00
Pau Espin 56eda35874 Introduce VTY option to forbid use of TCH for non-voicecall signalling
Usual allocation mechansim, when some signalling channel is needed,
first tries to reserve an SDCCH, and if all of them are exhausted, then
attempts to reserve a TCH as a last resort.
This, however, may cause TCH starvation under certain situations, for
instance if there high load on other services (LU, SMS, etc.).
Hence, it may be desirable for the operator to forbid reservation
of TCH slots once SDCCH become exhausted. This commit is thus adding a
VTY command which allows forbidding it. The default behavior (allow using
TCH timeslots when SDCCHs are exhausted) is kept as before.

The above mentioned prohibition is applied only to non-voicecall related
signalling services. That's because voicecall services will end up
requiring a TCH anyway, and forbidding reservation of TCH straighaway
when SDCCHs are exhausted would mean no voice calls could be initiated
while still TCHs would be available.

Related: SYS#5548
Change-Id: Ib08027125145df26602069bfb51847063b0ccc0c
2021-07-23 13:36:03 +02:00
Neels Hofmeyr e5a761c6b8 RES IND: parse msg and store interference levels in lchans
Also show the current interference levels of unused lchans in the vty.

Related: SYS#5313
Change-Id: Iccc1391e8419604bb09e464db8455e053dfbc982
2021-07-11 20:28:02 +02:00
Pau Espin cc75145131 Rename osmo dyn ts enums to contain SDCCH8
They will gain support to be activated as SDCCH/8 soon too.

Related: OS#5309
Depends: libosmocore.git I56dcfe4d17899630b17f80145c3ced72f1e91e68
Change-Id: Id5b89fe589a52ff88486435ac43809edb4b80f98
2021-07-06 07:16:15 +00:00
Vadim Yanitskiy 997a257f8d power_control: constrain BS power reduction on BCCH carrier
BS Power Control is not allowed on the BCCH/CCCH carrier, unless
the BTS is operating in the BCCH carrier power reduction mode.

Allow constrained BS power reduction (up to 6 dB) on active logical
channels iff BCCH carrier power reduction mode is enabled.

Take into account that the maximum power difference between a timeslot
used for BCCH/CCCH and the timeslot preceding it shall not exceed 3 dB.

Change-Id: I2cc6a86731984f586ef35b43a8d3de631f7d8a2f
Related: SYS#4919, SYS#4918
2021-07-05 12:17:59 +00:00
Vadim Yanitskiy 38a839e120 gsm_data.h: remove declaration of non-existing ts_pchan()
Change-Id: I2471d0f2825661e60539d9504632fc80145c603d
2021-06-29 15:10:30 +02:00
Neels Hofmeyr 68536ccf8b support A5/4 in inter-BSC Handover
inter-BSC into this BSC: from BSSMAP Handover Request, parse and store
Kc128. All else is already implemented: depending on the chosen
encryption algorithm, Kc128 will end up in the Channel Activation.

inter-BSC out of this BSC: nothing is needed to support A5/4, the BSSMAP
Handover Required message does not contain any encryption related
information. The MSC already knows the chosen algorithm.

Related: SYS#5324
Change-Id: I7e9590e8c96aa50086148863ad9a2741b978e614
2021-06-22 05:56:09 +00:00
Neels Hofmeyr 498e55a9a4 implement A5/4 in Ciphering Mode procedure
Receive and store the Kc128 key from MSC, and use as key sent to BTS if
A5/4 is the chosen encryption algorithm.

(A5/4 in handover will follow in a separate patch)

Related: SYS#5324
Change-Id: I7c458c8a7350f34ff79531b3c891e1b367614469
2021-06-18 23:31:31 +02:00
Pau Espin f274976df3 Introduce counters to track SRVCC procedures
Related: SYS#5337
Change-Id: I5c20da56d465dbcf4366130394f7c42635a24cc7
2021-06-17 14:05:40 +00:00
Pau Espin b9a6263823 Introduce VTY command to disable srvcc fast-return on target BTS
Related: SYS#5337
Change-Id: I2ac91b5dffc9b6de60576aabe21a15f24fea38cb
2021-06-17 14:05:40 +00:00
Neels Hofmeyr b96ea3c97f gsm_data.h: add comments about immutable activ/modif/assign request info
Change-Id: I7997b802d997073ae6a05db2f40e82cb8e83764f
2021-06-10 16:15:35 +02:00
Neels Hofmeyr ee921cf903 VTY: add lchan re-assignment command
Add VTY command to trigger an intra-cell re-assignment, also allowing to
re-assign to a secondary VAMOS lchan.

Related: SYS#5315 OS#4940
Change-Id: If006f5caaf83b07675f57e5665cfa79328da55e6
2021-06-10 16:15:35 +02:00
Neels Hofmeyr d37dcb9f68 RSL: rx and tx VAMOS Channel Number cbits for VAMOS lchans
Add the Osmocom-specific extension to indicate VAMOS shadow lchans in
RSL, in lchan lookup and RSL message transmission.

Note that RR messages containing cbits (Assignment Command, Handover
Command, ...) must *not* send Osmocom specific cbits to the MS. Only the
RSL messages directed to the BTS send Osmocom specific bits.

Related: SYS#5315 OS#4940
Depends: If33c1695922d110c0d2c60d5c0136caf2587194e (libosmocore)
Change-Id: I957eff0d2c33ec795eda75a4bff21965b0179f73
2021-06-10 16:15:35 +02:00
Neels Hofmeyr 43aeeaf05a RSL chan_nr: replace OSMO_ASSERT with error handling
It's bad to abort the program for an incompatible chan_nr.  Instead of
OSMO_ASSERT(), make sure that error handling happens all they way to the
original callers of gsm_lchan2chan_nr etc.

This is also preparation to add further error causes: Osmocom specific
cbits needed for a non-Osmo BTS.

Related: SYS#5315 OS#4940
Change-Id: I71ed6437c403a3f9336e17a94b4948fca295d853
2021-06-10 16:15:35 +02:00
Neels Hofmeyr 426941e87f update the lchan name to always reflect VAMOS shadowness
Change gsm_lchan_name_compute() to a function that in-place updates the
lchan->name. That allows calling it numerous times with the talloc
handled internally. Rename it to lchan_update_name().

Add 'shadow' to lchan_update_name() and lchan_fsm_update_id() for VAMOS
shadow lchans, and also print the lchan index that it is a shadow for,
instead of the index in the lchan array.

When set_pchan_is() updates the VAMOSness of the lchans, call
lchan_fsm_update_id(). From lchan_fsm_update_id() also call
lchan_update_name().

This is a bit convoluted for legacy reasons. There are utility programs
and C tests using bts_trx.c but not lchan_fsm.c. lchan_update_name()
lives in gsm_data.c for that reason. This patch calls
lchan_update_name() from lchan_fsm_update_id() and not vice versa to
avoid having to add stubbed lchan_fsm_update_id() functions to all
utility programs and C tests.

We can't easily unify the lchan->name and lchan->fi->id without lots of
refactoring rippling through all those little utility programs and C
tests.

Change-Id: I7c2bae3b895a91f1b99b4147ecc0e3009cb7439a
2021-06-10 16:15:35 +02:00
Neels Hofmeyr d163aa3805 add VAMOS secondary lchans to timeslot struct
So far there is a bunch of code setting a primary lchan in VAMOS mode.
This patch now adds the actual secondary "shadow" lchans that may be
combined with a primary lchan in VAMOS mode to form a multiplex.

VAMOS lchans are put in the same ts->lchan[] array that keeps the
primary lchans. They are at most two additional usable lchans (for a
TCH/H shadow) added to either TCH/F or TCH/H.

Keeping these in the same array allows looping over all lchans easily.
The ts->max_primary_lchans indicates the index of the first VAMOS shadow
lchan.

Related: SYS#5315 OS#4940
Change-Id: I928af99498bba488d317693f3144d4fccbbe9af3
2021-06-10 16:15:35 +02:00
Neels Hofmeyr 2aac1765e6 implement CHANnel ACTIVate to VAMOS mode
Related: SYS#5315 OS#4940
Change-Id: If3ac584e4223ef7656c7fedc3bf11df87e4309ec
2021-06-10 16:15:35 +02:00
Neels Hofmeyr 19d797c2fb lchan_fsm: introduce lchan.activate.ch_mode_rate to allow tweaking
lchan->activate.info.ch_mode_rate should remain unchanged, it is the
immutable request data. However, for VAMOS, we will want to
automatically see that the chan_mode is chosen correctly.

As a first step, place a mutable ch_mode_rate copy at
lchan->activate.ch_mode_rate, i.e. not in .activate.info, but in
.activate. Use that everywhere.

This is mostly a non-functional change, preparing for a subsequent patch
that adds handling of VAMOS shadow lchans.

As side effect of adding lchan_activate_set_ch_mode_rate_and_mr_config()
after MODE_MODIF_ACK (enabling the voice stream after a channel mode
modify), fix AMR config: the call to lchan_mr_config() was missing.

Change-Id: Icc9cc7481b3984fdca34eef49ea91ad3388c06fe
2021-06-10 16:14:57 +02:00
Neels Hofmeyr edd5f5158d add lchan->vamos.is_secondary flag
VAMOS shadow lchans do not exist yet, but add the indicator flag that
tells whether an lchan pointer is a primary or a shadow lchan.

In Mode Modify: based on the flag, choose a different default TSC Set
for shadow lchans; do BTS type compat checking for shadow lchan use.

Actual lchans with vamos.is_secondary == true will be introduced by
patch: 'add VAMOS secondary lchans to timeslot struct'
I928af99498bba488d317693f3144d4fccbbe9af3

Change-Id: I4072fc7703c592df699fe8e27c02df09acde0909
2021-06-10 16:14:57 +02:00
Neels Hofmeyr e3e317242c implement Channel Mode Modify to VAMOS mode
Put a (primary) lchan in VAMOS speech mode.
This is not yet about activating shadow lchans, this merely puts any
lchan in a VAMOS capable channel- and speech mode.

Protocol:

In RR Channel Mode Modify, send a spec conforming VAMOS channel mode as
well as an Extended TSC Set, wich adds the TSC Set to the training
sequence code value.

In RSL MODE MODIFY, send Osmocom specific extensions to indicate the TSC
Set and TSC, as well as the VAMOS channel mode; only to OsmoBTS type
cells.
- Set the Channel Mode's Channel Rate to Osmocom specific
  RSL_CMOD_CRT_OSMO_TCH_VAMOS_Bm / RSL_CMOD_CRT_OSMO_TCH_VAMOS_Lm
- Add the Osmocom specific Training Sequence IE containing both TSC Set
  and TSC.
(These are documented in the Abis manual.)

Implementation:

The internal API to request a Mode Modify is lchan_modify(info). Add to
this info the 'vamos' bool, set to true when the modification should put
the lchan in VAMOS channel mode or not.

When info.vamos == true, make sure the channel mode value is a VAMOS
one: in the copy of info->ch_mode_rate at lchan->modify.ch_mode_rate,
convert to the right VAMOS/non-VAMOS equivalent channel mode.

When the modification is through, set lchan->vamos.enabled
appropriately.

This patch also builds on Ic665125255d7354f5499d10dda1dd866ab243d24
'allow explixit TSC Set and TSC on chan activ / modif / assignment'
placing tsc_set and tsc values in the TSC related IEs.

Related: SYS#5315 OS#4940
Change-Id: Ibf53f4797d7491b17a33946fd7d920f038362b4c
2021-06-10 16:14:57 +02:00
Neels Hofmeyr d9b7aedb77 change bs_power to bs_power_db
The RSL BS Power IE in measurement reports is encoded as dB / 2.
Instead of using this coding all over the code, converting to dB and
often printing confusing values in logging etc, store as plain dB.

The conversions should be at the points where a "weird" format is
defined: the RSL encoding needs divided-by-two, so apply it there. The
meas_vis is (now unfortunately) defined as div-two, and so on. But
internally we now just store the plain dB value and calculate with it
without duplicating the wire decoding step everywhere.

Rename to bs_power_db to clarify the unit of the stored value.

Change-Id: I229db1d6bcf532af95aff56b2ad18b5ed9d81616
2021-06-05 14:35:16 +00:00
Vadim Yanitskiy cdaf3ec006 Make interference measurement parameters configurable
According to 3GPP TS 45.008, the BSS shall monitor the levels of
interference on its IDLE traffic channels.  The actual measurements
are performed in the BTS and then reported to the BSC over the
A-bis/RSL link(s) in RF RESource INDication messages.

3GPP TS 45.008 defines the following measurement parameters:

  * Intave: Interference Averaging period (see table A.1),
  * Interference level Boundaries (see table A.1).

Both parameters are sent to the BTS over the A-bis/OML, and can
now be configured via the VTY interface.  Only those BTS models
which 'speak' the OML protocol defined in 3GPP TS 52.021 will
actually get the configured parameters, others will keep using
the hard-coded parameters.

Change-Id: I99ebf57aac1f3ca7e0497c3b4f6b0738c6ed7e47
Related: SYS#5313, OS#1866
2021-06-04 19:42:43 +00:00
Neels Hofmeyr 3512e3cf1b drop unused func decl gsm_lchan_as_pchan2chan_nr()
Change-Id: I1c14e72d4387767349723ec8948149841b45d85a
2021-06-04 11:36:24 +00:00
Neels Hofmeyr 858a0211a0 lchan_fsm: introduce lchan.modify.ch_mode_rate to allow tweaking
lchan->modify.info.ch_mode_rate should remain unchanged, it is the
immutable request data. However, for VAMOS, we will want to
automatically see that the chan_mode is chosen correctly.

As a first step, place a mutable ch_mode_rate copy at
lchan->modify.ch_mode_rate, i.e. not in .modify.info, but in
.modify. Use that everywhere.

This is a non-functional change, preparing for a subsequent patch that
adds handling of VAMOS shadow lchans.

Change-Id: I8a3daac0287f15a59d3688388bb13e55facb2cea
2021-05-31 05:20:03 +00:00
Neels Hofmeyr 27c07690d9 replace ts_*_for_each_lchan() with ts_for_n_lchans()
So far we have a couple of macros iterating a specific number of lchans,
depending on dynamic timeslot state etc. With addition of VAMOS lchans,
this would become more complex and bloated.

Instead of separate iteration macros for each situation, only have one
that takes a number of lchans as argument. That allows to more clearly
pick the number of lchans, especially for non-trivial VAMOS scenarios.

Related: SYS#5315 OS#4940
Change-Id: Ib2c6baf73a81ba371143ba5adc912aef6f79238d
2021-05-31 05:20:03 +00:00
Neels Hofmeyr e262919892 add fields to reflect nr of lchans in ts struct
So far the number of usable lchans is determined on-the-fly by the
physical channel config. With VAMOS, this becomes more complex, namely
determining whether the BTS is vamos capable.

Instead of calling a function to determine the number of lchans for
every use, rather place the number of valid lchans in int members of the
timeslot struct, and initialize those during timeslot setup.

Actual use of these new fields will follow in a subsequent patch, which
introduces the ts_for_n_lchans() macro to replace current lchan
iteration macros.

Related: SYS#5315 OS#4940
Change-Id: I08027d79db71a23e874b729c4e6173b0f269ee4f
2021-05-31 05:20:03 +00:00
Neels Hofmeyr c33eb8d569 allow explixit TSC Set and TSC on chan activ / modif / assignment
Activating / modifying to a VAMOS mode will require picking specific TSC
Set / TSC. It is a bad idea to pick the TSC in each message encoding
function, rather make this choice centrally.

So far we pick the training sequence code to use based on the timeslot
configuration, and this TSC is determined only upon encoding the RSL
messages.

Instead, pick the TSC to use upon the initial lchan activation /
modification request; store this in the request structs and pass through
the activation / modification code paths.

For VAMOS modes, we also need to pick a TSC Set. Do so also upon activ /
modif request. Note that the TSC Set is not yet applied in this patch,
it will be applied in upcoming VAMOS patches.

The activ / modif request may pass -1 for tsc_set and/or tsc to indicate
no specific choice of TSC Set and TSC, resulting in the same behavior as
before this patch.

For example, lchan->activate.info.tsc* may be passed as -1. The exact
choice for tsc_set and tsc is then stored in lchan->activate.tsc*, i.e.
one level up (the .info sub-struct is considered as immutable input
args). The lchan->activate.tsc* are the values actually encoded in RSL
messages. After the ACK, the lchan->activate.tsc* is stored in
lchan->tsc* to indicate the TSC actually in use. Same for modif.

Note that in 3GPP TS 45.002, the TSC Set are numbered 1 to 4, while the
TSC are numbered 0 to 7. On the wire, though, TSC Set is sent as 0 to 3
value. This is a weird discrepancy, odd choice made by the spec authors.
For conformance with the spec wording, I decided to pass the TSC Set
number as a 1-4 ranged value, and only convert it to the 0-3 on-the-wire
format upon message encoding. So log messages and VTY output will
indicate the first TSC Set as "1", but the first TSC as "0", as defined
in 3GPP TS 45.002, even if that is somewhat weird.

Related: SYS#5315 OS#4940
Change-Id: Ic665125255d7354f5499d10dda1dd866ab243d24
2021-05-31 05:20:02 +00:00
Neels Hofmeyr 5df7e771a8 gsm48_lchan2chan_desc(): expose TSC as param
Expose the training sequence code used in the RSL Channel Description IE
as an input parameter.

So far the Channel Description IE is always composed with a training
sequence code from gsm_ts_tsc(). For RSL commands enabling VAMOS mode,
specific training sequence codes are required.

So far, all callers still use gsm_ts_tsc(), making this a patch without
any functional change. Upcoming patches will pass specific TSC as
configured for VAMOS instead, in specific places.

Related: SYS#5315 OS#4940
Change-Id: I49503a6f5d25bb3bc9a0505bd79ed1d5c4f50577
2021-05-28 17:22:59 +00:00
Neels Hofmeyr 69def1f97e hodec 2: do intra-cell congestion resolution by Assignment
So far we do all channel reassignments by Handover Command. Since
osmo-bsc now supports rassignment of ongoing voice calls, do intra-cell
congestion resolution by Assignment Command.

In effect, add support for expecting an Assignment Command in
handover_test, and expect assignments instead of handovers for
intra-cell congestion resolution test cases.

Related: SYS#5330 OS#3277
Change-Id: Id56a890106b93fcee67ac9401b890e7b63bba421
2021-05-28 17:22:59 +00:00
Neels Hofmeyr cb0aaad5d4 assignment_fsm: allow assignment to a specific lchan
So far the assignment FSM always tried to satisfy the channel mode and
rate by either re-using the current lchan or finding a new, unused
lchan. For VAMOS however, we want to pick one specific lchan.

Add target_lchan to struct assignment_request and skip all mode matching
and lchan selection when a specific target_lchan is set.

Related: SYS#5315 OS#4940
Change-Id: I71e0d4ff4746706e0be5266e4574d70ca432e3d7
2021-05-28 17:22:59 +00:00
Neels Hofmeyr d508143dd3 AMR config cleanup step 3: generate AMR LV on msg composition
Firstly, do not store the encoded AMR length-value bits in gsm_lchan->*
before an activation/modify has actually succeeded.

And secondly, do not store the AMR LV structure in struct gsm_lchan at
all, but only generate the TLV exactly when a message is being composed.

In gsm48_multirate_config(), generate the LV directly to a msgb instead
of a static buffer first. gsm0408_test.c expected output verifies that
the generated LV bytes remain unchanged.

In lchan_mr_config(), introduce a target mr_conf argument, so that Chan
Act and Mode Modify may generate the filtered AMR config to different
locations (lchan->{activate,modify}.mr_conf_filtered).

Only after receiving an ACK for Activate/Modify, set
lchan->current_mr_conf from lchan->{activate,modify}.mr_conf_filtered.

Use the properly scoped lchan->activate.mr_conf_filtered for Chan Act,
lchan->modify.mr_conf_filtered for Mode Modify and
new_lchan->current_mr_conf for Handover Command as appropriate.

Related: SYS#5315 OS#4940 OS#3787 OS#3833
Change-Id: Ie57f9d0e3912632903d9740291225bfd1634ed47
2021-05-27 17:06:21 +02:00
Neels Hofmeyr 08e072bae0 move lchan->csd_mode into channel_mode_and_rate
The GSM48_CMODE_DATA_* rates are completely unused in OsmoBSC anyway,
but there is some code in abis_rsl.c checking its value, and if we were
to start using it that is the place where it should be.

Related: SYS#5315 OS#4940 OS#3787 OS#3833
Change-Id: Ie0e065a5dca5f4a31d5d81e3528a539214a74170
2021-05-27 17:06:21 +02:00
Neels Hofmeyr 3625c90c22 eliminate lchan->rsl_cmode
Related: SYS#5315 OS#4940
Change-Id: I1c167b22bb6638a929488d093bde0f1a5fb227ad
2021-05-27 17:06:21 +02:00
Neels Hofmeyr 0951d75665 make sure channel mode and s15_s0 are updated only after an ACK
I noticed during testing that an lchan used as TCH/F in fact still had
its channel mode set to Signalling -- because on Assignment, the Speech
mode used to be placed in the *previous* lchan and the new lchan was
never updated after the Activ ACK. This is unbearable confusion which I
complained about numerous times, so far mostly for cosmetic reasons. But
implementing re-assignment properly actually requires this to be cleaned
up.

Keep all volatile chan mode settings in lchan->activate.* or
lchan->modify.*, and only update lchan->* members when an ACK has been
received for those settings. So a failed request keeps a sane state.

Make sure that those settings are in fact updated in the proper lchan,
upon an ACK, so that subsequent re-assignment or mode-modify know the
accurate lchan state.

Related are upcoming patches that sort out the AMR multirate
configuration in a similar fashion, see
Iebac2dc26412d877e5364f90d6f2ed7a7952351e
Ia7519d2fa9e7f0b61b222d27d077bde4660c40b9
Ie57f9d0e3912632903d9740291225bfd1634ed47.

Related: SYS#5315 OS#4940 OS#3787 OS#3833
Change-Id: Ie0da36124d73efc28a8809b63d7c96e2167fc412
2021-05-27 17:06:21 +02:00
Neels Hofmeyr 5234c64bd0 assignment_fsm: send BSSMAP response only after Assignment Request
So far, only the MSC asked for Assignment via Assignment Request, which
we answer with a BSSMAP Assignment Complete or Assignment Failure when
done.

When Assignment is triggered for any other reason (congestion
resolution, VAMOS, VTY), we will not send any such messages to the MSC.

Additional enum values will be added in subsequent commits:
Id56a890106b93fcee67ac9401b890e7b63bba421 ASSIGN_FOR_CONGESTION_RESOLUTION
If006f5caaf83b07675f57e5665cfa79328da55e6 ASSIGN_FOR_VTY

Related: SYS#5315 OS#4940
Change-Id: Ie0cddbdb00abcec78e153f4ae6d04ce75080a111
2021-05-27 15:01:57 +00:00
Neels Hofmeyr d5cb0eb8fd lchan and assignment FSMs: make Channel Mode Modify more sane
The Channel Mode Modify procedure is currently implemented for changing
a TCH lchan from signalling to voice mode. For that, however, it is
re-using (abusing) the channel activation structs and state transitions,
and thus always implies activating a voice stream when the mode
modification is done.

I will add a Channel Mode Modify to enable VAMOS mode soon, so I require
separate structs and state transitions which also work on an lchan that
already has a voice stream established: a struct lchan_modify_info and
LCHAN_EV_REQUEST_MODE_MODIFY, and dedicated assignment FSM state
ASSIGNMENT_ST_WAIT_LCHAN_MODIFIED.

For the part where a Channel Mode Modify enables a voice stream after
switching from signalling to speech mode, still use the channel
activation code path, but only once the mode modification is done.

General improvements:
- To ask for a mode modification, emit an FSM event that ensures a mode
  modify only happens when the lchan state allows it.
- The new lchan_modify_info struct reflects only those parts that have
  an effect during a mode modification (before the lchan_activate_info
  was fully populated, many values not having an effect).
- More accurate logging, indicating "Mode Modify" instead of "Channel
  Activation"

A TTCN3 test for the Channel Mode Modify procedure is added in
Idf4efaed986de0bbd2b663313e837352cc139f0f, and the test passes both
before and after this patch is applied.

Related: SYS#4895
Change-Id: I4986844f839b1c9672c61d916eb3d33d0042d747
2021-05-21 15:43:30 +02:00
Neels Hofmeyr 9607d09203 cosmetic: rename lchan_activate_mode to lchan_activate_for
In subsequent patches, I will add enum lchan_modify_for and enum
assignment_for, I prefer to have similar lchan_activate_for naming.

Change-Id: Ia4420fcd1234dbee92e768e5a32eab13fba29ea9
2021-05-21 15:43:30 +02:00
Neels Hofmeyr 794e1281d8 cosmetic: rename FOR_* to ACTIVATE_FOR_*
Soon, there will also be enums with ASSIGNMENT_FOR_* and MODIFY_FOR_*
naming. Add the ACTIVATE_ prefix to the existing enum to clarify.

Change-Id: I12190d4d154a1da6a9ebc9a755ccc2fe382ff188
2021-05-21 15:43:30 +02:00
Michael Iedema 858ac62b88 stats: add BTS uptime counter
Change-Id: Ib17674bbe95e828cebff12de9e0b30f06447ef6c
2021-05-04 16:09:46 +00:00
Neels Hofmeyr ef28721c16 gsm_lchan_name_compute with ctx
Use a talloc ctx directly without an intermediate static buffer.

A subsequent patch will add a name tweak for VAMOS secondary lchans, so
it felt appropriate to first clean this.

Change-Id: Idb922605c15242a2cdc7c34668c845a179a15660
2021-04-28 16:32:19 +02:00