This code is available in libosmocore since ~3 years ago
(fdf8b7b1beeb0cda262c5fb060a933aa7edb5e9a). Let's use it instead of
maintaining duplicated code which diverges over time.
Depends: osmo-bsc.git Iae058c35506bc25c9f4790889b89ac46aea664b6
(contains cherry-pick of bug fixed in osmo-bsc.git).
Change-Id: I53ad3067623077b6a8737c2a0aecc8b46bf71a15
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
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
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
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
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
Move the conversion from chan_mode to lchan type out of the
lchan_select_by_chan_mode() function, so that the conversion can be used
by other code paths, coming up in VAMOS patches.
Related: SYS#5315 OS#4940
Change-Id: I296651ebadba81f8b3db0d9bb5b5377877a43677
Prepare for VAMOS, where there will be secondary "shadow" lchans serving
secondary MS on the same timeslots. For those, RSL messages will need to
reflect a different stream ID aka TEI, via an rsl_link_vamos.
Make sure that every code path that sends an RSL message for a specific
lchan selects the RSL link via the new function rsl_chan_link(). When
VAMOS is implemented, this function can select the proper RSL stream.
Rename gsm_bts_trx.rsl_link to rsl_link_primary. This makes sure I'm not
missing any uses of the RSL link, and clarifies the code.
Related: SYS#5315 OS#4940
Change-Id: Ifbf16bb296e91f151d19e15e39f5c953ad77ff17
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
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
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
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
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
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
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
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
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
Change lchan_set_last_error() to macro so that the error log reflects
where the error was encountered.
Change-Id: I571fdf2d418c52d120215cf19e57a3c96d67af07
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
A crash was reported in bssmap_le_tx_reset() sending a RESET with
sccp_user == NULL. Looking at the issue I noticed that when the
sccp_user is torn down, the RESET FSM should also be terminated.
Add bssmap_reset_term_and_free() to the generic RESET FSM implementation
and call from lb_stop() before sccp_user is set to NULL.
Related: OS#5134
Change-Id: If412ef990fcdde8ff88098a5169e86f05cd1c7f0
Whenever SRVCC EUTRAN->GERAN is performed by the CN, it will set the
Last Used E-UTRAN PLMN Id in order for the BSS to inform the MS
about EUTRAN neighbors once the call is over.
The last part (sending EUTRAN neighs) is already implemented, since same
thing is done as per CSFB. However, we lacked the first part, where the
EUTRAN PLMN Id is recorded for later use.
Actually, in both cases, we end up building the list of neighbors
without taking into accound the PLMN value (hence no filtering of
configured neighs), but it only sends such a list if any PLMN was stored
there, which means this patch is still necessary for a quick fallback to
4G after the call is over.
Related: SYS#5337
Depends: libosmocore.git Change-Id I0e55e947b6fef6dad0cf1a6c16b781bef4cc76c5
Change-Id: Ia5008f11a4c36ef8085a2037d4abddd131086e6e
This patch caused major breakage in my setup, with BSC printing at
startup: "(bts=0,trx=0) Failed to generate System Information".
And bts-trx printing all the time:
"sysinfo.c:162 PH-RTS-IND: Unable to determine actual BS_AG_BLKS_RES
value as SI3 is not available yet, fallback to 1"
This reverts commit c1a5310a3e.
Change-Id: I5da365c93aedc6668a77b82ee9b68cbec64967e3
The effects of the neighbor configuration depend on the LAC, Cell
Identity, ARFCN, BSIC configuration of neighbor cells. Make sure that
the neighbor ARFCN list in the System Information is updated.
This may seem rather aggressive: updating the SI of all BTS if only one
config item changed. But indeed even modifying one config item of one
BTS may cause a change in the neighbor relations that many other BTS may
have to the changed BTS. For example, if many BTS configure a
'neighbor lac-ci 42 23', and this cell's config changes to LAC 43, all
of those other BTS need to update their neighbor ARFCNs.
Also update the system information even before the BTS are connected and
started up. The main benefit here is that the VTY 'show bts N' command
then already lists the correct neighbor ARFCNs.
In gsm_bts_trx_set_system_infos(), make sure that the updated SI is only
sent to TRXes that are actually usable, otherwise abis_rsl_sendmsg()
spams the log with complaints that a message's dst == NULL. Still return
an error rc in case a TRX is not connected, so that the CTRL command
bts.N.send-new-system-informations accurately returns whether SI were
actually sent to all TRXes.
The desire to have the ARFCNs listed in the VTY before starting up BTSes
came during analysis for Ifb54d9a91e9bca032c721f12c873c6216733e7b1,
which fixes a bug that is now much easier to verify being fixed.
Change-Id: I2222e029fc225152e124ed1e8887f1ffd4a107ef
From 3GPP TS 48.008 sec 3.1.30 "Common ID":
"""
If the SCCP connection is established due to CSFB from E-UTRAN and the MSC supports
return to the last used PLMN after CS fallback, then it should send the COMMON ID message
to the BSS including the Last used E-UTRAN PLMN ID information element if available at
the MSC immediately following the successful SCCP connection setup.
"""
Furthermore, 3GPP TS 48.008 version 16.0.0 Release 16 "3.2.1.21 CLEAR COMMAND",
for field CSFB Indication, states:
"""
NOTE: This information element doesn't serve any useful purpose. MSCs should not send the
information element unless it is required by the recipients (due to the need to interwork
with older versions of the protocol). It is expected that in future versions of the present
document, this information element will be deleted from this message.
"""
Hence, build up the EUTRAN neighbor list based on whether we received
the Last E-UTRAN PLMN ID IE during Common Id. In the future, we should
probably filter the list while populating it based on the received IE.
This change will also allow reusing same mechanism for SRVCC
EUTRAN->GERAN support, where te Last E-UTRAN PLMN ID IE can be found
inside "Old BSS to New BSS information" IE in msg HANDOVER REQUEST.
Related: SYS#5337
Change-Id: I5d290ac55eca5adde1c33396422f4c10b83c03d5
sysmoBTS is a BTS model sold by Sysmocom, which runs osmo-bts.
The later may also work with some other back-ends, including
the genaral purpose SDR hardware. Therefore, it's more
logical to call it 'osmo-bts'.
Change-Id: I93ab4dbf483e0786c35685b75ee4ea83bd591f7b
Calculating the Cell Allocation (basically a bit-vector of all the
frequencies allocated to a cell) on the OML link establishment has
several downsides and potential problems:
* Theoretically, more than 64 ARFCNs can be allocated for a cell
via the VTY interface. The problem here is that the Mobile
Allocation IE cannot contain more than 64 channels.
* The BSC's operator will neither be warned by the interactive
VTY shell during configuration, nor during the startup.
* The BSC will accept such a configuration, but then will be
unable to encode the Mobile Allocation IEs at run-time.
This change aims to improve the situation by separating part of
the logic from generate_cell_chan_list(), and invoking this
part directly from the VTY commands. This way it will become
impossible to configure more than 64 ARFCNs, neither via the
config file, nor interactively from the VTY.
Change-Id: I98211fb0684a973239f5760e1de52a24a1f4c33c
It is observed that a CHANnel ReQuireD with access delay
greater than 63 can be received from the Ericsson RBS.
This results in osmo-bsc sending back a CHANnel ACTIVation with
a Timing Advance IE containing the access delay value.
The RBS NACKs this, leading to a BORKEN Channel.
This patch makes the maximum acceptable access delay vty-configurable
and Ignores CHANnel ReQuireD RSL Messages with Access Delay IE greater
than that configured. Default value is 63.
Related: OS#5096
Change-Id: Ie8987bcc0e43921bc753162b77a0efc68799b3ce
The neighbor configuration storage is fundamentally broken: it requires
all local cells to be configured before being able to list them as
neighbors of each other. Upon config write-back, the neighbor config
however is placed back inline with the other config, and hence a
written-out neighbor config no longer works on program restart.
The cause of this problem is that the config is stored as explicit
pointers between local cells (struct gsm_bts), which of course requires
the pointer to exist before being able to reference it.
Instead, store the actual configuration that the user entered as-is,
without pointers or references to objects that need to be ready. Resolve
the neighbors every time a neighbor is needed.
Hence the user may enter any config at any place in the config file,
even non-working config (like a BTS number that doesn't exist), and the
relation to actual local or remote neighbor cells is made at runtime.
Abort program startup if the initial neighbor configuration contains
errors.
Related: OS#5018
Change-Id: I9ed992f8bfff888b3933733c0576f92d50f2625b
So far the list of penalty timers was stored for an opaque target
pointer. That was either a gsm_bts pointer for a local BTS, or a cell
identifier list pointer for a remote-BSS cell.
Reasons to refactor penalty timers:
- The cell identifier list pointer came from the neighbor configuration
storage, but the way cell neighbor config is stored will change in a
subsequent patch. There will be no more cell identifier lists there.
- Storing object pointers is inherently unsafe -- if an object gets
removed and another gets allocated, the penalty timer could
theoretically remain in force for an unrelated object.
Rather store penalty timers for specific Cell IDs. Since remote-BSS
neighbors can be requested by a cell identifier *list*, use a
gsm0808_cell_id_list2 as key in the list of penalty timers.
Fix handover_test.c: have different CI for each local BTS. So far it was
the same LAC+CI for all BTSes, which now would make the test fail,
because any penalty timer would appear to apply to all local cells.
Related: OS#5018
Change-Id: I72dd6226a6d69c3f653a3174c6f55bf4eecc6885
Allow selection of RX diversity from VTY
Options are a,ab,b
Default is 'a' so there is no change from previous behavior
Change-Id: I430762b8cfa51060841d90ba4446de73bd557c6c
This commit adds support for Selection of syncronization source.
Options are internal for E1 and external for GPS
Change-Id: Ia3d1acd6b3442238b35fc911092e12a6ac989adb
The function is not really handover specific, and will be used in other
places in subsequent patches.
Change-Id: Icae8b9045e497f850f22cb3b6f93acbf61b84746
On lchan activation, we already know the Timing Advance in most
situations: from the Channel Request RACH, or from a previous lchan in
the same cell. Place this information in lchan->activate.info.ta.
So far, the lchan->last_ta (until recently called rqd_ta) was used to
store the initial TA for channel activation -- move the initial TA to
lchan->activate.info.ta, for proper scoping.
Only an inter-cell handover does not yet know a Timing Advance (until
the Handover Detection RACH is received), so indicate
activate.info.ta_known = false for that case.
If ta_known is false, do not include an Access Delay IE in the Channel
Activation message, ensuring that the BTS does not use an arbitrary TA
that is likely inaccurate.
The effect for OsmoBTS is that we will *not* start the downlink SACCH on
channel activation for inter-cell handover, but will wait for a HO RACH
first, and then use the correct TA when enabling downlink SACCH.
Related: OS#4008 SYS#5192
Change-Id: I986bf93e8acd6aef7eaf63ac962480b680aa894f
Originally, the lchan stored only the Timing Advance from the initial
channel request, hence it was called rqd_ta.
Since quite a while now, rqd_ta also stores the most recent Timing
Advance from each received Measurement Report. So rename to last_ta.
This is cosmetic preparation for an upcoming patch that clarifies
whether the Timing Advance is already known for Channel Activation.
Change-Id: I1049526a173819baeb4978db5bf018ba3f1006a0
This is required in order to tell MS that osmo-pcu now supports
Network Assisted Cell Change (NACC).
Other BTS are not enabled by default since NACC support is not known to
work nor tested there.
Depends: libosmocore.git Change-Id I61991266b95d0c13d51b47906cc07846e9cf1390
Related: SYS#4909
Change-Id: If91d85331d402c3ab9c32b70c2c66cd7ba6ceb28
Add bool log argument to lchan_avail_by_type() and omit logging when
passed as false. From handover_decision_2.c, pass 'log' as false, from
all other callers pass true, i.e. for unchanged behavior.
Rationale:
Usually, we use lchan_avail_by_type() to select a new lchan to initiate
actual service. For that, it is interesting to see how osmo-bsc decides
which lchan will be used.
For handover decision 2, we since recently call lchan_avail_by_type()
for each and every handover candidate, to determine whether it will
occupy a dynamic timeslot or not (to know whether we would congest the
other TCH kind). So this happens for each permutation of source lchan
and target cell. That produces a lot of logging, out of proportion of
being useful to the maintainer.
Change-Id: Ia403f8fc853ca9ea9e81f7a7395df6b23845ebed
This new CTRL interface allows users of this BSC (such as attached PCU)
to gather neighbor information.
This interface is needed for PCU to translate ARFCN+BSIC keys provided
by MS in the Um side into CGI + RAC keys used to identify target cells
in RIM procedures against SGSNs on the Gb interface.
This patch extends the already existing neighbor information storage in
the VTY by allowing storage of CGI + RAC (RAC couldn't be stored
beforehand).
Related: SYS#4909
Depends: libosmocore.git Change-Id If48f412c32e8e5a3e604a78d12b74787a4786374
Change-Id: Ib07c9d23026332a207d4b7a0f7b4e76c0094e379
The existing code uses short-lived FSMs which are allocated straight
before START, and which are free'd after DONE state is reached.
While that works, it makes state introspection a bit hard, as one
cannot show the FSM states, etc.
Let's change to a different model where the per-OM2k-MO FSMs are
always around (in state INIT after object creation). While at it,
also introduce a RESET event that can reset each FSM instance back
to INIT state, i.e. in case of OML link failure.
Change-Id: Ia37cffff5c451e1d79a52ccae41ab5718b4661d4
Neels Hofmeyr
Pau Espin
Vadim Yanitskiy
Keith Whyte
Harald Welte