This change implements an additional channel allocation mode, which
can be employed during a TCH channel allocation for assignment.
Selection between ascending and descending order is performed
depending on pre-configured parameters:
* Uplink RxLev threshold and number of samples for averaging,
* C0 (BCCH carrier) channel load threshold.
This is useful in setups where Tx power of the RF carriers cannot be
adjusted +dynamically at run-time and thus BS Power Control cannot
be performed. In such setups the BCCH carrier is transmitting at
relatively higher power than the other RF carriers. The key idea
is to allocate channels in a smarter way, so that UEs with poor signal
would get channels on carriers with high Tx power, while UEs with good
signal could use carriers with lower Tx power.
Change-Id: I1b7a0d706976b73cc5c30a8714b830811addfe8d
Related: osmo-ttcn3-hacks.git Ia522f37c1c001b3a36f5145b8875fbb88311c2e5
Related: SYS#5460
A follow-up patch implements a special channel allocation mode, which is
only working for assignment (basically TCH selection for a voice call).
This mode cannot be employed for initial CHANNEL REQUEST or handover due
to the absence of an already established lchan.
Adding this mode to the existing VTY command syntax would be confusing:
channel allocator (ascending|desscending|dynamic)
^^^^^^^
so this patch extends the VTY syntax in a way that it becomes possible
to configure different channel allocator modes for different cases:
OsmoBSC(config-net-bts)# channel allocator mode ?
set-all Set a single mode for all variants
chan-req Channel allocation for CHANNEL REQUEST (RACH)
assignment Channel allocation for assignment
handover Channel allocation for handover
The old command syntax, which is basically 'set-all', is kept for
backwards compatibility, but marked as deprecated.
Change-Id: I3ae73b36ee9433cc768376b56f0765e5f416162f
Related: SYS#5460
I find it weird that we store the A5 algorithm ID in a format that
is used on the wire: N + 1 (valid for both A-bis and A interfaces).
What confused me even more is that in some functions we print it
as if it was in a normal, human-readable format. And this is
also why one can see weird constructions like:
if (lchan->encr.alg_id > ALG_A5_NR_TO_RSL(0)) { ... }
Let's ensure that our internal structures use the A5/N format:
alg_id=0: A5/0 (0x01 on the A-bis/A interface)
alg_id=1: A5/1 (0x02 on the A-bis/A interface)
alg_id=2: A5/2 (0x03 on the A-bis/A interface)
...
alg_id=7: A5/7 (0x08 on the A-bis/A interface)
so that we can print and compare the value of alg_id without using
additional arithmetics. Let's also rename 'alg_id' to 'alg_a5_n'
as it most clearly indicates which representation it is storing.
This is how the above code snippet would look like:
if (lchan->encr.alg_a5_n > 0) { ... }
Change-Id: Ieb50c9a352cfa5481aebac2379e0a461663543ec
This was overlooked during the code review. GCC does not complain
because internally both 'enum handover_scope' and 'bool' are
interpreted as 'int'. Found this while running my WIP testcase
TC_srvcc_eutran_to_geran_a5_3. This change makes it pass.
Change-Id: I807fd4a0e700e54c67ca3547d9c0c1b442dd1c54
Fixes: I4e5b1163a71443d706f14ce4bfd5c2294c320432
Related: SYS#5838
According to 3GPP TS 44.018, section 9.1.15, the RR Handover Command
message may optionally contain the Cipher Mode Setting IE (10.5.2.9).
Section 9.1.15.10 states that this IE may be omitted in case of the
intra-RAT GERAN-to-GERAN handover, however in case of the inter-RAT
handover (e.g. EUTRAN-to-GERAN), this IE *shall* always be included.
Change-Id: I1d270e82d0a9b12897fc94dae4e8999aa132a22f
Related: SYS#5838
The ho_fail() macro includes a newline, so the callers should not add
one. Fix these cases where the extra '\n' fragments the logged message.
Related: SYS#5839
Change-Id: Ifdbce98be70c1aa127ae008d7a77b9795fd250d3
So far we completely ignore the codec list from the MSC in Handover
Request messages. This leads to error messages in subsequent handovers
because there is no Codec List stored on the conn:
DHODEC ERROR handover_decision_2.c:390 [...] No Speech Codec List present, accepting all codecs
Besides the error log, in hodec2 we may subsequently take bogus or
unexpected codec decisions, ignoring the MSC's choice of codecs, or in
the worst case picking an unsupported codec.
This also has implications on what type of lchan we choose for handover
target in hodec2: say, if no half rate codec is supported as per the
MSC's request, we normally avoid handover to a TCH/H, etc.
Intra-BSC HO after an Inter-BSC incoming HO is the only case where this
problem occurs, in every other scenario there is an Assignment Request
from the MSC, from which we properly store the MSC's codec list.
3GPP TS 48.008 does indicate that on AoIP this codec list shall be
included. So reject HO Request with missing Codec List, as we already do
for Assignment Request on AoIP.
This makes TTCN3 BSC_Tests for inter-BSC incoming HO fail, because our
tests so far omit the Codec List (MSC Preferred) on AoIP. The related
fix of the tests is If06de9c9b43d79f749447a4e2a340176eef75c79.
Related: SYS#5839
Depends: If06de9c9b43d79f749447a4e2a340176eef75c79 (osmo-ttcn3-hacks)
Change-Id: I117cc29d6d11db77d160de654f43f5993db6ee21
In the field we saw Handover Requests without any Chosen Encryption
Algorithm IE, and osmo-bsc completely failed on those. This made me
understand my mistake from when I wrote this handover code.
So far, from a BSSMAP Handover Request, we (I) used only the Chosen
Encryption Algorithm IE to pick the encryption to use on the target
lchan. That is very wrong.
Instead, figure out the intersection of permitted algorithms MSC & BSC,
and pick the best of those. Which means, actually, completely ignore the
Chosen Encryption Algorithm IE.
In the message, the permitted algorithms are passed as a bitmask. The
current code using gsm0808_dec_encrypt_info() passes this on as an
array. In order to select_best_cipher(), I could convert that array back
to a bitmask. Instead pass the bitmask on from message decoding
alongside the struct gsm0808_encrypt_info in req->ei_as_bitmask.
In handover_end(), change the condition so that we can also pass
HO_RESULT_FAIL_RR_HO_FAIL to emit a Handover Failure.
Related: SYS#5839
Change-Id: Iffedc981b60d309ed2e5decd5efedee07a757b53
We have lots of counters for intra-BSC handover *away from* a given BTS,
but still missing are counters indicating how many handovers *targeted*
a given BTS. Also count incoming HO.
Related: SYS#4878
Related: Iba229313d73fa20266f6d4eac5820579fb14c604 (osmo-ttcn3-hacks)
Change-Id: Id9f2c6e2865ebe680879018fff08d283ce24c983
I was a bit confused that grep did not find HO counters being used, so
let's add some comments to better explain and provide a grep hook.
Related: SYS#4878
Change-Id: I242de13e657286e09428a8ca6e583d8b5155faa2
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
In an upcoming patch, handover_decision_2.c will use this indicator to
decide whether to start a penalty timer:
"hodec2: add low-rxqual-assignment penalty timer (2/2)"
Id00a07313fe04eec509b336c0637b59c707760e0
Related: SYS#5198
Change-Id: I5de385e0666f716184a62e6e70d656545ac5d2ee
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
Both VAMOS- and non-VAMOS speech modes should result in indentical voice
handling. So make sure that all chan_modes are converted to non-vamos
before comparing / evaluating in switch statements.
Change-Id: I791e7966b1f8eaa3299a8a46abeb313cf5136e0b
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
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
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
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
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
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
This is a non-standard RSL message that must be sent after each traffic
channel has been established. Without it, any voice call will be
disconnected within seconds.
This is a hack; we need to store the subscribers classmark2 value and
use it here.
Change-Id: I6cb6d25e405aa888c4df4022d897330a6af9e946
Related: OS#2389
An inter-BSC-OUT handover ends with a Clear Command, which HO_OUT_ST_WAIT_CLEAR
waits for. Actually tell the handover_fsm.c about an incoming Clear Command, so
that the inter-BSC-OUT success can be counted.
Similarly, count failing handover results for an unexpected Clear Command from
the MSC.
Related: OS#4736
Change-Id: I0c489838a99f930e2104619ca745191d2a736f1b
So far, during inter-BSC outgoing handover, when receiving an RR Handover
Failure from the MS, it would be counted as 'error'. Instead, add the 'failed'
counter like for all other HO types.
It may make sense to omit the 'failed' counter for inter-BSC *incoming*
handover, because then we won't receive an RR Handover Failure message. I
probably got those two mixed up during initial development.
Related: OS#4736
Change-Id: I9a61d5cc7273a830ba4e66e43e4aac6cdb707471
To handle cases of unknown handover type (like failure to find the target
cell), return -1 as counter code; treat -1 as skipping in ho_count_bsc() and
ho_count_bts().
The handover:* counters indicate overall counts, without knowing whether inter-
or intra-BSC, or whether the target ARFCN even exists. So they need to be
counted separately, and must not serve as fallback category in
result_counter_bsc() and result_counter_bts().
Related: OS#4736
Change-Id: Ie311e599d7bd35d33cf471c6c63e649246e8396a
Move initial 'handover:attempted' counts from bsc_subscr_conn_fsm.c to
handover_fsm.c, where all the other counters are handled.
Add missing increments for the overall 'handover:*' counts.
Related: OS#4736
Change-Id: I783bdedafc0eb8f2df9ea100792846fecc7ccbf7
In some (error-) cases we might be unable to determine which BTS to use
when counting handover events. We don't want to loose these events
because then ctr(bsc) == sum(ctr(bsc->bts)) would not be true anymore.
Those events are now counted by a counter in struct gsm_network which
uses an index that is out of range for regular BTS (65536).
Change-Id: Ic0f3edd5dc014c4eac5e8423133633a3e5d4c13e
Related: SYS#4877
Currently the counters don't distinguish between intra-cell and
intra-bsc handover.
Add _CTR_INTRA_CELL_HO_ and _CTR_INTRA_BSC_HO_ counters to track
intra-cell/bsc handover separately.
Change-Id: I3a1195640b99813036c9f1426ee5f07548e26547
Related: SYS#4877
Our current handover counters only count success/failures per BSC. It
would be nice to also count which BTS is part of a (successful/failed)
handover.
This patch duplicates the BSC counters for the BTS and changes the
ho_count and related macros to also count per BTS. If a BTS is NULL
(when conn->lchan is NULL) counting for the BTS is ignored.
Change-Id: I025ef14e2cfd2eea8880212c9406372ce0bf9296
Related: SYS#4877
Place all code related to the object into the related file.
Having all the data model in one file made sense in early stage of
development to make progress quickly, but nowadays it hurts more than
helps, due to constantly growing size and more and more bits being
added to the model, gaining in complexity.
Currently, having lots of different objects mixed up in gsm_data.h is a hole
of despair, where nobody can make any sense were to properly put new stuff
in, ending up with functions related to same object in different files
or with wrong prefixes, declarations of non-existing functions, etc.
because people cannot make up their mind on strict relation to objects
in the data model.
Splitting them in files really helps finding code operating on a
specific object and helping with logically splitting in the future.
Change-Id: I00c15f5285b5c1a0109279b7ab192d5467a04ece
We already have counters for Rx side, now we also count Tx side.
See comments in the msc_ctr_description array implementation for
the details.
Change-Id: I89a173f6bdd9a3c21233fe01d07ab2ff0442bb10
Fix neighbor config to match OsmoBSC manual: implement the plan for neighbor
configuration that was so far only described in the manual without actually
being in operation.
This first allows re-using ARFCN+BSIC pairs in and across BSS.
So far the handover_start() code always looked for handover target cells across
*all* local cells, even if they were not listed as neighbors to a source cell.
Imply all cells as neighbors only as long as there are no explicit neighbors
configured. As soon as the first 'neighbor' line appears in a 'bts' config,
only the listed neighbors are regarded as handover target cells. (The
'neighbor-list' commands are not related to this, only the relatively new
'neighbor (bts|lac|cgi|...)' commands affect actual handover procedures.)
TTCN3 tests TC_ho_neighbor_config_1 thru _7 play through the various aspects of
neighbor configuration: both the legacy implicit all-cells-are-neighbors as
well as allowing only explicit neighbors by config.
Related: OS#4056
Related: osmo-ttcn3-hacks Ia4ba0e75abd3d45a3422b2525e5f938cdc5a04cc
Change-Id: I29bca59ab232eddc74e0d4698efb9c9992443983
If no target cell got selected in a handover attempt, enum value NO_HANDOVER is
used. In that case, do not log a lot of errors saying
"invalid enum handover_scope value: none" -- they are misleading.
Change-Id: I98e748bea58ebb02812b6aaa6431c7d4b813242d
Clarify some in-code comments.
Fix descriptions of some handover timers, which still talked of "MO" and "MT"
handover -- which we now call "inter-BSC out" or "inter-BSC in" instead.
Change-Id: I8429a830edd0325893ac90f22fcc05309617bd2d
Move the HO_ST_WAIT_MGW_ENDPOINT_TO_MSC state up to right after the lchan is
done establishing. For AoIP, the local RTP address towards the MSC already
needs to be known before the Handover Request Acknowledge is sent, so the AoIP
Transport Layer Address IE can be included. This patch only modifies the
handover FSM, a subsequent patch adds the IE.
Change-Id: I00c18b78573386145af71c4b39f7f22aec24579b
To support the 3 possible preferences, the changes needed were:
- Replace 'full_rate' bool with a 3 option enum to represent
the channels types for signalling
- Switch from _pref/_alt to using an array sorted in preference
order
Originally merged as Change-Id I4c7499c8c866ea3ff7b1327edb3615d003d927d3,
reverted because the change broke voice calls. Re-submitting with the fix:
don't forget to set conn->assignment.requires_voice_stream.
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Change-Id: I7513d2cbe8b695ba6f031ad11560c63a6535cf2d
osmo-mgw.git also includes fixes of the MGW endpoint FSM, for example
I92a9944acc96398acd6649f9c3c5badec5dd6dcc.
Depends: I9a3effd38e72841529df6c135c077116981dea36 (osmo-mgw)
Change-Id: I03e6b48d9b0a5370310d5f56809259ff7909cf9d
Move the T_defs API to libosmocore as osmo_tdefs: remove the local T_defs API
and use libosmocore's osmo_tdef* API instead.
The root reason is moving the mgw_endpoint_fsm to libosmo-mgcp-client to be
able to use it in osmo-msc for inter-MSC handover.
When adding osmo_tdef, the new concept of timer groups was added to the API. It
would make sense to apply group names here as well, but do not modify the VTY
configuration for timers. The future might bring separate groups (or not).
Depends: Ibd6b1ed7f1bd6e1f2e0fde53352055a4468f23e5 (libosmocore)
Change-Id: I66674a5d8403d820038762888c846bae10ceac58
Vadim Yanitskiy
Neels Hofmeyr
Neels Hofmeyr
Pau Espin
Harald Welte
Daniel Willmann
Martin Hauke
Sylvain Munaut