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
For statistical clarity and site tuning, it is sometimes
desirable to completely disable the use of TCH for signaling.
In the existing version of this VTY command, there is no way to
accomplish this. We can only restrict TCH for signaling non-voice
related actions.
This patch deprecates 'allow-tch-for-signalling (0|1)' and
adds 'tch-signalling-policy (never|emergency|voice|always)' to
provide more options.
Change-Id: I4459941ddad4e4a3bec8409b180d9a23a735e640
The all_allocated_update_bsc() does inefficient iterating to count
active/inactive lchans, which scales badly for high numbers of TRX
managed by osmo-bsc.
We need to update the all_allocated flags immediately (periodic counting
alone would suffer from undersampling), so, until now, we are calling
this inefficient function every time a channel state changes.
Instead of iterating all channels for any chan state changes anywhere,
keep global state of the current channel counts, and on channel state
change only update those ts, trx, bts counts that actually change.
A desirable side effect: for connection stats and handover decision 2,
we can now also use the globally updated channel counts and save a bunch
of inefficient iterations.
To get accurate channel counts at all times, spread around some
chan_counts_ts_update() calls in pivotal places. It re-counts the given
timeslot and cascades counter changes, iff required.
Just in case I missed some channel accounting, still run an inefficient
iterating count regularly that detects errors, logs them and fixes them.
No real harm done if such error appears. None show in ttcn3 BSC_Tests.
It is fine to do the inefficient iteration once per second; channel
state changes can realistically happen hundreds of times per second.
Related: SYS#5976
Change-Id: I580bfae329aac8d4552723164741536af6512011
Use the same one as used to decode the message in osmo-bts.
This patch doesn't cause a change in logic since both headers are binary
identical.
Change-Id: Ideb863fdaedf77caac1a320de6696ba4f507a398
After the lchan release, the gscon would go into the Clear dance with an
arbitrary cause value. Instead, explicitly ask for a Clear upon
pre-emption, with the proper cause value.
Related: OS#5535
Change-Id: I20108f7b4769400b89b7b0d65c8dab883bf87c46
The variables are unsigned, so -1 gets actually translated to UNIT16_MAX
when the value is casted to uint16_t. Let's do that explicitly so that
readers don't think those are signed variables.
Change-Id: I02ad80e5d10f1a47cdf712f7f7c576a2e20fe607
If an lchan needs to be released to make room for an emergency call,
send the proper release cause ("pre-emption").
Related: OS#5534
Change-Id: I0423621d15ace11a53ae1653e5e7f5cb93605edb
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
The naming confused me so that I wrote buggy code again. Hopefully this
clarifies which representations the code paths are using.
In the macro code, highlight the error case of n <= -1 explicitly.
Also add ALG_A5_NR_TO_PERM_ALG_BITS. I need the 1<<n case in an
upcoming patch.
Related: SYS#5839
Change-Id: I7557ae97764bba09c906748a18e9031dfb362611
Let's have a short and consistent naming for both ACCH repetition
and temporary ACCH overpower structures, like it's done in osmo-bts.
Change-Id: I39b98dcd14219402959646524315d5afea7c08cf
Related: Ib1d51f91139b4c2fe794e37fc8543b2d7a9b9c07
Let's have a short and consistent naming for both ACCH repetition
and temporary ACCH overpower structures, like it's done in osmo-bts.
Change-Id: Ia12c83ad1af4744ce28ba655ac806784f746e88a
Related: Ib1d51f91139b4c2fe794e37fc8543b2d7a9b9c07
The linter (executed by Jenkins) complains:
src/osmo-bsc/abis_rsl.c:543: ERROR:POINTER_LOCATION: "(foo*)" should be "(foo *)"
and blocks changes, adding V-1 when I am changing the related code.
Change-Id: I0cf00ff898e69734850659e8ba0e2ff023f9b2dd
Add chan_counts_for_trx() and chan_counts_for_bts(). Drop
bts_count_free_ts() and trx_count_free_ts().
Rationale:
The bts_count_free_ts() and trx_count_free_ts() always returned the
number of free lchans, not timeslots. Hence, passing the pchan type as
argument never really matched the semantics.
Especially, when looking for free SDCCH, there is no clear match on a
gsm_phys_chan_config enum value: SDCCH8_SACCH8C, CCCH_SDCCH4,
CCCH_SDCCH4_CBCH, SDCCH8_SACCH8C_CBCH? -- GSM_LCHAN_SDCCH is clear.
==> Rather count free lchans by enum gsm_chan_t.
Counting lchans of distinct types required separate iterations for each
lchan type.
==> Rather compose an array of counts for all types, in one go.
I need to count the amount of free SDCCH lchans in an upcoming patch to
implement the performance indicator allAvailableAllocatedSDCCH (cumulate
time for which no SDCCH are available).
To implement allAvailableAllocated{SDCCH,TCH}, I need a count of both
the used as well as the total lchans for a type: it does not make sense
to flag "all available allocated" if none are ever available.
To properly count dynamic ts, I need the maximum total that can be
possible at any time. And to count currently free lchans, I need the
current total. This may seem counter intuitive, but consider, e.g.:
- Obviously, if a cell has only static TCH/F timeslots, it does not make
sense to flag that all available TCH/H are occupied, because no TCH/H
are available ever. Just stating this as contrast to dyn TS.
- If a cell has OSMO_DYN timeslots, I *do* want to flag that all TCH/H
are occupied when all dyn timeslots are fully occupied.
- If those OSMO_DYN however are all used as TCH/F, the current total of
TCH/H becomes zero, and it seems like TCH/H should not be considered.
- To count the nr of currently free lchans, I need the currently
possible total of lchans and the nr of occupied lchans.
So return both a maximum total and a current total of lchans. In above
example, the maximum total shows that there would be TCH/H possible.
BTW, it would be nice to keep a chan_counts array on trx, bts and bsc
level and update as channels are allocated and released, instead of
counting them all over periodically. But it's less error prone this way.
Related: SYS#4878
Change-Id: I2fb48c549186db812b1e9d6b735a92e80f27b8d3
As stated in "GSM/EDGE Evolution and Performance", section 12.3,
both features *can* be enabled simultaneously.
Change-Id: I2189f01bd78625dab3d642597240338ee581fc98
Related: SYS#5319
nanoBTS would NACK a CHANnel ACTIVation message for an 'intra cell
channel change' if it does not contain the Timing Advance IE. And
this is right, because according to 3GPP TS 48.058, section 8.4.1,
point '4)', it *must* be included.
Indeed, the actual Timing Advance value is not known during the
manual channel activation triggered from the VTY interface. So
let's merely indicate 0 if it's not known.
Change-Id: Iee7ddb4cf1a9a7bb9b34e6c9f6f9899da480fbd0
These are not needed anymore since we re-introduced libbsc, specially to
avoid all this churn.
Some specific methods are explicitly required to be overwritten by
tests, so we specificially mark those with __attribute__((weak)) in
order to be able to overwrite them.
This is the last step towards fixing interdependency mess of symbols and
stubs, and requires previous patches in order to have tests apssing
fine.
Change-Id: Ic7401b8a6eb903882e30fda1cf091ac99a254ef0
* 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
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
This fixes call setup issues when more than ~1km from the tower.
NOTE: We use the last reported TA from the UE in the CHANnel ACTIVation.
When the UE is more than 1km from the tower, (unshifted) TA in the
measurement report can be 8 or greater. Once we send TA of 8 in the
CHAN ACTIV message, the lchan is unrecoverable.
Change-Id: I1c9bd5bf2fd126e62bcbec419f3499d2e0465559
To configure temporary overpower, new VTY commands are added. This patch
also addes the logic needed to attach the temporary overpower IE to the
RSL CHANNEL ACTIVATE message.
Change-Id: I488a91bb4ed86f630db56564a0cd293f39f0f690
Related: SYS#5319
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
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
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
If the RES IND message is invalid, let's not return ENOENT which
translates to "No such file or directory", instead return EINVAL.
Related: SYS#5313
Change-Id: Ifd700e90c881874d428f2860603a4ddbf13d705e
If all channels of a BTS are in use and there are no interference
ratings to be reported, the Resource Information IE may be empty. Do not
log this as an error, it is not something that needs operator attention.
Related: SYS#5313
Change-Id: I75b851ef1269674f43db3fb3a48518e76182d7f0
We already looked it up, it's not necessary to look it up again by
calling lchan_select_by_type(). Let's instead call
lchan_select_set_type() directly on the lchan pointer.
Related: SYS#5309
Change-Id: I1054c18f58c9e249f263e3e97a365a1fd8b03a93
The VTY defun already indicates BSC_VTY_ATTR_RESTART_ABIS_OML_LINK
correctly, but so far we would immediately start using the new values
internally, and wrongly interpret interference levels. Fix that.
Have bts->interf_meas_params twice: interf_meas_params_cfg for the VTY
configured values, and interf_meas_params_used for the values that the
BTS actually knows about, after they were sent via OML.
In a running BSC, when changing the interference level boundaries on the
telnet VTY, the BTS is not immediately told about the change. That would
require a BTS restart. Hence store the cfg values separately in
interf_meas_params_cfg. For comparing/printing interference levels in a
running BTS, only employ the values that were actually sent via OML and
placed in interf_meas_params_used.
Related: SYS#5313
Change-Id: Iad8cf4151ff7f86dc0549158ed5d91d788d40b1f
This commit improves some cosmetic and logical aspects from recent
commit (see "Fixes" below).
* Fix typo s/free_tcch/free_tchh/"
* Improve some comments
Fixes: fdb87343d7
Change-Id: Id6217c929068b0182cb2d4a9922bfbf544c8c75d
In case an MS requests a channel to establish a voice call, we usuually
try to assign an SDCCH to negotiate the call and finally make the MS
switch to a TCH. However, it doesn't make much sense to provoke a switch
of a dynamic TS into SDCCH8 if that would mean we end up with no TS
available for TCH at the next step close in time. In that case, we are
better assigning the TCH directly so that the full call can be
established successfully.
Related: SYS#5309
Change-Id: I3b32968949a7bdcbebf5a823359295bac51d8e08
Vadim Yanitskiy
Michael Iedema
Neels Hofmeyr
Pau Espin
Harald Welte
Keith Whyte
Philipp Maier