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
When calculating average lchan duration based on the new stats for
BTS_CTR_CHAN_{TCH,SDCCH}_ACTIVE_MILLISECONDS_TOTAL there are
discrepancies which emerge. Specificially in bandwidth-constrained
environments, there are still-unknown failure states which can
occur that cause the TCH or SDCCH activity count to increment but
zero milliseconds of activity on the lchan to accumulate. This
portrays a failure as a success.
These new fully-established stats are intended to provide a more
accurate denominator when calculating average lchan duration as
they are incremented in proximity to the duration timestamp
initialization.
Change-Id: I417940ad9479719f5324fb12d45883cd3cb2c578
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
Reduce some code dup in all_allocated accounting and cosmetically
prepare for upcoming performance fix.
Have a struct all_allocated, allow easy re-use of function
all_allocated_update().
Rename function to all_allocated_update_bsc(). Upcoming patch will also
add all_allocated_update_bts().
Related: SYS#5976
Change-Id: Id7a82c65d56a87818fc35bbeedf67e2af2f89f11
This patch adds two stats which track cummulative lchan lifetime by
type TCH and SDCCH. These new counters will accomplish two things:
1) Provide a glanceable way to see if lchan durations look healthy. When
examining a site, short-lived (<5s) and long-lived (>30s) TCH lchans
are difficult to tell apart. If we only see short-lived TCH lchans,
there is most likely an RF or signaling problem to investigate. This
new counter will expose channel ages in the VTY output
2) Provide a more accurate count for Erlangs per site. Currently, we
are basing Erlangs on active TCH channel counts per stats period. This
method skews high very quickly. Each active TCH in that period
translates into the full 10s of activity. This counter should improve
accuracy by two orders of magnitude.
Change-Id: Ie3771233ecbd4bc24a24fb22c1064a18e7b8b2b0
This reverts commit 5e2ac29703.
This patch was found to be a troublemaker regarding osmo-bsc
performance, since it's scheduling one timer every 100ms for each
channel. On a BSC with dozens of BTS, each with several TRX, this ends
up in a huge amount of timers scheduled in a tight timeframe, which ends
up in osmo-bsc spending CPU time getting in and out of the poll() main
loop.
Related: SYS#5922
Change-Id: Ibd5123e7f04ae8f4eb8f08b63525527f526f0b2c
This allows external monitoring to see where the T3113 timer has been
adjusted to, in case it is set dynamically.
Change-Id: I533f2ca3c8e66c143154cbf03b827c9cbbacccdf
Reaching this point will only make system load (CPU, mem) grow, making
it hard for the process to keep up with work to do, with no benefit
since the requests will anyway be scheduled too late.
Related: SYS#5922
Change-Id: I6523c6816a4d16b71084d004e979be40cf0aeeb0
This patch adds two stats which track cummulative lchan lifetime by
type TCH and SDCCH. These new counters will accomplish two things:
1) Provide a glanceable way to see if lchan durations look healthy. When
examining a site, short-lived (<5s) and long-lived (>30s) TCH lchans
are difficult to tell apart. If we only see short-lived TCH lchans,
there is most likely an RF or signaling problem to investigate. This
new counter will expose channel ages in the VTY output
2) Provide a more accurate count for Erlangs per site. Currently, we
are basing Erlangs on active TCH channel counts per stats period. This
method skews high very quickly. Each active TCH in that period
translates into the full 10s of activity. This counter should improve
accuracy by two orders of magnitude.
Change-Id: I1b0670c47cb5e0b7776eda89d1e71545ba0e3347
* Don't copy features for osmo-bts and nanobts initially, wait until
BTS reported its features
* Checks for BTS features in VTY cmds: pass if features are not known
(not yet reported by the BTS), fail if the feature is missing
* Once BTS reports its features, check relevant VTY config parts again
Related: SYS#5922, OS#5538
Change-Id: I7fca42a39a4bc98a6ea8b9cfab28c4bad3a6a0aa
Only if we store data like the CBSP message_id and serial_number
we are able to later (in a subsequent patch) match a CBSP KILL
for ETWS/PWS and stop emergency broadcast.
Change-Id: Ide74638880d7e3c6a7c774bf6320d3dce4b11c74
Related: OS#5540
Let all changes of the bts model go through this function, so we can in
a future patch copy over the bts model's features to the bts.
Related: SYS#5922, OS#5538
Change-Id: I8475c8c20eb72411e8ca820181d1c8603c22a56d
The range used for this variable is 0-100, so no need to use a signed
integer. Morever, uint8_it is enough for the range.
Change-Id: I863d9531baf5308b45a2ebe60266ba02d1041cc3
Now that we have separate header/code files for the power control,
let's move the related definitions there. This change makes the
code consistent with osmo-bts, where it's already done this way.
Change-Id: I1cb3f6bfba0306e8f371dcd5162d1813beb3a088
At the moment the BTS configuration is checked, but the check does not
have much consequence other than that some initialization that is not
executed. The BTS will go into the OML bootstrap phase anyway and most
likely fail at some later point due to the invalid configuration. To
reduce noise and unexpected behaviour of the BTS lets make sure that the
OML boostrap phase can only proceed when the BSC conciders the
configuration as valid.
Change-Id: I42c1c26a9b800600787b1266a871f95f2114c26e
Related: SYS#5369
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
Same as all_allocated:{sdcch,tch}, but already trigger when all
non-dynamic timeslots are allocated.
Related: SYS#4878
Related: Ib3997a827c9cc43d1361bb0cf3bfab9f6d91bf82 (osmo-ttcn3-hacks)
Change-Id: I2fa14531f16d3f07085620f1c50eb839c420da6a
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
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
Controversy: this duplicates bts.N.rsl_connected. I would like to add
this duplication for consistency, since we now have these counters:
bsc.0.num_trx:rsl_connected
bsc.0.num_trx:total
bts.N.num_trx:total
and the old
bts.N.rsl_connected
which does not fit well with above naming scheme. Any user will be
justified to expect a stat named bts.N.num_trx:rsl_connected as well.
Determine bts.N.num_trx:rsl_connected in the new function
bsc_update_connection_stats(), where the other num_trx:* are set.
Related: SYS#5542
Related: I5be1cb470930354c4561cbed301bc50a32484ed9 (osmo-ttcn3-hacks)
Depends: I137992a5479fc39bbceb6c6c2af9c227bd33b39b (libosmocore)
Change-Id: I55b55159fe13d937e441d8c2ed915734463e1154
This is similar to bsc.0.num_trx:total but per single BTS.
Related: SYS#5542
Related: I5be1cb470930354c4561cbed301bc50a32484ed9 (osmo-ttcn3-hacks)
Depends: I137992a5479fc39bbceb6c6c2af9c227bd33b39b (libosmocore)
Change-Id: I283d38e7a8c032e274a5bd2fa150ec2c9a7157b4
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
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
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
Adds gsm_bts_stats_reset() to clear the stats and calls it from the
different models.
Change-Id: Ic42687cd73e3546edaa99fb1268a5960ffa43b12
Related: SYS#5541
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
Store the config option whether the channel allocator should try to
avoid lchans with higher interference levels reported in RES IND.
The actual implementation of avoiding interference follows in
I844494092193811dfd9fa4d52983cbaed0fc9248
Related: SYS#5313
Change-Id: I8b62d0b41ad9e908b27713db9219e3dbc1ebaab7
They will gain support to be activated as SDCCH/8 soon too.
Related: OS#5309
Depends: libosmocore.git I56dcfe4d17899630b17f80145c3ced72f1e91e68
Change-Id: Id5b89fe589a52ff88486435ac43809edb4b80f98
The BCCH carrier (sometimes called C0) of a BTS shall maintain
discontinuous Downlink transmission at full power in order to
stay 'visible' to the mobile stations. Because of that, early
versions of 3GPP TS 45.008 prohibited BS power reduction on C0.
However, starting from version 13.0.0 (2015-11) there is a feature
called 'BCCH carrier power reduction operation'. This is a special
mode of operation, where the variation of RF level for some
timeslots is relaxed for the purpose of energy saving.
In BCCH carrier power reduction operation, for timeslots on the
C0 carrier, except timeslots carrying BCCH/CCCH, the output power
may be lower than the output power used for timeslots carrying
BCCH/CCCH. In this case the maximum allowed difference in output
power actually transmitted by the BTS is 6 dB.
Introduce a VTY command to turn on and off the BCCH carrier power
reduction operation. Also introduce a CTRL command. On the
A-bis/RSL, abuse the BS POWER CONTROL message by setting
the Channel Number IE to 0x80 (RSL_CHAN_BCCH).
Currently, only osmo-bts-trx is supported. A value greater than
zero makes it reduce the power on *inactive* timeslots of the
BCCH carrier. Sending zero disables the BCCH power reduction
mode completely.
For more details, see 3GPP TS 45.008, section 7.1, and 3GPP TR 45.926.
Change-Id: I047fce33d4d3e4c569dd006ba17858467a2f4783
Related: SYS#4919
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
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
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
Vadim Yanitskiy
Michael Iedema
Neels Hofmeyr
Pau Espin
Harald Welte
Oliver Smith
Philipp Maier
Daniel Willmann
Keith Whyte