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
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
This allows running CBCH/ETWS related procedures only when the CBCH
towards MS under that cell is operative.
This also allows providing awarness of per-cell status to the CBSP peer
as required per specs.
Related: SYS#5910
Change-Id: Ia93919be94132fc010acb5bbfef0a6fd51c42981
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
This way we separate all the VTY boilerplate from the actual logic, as
we usually do in all other subsystems.
Change-Id: Ifc7d1693d745dd2a3c31e3ee9610d8c634b50812
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
As per TS 48.049 Table 8.1.3.1.1 the WRITE-REPLACE message always
has a Warning Security Information IE if it relates to ETWS. This
is also implemented in the libosmocore CBSP parser.
As the previous Change Id369bb3676ba279bafc234378fbe21dbc7b0614b has
pointed out, the CBSP parser structure doesn't even permit any way
of handing a decoded message to us without the warning_sec_info
static struct member.
So as a result, there's also no need to dynamically allocate
bts_etws_state.input.sec_info via talloc. We can have it in-line
as a static struct member and reduce code complexity and runtime
memory allocations.
Change-Id: Ib1b8e4af37b1f9f9398b81dad29942e82218c70b
This way we avoid triggering timers and doing extra poll loops for each
BTS which is configured but not up. It also has the effect of removing
logging about estimating paging buffers for BTS which are down, which
can be confusing.
Furthermore, since work is delayed until the TRX and cell in general is
configured, the first estimation is properly done now since the correct
configuration is in place at that time.
Related: SYS#5922
Change-Id: I1b5b1a98115b4e9d821eb3330fc5b970a0e78a44
This allows different parts of the code to hook to some signals which
allow start/stopping processes based, for instance, on whether C0 is
available or not.
This can be later used by paging or CBSP code. Also ACC code can be
ported to this new system (acc_ramp_nm_sig_cb()).
Same signal can be used for other NM objects, but is left unimplemented
until there's use for them.
Change-Id: I206d4c7863a77fbab6a600126742a6a6b8fc3614
Especially during emergencies / natural disasters, it is particularly
likely that networks become unreliable and BTSs disconnect and
reconnect. If upon reconnect there still is an active ETWS/PWS
emergency message active for this BTS, send it to the BTS to ensure
it re-starts broadcasting that message until disabled.
Change-Id: I175c33297c08e65bdbf38447e697e37f8a64d527
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
We want to recalculate the timer based on last time the work_timer was
triggered (that is, the time when the worker re-armed the pag req to
retransmit). We don't want to recalculate based on the last time the pag
ret tro retransmit was scheduled.
In loaded paging queue, there's lots of retrans (let's say 200) and it
may take more than 500ms to actually retransmit them. That means in most
cases we could end up in a situation where only pag req to retrans where
in the queue, hitting this recalculate path. Since the 500ms were for
sure elapsed, that would most probably schedule the work_timer at {0,0}
for each new paging request that arrived. As a result, the worker would
be scheduled lots of times per second (once for each new req arriving)
and only submitting 1 pag req (the new one) plus potentially 1 or
serveral pag req to retransmit.
In summary, there was not throthling applied in the scenario where only
pag req to retransmit where in the queue and new pag reqs kept arriving.
This incurrs into augmented paging throughput and also augmented
frequency of polls().
Related: OS#5922
Fixes: 4821c9f4df
Change-Id: I7ce6f436286b50dc31331d218ff256cf7be3f619
There's no need to use pointers there, it is only asking for errors from
code handling the data structe from the signal by attempting to change
them. Even for mem size point of view it doesn't make sense, since it's
3 byte vs a 4 byte pointer.
Furthermore, this is a preparation for new commit, where the NM object
current state will be updated before emitting the signal. This patch
eases a lot the follow up mentioned patch.
Change-Id: I9b648dfd8392b7b40bfe2b38f3345017481f5129
One callback function was being registered for each BTS.
That means, when a C0 RCARRIER of one specific BTS changed NM state,
the outcome on whether to trigger/abort ramping would end up being
applied to all BTS.
Change-Id: I56c4dd1809fdcf8441a69bf77ad173e1ccc8eea7
This makes sure code accessing those fields is not changing its values,
since it would make no sense to change those. Follow up commit will make
convert those pointers to be full structs instead, as there's no need to
have pointers there.
Change-Id: I9979e62eac861e25bbe2161ab187ddb2b40fd097
Having 2 signals makes all code handling them more complex, specially
because S_NM_STATE_CHG_OPER could actually provide any change in
admin/oper/availability.
Both signals already provided the same kind of data (the whole
admin/oper/avail state change), so let's simply merge the signals
themselves. Current code really doesn't act differently for those 2
signals anyway.
Change-Id: Ia86d20a42b859063d0327b940ba528ec1438b04a
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
Before this patch, on each BTS a 500ms timer was used to schedule some
work, sending up to 20 paging requests verytime.
This means, however, for an initial paging request it may take up to
500ms delay to be scheduled to the BTS, which is huge.
While we still want to maintain this 500ms interval for retransmits, it
doesn't make sense to wait that much for other cases. It's far better
sending less requests (10 instead of 20) every half time (250ms instead
of 500ms), since it will spread the load and paging more over time,
allowing for other work to be done in the middle.
Change-Id: I7a1297452cc4734b6ee8c38fb94cf32f38d57c3d
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
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 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
Its name is totally misleading, since they seem to be related to
GetAttributes messages rather than SetAttributes.
Change-Id: I306cb407dbd9b98e301b5d93046bdadcb466b82b
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
When bad RxQual causes handover to a cell with weaker RxLev, then
handover oscillation *will* happen, as shown in test_rxqual.ho_vty.
Introduce a penalty timer for a cell where we had bad RxQual.
This delays handover back to the cell with stronger RxLev by the penalty
timeout; hopefully the interference is gone after the timeout.
Usually, we set new configuration elements so that osmo-bsc behaves the
same as before the config item was added. In this instance, this makes
no sense, because no-one ever wants handover oscillation from bad
RxQual, which is guaranteed to happen without the new penalty timer. Set
it to 60 seconds by default, same as other penalty timers.
Related: SYS#5911
Change-Id: I057b156604a104a26a7ce45d1c7adadbf452c932
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
On receipt of the Perform Location Request message, the BSC needs
to forward it to the SMLC. If the abovementioned IEs are present
in the original message, they must be delivered to the SMLC too.
Change-Id: Ifeb359b0468845da0b4fed9e2e4b79256067fa81
Depends: libosmocore.git I8775a93cf4089b1752d040e43d2cba6b8997f955
Related: SYS#5891
On receipt of the Perform Location Request message, the BSC needs
to forward it to the SMLC. If the LCS Client Type IE is present
in the original message, it must be delivered to the SMLC too.
Change-Id: Id3262e67c3dc25cb93fbd52a40689c5529ca2d41
Related: SYS#5891
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
Historically, we first only had
BSS_MAP_MSG_ASSIGMENT_RQST
^
with missing N. libosmocore has this renamed a long time ago and
provides a shim #define that makes the typo version still work.
Having the typo is bad for grepping, so rather use the non-typo name.
Also rename the constant for the ass req counter which so far has a
similar typo, and fix the same typo in the counter description.
The counter name exposed on CTRL luckily doesn't have this typo in it.
Change-Id: Ieaa4f4e6e6f7e1563b1bd15a83f0c1a9112d2312
Teach osmo-bsc to handle empty N-Connect. So far we were always
expecting user data in an SCCP N-Connect from an MSC. However, it is
perfectly valid for an initial BSSMAP request to follow later.
This is relevant for:
- Handover Request (incoming inter-BSC handover)
- Perform Location Request (query physical location of the MS)
Add state WAIT_INITIAL_USER_DATA with new timeout net X25. Always enter
this state so that we don't have two separate code paths for handling
initial user data.
Related: SYS#5864
Change-Id: I535c791fa01e99a2226392eb05f676ba6c3cc16e
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
Vadim Yanitskiy
Michael Iedema
Pau Espin
Neels Hofmeyr
Harald Welte
Oliver Smith