Let's split all lchan and power_control specific stuff into their own headers,
it helps finding out data and operations available related to them.
We already have similar classification in osmo-bsc.
Change-Id: I6424dcbd2e329fc1a516f8886359554ed7e9487e
Have a more stable loop with less temporary oscillations at the expense
of increased reaction time.
4 SACCH blocks (P_CON_INTERVAL=2) is the minimum interval to get stable
measurements for the last requested MS Power level. With P_CON_INTERVAL=1,
are also made during a period with stable power being use to transmit,
but the MS Power level used (and announced in MR) is not the last one
requested by the BTS, but the one requested in the previous loop
iteration. This can make the MS and BTS bounce 2 values forth and back,
and create some temporary oscillation.
See osmo-bsc User manual section "Power Control" for more information.
Related: SYS#5371
Change-Id: I91c505447f68714239a4f033d4f06e91893df201
It helps better understanding the code, and will allow handling
situations where for instance a POWERON in in transit while the BTS is
instructed to shutdown, hence a POWEROFF needs to be sent.
Change-Id: Iaf62217ceab7420afa4140cba61e1c2f983c61b4
Avoid re-connecting to a new BSC while BTS is in shutting down. All the
FSMs are complex enough to even try to re-start when stopping has not
yet finished...
Change-Id: I1727828a16f4ec8043b00cc6b2e02a4c35f71377
Prior to this patch, the power ramping started when the PHY is
available, but that doesn't necessarily mean the RCARRIER is enabled.
Due to this, it was spotted a situation where BTS bootstrap failed after
PHY turning up, when RSL connection establishment failed. Hence
bts_shutdown_fsm triggered a shutdown while an active power ramping up
was ongoing...
Change-Id: I17208b74ea2649b1bbb717aee0aa355e42b7e860
This is a preparation commit in order to move power loops up in the
stack in order to have DTXu information available, in order to decide
whether SUB or FULL ul measurements should be used in the MS Power
Control Loop.
Function rsl_tx_meas_res() is stripped from code changing state, and it
simply encodes content and transmits the message.
Change-Id: Id67259ec9ac4c2c33bd0eef3f64450affbe3fb9f
GSM/EDGE Evolution and Performance, Section 12.3 suggests Temporary
Overpower as another solution to improve SACCH/FACCH performance in
case of bad C/I. The idea here is that you increment the DL transmit
power by 2..4dB only for FACCH/SACCH bursts, while keeping all voice
bursts at the lower (normal) level as determined by BS power control.
SACCH blocks can be recognized by the channel type, since they're
always transmitted in specific frames of a multiframe. FACCH blocks,
however, are not predictable and can substitute voice blocks at
(almost) any time. Thus we need to mark FACCH bursts as such in
the logical channel handlers (using TRX_BR_F_FACCH).
Change-Id: Ie8a626fefccf1eb07271058e5126ec106cb1abcf
Related: SYS#5319
The ip.access style dynamic timeslots are a bit special in a way that
on the A-bis/RSL we always use the Channel Number value of TCH/F,
even in PDCH mode. This is why gsm_lchan2chan_nr() would always
return values corresponding to TCH/F for TCH/F_PDCH.
This behavior is only acceptable in the context of RSL messages, while
other parts of the code base may not work properly due to this trick.
A good example is the scheduler in osmo-bts-trx, where we have to
patch Channel Number value to make channel activation work.
DPCU INFO pcu_sock.c:853 Activate request received: TRX=0 TS=5
DL1C INFO l1sap.c:2043 (bts=0,trx=0,ts=5,ss=0) Activating channel TCH/F on TS5
DL1C NOTICE scheduler.c:1097 (bts=0,trx=0,ts=5,ss=0) Activating PDTCH
DL1C NOTICE scheduler.c:1097 (bts=0,trx=0,ts=5,ss=0) Activating PTCCH
In the code branch responsible for channel deactivation, we somehow
forgot to add the same workaround, so deactivation does not work:
DL1C INFO l1sap.c:2076 (bts=0,trx=0,ts=5,ss=0) Deactivating channel TCH/F on TS5
DTRX INFO trx_if.c:255 phy0.0: Enqueuing TRX control command 'CMD NOHANDOVER 5 0'
DRSL NOTICE rsl.c:1286 (bts=0,trx=0,ts=5,ss=0) (bts=0,trx=0,ts=5,ss=0) not sending REL ACK
Because of that, TCH/F_PDCH timeslots actually remain active after
deactivation, so the scheduler keeps producing L1SAP DATA.ind.
DL1P NOTICE l1sap.c:126 (bts=0,trx=0,ts=5,ss=0) assuming active lchan, but state is NONE
DL1P ERROR l1sap.c:732 1583426/1194/00/29/14 No lchan for DATA MEAS IND (chan_nr=PDCH on TS5)
DPCU NOTICE pcu_sock.c:973 PCU socket not connected, dropping message
DL1P NOTICE l1sap.c:126 (bts=0,trx=0,ts=5,ss=0) assuming active lchan, but state is NONE
DPCU NOTICE pcu_sock.c:973 PCU socket not connected, dropping message
DL1P NOTICE l1sap.c:126 (bts=0,trx=0,ts=5,ss=0) assuming active lchan, but state is NONE
DL1P ERROR l1sap.c:732 1583430/1194/04/33/18 No lchan for DATA MEAS IND (chan_nr=PDCH on TS5)
DPCU NOTICE pcu_sock.c:973 PCU socket not connected, dropping message
DL1P NOTICE l1sap.c:126 (bts=0,trx=0,ts=5,ss=0) assuming active lchan, but state is NONE
DPCU NOTICE pcu_sock.c:973 PCU socket not connected, dropping message
Instead of patching Channel Number in various places, let's rather
make the RSL specific behavior configurable by having two variants
of gsm_lchan2chan_nr().
Change-Id: I01680140c7201bf5284b278bceaea8ae01c122b2
Fixes: OS#5238
Previous code creating a new line was really a workaroudn to have it
working while previous lines were being stacked internally inside
libosmo-abis.
Let's handle reference counts for the line properly and erase +
re-create it every time.
Recent patches to libosmo-abis fixed a crash happening when refcount
being 0 and destroying the object (object was not removed from a global
llist).
Depends: libosmo-abis Change-Id I1314d6b917ecb622994507475eb894e649a1a2ad
Change-Id: Ic37ae5bf657247e8cce99182c40d9adf890a5e41
This feature is not yet used by any bts_shutdown_fsm caller, but will be
used in the future when Abis link goes down.
Change-Id: I5dc282fdbcf862067be326e72b6183dd544222ae
This step is required while turning off the BTS without killing the
process. Right now only osmo-bts-trx supports this feature, so this
function is only available and used by osmo-bts-trx.
Later on, when the feature is support more generally, we can move call
to this function to common place like bts_shutdown_fsm or alike.
Change-Id: I3253112700a31b85db82dc7ccadec8542bac745e
Once the TRXC link is available, we can signal SW_ACT which will
transit rcarrier and bbtransc NM FSMs to Disabled Offline and announce
availability to be configured to the BSC through transmission of
Software Activated Report.
Change-Id: I6e62ec2fdd4cae58b52d83fa851552f7ed51c821
This will allow in the future advertising children objects that the
parent object has been configured. It is useful for instance to let TRX
know that the BTS is configured.
Change-Id: Ie319465fd0e991bab8451ea34ec72ff3702533d2
There's no real use for this queue. If the link is gone, it makes no
sense to keep old messages. Instead, BTS should generate new messages
sharing current state when link becomes established (it actually does
so already).
Change-Id: Iecd3c7cb96f5fff3b4c7e04c74e031df0f7a6987
This way it can be changed together with operative/availability state,
and changes announced to the BSC if present.
This commit presents no real change in osmo-bts behavior, since the only
place where adm_state is passed different than -1 is in
st_op_disabled_notinstalled_on_enter(), which is actually never called
(yet) since it's the initial state and no other states transition later
to it.
However, this will change in the future once we support re-connecting to
a (possibly different) BSC, which means objects will need to be moved to
that state to restart the whole OML install procedure on the new BSC.
Change-Id: Ifdc6a1dfb673c0ab915ddf2a9d372928f4f86b4c
The pointer was used as "struct bsc_oml_host" sometimes, and other times
as "struct llist_head". It just worked because bsc_oml_host->list is the
first item in the script. The code was really confusing, also because
the bts list of items has a name really similar to the one currently
assigned. Let's rename the currently assigned address to "current_bsc",
store it always as "struct bsc_oml_host*" and finally use llist_entry
helpers when needed.
The related code is also moved to a helper function to enclose there the
logic to get next BSC in list. This change actually changes the logic
where a remote address is removed from VTY, since now the next address
in list is picked at the time, and later when reconnecting the list is
forwarded another time, meaning one address will be skipped.
This could be considered a bug, but this situation is really special
and anyway the entire logic will be changed in new commits where we'll
keep reconnecting in loop without exiting when reaching the end of the
list, so we are fine with it. Think of this commit as a preparation
commit for next ones.
Change-Id: I3cc8a4148b3d63bc185b72dab8108105a6644910
This clarifies the different states and transitions between them:
OML LINK UP: CONNECTING->CONNECTED
ANY LINK DOWN: CONNECTING->CONNECTING, CONNECTED->FAILED
In follow up commits, support to reconnect instead of exit after the BTS
has already connected will be added, so only the last transition needs
to be changed.
Related: SYS#4971
Change-Id: I43e83b1b04fbaa1f87818c096e6ad3920801b1f6
Similar to what is already provided for power control loops. However,
there's no existing way to communicate TA control parameters from the
BSC to the BTS, so implement them locally in BTS vty.
Related: SYS#5371
Change-Id: I9fa71f836bb9a79b0ef2567bfcfdf38ff217840b
As per 3GPP TS 45.008 sec 4.2, the ms_pwr received in L1 SACCH Header is
the value used over previous measurement period. Hence, we need to feed
the algo with the measurements taken over that same period.
Related: SYS#4917
Change-Id: I13c0014fdd73f823ae5b1256c35bfa7d97cfa334
Field is renamed to look similar to similar fields in power control
loop. This is a preparation commit, next one will add functionality to
skip SACCH blocksi (P_CON_INTERVAL).
Related: SYS#5371
Change-Id: I169ce58ab827e38b64f4b15f935097a9118fa118
First step improving and reworking TA loop:
Move trigger of the loop to similar place done by BS/MS Power Control
Loop, that is, upon receivial of UL SACCH block, which contains
information about the TA used to transmit the block encode in L1SACCH
Header. Hence, from computed received TOA and TA used when transmitting
from the MS, we can infer the desired TA to be used by the MS, which
will send back to it later during DL SACCH block.
The values taken are actually the ones calculated for the previous SACCH
block and stored in lchan->meas.ms_toa256. That's because L1SACCH
contains the TA used for the previous reporting period, similarly to
what's specified for MS Power Control loop (TS 45.008 sec 4.2):
"""
The MS shall confirm the power control level that it is currently employing
in the SACCH L1 header on each uplink channel. The indicated value shall
be the power control level actually used by the mobile for the last burst
of the previous SACCH period.
"""
(The reader may observe that currently this is not properly done for MS
Power Control loop when calling lchan_ms_pwr_ctrl(): this is a bug.)
This new method also permits changing TA quicker, since we have more
confidence that the TA we request is aligned with the one used to
transmit, and we don't simply increment/decrement based on the value we
request to transmit.
Related: SYS#5371
Change-Id: I2d0f128c8dcac93ee382283a1c91fca76623b8fc
During live testing, it has become apparent that some IMM ASS still fail
when sending the RR IMM ASS directly upon the target channel becoming
active.
Add a bit of delay after activation, to give some time for the channel
to light up for the MS. Default is 50ms.
Related: OS#5559
Change-Id: Ia1e63b98944dc840cde212fc732e20277cdc5585
params->rxqual_meas.upper_thresh is left unchecked in
lchan_bs_pwr_ctrl() on this commit on purpose, to keep this
commit with old behavior wrt to algo logic.
Change-Id: If7e3987df89d680cfa443195ab2f225681d0e6cf
This commit extends existing MS Power Control Loop algorithm to take
into account computed C/I values on the UL, received from MS. The
related C/I parameters used by the algorithm are configured at and
provided by the BSC, which transmits them to the BTS similar to already
existing parameters.
Using C/I instead of existing RxQual is preferred due to extended
granularity of C/I (bigger range than RxQual's 0-7).
Furthermore, existing literature (such as "GSM/EDGE: Evolution and Performance"
Table 10.3) provides detailed information about expected target values,
even different values for different channel types. Hence, it was decided
to support setting different MS Power Parameters for different channel
types.
These MS Power Parameters are Osmocom specific, ie. supported only by
newish versions of osmo-bts. Older versions of osmo-bts should ignore
the new IEs added just fine. The new IEs containing the MS POwer
Parameters are not send for non osmo-bts BTSs, hence this commit is
secure with regards to running osmo-bsc against an ip.access BTS such
as nanoBTS.
Related: SYS#4917
Depends: libosmocore.git Change-Id Iffef0611430ad6c90606149c398d80158633bbca
Change-Id: I5dfd8ff9ab6b499646498b507624758dcc160fb6
We have two osmocom specific timers used in the BTS, X1 and X2. Expose
those on the VTY configuration, as timer group 'bts'.
This prepares for a subsequent patch, where I would like to add another
configurable timer. This provides the basic infrastructure for that.
Related: SYS#5559
Change-Id: I0f56f9425134679219884b0c3c2f29e77aff5e64
When an Immediate Assignment comes in targeting an lchan that is not yet
active, then hold back the RR Immediate Assignment until the channel
becomes active.
This allows the BSC to send the Immediate Assignment before first
waiting for the Channel Activation ACK, saving one Abis roundtrip, and
helping avoid double allocation on high latency Abis links.
Related: SYS#5559
Related: I56c25cde152040fb66bdba44399bd37671ae3df2 (osmo-bsc)
Related: Ifb2c62431a91dafa6116b5d6b9410930f00a6e18 (osmo-ttcn3-hacks)
Change-Id: Ie52765b238b01f22fb327fe12327fbf10abcad4c
At the moment we can only configure a single BSC in the BTS
configuration. This also means that if this single BSC fails for some
reason the BTS has no alternate BSC to connect to. Lets extend the
remote-ip parameter so that it can be used multiple times so that an
operater can configure any number of BSCs that are tried one after
another during BTS startup.
Change-Id: I205f68a3a7f35fee4c38a7cfba2b014237df2727
Related: SYS#4971
When the paging queue is filled up to a critical level, pagings from the
PCU should be dropped as each immediate assignment paging from the PCU
is worth 4 normal CS pagings. Also the PCU may still issue pagings if the
paginging queue is already full and CS pagings are dropped. In a
congestion situation it is more important to get the CS rather than PS
pagings through.
Change-Id: I30f97672d7a0c369c4a656e878ab8cbbd83e31ea
Related: SYS#5306
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, in the recent 3GPP TS 45.008 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.
The power reduction operation can be controlled by the BSC by
sending BS POWER CONTROL on the A-bis/RSL with the Channel Number
IE set to 0x80 (RSL_CHAN_BCCH). This makes osmo-bts reduce the
transmission power on inactive timeslots of the BCCH carrier.
This is a non-standard, Osmocom specific extension, so indicate
support of this feature to the BSC in the feature vector. Also
add a VTY command to allow enabling/disabling the power reduction
locally. Add some signalling notes to the A-bis/RSL manual.
For more details, see 3GPP TS 45.008, section 7.1.
Change-Id: I3dcee6e910ccc61c5c63c728db9ea04327e2fc98
Depends: I69283b3f35988fc7a1a1dcf1a1ad3b67f08ec716
Related: SYS#4919
This new extension protocol is used to forward Osmocom PCUIF messages
BSC<->BTS<->PCU.
It will be sent re-using the IPA multiplex of the OML link between
BSC and BTS. BTS is responsible for forwarding the message over the unix
socket to the PCU.
PCUIF existing RX path needs to be reworked in order to accept
variable-size messages, in order to be able to transparently forward
messages without knowing about them (the new container message is
variable-length).
Related: SYS#5303
Change-Id: I73fdb17107494ade9263a62d1f729e67303fce87
The PDCH multiframe contains 48 data slots, 2 PTCCH slots, and
2 IDLE slots. The later two can be used for the interference
measurements, since the UEs shall not transmit on them.
bts_report_interf_meas() is called every 104 TDMA frames, what
corresponds to 2 PDCH multiframe periods. Report interference
levels on PDCH timeslots from this function.
Change-Id: I56f83db5264c246ec1b4b8a973105a4fc09931fb
Related: SYS#5313, OS#1569
In trx_sched_ul_burst(), treat all BURST.ind and NOPE.ind mapped
to inactive logical channels as interference. Average the RSSI
values on the fly using a sliding average with constant a=0.5.
Report averaged values for each logical channel every 104 TDMA
frames (SACCH period) by calling gsm_lchan_interf_meas_push().
Change-Id: I4686448e42a40df56c1d27a14fd0a4d43fd144a5
Related: I78b6d8beffa5228a28231b75728e7aebdd3cb23c
Related: SYS#5313, OS#1569
With the new ordering, all TRXC_* values starting from TRXC_TCHF
belong to dedicated channels. This is useful for the interference
reporting logic, where we're not interested in broadcast channels.
Change-Id: I7148f4d0bd1abbfe309bc5477e32a56d884533ea
Related: SYS#5313, OS#1569
This change implements general interference averaging logic for
the higher layers. In l1sap_info_time_ind(), where we receive
TDMA time updates from BTS model, call rsl_tx_rf_res() for each
transceiver according to the interval defined by the Intave
parameter received from the BSC. In rsl_tx_rf_res() perform
the actual averaging for each inactive logical channel, and
then send everything to the BSC over the A-bis/RSL.
The BTS model specific code needs to report the measurements
for each logical channel every 104 TDMA frames (SACCH period)
by calling gsm_lchan_interf_meas_push().
Change-Id: Id80fdbef087de625149755165c025c0a9563dc85
Related: SYS#5313, OS#1569
Pau Espin
Vadim Yanitskiy
Neels Hofmeyr
Philipp Maier