Looks like this structure was copied from openbsc/osmo-bsc as-is.
The ms_mode[] makes no sense in the context of BTS, so remove it
and rename bts_mode[] to mode[] for the sake of brevity.
Change-Id: I7442360ed857554440a0b9854f2d2bbab9dc5a71
Related: SYS#5917, OS#4984
This configuration will be used as a fall-back when the MultiRate
configuration IE is not included in the CHAN ACT/MODIFY messages.
Change-Id: Ie96af636105ee1ffe2d9a0bd9eea375faebad149
Related: osmo-bsc.git Ic5f8d55d250976d8d4c9cae2d89480fd52326717
Related: SYS#5917, OS#4984
Once we have an Uplink speech or FACCH frame decoded, we need to
hand it over to the upper layers indicating TDMA frame number of
the *first* burst corresponding to the beginning of a block.
Currently we use libosmogsm's gsm0502_fn_remap() API to calculate
the first TDMA frame number from the given last frame number.
This API involves iterating over the pre-calculated offset tables
for different channel and payload types, and thus imposes some
additional CPU cycles. Another downside of the current approach
is that we have to perform such lookups several times for each
decoded L2 frame, e.g. for FACCH on TCH/AHS we do it three times!
In this patch I propose an alternative approach of storing TDMA
frame numbers in the measurement history, together with the
associated samples. This way we can easily get N-th frame number
from there without performing any additional computations, other
than what we already do during the measurement processing.
Change-Id: Id9a2b7b0f1a1ad7cfbbab862faf521e135c90605
FACCH/H takes out two speech frames, so we send two BFIs once we
have received it in rx_tchh_fn(). The upper layers responsible
for handling of the Uplink measurements expect a fixed amount of
measurement samples, so currently we do:
* send a FACCH frame with the associated measurememnts (S6N6),
* send the 1st BFI with invalidated measurements (RSSI=0),
* send the 2nd BFI with the stored measurememnts of FACCH.
This is achieved by preserving a copy of the FACCH measurememnts
in chan_state->meas_avg_facch and then using it two bursts later.
The same goal can be achieved a lot easier by sending the associated
measurements with both BFIs as if no FACCH was received:
* send a FACCH frame with invalidated measurememnts (RSSI=0),
* send the 1st BFI with the associated measurememnts (S6N4),
* send the 2nd BFI with the associated measurememnts (S6N4).
This eliminates the need to store anything outside of the existing
measurement history and simplifies the code a lot. Also, this
eliminates the need for using a dedicated averaging mode S6N6.
Varified by running BTS_Tests.TC_meas_res_speech_tchh_facch.
Change-Id: I7902b4709bc3f418174e8373f52e87bb31cdc826
Related: I1ad9fa3815feb2b4da608ab7df716a87ba1f2f91
It makes no sense to store BER10k value of an Uplink FACCH frame
in order to indicate it in a BFI later on. Given that these BFIs
are generated artificially, it's fine to indicate BER10k=0.
Change-Id: I24d12892760dca0ad0a5c2abca9fc66523d9e614
Related: I1ad9fa3815feb2b4da608ab7df716a87ba1f2f91
Compared to TCH/F, TCH/H is a bit special in a way that:
* speech frames are interleaved over 4 consecutive bursts,
* while FACCH frames are interleaved over 6 consecutive bursts.
This is why in rx_tchh_fn() we allocate a buffer large enough to
store up to 6 bursts. Let's say we have that buffer filled up
completely with all 6 bursts (from 'a' to 'f'). Now attempting
to decode them may yield either a speech frame or a FACCH frame:
+---+---+---+---+---+---+
| a | b | c | d | e | f | Burst 'a' received first, 'f' last
+---+---+---+---+---+---+
^^^^^^^^^^^^^^^ Speech frame (bursts 'a' .. 'd')
^^^^^^^^^^^^^^^^^^^^^^^ FACCH frame (bursts 'a' .. 'f')
For FACCH we use measurement averaging mode SCHED_MEAS_AVG_M_S6N6,
so that 6 last samples are averaged - so far so good. For speech
we use SCHED_MEAS_AVG_M_S4N4, so that 4 last samples corresponding
to bursts 'c', 'd', 'e', 'f' are averaged - this is wrong.
We actually need to average the *first* 4 samples corresponding to
bursts 'a', 'b', 'c', 'd' in the case of speech. Let's add and use
a new averaging mode SCHED_MEAS_AVG_M_S6N4 for that.
Change-Id: Iea6f4e5471550f4c2b57aaebeac83c80e879489d
This is a purely cosmetic change. The new naming clearly indicates
how deep to go back in the measurement history (S) and how many
samples to average (N). For example:
* SCHED_MEAS_AVG_M_S4N4 - go S=4 steps back and average N=4 samples;
* SCHED_MEAS_AVG_M_S6N2 - go S=6 steps back and average N=2 samples.
Change-Id: I96a8dd08084c7c179f879fc00e75c5edcfb11caa
DSUM is somewhat similar to DMAIN, generic logging category used
in other Osmocom projects. This category is rarely used in a few
places, where the other categories could fit better. Remove it.
Change-Id: Ia9db783bc92b23ba87b4fdf1e4ed07d59ea6bbce
As a side effect, we have to sacrifice a unit test (TC_inval_dummy)
because it becomes impossible to pass a dummy or invalid SACCH block
to lchan_bs_pwr_ctrl().
Change-Id: I937117cf26fb718d57920382f6972390ad498c51
Related: SYS#4918
Currently an Uplink SACCH block is being passed to LAPDm first, and
then gets forwareded to the BSC in handle_ms_meas_report(), together
with the Uplink measurements collected so far.
This approach has a serious flaw: handle_ms_meas_report() won't be
called if an Uplink block contains SAPI=3 data (SMS) or was not
decoded at all (len=0) fow whatever reason. Therefore, no RSL
MEASurement RESult message will be sent to the BSC.
Rename handle_ms_meas_report() to lchan_meas_handle_sacch(), and call
it from l1sap_ph_data_ind(). This way perioduc RSL MEASurement RESult
messages will be sent regardless of what happens on Uplink SACCH.
Change-Id: Ifed91f87fd653debc87a09da3fd31ad64a13f330
Fixes: TC_meas_res_speech_{tchf,tchh}_sapi3
Related: SYS#5319
The new fields in 'struct abis_rsl_osmo_temp_ovp_acch_cap' allow:
* selectively enabling SACCH and/or FACCH,
* setting the RxQual (BER) threshold.
Both features are implemented in the follow-up commits.
Change-Id: I370c8f95fb64eceb60a9dc2eae1412f8a0df0f4e
Depends: Ia28293a12de0af71f55e701fb65c46e905dae217
Related: SYS#5319
For the sake of consistency, call repeated_dl_facch_active_decision()
from handle_ms_meas_report(), so we have all functions using the
measurement results for Downlink executed in a single place.
Change-Id: Ibd5377ce642e49161f320ac8c33e9f966b3ddfaf
Related: SYS#5114, SYS#5319
It can happen when using several TRX that all of them go alreadyunder
shutdown target tx power level, but that due to configuration the BTS
still may want to keep pushing the tx power level even lower. Hence, we
end up in a situation where the FSM is trying to close all the TRX while the
power ramp procedure is ongoing for some of them. As a result, race
conditions can happen where for instance the power ramping procedure for
one TRX ends and calls the cb to send SETPOWER after the TRX PHY has
been closed (and hence TRXC link is unavaialble).
If that happens, the trx_if lower layers store the SETPOWER and attempt
a later retransmit, which may take up to 2 seconds after TRX becomes
active if BTS reconnects immediatelly.
Hence, we end up in some test cases where BTS reconnects and configures
some TRX while others are kep unconfigured for a while due to the
mentioned delay, hence the test attempting to use the TS while it hasn't
been yet configured.
The solution is to avoid this kind of unexpected events with ongoing
powe ramp once we have decided tx power is lower enough to shutdown the
TRX completely. Hence we abort the pending power ramp procedure.
Change-Id: Ibca581131eb142d7c38c917a0d6990efec03123c
Currently, only osmo-bts-trx is capable of reporting the interference
levels to L1SAP. Thus it does not make sense to trigger the averaging
logic and send empty reports over the A-bis/RSL and the PCUIF.
Change-Id: Ic17eb46bdca3c33ac4d6e560a093b635b75424a5
Related: SYS#5313
Starting from [1], interference levels on PDCH timeslots are also
reported over the A-bis/RSL. They may be useful for the BSC to
determine whether dynamic PDCH timeslots might be better used for
new circuit switched connections, or whether alternative PDCH slots
should be allocated for interference reasons.
* Handle GSM_LCHAN_PDTCH in lchan_report_interf_meas().
* Rework pcu_tx_interf_ind() to accept 'struct gsm_bts_trx'.
* Call pcu_tx_interf_ind() from l1sap_interf_meas_report().
Regarding pcu_tx_interf_ind(), it's better to call this function
from the upper layers once, rather than calling it from various
places in the model specific code.
[1] I5b4d1da0920e788ac8063cc765fe5b0223c76758
Change-Id: I3fbaad5dbc3bbd305b3ad4cb4bfb431a42cfbffc
Related: SYS#5313
It's cleaner from the architectural point of view to have the
interference measurements processed in a separate function.
Change-Id: I3981608e01a50585359cad673c38c8a305027d30
Related: SYS#5313
It may happen that the BSC requests logical channel activation on a
dynamic timeslot, which is in a process of switching from one pchan
type to another due to a preceding channel activation request.
In this case 'struct gsm_bts_trx_ts' already holds an msgb with the
preceding RSL CHANnel ACTIVation message, that is normally handled
once the PHY completes the process of timeslot re-configuration.
On receipt of subsequent RSL CHANnel ACTIVation messages, in function
dyn_ts_l1_reconnect() we overwrite the preceeding msgb (memleak), by
the most recent one. And once the timeslot re-configuration is done,
only the most recent CHANnel ACTIVation message gets ACKed.
In order to avoid this, let's move the msgb ownership to 'struct
gsm_lchan', so it cannot be overwritten by the CHANnel ACTIVation
message that is related to a different lchan on the same timeslot.
Change-Id: Ia625c2827fca883ea712076706d5ef21ed793ba6
Related: I3b602ac9dbe0ab3e80eb30de573c9b48a79872d8
Fixes: OS#5245
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
The TSC (Training Sequence Code) value in 'struct gsm_bts_trx_ts'
is always initialized in oml_rx_set_chan_attr() during the OML
bootstrapping, so there is no need for gsm_ts_tsc() - remove it.
Store the initial TSC value in 'struct gsm_bts_trx_ts', so we can
apply a different TSC value during the RSL CHANnel ACTIVation.
Store the Training Sequence Code/Set in 'struct trx_dl_burst_req'.
These values are indicated to the transceiver (TRXDv2 PDUs, 'MTS'
field) and used by the new TRX_{GMSK,8PSK}_NB_TSC macros.
Change-Id: I3744bc308b99ef941e6e9d139444e414abebc14b
Related: SYS#4895, OS#4941
Ensure that we check the PHY capabilities in both cases:
* RSL CHANnel ACTIVation, and
* RSL CHANnel MODE MODIFY,
by calling bts_supports_cm() from rsl_handle_chan_mod_ie().
Modify bts_supports_cm() to accept a 'struct rsl_ie_chan_mode',
so we can handle VAMOS enabled channel modes and CSD later on.
Change-Id: I31a444592436705ec9d6ddade3cbfa7f8cb4bb91
Related: SYS#5315, OS#4940
This change implements TRXD PDU batching approach b), which is described
in section 25.3.4 of the user manual [1]. This approach is quite easy
to implement on the transceiver side, so we can enable it by default.
.Example: datagram structure for combination b)
----
+--------+----------------+---------+------------------------+
| TRXN=N | TDMA FN=F TN=0 | BATCH=1 | Hard-/Soft-bits |
+--------+----------------+---------+------------------------+
| TRXN=N | TDMA FN=F TN=1 | BATCH=1 | Hard-/Soft-bits |
+--------+----------------+---------+------------------------+
| TRXN=N | TDMA FN=F TN=2 | BATCH=1 | Hard-/Soft-bits |
+--------+----------------+---------+------------------------+
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+--------+----------------+---------+------------------------+
| TRXN=N | TDMA FN=F TN=7 | BATCH=0 | Hard-/Soft-bits |
+--------+----------------+---------+------------------------+
----
Other PDU batching approaches can be introduced later.
[1] https://downloads.osmocom.org/docs/latest/osmobts-usermanual.pdf
Change-Id: I9b4cc8e10cd683b28d22e32890569484cd20372d
Related: SYS#4895, OS#4941
Currently, in bts_sched_fn() we send a Downlink burst to the PHY
immediately after calling the associated logical channel handler.
Together with the obvious performance advantages, this approach
imposes some serious limitations. The code has already become
quite complex with the introduction of the baseband frequency
hopping, and now it's not possible anymore to extend it further.
TRXD PDU batching, which is essential for VAMOS implementation,
requires us to make the scheduler more flexible at the expense of
increased memory consumption and additional CPU cycles. This patch
splits up Downlink burst scheduling into 3 main steps:
1. bts_sched_init_buffers(): initialization of per-TRX Downlink
burst buffers allocated by phy_instance_create(). For C0/TRX0
all timeslots are pre-initialized with dummy burst.
2. bts_sched_fn(): generating burst bits for all active lchans.
3. bts_sched_flush_buffers(): sending everything to the PHY.
This approach allows us to a) get rid of the ugly tail in bts_sched_fn()
that was responsible for sending dummy bursts on C0/TRX0; b) implement
the PDU batching and have several variants of bts_sched_flush_buffers()
providing the alternative batching approaches later on; c) implement
PDU merging for the upcoming shadow transceivers.
Change-Id: Iec78989517865b3275a9784d1042a5ebd1d2815f
Related: SYS#4895, OS#4941
BCC takes 3 LSB bits of the BSIC, so we should apply 0b111 or 0x07.
The BSIC is specified in 3GPP TS 03.03 section 4.3.2.
Change-Id: Id24ad64e6c6de080ab43faa272daf844fbba6954
Related: SYS#5315, OS#4940
We assume that it's legal to have dangling PHY instances that are
not associated with any TRX instances in the configuration file.
Obviously, such PHY instances have pinst->trx set to NULL.
The DSP based models seem to handle dangling PHY instances without
any problems, so let's ensure that we always check pinst->trx
against NULL in the osmo-bts-{trx,virtual} specific code.
Change-Id: Ib7d9cb7ae47fead723fa46454cd64bf6e88756bb
Fixes: CID#236092 "Dereference before null check"
Together with the 'generic' structures which used to be shared between
osmo-bsc and osmo-bts some time ago, we also have the following
osmo-bts-trx specific structures (in hierarchical order):
- struct l1sched_trx (struct gsm_bts_trx),
- struct l1sched_ts (struct gsm_bts_trx_ts),
- struct l1sched_chan_state (struct gsm_lchan).
These structures are not integrated into the tree of the generic
structures, but maintained in a _separate tree_ instead. Until
recently, only the 'l1sched_trx' had a pointer to generic
'gsm_bts_trx', so in order to find the corresponding 'gsm_lchan' for
'l1sched_chan_state' one would need to traverse all the way up to
'l1sched_trx' and then tracerse another three backwards.
+ gsm_network
|
--+ gsm_bts (0..255)
|
--+ l1sched_trx --------------------> gsm_bts_trx (0..255)
| |
--+ l1sched_trx_ts --+ gsm_bts_trx_ts (8)
| |
--+ l1sched_chan_state --+ gsm_lchan (up to 8)
I find this architecture a bit over-complicated, especially given
that 'l1sched_trx' is kind of a dummy node containing nothing else
than a pointer to 'gsm_bts_trx' and the list of 'l1sched_trx_ts'.
In this path I slightly change the architecture as follows:
+ gsm_network
|
--+ gsm_bts (0..255)
|
--+ gsm_bts_trx (0..255)
|
--+ l1sched_trx_ts <----------------> gsm_bts_trx_ts (8)
| |
--+ l1sched_chan_state --+ gsm_lchan (up to 8)
Note that unfortunately we cannot 1:1 map 'l1sched_chan_state' to
'gsm_lchan' (like we do for 'l1sched_trx_ts' and 'gsm_bts_trx_ts')
because there is no direct mapping. The former is a higl-level
representation of a logical channel, while the later represents
one specific logical channel type like FCCH, SDCCH/0 or SACCH/0.
osmo-bts-virtual re-uses the osmo-bts-trx hierarchy, so it's also
affected by this change.
Change-Id: I7c4379e43a25e9d858d582a99bf6c4b65c9af481
lower layer specific APIs require first to enable the TRX object
(GsmL1_PrimId_MphInitReq, which requires ARFCN received during Set
Radio Carrier Attributes) before enabling the per-TS structure.
Hence, OPSTART must happen in RCARRIER MO before OPSTART can be sent to
the Radio Channel MOs, otherwise the initialization of the TS objet will
fail and OPSTART for the RadioChannel MO will send back a NACK.
In order to avoid this, we need to keep the RadioChannel MO announced as
"Disabled Dependency" until RCARRIER is OPSTARTed.
Related: OS#5157
Change-Id: I8c6e5ff98c32a3cd5006f5e5ed6875bcabb1d85f
Historically the logical channel handlers like rx_data_fn() used to accept
quite a lot of arguments. With the introduction of additional measurement
parameters it has become clear that we need to group the arguments into
structures. This is why both 'trx_{dl,ul}_burst_{req,ind}' structures
were introduced.
However, both channel type and burst ID were kept untouched, so until
now we had them being passed between the scheduler functions here and
there. This change is a logical conclusion of the original change
mentioned above.
As a part of this change, the new LOGL1SB() macro is introduced. It
does accept a pointer to 'trx_{dl,ul}_burst_{req,ind}' and expands the
context information for the old LOGL1S() macro.
Change-Id: Ic5a02b074662b3e429bf18e05a982f3f3e7b7444
gsm_bts_trx_alloc() already does initialize some fields of the
allocated 'struct gsm_bts_trx' instance, and having an additional
function for initializing the other fields makes no sense.
Note that I intentionally didn't merge a call to bts_model_trx_init()
into gsm_bts_trx_alloc(), because this would break some assumptions
regarding the order of initialization and cause regressions.
This also allows us to not call bts_model_trx_init() from tests.
Change-Id: I4aefaf47b05a67ec0c4774c1ee7abcc95e04cc13
First of all, there is no reason to use a void pointer because
it's always 'struct phy_instance'. Also, no need to encapsulate
this pointer into 'role_bts' because there are no other roles in
osmo-bts (we used to have shared headers years ago).
This commit also fixes a bug in test_sysmobts_auto_band(), where a
pointer to 'struct femtol1_hdl' was directly assigned to trx.pinst.
Change-Id: I9bd6f0921e0c6bf824d38485486ad78864cbe17e
This significantly simplifies setups in which not only the IP DSCP
but also the IEEE 802.1Q PCP is to be set for RTP packets.
Depends: libosmo-abis.git I52c08f4b2a46981d002ef0c21e6549445d845a6e
Change-Id: Ia3a91e6788285be3e2e73defee63e6bd79c6258e
Related: SYS#5427
TRXDv2 brings significant changes to the whole PDU structure, not
just the header. Let's highlight this in the code / strings.
Change-Id: Id0274bd1ae5c419548596ed1852e6a28ec62b713
Related: SYS#4895, OS#4941, OS#4006
The measurement results / TCH indications that are handed when decoding
the TCH/H are off by two bursts. Since a measurement result / TCH block
is expected every two bursts anyway the problem can only be noticed when
a FACCH transmission is going on and the frame numbers of the BFI TCH
blocks appear to be missaligned towards the FACCH block.
The reason is that the incoming bursts are shifted into a 6 burst wide
buffer. The decoding functions always look at the beginning of that
buffer while the bursts are shifted into the buffer from the end. A
facch will always fit exactly in that buffer but TCH/H blocks are only
4 bursts wide and thereofre they need two additional bursts until they
reach the coverage of the decoding function. Lets fix this by putting
the correct frame number (from two bursts before) into the remap
functions in order to get the correct beginning of the block.
Since the FACCH transmission uses six blocks it takes out two TCH
blocks. This means that if we count the FACCH block we end up with a gap
of one TCH voice block. Lets generate a dummy measurement to compensate
the gap. This will also match the behavior of the osmo-bts-sysmo phy.
Change-Id: I1ad9fa3815feb2b4da608ab7df716a87ba1f2f91
Related: OS#4799
The MS sets the SRR bit in the L1 SACCH header to request DL-SACCH
repetition from the BTS. At the moment we access the l1_info stored in
tle lchan struct each time we want to check the status of the SRR bit.
However, it is more convinient to do this once at reception and store
the status of the status of the flag in a separate struct member.
Change-Id: Ieddd45d7890343d64db14b9c726f6fa2f25714f6
Related: SYS#5114
in struct gsm_lchan and also in other places l1_info is handled in its
binary form. Libosmocore now offers structs to handle l1 info, so lets
use those structs to get rid of all the manual decoding of l1_info.
Depends: libosmocore I23c1890b89d5a0574eb05dace9f64cc59d6f6df7
Change-Id: I5eb516d7849750f3dd174d48c9f07dabf2c80515
So far, the only way to configure GSMTAP Um logging is to use the
cmdline argument '-i'. Let's deprecate it, and add a VTY command
to allow setting the remote host from configuration file.
The legacy '-i' option, if provided, overrides the configuration
file option, and will also appear in 'write file'.
Change-Id: I17676a21c4e0c9cbc88f2c5c53a39c6c6c473ca1
Tweaked by: Vadim Yanitskiy <vyanitskiy@sysmocom.de>
The only reason why it was not 'const' is that in lchan_new_ul_meas()
we may need to overwrite 'ulm->is_sub'. This can still be done after
memcpy()ing a new set of samples to the destination buffer.
Change-Id: I0cabf75f8e0bf793c01225a4a8433e994c93f562
Related: OS#5024
This patch PCUIF extends the SAPI 4 that is used
to transfer SI13 only, so that it can transfer SI1 and SI3 as well.
The system information SI1, SI3 and SI13 is needed by the NACC RIM
application which runs inside osmo-pcu.
Depends: osmo-pcu I5138ab183793e7eee4dc494318d984e9f1f56932
Change-Id: Ib7aeb41e634ad6fcab3766a4667b0267c749436a
Related: SYS#5103
It makes more sense to use a reduce step size that is smaller than
the increase step size. This way both MS/BS power control loops
would be able to react quickly of the signal gets weaker, while
the good signal would not trigger radical power reduction.
Change-Id: Ie358fd828a68bfa1d23559197e8df8478fb4535e
Related: SYS#4918
In change [1] the new power control structures and default params
were introduced. In change [2], the existing VTY commands for MS
power control in the BTS were deprecated and changed to use the
new structures as storage. Finally, in change [3], handling of
the power control parameters on the A-bis/RSL was implemented.
This change is the final logical step in the mentioned chain: it
makes both MS/BS power control loops use the new parameters, and
removes the old structures. The actual implementation of both
power control loops remains the same, however the expected output
of some unit tests for the Downlink loop needs to be changed:
- TC_fixed_mode: disabling dynamic power control becomes a separate
step of the test script since the field 'fixed' is removed;
- TC_rxlev_target: RxLev thresholds are printed 'as-is'.
Not all of the new parameters are used by the power control loops
yet. Further improvements to be done in the follow up commits.
[1] I6d41eb238aa6d4f5b77596c5477c2ecbe86de2a8
[2] Icbd9a7d31ce6723294130a31a179a002fccb4612
[3] I5a901eca5a78a0335a6954064e602e65cda85390
Change-Id: Ib18f84c40227841d95a36063a6789bf63054fc2e
Related: SYS#4918
For the sake of simplicity, the old structures that are still used
by MS/BS power control loops are kept in place. Migration to the
new structures requires additional changes to the existing power
control logic, so it will be done in the follow-up changes.
The new parameters are integrated as follows:
+ struct gsm_bts - a BTS instance:
| Hard-coded default (fall-back) parameters for all transceivers.
|
+-+-> struct gsm_bts_trx - a TRX instance (transceiver):
| Default parameters for all logical channels inherited from
| 'struct gsm_bts' at start-up. May be overwritten by the
| BSC using ip.access specific 'Measurement Pre-processing
| Defaults' message on the A-bis/RSL interface.
|
+---> struct gsm_lchan - a logical channel (e.g. TCH or SDCCH):
Connection specific parameters inherited from 'struct
gsm_bts_trx'. May be overwritten by parameters sent
by the BSC in CHANnel ACTIVation and other messages.
Change-Id: I6d41eb238aa6d4f5b77596c5477c2ecbe86de2a8
Related: SYS#4918
In Change-Id I1fd513ea03297918d15d4b28ed454f9b6dd6ebfa we introduced
patching of SI4 to indicate GPRS presence in terms of PCU connection
status. Unfortauntely this didn't account for optional IEs being
present in SI4, and hence overwrote any CBCH related information
elements, if present.
This in turn meant that since the above-mentioned commit, you could
have either a GPRS-capable, network, or a Cell Broadcast capable one.
Change-Id: I0ee0cf736e2fb74a6759a68101f699b4ec2ef54e
Related: OS#3075
We already have MS Power Control, which according to 3GPP 45.008
shall be implemented in the MS to minimize the transmit power in
the Uplink direction. The BS Power Control may optionally be
implemented by the network side for the same purpose.
Using Downlink signal measurements reported by the MS, the BSS
(either BSC, or BTS) may control Downlink attenuation in a way
that the transmit power remains as low as possible, or remains
in a specific range corresponding to good RxLev values on the
MS side. This change implements autonomous BS Power Control,
that can optionally be enabled by the BSC.
BS Power Control re-uses parts of the MS Power Control code,
so all parameters can be configured in the same way - via the
VTY interface or a configuration file. This basically means
that features like hysteresis and EWMA based filtering are
also available for BS Power Control.
The only difference is that RxQual values higher than 0 would
trigger the logic to reduce the current attenuation twice.
Note that one of the unit tests ('TC_rxlev_max_min') fails,
as the power step limitations for raising and lowering look
wrong to me, and the related discussion is still ongoing.
Change-Id: I5b509e71d5f668b6b8b2abf8053c27f2a7c78451
Related: SYS#4918
3GPP TS 44.006, section 11 describes a method how the uplink
SACCH transmission can be repeated to increase transmission
reliability.
Change-Id: I7e4cc33cc010866e41e3b594351a7f7bf93e08ac
Related: OS#4795, SYS#5114
3GPP TS 44.006, section 11 describes a method how the downlink
SACCH transmission can be repeated to increase transmission
reliability.
Change-Id: I00806f936b15fbaf6a4e7bbd61f3bec262cdbb28
Related: OS#4794, SYS#5114
3GPP TS 44.006, section 10 describes a method how the downlink
FACCH transmission can be repeated to increase transmission
reliability.
Change-Id: I72f0cf7eaaef9f80fc35e752c90ae0e2d24d0c75
Depends: libosmocore I6dda239e9cd7033297bed1deb5eb1d9f87b8433f
Related: OS#4796 SYS#5114
This part adds the common lchan flags to indicate whether DL SACCH
should be activated.
Note that currently, osmo-bsc *always* sends the MS Power IE as well as
the TA IE, also for inter-cell HO, so in the osmoverse, nothing will
change until we also adjust osmo-bsc. See OS#4858.
Change-Id: Ibea973ccadf5d424213f141f97a61395856b76de
Similar to bts_vty_init(), BTS specific bts_model_vty_init()
requires a pointer to 'struct gsm_bts'. Not only it's used
as a parent talloc context, but also stored locally, so then
it can be used by some VTY commands.
Let's expose the global 'struct gsm_bts' from main, and pass
the application's talloc context like was done in [1].
This finally makes the BTS model specific options appear in
the automatically generated VTY reference (--vty-ref-xml).
[1] Ic356a950da85de02c82e9882a5fbadaaa6929680
Change-Id: Iee7fee6747dd1e7c0af36f9b27326f651ae37aaf
Related: SYS#4937, OS#3036
Otherwise only those commands that are registered by libosmocore
appear in the generated XML VTY reference - change the order.
Instead of a pointer to 'struct gsm_bts', pass the application's
talloc context, as it's only used for dynamic command allocation.
Change-Id: Ic356a950da85de02c82e9882a5fbadaaa6929680
Related: SYS#4937, OS#3036
All the Operative State logic to manage a RadioCarrier//BBTransc NM objects is
centralized in these FSM, where other parts of the code simply send
events to it.
This allows keeping state consistent and offloading logic from each bts
backend, since they are only required to submit events now.
The idea in the long run is to also replace other NM objects with
similar FSMs.
This improved logic fixes bug where PHY + RSL link became available before
OPSTART and hence op state changed to Enabled before receiving any OPSTART message.
Change-Id: Ifb249a821c4270918699b6375a72b3a618e8cfbe
This fixes old behavior mimicing broken behavior in nanoBTS (according to TS 12.21)
where BTS Site Mgr NM object was announced as Enabled despite no OPSTART
was sent by the BSC.
With this new FSM, BTS SiteManager will be announced as Disabled Offline
during OML startup conversation, instead of Enabled.
The new osmo-bsc OML management FSMs use this change in behavior to find
out whether it should use the old broken management states (without
Offline state, as per nanoBTS) or use the new state transitions (which
allow fixing several race conditions).
Change-Id: Iab2d17c45c9642860cd2d5d523c1baae24502243
Recently we've introduced EWMA based uplink power filtering, that
should reduce Uplink power oscillations. However, the power loop
is still quite sensitive to small deviations from the target power
level: even such an insignificant deviation like 2-5 dBm triggers
the loop to increase or decrease the MS power level. Even if the
EWMA based filtering is enabled with 80% smoothing (alpha = 0.2).
This change introduces a new configuration parameter - 'hysteresis':
uplink-power-target <-110-0> hysteresis <1-25>
that together with the 'uplink-power-target' defines a range:
[target - hysteresis .. target + hysteresis]
in which the MS power loop would not trigger any power changes.
This feature is now *enabled* by default, so given that:
- default 'uplink-power-target' is -75 dBm, and
- default 'hysteresis' is 3 dBm,
the default target Uplink power range is: -78 dBm ... -72 dBm.
Change-Id: Iacedbd4d69d3d74e2499af5622a07a8af0423da0
Related: SYS#4916
So far the Uplink power control loop did not filter the Uplink RSSI
measurements (reported by the BTS) at all. The lack of filtering
makes our implementation too quick on the trigger, so in the real
deployments there will be unneeded Tx power oscillations.
In order to reduce this effect, let's implement a very simple EWMA
(also known as Single Pole IIR) filtering that is defined as follows:
Avg[n] = a * Pwr[n] + (1 - a) * Avg[n - 1]
where parameter 'a' determines how much weight of the latest UL RSSI
measurement result 'Pwr[n]' carries vs the weight of the average
'Avg[n - 1]'. The value of 'a' is usually a float in range 0 .. 1, so:
- value 0.5 gives equal weight to both 'Pwr[n]' and 'Avg[n - 1]';
- value 1.0 means no filtering at all (pass through);
- value 0.0 makes no sense.
This formula was further optimized with the use of '+=' operator.
The floating point math was also eliminated by scaling everything
up (by 100). For more details, see:
https://en.wikipedia.org/wiki/Moving_averagehttps://en.wikipedia.org/wiki/Low-pass_filter#Simple_infinite_impulse_response_filterhttps://tomroelandts.com/articles/low-pass-single-pole-iir-filter
The EWMA filtering is now *enabled by default*, but can be disabled
or (re-)configured over the VTY at any time:
! Completely disable filtering
no uplink-power-filtering
! Enable EWMA smoothing with the given parameters
uplink-power-filtering algo ewma beta <1-99>
Note that the VTY command expects 'beta' instead of 'alpha':
alpha = (100 - beta)
and the value must be in %. This is done for simplicity:
1% means lowest smoothing,
99% means highest smoothing.
Let's say we have EWMA filtering enabled with alpha = 0.4, and get
-98 dBm on the input, while the last output value was -60 dBm.
The new output would be:
Avg[n] = 0.4 * Pwr[n] + 0.6 * Avg[n - 1]
Avg[n] = (0.4 * -98) + (0.6 * -60)
Avg[n] = -75.2 => around -75
Of course, this is not a silver bullet, but better than nothing.
Change-Id: Ib6dcadbf14ef59696c6a546bd323bda92d399f17
Related: SYS#4916
With PCU interface version 10 it supports IPv6 NSVC. The new OML IE
NM_ATT_OSMO_NS_LINK_CFG allows to configure IPv6 NSVC.
Change-Id: I310699fabbfec4255f0474f31717f215c1201eca
Vadim Yanitskiy
Pau Espin
Neels Hofmeyr
Philipp Maier
Harald Welte