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
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
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
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
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
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
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
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>
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
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
There are some situations where it is useful to be able to change the
Radio Link Timeout at runtime, without restarting the BTS.
This adds a new (hidden) command for this:
"bts <0-255> radio-link-timeout (oml|infinite|<4-64>)"
Change-Id: I64674a432cf7751b16d5d0b52f66766fa6e37028
Move all struct gsm_bts_trx references from bulky gsm_data to its own
file containing all related definitions and implementations. Also move a
few functions clearly related to that object which were placed in bts.*
Change-Id: Iebaf5b221c48b571f45408af867ce6f9c0cd9f4a
bts.h refers to struct gsm_bts object, but we still had a bunch of stuff
in bulky gsm_data.* from old days. Let's move stuff where it belongs to
start clean up of gsm_data.
Change-Id: I0a4219e3f64f625ee8b364bf408b8d2bcc8085c5
Thies field is used to store and retrieve whether MS power needs to be
calculated and updated by osmo-bts software or autonomously by lower
layers. Previous name was not clear
and may have been understood as indicating whether MS Power Control loop
is done or not in general, and the responsible for that is located under
lchan's ms_power_ctrl.fixed.
Related: OS#1851
Change-Id: Ic690ab69866a7377f1597e24aa7b0214831c1cbe
Let's keep some statistics about the min/max/average frame number
advance that we're observing above L1SAP when comparing the time in the
PH-RTS.ind and the frame number we observe in PH-DATA.ind of data
that was received on the uplink.
The statistics are currently only shown in the VTY, but this is a
precursor to using them to correctly advance the LAPDm timers in a
follow-up patch.
Change-Id: I8f739fdb808a614f080afbc4654641ec3df19eb2
Related: OS#2294
Related: OS#3906
osmo-bts cannot provide GPRS service while osmo-pcu is not connected.
The BSC has no knowledge of the PCU connection state. Prevent MSs
from trying to register for GPRS while the PCU is disconnected by
erasing the GPRS Indicator in SI3.
Change-Id: I1a6f5c636c0fe098ee31c280d4572a3f8122b44b
Depends: I690cf308311f910005a325d50f5d5d825678d2b2 (libosmocore.git)
Depends: I08e0ca9a8d13c7aa40b9d90f34f0e13adb87d4e0 (libosmocore.git)
Depends: I8b1ee2405f6338507e9dfb5f1f437c4c2db2e330 (libosmocore.git)
Related: OS#3075
No need to pass -t num_trx anymore to specify number of TRX to use. It
is calculated based on dynamic allocation from VTY config.
Using parameter -t is flagged as deprecated and is transformed into a
NOOP por backward compatibility.
As a result, TRX now are allocated after the BTS is allocated and
initial config (pre-VTY) is applied.
A new function bts_trx_init() is added, to set default config on each
TRX during allocation and before setting VTY config on it.
A new per BTS model function bts_model_trx_init() is added, to allow
per model specific default configuration of each TRX.
Change-Id: Iab1a754ab12a626759f9f90aa66f87bdce65ac9c
osmo-bts has a table of pchan/channel mode combinations for every
bts. This table models the codec capabilitys of the BTS hardware.
However, having the speech codec apabilities modeled inside the
BTS feature list would be much more comfortable and since the
feature list is communicated back to the BSC we would get the
codec capabilities inside the BSC domain as well.
- remove the pchan/channel mode tables
- set speech codec variants for each BTS type
- fix bts_supports_cm so that it queries the feature list
Change-Id: I977dc729ba856631245aedf76afd48eac92166f7
When the BSC sends a MODE MODIFY request with an unsupported
codec, the BTS must respond with a negative acknowledge.
Currently the codec parameter is not checked at all, which may
lead into malfunction or crash of the BTS.
- Introduce a mechanism to check the codec/rate against a
table that is set up in the phy specific code.
- Add tables with supported codec/rate combinations for
octphy, sysmobts, and trx.
Change-Id: Id9b222b7ab19ece90591718bc562b3a8c5e02023
Related: SYS#3212
* use GSM_BTS_HAS_SI() from OpenBSC instead of local copy
* arrange GSM_BTS_HAS_SI() checks to improve readability
* constify SI scheduler parameters
Change-Id: If74bc536fe7d2bfbc976c07d882151873ecda4f2
Related: OS#1660
Do not assume that 1 == BS_AG_BLKS_RES but take that information from
SI3. Note: due to current implementation quirks we activate channels
before SI3 obtained, than we deactivate channels upon receiving SI3 and
activate them again. This might not be necessary once we migrate to
proper OML state machines.
This affects lc15 and sysmo hw.
Change-Id: I11377b12680ac3b2f77f80e742b6f0af63fc9c1e
Related: OS#1575
Currently the DSP is instructed to achieve a given uplink
power target but there are circumstances (e.g. EMV testing)
where we need more control over it. The "manual/software/osmo"
power control can only be implemented per TRX and not per
lchan. Add a very very basic control that checks the MS Power
used by the phone, the actual receive level and then adjust
the power.
The code doesn't take the history into account, if the phone
can not reach the requested power level the code will be stuck
(e.g. no timeout based on multiframes). It has a mode for a
fixed power control but no way to set it yet.
The change of the mode requires a restart of the software.
Pau Espin
Vadim Yanitskiy
Philipp Maier
Harald Welte
Neels Hofmeyr