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 cfg_out macro is used like a function in the code below its
definition. This means a colon will follow after it is used. When
the vty_out call in the macro already has a colon the final result will
be vty_out(...);;. This works fine as long the macro is not used in one
line if/else if/else constructs without curly braces {}. The compiler
will interpret the double colon as two lines of code and run into an
error then. Lets fix this by removing the colon from the vty_cout in the
macro.
Change-Id: I2c23c38ce892067add0f95f3e504a9c559e24519
These new commands are useful for debugging MS/BS power control
loops, e.g. one can change power control mode, overwrite the
current BS power reduction or MS power level at run-time.
Change-Id: I1ebb033b02c2bc3b1fa7de874e0035a07297f266
Related: SYS#4918
The loopback mode was added for testing, and may be dangerous if
enabled in production. Let's make it appear only in expert mode.
Change-Id: I3f68acd7f2b0231f78516f59fb5e8ef56fb69dbf
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
MS/BS Power Control parameters have been recently moved to the BSC
and now signaled to the BTS over the A-bis/RSL link. Let's make
sure that the existing VTY commands for Uplink Power Control do:
- trigger deprecation warnings if present in the config file,
- not show up in the online VTY help nor VTY reference,
- affect the fall-back parameters in 'struct gsm_bts',
- still get printed by 'show running-config' command.
Change-Id: Icbd9a7d31ce6723294130a31a179a002fccb4612
Related: SYS#4918
It does not make sense to dump CCCH/CBCH as dedicated channels:
OsmoBTS# show lchan
BTS 0, TRX 0, Timeslot 0, Lchan 4: Type CCCH
State: ACTIVE
BS (Downlink) Power Control (autonomous):
Channel reduction: 0 dB (max 0 dB)
TRX reduction: 0 dB
Actual / Nominal power: 13 dBm / 13 dBm
MS (Uplink) Power Control (autonomous):
Current power level: 0, -39 dBm (max 0, -39 dBm)
Channel Mode / Codec: SIGNALLING
LAPDm SAPIs: DCCH --, SACCH --
Valid System Information: 0x00000060
MS Timing Offset: 0, propagation delay: 0 symbols
Radio Link Failure Counter 'S': 0
so let's only dump SDCCH, TCH/F, and TCH/H.
Change-Id: Id7880de56a93cc9fa4ca576b094cef35ee269822
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
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
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
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
It's more convenient to use one command to enable/disable sending
of all kinds of UL/DL messages at once, rather than specifying
all of them individually.
Adjust config_write_bts_single(), so it would not print unknown
GSMTAP SAPI entries if gsmtap_sapi_mask is set to UINT32_MAX.
Change-Id: Icd7fce860ecdcf8ffa107bdfee7ec94ea9ea6cb2
This allows for instance ramping up from -10 dBm -> -4 dBm if NOMTXPOWER
of SDR is really low (below 0dBm) or because the max_power_red is >=
NOMTXPOWER.
Related: SYS#4920
Change-Id: I0f27fb7b86b58c5a80f5342b66ff4f5d1b775498
According to 3GPP TS 08.58, section 9.3.4, BS Power IE indicates
the transmission power attenuation on a particular channel:
+--------------+---------+-----------------+
| Reserved (3) | FPC (1) | Power level (4) |
+--------------+---------+-----------------+
so let's change handling of this IE as follows:
- s/bs_power/bs_power_red/g, so it reflects 'reduction';
- store power attenuation value in dB, not in 2 db steps;
- get rid of ms_power_ctrl.bts_tx_pwr, it's always 0 anyway;
- fix rsl_tx_meas_res(): use lchan->bs_power_red;
- always check if FPC (Fast Power Control) flag is set;
- we don't support it, so reject messages containing it;
- fix rsl_rx_chan_activ(): properly apply the bitmask.
Change-Id: I16cc50dfca102030380a06e16c234d5f6698f38f
It was a very bad idea to mix "public" BTS features, that are
reported to the BSC via OML, and those features, that are used
locally (and exclusively) in osmo-bts.
Why? At least because we already have the BTS feature manipulation
API in libosmocore, that is used by osmo-bsc, but for some reason
not by osmo-bts. New features added to libosmocore would clash
with the existing "internal" ones like BTS_FEAT_MS_PWR_CTRL_DSP.
So what this change does can be described as follows:
- remove duplicate definition of the "public" features,
- use libosmocore's API for the "public" features,
- separate both "internal" and "public" features:
- the "public" features continue to live in bitvec,
- the "internal" features become flags,
- s/BTS_FEAT/BTS_INTERNAL_FLAG/g.
Change-Id: Icf792d02323bb73e3b8d46384c7890cb1eb4731e
Send test failure event report OML message to the BSC. I found this
useful while manually testing related handling code in OsmoBSC.
Related: OS#1605
Change-Id: I0c4eba1636d8faf5012db26643bdf1d9fb6bfa1e
Neels Hofmeyr
Philipp Maier
Vadim Yanitskiy
Harald Welte
Pau Espin
Oliver Smith