There exists a VTY command for sending default power control params,
but so far there was no CTRL counterpart for it. This patch adds a
SET command 'send-power-control-defaults':
$ osmo_ctrl.py \
--host 127.0.0.1 -p 4249 \
--set "bts.0.send-power-control-defaults" 1
Similar to 'send-new-system-informations', this command takes an
arbitrary dummy value (required for SET), which is simply ignored.
Change-Id: Ib370bd97ee2d9f72f8bec553550b1792d1345387
Related: SYS#6138
Increase the reaction time at the expense of more stable loop with less
temporary oscillations.
See updated user manual documentation in this commit for a larger
description.
Related: SYS#5371
Change-Id: I46be244a5e01a74086e3a977ec3ea139742a0074
Improve the current VTY support to allow enabling/disabling C/I logic
independent from value setting. This way C/I support can be quickly
disabled & enabled.
Reminder: changing power parameters still require VTY Command "bts NR
resend-power-control-defaults" to be excuted prior to new parameters
being applied on the BTS.
Related: SYS#4917
Change-Id: Id1224c2d9a52db2ed805c49e048d3086ed0167f5
Setting LOWER_CMP_N and UPPER_CMP_N for all channel types can be quite
cumbersome and end up in lengthy config files. Let's instead add a
placeholder command to apply it to all channel types of a BTS at once.
This is useful specially since a user disabling C/I capabilities
probably does so because it may require a fair amount of fine-tuning
parameters to have it working perfectly. Hence, a user not willing to
spend time configuring those parameters correctly (and for which default
ones doesn't work properly) will require quick way to get rid of C/I
based MS Power Control Loop. By disabling C/I comparison, osmo-bts will
rely on RxLev only when applying the MS Power Control Loop, which is
fine for non noisy environments.
Related: SYS#4917
Change-Id: I0e1a1a9228a15e9ec9c41b7952b03e1d25309706
TS 45.008 section 4.7.1:
"""
Upon receipt of a command from an SACCH to change its power level on the corresponding uplink channel, the MS
shall change to the new level at a rate of one nominal 2 dB power control step every 60 ms (13 TDMA frames), i.e. a
range change of 15 steps should take about 900 ms. The change shall commence at the first TDMA frame belonging to
the next reporting period (as specified in subclause 8.4). The MS shall change the power one nominal 2 dB step at a
time, at a rate of one step every 60 ms following the initial change, irrespective of whether actual transmission takes
place or not.
"""
Since the reported MS_PWR in L1 SACCH Header is, according to specs, the
one used for the last block of the previous SACCH period, it becomes
clear the first SACCH block after a requested MS Power Level change by
the network may contain mismatches between the announced MS_PWR by the
MS and the measured Rxlev/RxQual. Hence, let's better use a
P_CON_INTERVAL of 1 which retriggers the MS Power Control Loop every second
SACCH block.
Related: SYS#5371
Change-Id: Iade5b597e0e56b07c6d78995fcec7c641e4e643f
This commit extends existing VTY and RSL infrastructure to configure and
manage MS Power Parameters used in MS Power Control loop, by adding
support to set up Carrier-to-Interference (CI) 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: I7e76ec47b323d469f777624b74b08752d1f5584f
BS Power Control is not allowed on the BCCH/CCCH carrier, unless
the BTS is operating in the BCCH carrier power reduction mode.
Allow constrained BS power reduction (up to 6 dB) on active logical
channels iff BCCH carrier power reduction mode is enabled.
Take into account that the maximum power difference between a timeslot
used for BCCH/CCCH and the timeslot preceding it shall not exceed 3 dB.
Change-Id: I2cc6a86731984f586ef35b43a8d3de631f7d8a2f
Related: SYS#4919, SYS#4918
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, starting from version 13.0.0 (2015-11) 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.
Introduce a VTY command to turn on and off the BCCH carrier power
reduction operation. Also introduce a CTRL command. On the
A-bis/RSL, abuse the BS POWER CONTROL message by setting
the Channel Number IE to 0x80 (RSL_CHAN_BCCH).
Currently, only osmo-bts-trx is supported. A value greater than
zero makes it reduce the power on *inactive* timeslots of the
BCCH carrier. Sending zero disables the BCCH power reduction
mode completely.
For more details, see 3GPP TS 45.008, section 7.1, and 3GPP TR 45.926.
Change-Id: I047fce33d4d3e4c569dd006ba17858467a2f4783
Related: SYS#4919
So far osmo-bsc would enable Uplink DPC (Dynamic Power Control) only
for osmo-bts, and the 'static' mode for all other BTS models. This
decision dates back to the time when ip.access specific encoding for
dynamic power control parameters was not implemented, and the MS
Power Parameters IE was sent empty in the RSL messages.
Let's make a step forward by enabling Uplink DPC by default for
all BTS models which declare the API for vendor-specific encoding
of the power control parameters. Currently this includes osmo-bts
and nanoBTS, both supporting ip.access specific format.
Change-Id: If86d27d4332af3d82f862737340d061e42e34eba
Related: SYS#4918
Vadim Yanitskiy
Pau Espin