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.
This patch adds a function bts_update_agch_max_queue_length()
to compute a limit of the AGCH queue. This is based on the idea,
that the AGCH queue has a limited drain rate and that CHANNEL
REQUESTs must be answered within a certain time frame, given
by the minimum value of T3126 (see GSM 04.08). When the AGCH queue
reaches that limit, the last message would be delivered in time if
there were no other delays involved (which is not the case).
The calculation is based on the ratio of the number RACH slots and
CCCH blocks per time:
Lmax = (T + 2*S) / R_RACH * R_CCCH
where
T3126_min = (T + 2*S) / R_RACH
R_RACH is the RACH slot rate (e.g. RACHs per multiframe)
R_CCCH is the CCCH block rate (same time base like R_RACH)
The value depends control_channel_desc.ccch_conf and
rach_control.tx_integer (both from SYSINFO_TYPE_3) and should
therefore by called at least each time after one of these is changed.
For this reason, a signal callback is registered under
SS_GLOBAL/S_NEW_SYSINFO which invokes bts_update_agch_max_queue_length().
Sponsored-by: On-Waves ehf
Based-On: "bts: Calculate length of agch queue" by Ivan Kluchnikov
<kluchnikovi@gmail.com>
This patch adds a common function bts_ccch_copy_msg() that provides
and schedules AGCH and PCH messages. It is basically a frontend to
paging_gen_msg() and bts_agch_dequeue() and contains refactored code
from l1_if.c.
Sponsored-by: On-Waves ehf
Currently the LEDs are being accessed directly from within the
l1_if.c file. So the handling of rf mute and activate/deactivate both
access LED_RF_ACTIVE directly. This may lead to an inconsistent LED
status.
This patch replaces these calls to sysmobts_led_set() by an abstract
equivalent bts_update_status(), that uses a set of independant status
ids. The associated values can than be combined into a visible LED
status. Currently LED_RF_ACTIVE is on iff BTS_STATUS_RF_ACTIVE is set
and BTS_STATUS_RF_MUTE is not set.
Sponsored-by: On-Waves ehf
The sequence is as follows:
0) start osmo-bts
1) start connection attempts to BTS
2) issue L1-RESET.req
3) receive L1-RESET.conf
4) issue RF-ACTIVATE.req
5) receive RF-ACTIVATE.conf
6) receive attributes for TRX
7) receive opstart for TRX
8) issue MPH-INIT.req
[...]
The important point here is: We don't want the BSC to set TRX attributes or do
TRX opstart before our RF related hardware is initialized.
This code re-works osmo-bts to add support for the upcoming sysmocom BTS.
It also tries to add some level of abstraction between the generic
part of a BTS (A-bis, RSL, OML, data structures, paging scheduling,
BCCH/AGCH scheduling, etc.) and the actual hardware-specific bits.
The hardware-specific bits are currently only implemented for the sysmocom
femtobts, but should be (re-)added for osmocom-bb, as well as a virtual
BTS for simulation purpose later.
The sysmocom bts specific parts require hardware-specific header files
which are (at least currently) not publicly distributed.
Holger Hans Peter Freyther
Harald Welte