MS uplink power control is required in pretty much any BTS, and we
cannot assume that they PHY / L1 will always take care of it by
itself. So the correspondign code is moved to common/power_control.c
and called from the generic part of L1SAP.
The corresponding VTY paramter has been moved from the sysmobts-specific
trx VTY node to the common BTS VTY node.
There are three transitions:
1. LCHAN_CIPH_NONE -> LCHAN_CIPH_RX_REQ -> LCHAN_CIPH_RX_CONF
It is used to enable ciphering in RX (uplink) direction only.
2. LCHAN_CIPH_RX_CONF -> LCHAN_CIPH_RX_CONF_TX_REQ -> LCHAN_CIPH_RXTX_CONF
It is used to additionally enable ciphering in TX (downlink) direction.
3. LCHAN_CIPH_NONE -> LCHAN_CIPH_RXTX_REQ -> LCHAN_CIPH_RX_CONF_TX_REQ
-> LCHAN_CIPH_RXTX_CONF
It is used to enable ciphering in both TX and RX directions. This is used
when the channel is activated with encryption already enabled. (assignment
or handover)
In order to follow the order of these transitions, the RX direction must
always be set before the TX direction.
If no cipher key is set (A5/0), ciphering is set to ALG 0, but lchan cipher
state remains at LCHAN_CIPH_NONE.
This part moves control channel message primitives from osmo-bts-sysmo to
common part.
In order to control ciphering fo BTS model, CIPHER (MPH_INFO) messages are
used.
The original code handled both the fact where a TIME indication would be
missed (and thus the frame number be higher than previous + 1), as well
as the two cases for combined / non-combined CCCH.
The L1SAP code removed some of those bits, which I'm re-introducing
here.
This is a regression of the code compared to the existing
sysmoBTS code, where the L1 tells us whether its AGCH or
PCH. However, it was not used even in the old code, so
we can afford to simply put a #warning here.
In case of a RACH INDICATION on CCCH, we need to set CHAN_NR to
0x88 (RSL_CHAN_RACH). In other cases, chan_nr needs to reflect
the actual logical channel (TCH/SDCCH) on whcih the handover happened.
... in an effort to avoid introducing new/more spaghetti code
Also, use offsetof() instead of pointer calculation to determine
the start of GsmL1_Prim_t.u.phDataReq.msgUnitParam.u8Buffer
This first part moves BCCH message primitives from osmo-bts-sysmo to common
part. A new file "common/l1sap.c" is introduced to implement handling of
layer 1 messages from/to BTS model.
Spotted by Ciaby while debugging an audio issue. Do not
send anything to port==0 to the BSC/NITB. Look at the
upper bits of the speech_mode to determine if sending is
allowed. 0x1 means recv_only and all other modes allow us
to send.
Manually verified with a single phone call with LCR bridge
mode to send a CRCX early but a MDCX sendrecv later. The
audio starts to flow after the MDCX message. Virtual Addr
space didn't increase over 10 calls. The l1p_msg is freed
by the caller.
The code might not re-set speech_mode from one call to
another but if it is ever != 0 it can be expected that
the BSC will always set it. This is because we do not
(and don't want to) allocate the lchan dynamically on
every usage.
Fixes: SYS#2111
Use the new libosmo-abis API to query the session for the
statistics and then send it as a TLV element to the BSC.
This can be used to do post processing about the call. E.g
to figure out if no audio arrived at all.
Andreas Eversberg
Harald Welte