In CSD (Circuit Switched Data) NT (Non-Transparent) mode, there
are RLP (Radio Link Protocol) frames inside the modified V.110.
wireshark alrady has a dissector for this, and we've introduced
a GSMTAP type for RLP some time ago. So with this patch, we now
generate such GSMTAP RLP frames.
Change-Id: I6a258458822bcb3fe7290a9b9b3d104beecda219
If the channel is activated for immediate assignment, the initial data
link establishment on main signaling link with SAPI 0 must have L3
infomation included in the SABM message. If this is not the case,
release the data link without notifying BSC.
Related: OS#5971
Change-Id: I6819b51a876b8743c2d4a04165b7900723a1631c
The E1/E2/E3 bits are set based on out-of-band knowledge of the
current user data rate. The actual bit values are defined in
3GPP TS 44.021, Figure 4 "Coding of data rates".
TODO: this is only valid for transparent services,
for non-transparent services see 3GPP TS 48.020.
TODO: lchan->csd_mode is never set to the actual CSD mode...
Change-Id: I1a14597dff746cf975140b294400a2cc05badccd
Related: OS#1572
According to TS 44.018 the UPLINK FREE message must be repeated when the
uplink is marked as free. The BSC sends the UPLINK FREE message once and
the BTS repeats it until UPLINK BUSY (uplink blocked by BSC) or
VGCS UPLINK GRANT (talker accesses the uplink) is sent.
It is important to stop sending UPLINK FREE message when a talker
accesses the uplink and before the VGCS UPLINK GRANT message is sent, so
that stopping must be controlled by the BTS.
Related: OS#5781
Change-Id: Ia23c59f5e9a73bbc384fbc317a2cfcf707e3c28f
Random access is allowed on VGCS / VBS channels to access the uplink or
to detect listeners. Uplink Access from a listener is only reported once
after activating the channel. Uplink Access from a talker is reported
each time the uplink becomes occupied. RSL TALKER/LISTENER DETECT
messages are sent to the bsc.
The VGCS UPLINK GRANT message is sent by the BTS itself. Timer T3115 is
used to repeat the message up to NY2 times until one valid frame is
received from the MS (CM service request). The UPLINK BUSY / UPLINK FREE
message must be sent by the BSC.
The uplink is released by UPLINK RELEASE message from the MS or from the
BSC. Afterwards the UPLINK FREE message causes the MS to leave the
uplink without any acknowlege. An RSL REL-REQ must be used to terminate
the link locally. (Without layer 2 DISC procedure.)
Change-Id: I1bd07ab6802341b09a06e89df356665ffaf6d2bf
Related: OS#4851
The RSL "Channel rate and type" field from the RSL Channel Mode IE
in RSL_CHAN_ACTIV and RSL_MODE_MODIFY_REQ messages is the only place
where the BSC differentiates between a normal TCH and the special
TCH modes used in VGCS or VBS. Let's copy this field from the RSL
message into the lchan state, so that BTS models can actually (in
subsequent patches) reflect it when activating the L1.
Change-Id: I6d531bf528bcb81f44d91336471a46ef790d7646
Related: OS#4851
GSM 06.31, 06.41 and 06.81 are the respective DTX specs for FR, HR
and EFR. In each of these specs, section 5.1.2 specifies the
expected shape of radio downlink in the presence of SIDs: one SID
frame after each talkspurt (after speech frames), and one SID frame
in every SACCH-aligned position every 480 ms (every 240 ms for HR),
or if the actual SACCH-aligned position is taken up by FACCH,
then just one SID frame as soon as possible after that FACCH -
and no transmitted SID frames in other positions.
This just-referenced spec section was written with the assumption
that it will only be applied when DTXd is enabled - however, if
the RTP stream for call leg B DL comes from call leg A UL (TrFO),
then we are going to receive SID frames in the stream intended for
our DL even when DTXd is disabled or not supported altogether.
The easiest solution is to apply FR/HR/EFR DTXd logic whenever
the incoming RTP stream contains SID frames, irrespective of physical
DTXd enable/disable state. If we apply such "logical DTXd" when
physical DTXd is disabled, the BTS model PHY will end up transmitting
induced BFIs (dummy FACCH or inverted CRC3) in those frame positions
where the "logical DTXd" function says "please transmit nothing".
The point remains, however, that the prescribed SID shape on the
radio downlink (expected positions of SID frames) won't happen on its
own: in the case of TrFO, whichever SID frames are present will be
in wrong positions for leg B DL, and even in the case of transcoded
calls the responsibility for DL SID shaping cannot be placed on the
RTP stream source because that source won't know where SACCH alignment
will lie. Therefore, the necessary DL SID reshaping has to be done
in the RTP stream receiver in OsmoBTS.
Related: OS#5996
Change-Id: I924ab21952dcf8bb03ba7ccef790474bf66fc9e5
It will be used too by osmux code present in another file. This is a
preparation commit to simplify the one adding osmux support.
Change-Id: Ie7fa57bb04db9ad9b03971467e12ee7b8e4c190a
The queue_limit_to method iterates the entire list of messages every
time a new message is added. Let's use msgb_{enqueue,dequeue}_count()
APIs to do that in constant time. It is true that since the queue is
limited to 1, there's usually at most 1 item in the queue so it's not a
real problem. However, when we add Osmux in the future, we may need to
tweak the amount of messages which can be in the list, due to Osmux
batching mechansim which may be more bursty sometimes.
In any case, this change doesn't make things worse for sure.
The patch also takes the chance to group the queue_limit_to + enqueue
into one function to avoid having the code spread several times.
Change-Id: I61818a3bb521c27bd21a8b6fa70581d27638ec9b
Looks like this structure was copied from openbsc/osmo-bsc as-is.
The ms_mode[] makes no sense in the context of BTS, so remove it
and rename bts_mode[] to mode[] for the sake of brevity.
Change-Id: I7442360ed857554440a0b9854f2d2bbab9dc5a71
Related: SYS#5917, OS#4984
The new fields in 'struct abis_rsl_osmo_temp_ovp_acch_cap' allow:
* selectively enabling SACCH and/or FACCH,
* setting the RxQual (BER) threshold.
Both features are implemented in the follow-up commits.
Change-Id: I370c8f95fb64eceb60a9dc2eae1412f8a0df0f4e
Depends: Ia28293a12de0af71f55e701fb65c46e905dae217
Related: SYS#5319
It's cleaner from the architectural point of view to have the
interference measurements processed in a separate function.
Change-Id: I3981608e01a50585359cad673c38c8a305027d30
Related: SYS#5313
It may happen that the BSC requests logical channel activation on a
dynamic timeslot, which is in a process of switching from one pchan
type to another due to a preceding channel activation request.
In this case 'struct gsm_bts_trx_ts' already holds an msgb with the
preceding RSL CHANnel ACTIVation message, that is normally handled
once the PHY completes the process of timeslot re-configuration.
On receipt of subsequent RSL CHANnel ACTIVation messages, in function
dyn_ts_l1_reconnect() we overwrite the preceeding msgb (memleak), by
the most recent one. And once the timeslot re-configuration is done,
only the most recent CHANnel ACTIVation message gets ACKed.
In order to avoid this, let's move the msgb ownership to 'struct
gsm_lchan', so it cannot be overwritten by the CHANnel ACTIVation
message that is related to a different lchan on the same timeslot.
Change-Id: Ia625c2827fca883ea712076706d5ef21ed793ba6
Related: I3b602ac9dbe0ab3e80eb30de573c9b48a79872d8
Fixes: OS#5245
Let's split all lchan and power_control specific stuff into their own headers,
it helps finding out data and operations available related to them.
We already have similar classification in osmo-bsc.
Change-Id: I6424dcbd2e329fc1a516f8886359554ed7e9487e
Harald Welte
Andreas Eversberg
Vadim Yanitskiy
Pau Espin