TSC (Training Sequence Code) is an optional parameter of the UL burst
indication. We need this information in order to decide whether an
Access Burst is 11-bit encoded or not (see OS#1854).
If this information is absent, we try to correlate the received synch.
sequence with the known ones (3GPP TS 05.02, section 5.2.7), and
fall-back to the default TS0 if it fails.
Since the new TRXD header version, the training sequence code is
indicated by the transceiver. Let's use it!
Change-Id: I1e654a2e49cb83c5f1e6249c0de688f99bc466b0
Related: OS#1854, OS#4006
C/I (Carrier-to-Interference ratio) is a value in cB (centiBels),
computed from the training sequence of each received burst,
by comparing the "ideal" training sequence with the actual one.
So far, there was no way to expose more measurements from OsmoTRX,
excluding both RSSI and ToA. Since the new version of TRXD header,
we can receive C/I indications and send the averaged (per 4 bursts)
values to OsmoPCU (as a part of PCUIF_DATA.ind).
Please note that we also need to attach C/I measurements
to the following L1SAP primitives:
- PRIM_PH_RACH.ind,
- PRIM_PH_DATA.ind,
- PRIM_TCH.ind,
but this will be done in the follow up changes.
Change-Id: Ia58043bd2381a4d34d604522e02899ae64ee0d26
Fixes: OS#1855
This change needs to be done in order avoid adding more and more
arguments to the UL logical channel handlers (such as rx_rach_fn).
Since we have different versions of the TRXD header, and may have
other burst-based PHYs in the future, some fields of an Uplink
burst indication have conditional presence.
Change-Id: Iae6b78bafa4b86d0c681684de47320d641d3f7c0
Related: OS#4006, OS#1855
Thanks to both TC_rach_content and TC_rach_count TTCN-3 test cases,
it was discovered that there are possible collisions when trying
to decode a regular 8-bit Access Burst as an 11-bit one. This is
exactly what we are doing in rx_rach_fn():
- calling gsm0503_rach_ext_decode_ber() first,
- if it failed, falling-back to gsm0503_rach_decode_ber().
With default BSIC=63, the following 8-bit RA values are being
misinterpreted as 11-bit Access Bursts:
Successfully decoded 8-bit (0x00) RACH as 11-bit (0x0000): bsic=0x3f
Successfully decoded 8-bit (0xbe) RACH as 11-bit (0x0388): bsic=0x3f
Successfully decoded 8-bit (0xcf) RACH as 11-bit (0x0036): bsic=0x3f
According to 3GPP TS 05.02, section 5.2.7, there are two alternative
synch. (training) sequences for Access Bursts: TS1 & TS2. By default,
TS0 synch. sequence is used, unless explicitly stated otherwise
(see 3GPP TS 04.60).
According to 3GPP TS 04.60, section 11.2.5a, the EGPRS capability
can be indicated by the MS using one of the alternative training
sequences (i.e. TS1 or TS2) and the 11-bit RACH coding scheme.
In other words, knowing the synch. sequence of a received Access
Burst would allow to decide whether it's extended (11-bit)
or a regular (8-bit) one. As a result, we would avoid possible
collisions and save some CPU power.
Unfortunately, due to the limitations of the current TRXD protocol,
there is no easy way to expose such information from the transceiver.
A proper solution would be to extend the TRX protocol, but for now,
let's do the synch. sequence detection in rx_rach_fn(). As soon as
the TRX protocol is extended with info about the synch. sequence,
this code would serve for the backwards-compatibility.
This change makes the both TC_rach_content and TC_rach_count happy,
as well as the new TC_pcu_ext_rach_content() test case aimed to
verify extended (11-bit) Access Burst decoding.
Related (TTCN-3) I8fe156aeac9de3dc1e71a4950821d4942ba9a253
Change-Id: Ibb6d27c6589965c8b59a6d2598a7c43fd860f284
Related: OS#1854
When the ph-data indications for the PDTCH are passed up to l1sap,
then a forumla is used to calculate the frame number of the beginning of
the block that is just passed up. This is not necessary since the start
frame number of the block is stored in *first_fn when the block arrives.
We should use this frame number instead. (For the measurement indication
it is already done this way).
Change-Id: I6c01987be78203acfa689c6decb2c806f8fff3d6
Related: OS#2977
Attempt to decode incoming RACH burst as 11-bit first
and fallback to 8-bit if unsuccessful.
Change-Id: Ia28741603636406744e5e22ffff1fb7a9689955a
Related: OS#1854
Commit acefd0586e introduced the "toa256"
resolution change.
Before the change, _sched_compose_ph_data_ind() used quarter-bits as
units, so multiplying the old "toa" value by four made sense.
However, after said change, the value is in 1/256th of bits, and hence
we need to report the toa256 value without any multiply-by-four.
Change-Id: I9f980236ea1cd635cb229290e187747cc8c86d8d
Related: OS#2977
The previous implementation unconditionally subtracted nanosecond
values from different time measurements, causing overflow if the
current measurement was taken in less of a fraction of a second
than the past measurement. Use timespecsub() instead, which
accounts for nanoseconds correctly.
This is a similar bug as fixed in osmo-pcu for issue OS#3225
While here, switch variables which are calculated based on
struct timespec to 64 bit types. While probably not strictly necessary
in practice, this makes the types used in calculations more compatible.
Change-Id: Idfd9c807e35cd7fb5c80625b9746121f81c24599
Related: OS#3467
Related: OS#3225
Each logical channel (e.g. SACCH, SDCCH, etc.) has a counter of
lost L2 frames. Let's use a bit better name for it, and correct
its description in the 'l1sched_chan_state' struct definition.
Change-Id: I92ef95f6b3f647170cfd434a970701406b0a7c82
Upper layer requires us to trigger all events coming from lower layers
in order to keep the RTP clock in sync. In this case, this is done by
sending an empty payload to indicate there's no data to send.
Change-Id: I0bdfb529f35253ca7e531bb9984a3839c3bfe7e8
Let' wait until the just-merged osmo_timerfd_* functions
of Change-Id Ibeffba7c997252c003723bcd5d14122c4ded2fe7 have made it
into the next tagged release, and then replace the implementation
here.
Change-Id: Ic0f0a7437b6acb535177e5ad6ac7a6d336654c66
Should fix following observed run time errors:
osmo-bts-trx/scheduler_trx.c:1627:65: runtime error: signed integer overflow: -1081823 * 4615 cannot be represented in type 'int'
osmo-bts-trx/scheduler_trx.c:1627:21: runtime error: signed integer overflow: 1852394502 - -697645849 cannot be represented in type 'int'
Related: OS#3213
Change-Id: I36e0d2d0d0c6e35e963f611135453c4a4c00bc99
When a bad voice frame is received, it is replaced by
a silence frame. This may cause unpleasant audio effects.
This change implements a functionality to craft a replacement
frame from the last known good frame using ECU implementation
from libosmocodec. At the moment, only FR is supported.
Depends: libosmocore I06a21f60db01bfe1c2b838f93866fad1d53fdcd1
Change-Id: Iae9e69a9578ae305bca42f834694af96a29084e6
This was useful for software simulation of burst delay, expressed
by ToA (Time of Arrival). Since we have FakeTRX toolkit, ToA value
may be simulated in a more flexible way, so let's remove this code.
Change-Id: Ied0fcfcf58b93efdc6de9666fbbf8fea104e2543
There's no need to express TOA as a float:
* We receive it as signed 16bit integer in units 1/256 symbol periods
* We pass it to L1SAP as signed integer in 1/4 symbol periods
So turn it into an int16_t with 1/256 symbol period accuracy throughout
the code to avoid both float arithmetic as well as loosing any precision.
Change-Id: Idce4178e0b1f7e940ebc22b3e2f340fcd544d4ec
In the past, rach_busy counting was performed below L1SAP, while
reporting was handled above. This lead to subtle differences between
the BTS models, such as osmo-bts-trx missing to increment rach_busy.
Let's move the rach_busy counting above L1SAP to share more code.
This means we need libosmocore Change-Id
I9439810c3a3ad89ea0302753617b850749af887c for the additional required
parameters in ph_rach_ind_param, as well as libosmocore Change-id
I2b1926a37bde860dcfeb0d613eb55a71271928c5 for osmo-bts-trx to determine
the RACH bit error rate.
Change-Id: I3b989580cb38082e3fd8fc50a11fedda13991092
Closes: OS#3003
It seems like some of the functions invoked by _sched_dl_burst()
do not sent nbits properly. This leads to a number of errors on
startup:
trx_if.c:593 Tx burst length 65535 invalid
It happens in conjunction with:
Transceiver.cpp:382:pushRadioVector: dumping STALE burst in TRX->USRP interface
Let's fix this by initializing nbits to 0 to make sure those bursts
are properly ignored.
Change-Id: Iaf85826861163c185925de528c8347ab22779e30
It is required for bts_shutdown used in trx_fn_timer_cb, and compiler
warns about implicit declaration.
Change-Id: I274662cd657ce8c36ed1d262d138590808bfafea
The upper layers (L1SAP, the common part of L1) *always* require frame
numbers in the uplink direction to be reported as the frame number of
the *first* burst, not the last burst of a given block.
This is particularly important in the case of passing up measurement
information, as we use this frame number to detect if the measurement
interval for that specific timeslot has just ended (and hence we must
process the measurements and send an uplink measurement report to the
BSC.
Before this patch, the measurement results were reported with the *last*
frame number, which caused the common/measurement.c code never detect
the end of a measurement window.
On TS2, tons of the following log messages were observed:
<0004> measurement.c:199 (bts=0,trx=0,ts=2,ss=0) no space for uplink measurement, num_ul_meas=104
With this patch, it behves as expected: the measurements of 25 blocks
(= 100 bursts) are aggregated, after which point the report is computed
and sent. Subsequently, num_ul_meas is reset to 0 and the cycle
restarts.
Related: OS#2329
Change-Id: I1065ae9c400bb5240a63ab8213aee59aeb9ceeff
Almost all log statements in scheduler_trx.c were using the wrong
logging subsystem. Let's fix this. Also, make it more obvious from
the log subsystem help text
Change-Id: I4312f8ab0414eb38db0d62f05c95ab961f500c14
In rx_tchf_fn(), if gsm0503_tch_fr_decode() returns a negative
result, we cannot use that result as length argument to
osmo_fr_check_sid()
Change-Id: Ic4080b5bf6c865be3333f923f19a2340e1e272c8
Fixes: Coverity CID#178659
For some reason, osmo-bts-trx attempted to interpret/validate the
contents of the downlink TCH block that it was about to transmit. If
such checks are made, they should clearly be in the common part above
L1SAP, and not in the bts-model specific part.
Also, having the checks in place didn't allow us to send an all-zero
downlink block, as is required for detection of uplink FER in a loopback
testing setup, e.g. with CMU-300.
Change-Id: I6388de98e4a7e20843a1be88a58bba8d2c9aa0d5
The new name makes it clear what the function actually does: Send burst
data via the trx interface.
Change-Id: I5031541d4ae4244a62a18acf71139db2874927fa
using gettimeofday() is not suitable for the GSM frame timer, as it
relies on the normal 'wall clock' system time, which may be adjusted by
ntp, gps or other means at runtime.
Switching to a different clock source means we cannot use
osmo_timer_list anymore, but timerfd integrates just fine with our
libosmocore select() loop handling.
Change-Id: I51b19adde14ebb7ef3bb863d45e06243c323e22e
Closes: #2325
instead, let's introduce a specific function for that. Also, as this
can be easily determined from the frame number, skip one argument to
tx_tch_common().
Change-Id: Ibbb9b685cf0b6a45339b0874438a500dd6254bc2
* DTXu: don't set marker for broken frames
* do not attempt to send 0-length bursts to avoid flood of errors after
bts startup
Change-Id: Icb536f951386b9abe34c0dacbb203f3db1e41bb3
This issue occurs in case of osmo-trx restart which leads to losing clock from osmo-trx.
Function bts_shutdown from common/bts.c should be used in this case for proper bts shutdown.
Change-Id: Ie65cf2e8f98cb8bf3314a00048aa53c1f8cd4c25
The parameters related to support 11bit RACH are initialized in
osmo-trx. These parameter determaine the type of the RACH received
in osmo-pcu.
Change-Id: I164d449303373d0757719d5204f4716975fb517a
It is not an exceptional situation if the air-interface is experiencing
non-recoverable decoding errors. At bad signal conditions and/or
interference, this is perfectly normal. Let's use DEBUG instead of
NOTICE log level.
Change-Id: Ifd39c53ec22f57cdb5299e5d76ff6ff1482d3beb
Fill in values for BER, BTO, Link quality in L1SAP and send them to
PCU. Note: this increases the version of BTS <-> PCU protocol. It also
requires corresponding changes in libosmocore.
All BTS models provide measurements data unless direct DSP access for
PCU is enabled. For BTS-specific notes see below.
Octphy: conversion from sSNRDb to Link Quality uses formulae which works
in practice instead of what's documented for sSNRDb value. Subject to
change in future revisions.
TRX: C / I link quality estimator is not computed.
Change-Id: Ic9693a044756fb1c7bd2ff3cfa0db042c3c4e01c
Related: OS#1616
Existing interfaces are coded with the implicit expectation of using
a burst sequence length of 148, which is constant with GSM and GPRS.
That changes with EGPRS, where the burst length may be 444 due to
the use of 8-PSK instead of GMSK modulation.
Setup the interface to accept and return a length value with the
burst sequence. This allows 444 length bit vectors to/from the
EGPRS decoder/encoder. Length is explicitly used as a identifier for
8-PSK vs. GMSK modulated sequences.
Change-Id: I90b46b46b11b6ce280e7f8232d5a2fccec2d4f18
Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
Many erratic PDTCH blocks are expected. To not bloat the log,
notifications for this should be on debug level.
See http://lists.osmocom.org/pipermail/openbsc/2016-June/009457.html
(Thu, 30 Jun 2016 01:49:33 +0300 / Alexander Chemeris
<alexander.chemeris@gmail.com> / Re: GPRS on osmo-trx not working)
Change-Id: Ie318248aa2b8de455174e72a63c602c7aeae312c
Many erratic bursts are expected. To not bloat the log, notifications for this
should be on debug level.
See http://lists.osmocom.org/pipermail/openbsc/2016-July/009482.html
(Tue, 5 Jul 2016 15:38:27 -0700 / Tom Tsou <tom@tsou.cc>
/ Re: osmo-bts-trx error logs -- was: GPRS on osmo-trx not working)
Change-Id: If591c087ba8fd48564139e32930050ee8ab07001
* detect SID and set RTP Marker accordingly (emulate ONSET events)
* set proper FN in TCH_IND
* detect speech pause and do not send dummy 'bad' frames during that
time
Change-Id: Id518e5c667df7773c281effb9e75b66bf898f6fc
Related: OS#1750
Switch to using libosmocodec functions as a preparation step for DTX
support as they expose necessary bits.
Change-Id: Ie7423032fd06779d78876182ee63538d98906328
Related: OS#1750
Vadim Yanitskiy
Philipp Maier
Harald Welte
Pau Espin
Neels Hofmeyr