Define new data structure with respect to TS 44.060
10.4.8a.3.1, 10.4.8a.2.1, 10.4.8a.1.1 for puncturing scheme values
and initialize the variable introduced
The remaining_bits_len is correctly decremented while encoding
CSN_RECURSIVE_ARRAY for fixing the bug.
Details of the bug is in https://projects.osmocom.org/issues/1641
During introduction of basic EGPRS feature new hex dump message
PUASS, from a different working network log was used in Unit test.
It exposed the issue of incorrect handling of recursive array
encoding in osmo-pcu.
Fixes: OS#1641
This patch is for fixing encoding of padding bits according to the
3gpp spec 44.060 section 11, wherein it shall always start with 0
bit followed with spare padding bits.
During introduction of basic EGPRS feature new hex dump messages
from a different working network log were used in Unit test. These
exposed the issue of incorrect handling of padding bits encoding
in osmo-pcu.
Corrections in the existing test vector of rlcmac is also updated.
In testsuite tbf appropriate corrections for the Tbftest.err is
also done.
Make the gsmtap hostname const to avoid turning a constant into
a mutable character. We never tried to modify the string so the
warning didn't reveal a genuine issue.
pcu_main.cpp:49:28: warning: deprecated conversion from string constant to ‘char*’ [-Wwrite-strings]
static char *gsmtap_addr = "localhost"; // FIXME: use gengetopt's default value instead
This is the second attempt to fix what looks like a copy and paste
issue. The code assigns m_current_cs_ul and then compares the _dl
variant, then assigns m_current_cs_ul with a default value. It seems
to indicate that _ul should be used.
Fixes: Coverity: CID 1351733
Roll-out the refactoring change. The code did not include the
necessary update to the test result and there are some concerns
about it in itself and the right approach would have been to
fix the copy and paste issue, then do the refactoring.
This reverts commit 22d7e75e1f.
Previously this code used too much copy-paste of boilerplate code which
is error-prone and hard to read. Factor out actual (M)CS assignment into
separate function and use it for both DL and UL cases in respective
mode.
Fixes: Coverity: CID 1351733
This test will check that we exhaust the available TFIs, so the last
TFI is -16 and then we try to store to that address. It is surprising
that it worked!
Instrument TX and RX functions dealing with regular BTS (without direct
DSP access) to use GSMTAP. Previously only DSP-related functions were
instrumented.
This option allows user to use custom IP address instead of default "localhost".
Correspondingly gsmtap init moved from sysmoBTS-specific code up to "bts" struct
level. This way it can be easier reused by other implementations. The
lack of regressions was verified by checking following command on
sysmoBTS: "./osmo-pcu -c osmo-pcu.cfg -r 1 -i 192.168.10.1" where
192.168.10.1 is the host which was running wireshark and netcat:
"nc -u -l 192.168.10.1 -p 4729" to accept gsmtap flow.
This adds EDGE support and at the same time is changing a lot of code
on GPRS support as well. Due my business decision of completing as much
as possible during the time we had the unit test coverage is not as
extensive as I had hoped for.
This is just the beginning. We do not support mixed GPRS/EDGE support
and have plenty of things to improve throughput.
Thanks to On-Waves for supporting a project with so many unknowns and
uncertainty and Jacob for leading the effort at sysmocom.
Currently the MCS schemes are not supported when the leak rate is
being computed. This leads to a lower value for the leak rate, thus
limiting the throughput to GPRS-like ranges.
Use the payload size reported by GprsCodingScheme instead.
Sponsored-by: On-Waves ehf
Currently single BSN blocks of size 68 (a single unit from MCS-8)
are put into a MCS-6 block with padding according to TS 44.060
Annex J. Unfortunately, these packets are ignored by the E71. This
might be related to the currently incorrect usage of the puncturing
schemes and the RSB bit (the puncturing schemes are not updated and
the RBS flag is never set).
Avoid downgrading from MCS-8 to MCS-6 if there is no second block
available. Send the block twice instead.
Sponsored-by: On-Waves ehf
Comparing the coding scheme properties doesn't seem to be strong
enough, since create_dl_acked_block(fn, ts, index, index2) sometimes
had to combine data units of different size this way.
Check the registered size of the BSN blocks instead, since these must
match if two blocks are to be combined in a single RLC data message
with MCS7-9.
It is not yet clear, what exactly goes wrong with the current
implementation, but this commit fixes the problem which trigger the
assertion in create_dl_acked_block.
Sponsored-by: On-Waves ehf
Currently only one BSN block is encoded in each RLC data message,
even if MSC7-9 are used, which transport two independant (except for a
max BSN delta of 512) BSN blocks. In that case, the same block is
just put twice into the same message.
The current create_dl_acked_block(fn, ts) method handles
block selection (resend, new BSN, dummy block, ...) and restart
handling in one method and is too complex to extend it accordingly.
Therefore this commit move the block selection/creation handling into
a new method (take_next_bsn) which delivers the next BSN along with a
hint, whether it may be combined with another block. In that case,
the function can be called a second time (this time with a valid
previous BSN, that's the one returned by the first call) to get the
second BSN. The real block generation method
create_dl_acked_block(fn, ts, index, index2) is then called with both
BSNs as indices (the second must be -1, if there is only one BSN).
Note that every BSN returned by take_next_bsn should be passed to
create_dl_acked_block to avoid state inconsistencies.
Sponsored-by: On-Waves ehf
Currently the method is hard-coded to support a single BSN only.
MCS-7 to MCS-9 encode 2 data blocks into a single RLC data message.
This commit refactors create_dl_acked_block to process any number
of blocks internally.
Note that this does not extend the parameter list accordingly and
just duplicates the BSN if these MCS are being used.
Sponsored-by: On-Waves ehf
Currently the queue length is overwritten by the remaining chunk
length, which should be added instead. This may result in a lower
CS/MCS value than expected.
Add the chunk length instead if the TBF is present.
Sponsored-by: On-Waves ehf
Currently most offsets are hard-coded which makes it difficult to
access the data units and their headers when padding has to be taken
into account. These offset are already provided by the
gprs_rlc_data_info_init_ul/dl functions.
Change the encoder/decoder to use these values.
Note that some assumptions (bit alignment) are still present in the
code and checked by assertions.
Sponsored-by: On-Waves ehf
To access EGPRS data blocks, the optional padding must be taken into
account. Whether padding has been used must be dervied from the CPS
field in the header of the RLC EGPRS data message.
Add this function to decode the CPS value and extract that
information.
Sponsored-by: On-Waves ehf
The offsets of the data areas change when padding is used (see TS
44.060, 9.3.2.1 and Annex J for details).
Extend the parameter lists to pass the with_padding flag and use
that information to compute the correct offsets.
Sponsored-by: On-Waves ehf
Return the amount of optional padding bits, which is 6*8 for
MCS-3 and MCS-6 and 0 for all other coding schemes. The padding
is needed the encode 68 byte data blocks (MCS-8) with these schemes.
See TS 44.060, 9.3.2.1 and Annex J for details.
Sponsored-by: On-Waves ehf
This adds the following VTY command (config-pcu node):
- mcs <1-9> sets initial DL and UL MCS to the same value
- mcs <1-9> <1-9> sets initial DL and UL MCS separately
- no mcs sets the default values
Sponsored-by: On-Waves ehf
Currently only header type 3 (MCS-1 to MCS-4) is supported.
Add header structs to rlc.h and extend
Encoding::rlc_write_dl_data_header accordingly.
Sponsored-by: On-Waves ehf
Currently the state on the TBF is set to ASSIGN when it is created
and in general changed to FLOW when it is acknowledged by the MS. The
moment when the assignment is really transmitted to the MS (which can
take some time) is not reflected by the state. A TBF can considered
to be valid, when the assignment is received by the MS.
Add the state WAIT_ASSIGN that is entered when the assigment has been
send to the MS (more precisely: when the corresponding RTS has been
processed or the message has been sent to the BTS).
The TBF, its PDCH(s), and its TFI can be assumed to be valid, when the
TBF has a state of WAIT_ASSIGN or higher (assuming that the TBF
starting time has not been set, which is currently only done for SBA,
which are not associated with a TBF).
Note that due to queuing in the BTS there can still be a invalid
time period for immediate assignments, when the request is lingering
in the AGCH or PCH queues.
Sponsored-by: On-Waves ehf
The PACCH is specific to an MS and may change when a TBF is
established or removed (see TS 44.060, 8.1.1.2.2). For multislot
class type 2 phones, more than one timeslot may be used to transmit
RLC/MAC control messages.
Add a method that returns a set of TS which can be used for the
PACCH.
Sponsored-by: On-Waves ehf
Currently the selection of a pending control message is done round
robin. It can possibly happen, that a DL assigment is sent on a DL
TBF while an UL assignment is pending. The MS will replace the old
DL TBF in that case, so that it can no longer be used for the PACCH
so that the UL assignment is lost.
Give assigment requests for the same direction a lower priority.
Sponsored-by: On-Waves ehf
Currently the TBF whose PACCH has been used to send an assigment
is freed if it is in state WAIT_RELEASE. Sometimes this TBF could
be used for several assignments (e.g. an 'old' DL TBF is used to
assign an UL and then a DL TBF). The second of these assigments will
never be sent in that case. On the other hand, the MS replaces a
TBF of the same direction, so the old one can be freed in that case.
Only free the TBF if it is in state WAIT_RELEASE and has the same
direction like the new one.
Sponsored-by: On-Waves ehf
Tell the MS to use EGPRS if EGPRS is enabled on the TBF.
Note that only downlink TBF will be supported so far. Thus
single-phase uplink assignments may not work properly.
Sponsored-by: On-Waves ehf
The EGPRS support will need more information to encode the IMMEDIATE
ASSIGMENT. Instead of adding more parameters pass a pointer to the
TBF unless an SBA shall be done (indicated by tbf == NULL). All
values that can be derived from the TBF and are not needed for an SBA
are removed from the parameter list.
Return a negative value on error.
Sponsored-by: On-Waves ehf
Currently bitvec_write_field is used which just sets the bits as
given, while the spec 44.018 assumes LH encoding.
Use the bitvec_write_field_lh function instead.
Sponsored-by: On-Waves ehf
While the bitvec functions from libosmocore support LH encoding, the
C++ wrapper does not.
Add a bitvec_write_field_lh function that is similar to
bitvec_write_field, but writes L and H instead of ZERO and ONE.
Sponsored-by: On-Waves ehf
Currently the CCCH flag is cleared and the PACCH flag is set when a
multislot upgrade is scheduled for a downlink TBF, even if the MS has
never confirmed in any way that the PACCH really exists. This can
happen if the MS did not receive the DL IMM.ASS. Since the CCCH flags
gets cleared in that case, the IMM.ASSS is never retried and all
subsequent PACKET DOWNLINK ASSIGNMENTS will fail.
This commit delays the update of these flags until the MS has
responded with a corresponding CONTROL ACK.
Sponsored-by: On-Waves ehf
Currently the old TFI is always used as ID when a
PACKET DOWNLINK ASSIGNMENT is generated. This fails
if the old TBF has not been fully assigned yet. The
MS will then ignore the PDA.
This commit changes write_packet_downlink_assignment to accept
an additional parameter old_tfi_is_valid and uses the new TBF's
TLLI instead of the olf TFI if that parameter is set to false.
Sponsored-by: On-Waves ehf
Currently the checks for and the actual polling is done in several
places by copy & paste of several lines of code. This hinders changes
of they polling is handled internally and also is likely source of
programming mistakes.
Separate this into a check_polling function, that checks whether
polling is possible and returns the FN and the RRBP to be used in
that case. Otherwise the cause is logged (LOGL_DEBUG) and a negative
error value is returned. There are no other side effect beside the
logging.
If the call is successful, the set_polling method can be used to
actually register the polling.
Extend the encoder functions' parameters lists by an rrbp parameter.
Sponsored-by: On-Waves ehf
Currently tbf->control_ts is used to look up an incoming poll
response. Since that may eventually change, poll timeouts could
theoretically happen in that case.
Store the real poll TS in tbf->poll_ts at all places where
tbf->poll_fn is set. Do not use tbf->control_ts to look up
outstanding polls.
Sponsored-by: On-Waves ehf
Currently there are some places where tbf->control_ts != ts is
evaluated to check, whether ts is a control slot.
Replace these expressions by tbf->is_control_ts(ts) which does
the same whitout exposing internal fields.
Sponsored-by: On-Waves ehf
Currently the checks in that function are based on the different
internal TS values of a TBF. It is assumed that they match the TS
that the current RTS refers to.
This commit adds a TS parameter to create_ul_ass, create_dl_ass,
and create_ul_ack to make this more explicit.
Sponsored-by: On-Waves ehf
Currently existing TBF can be reused after an MS has sent a RACH
request. Since the MS can be or most probably is in packet idle mode
in that case, the TBF are no longer usable even if they share the
PDCHs and the control TS with the new one.
There are occasional freezes where the MS does no longer react to
messages sent on the PACCH.
This change aborts all pending TBFs if a new TBF is or has been
established via RACH.
Sponsored-by: On-Waves ehf
Currently the is a release() function which takes care of
statistics and shutdown of properly finished TBFs, but which
cannot be used for aborted TBFs.
This commit add an abort() method which handles unacked RLC blocks
as lost and doesn't start a release timer. This method will be
invoked by tbf_free() for downlink TBF.
Sponsored-by: On-Waves ehf
Aravind Sirsikar
Harald Welte