According to:
* 3GPP TS 44.060 version 16.0.0 "9.3.1a Delayed release of downlink Temporary Block Flow"
* 3GPP TS 44.064 version 16.0.0 "6.4.2.2 Unconfirmed Information (UI) Dummy command"
LLC UI Dummy frames are to be used when there no more data to send, only
in order to delay the release of a TBF. Hence, while not incorrect per
se, makes no sense to send those LLC UI Dummy frames inserted into
rlcmac blocks which already contain other LLC frames, since the MS in
that case is already being kept active.
It only makes sense to send those LLC UI Dummy frames when we have
nothing else to send, that is, alone inside a RLCMAC block without other
LLC frames.
Related: OS#4849
Change-Id: Ifae1a7b2b3dfad8df19585063088ba0df2749c8f
It's quite odd to see that in write_packet_downlink_assignment()
we initialize an 'RlcMacDownlink_t', so then the caller can use
the power of CSN.1 codec to generate the final sequence of bytes
to be transmitted, while in write_packet_uplink_assignment() we
already compose the final RLC/MAC message straight away using
the low-level bitvec API (like bitvec_write_field()).
I guess the reason is that at the time of writing this code, the
CSN.1 codec was not stable enough, so it was safer to generate
the message 'by hand'. This would also explain why we *decode*
the final RLC/MAC message in create_ul_ass() right after encoding.
Rewrite write_packet_uplink_assignment(), so now it initializes
a caller-provided 'RlcMacDownlink_t' structure. Given that it's
allocated on heap using talloc_zero(), do not initialize presence
indicators of fields that are not present in the message.
This would facilitate handling of frequency hopping parameters
in the upcoming changes, in particular we can now introduce a
function that would compose Frequency Parameters IE for both
write_packet_{downlink,uplink}_assignment().
Tested manually by running a GPRS-enabled network, as well as by
running test cases from ttcn3-pcu-test => no regressions observed.
Change-Id: I2850b91e0043cdca8ae7498a5fc727eeedd029b6
Related: SYS#4868, OS#4547
In order to be able to encode frequency hopping parameters, let's
pass a const pointer to 'gprs_rlcmac_pdch' (PDCH slot) directly,
instead of passing all related parameters separately.
Change-Id: I6bccad508f0fdccc4a763211008dd847a9111a8d
Related: SYS#4868, OS#4547
In get_paging_mi(), before this, an encoded buffer of Mobile Identity bytes is
returned. Code paths following this repeatedly decode the Mobile Identity
bytes, e.g. for logging. Also, in get_paging_mi(), since the TMSI is read in
from a different encoding than a typical Mobile Identity IE, the TMSI was
manually encoded into a typical Mobile Identity IE. This is essentially a code
dup of osmo_mobile_identity_encode(). Stop this madness.
Instead, in get_paging_mi(), return a decoded struct osmo_mobile_identity. Code
paths after this use the struct osmo_mobile_identity directly without repeated
decoding.
At the point of finally needing an encoded Mobile Identity IE (in
Encoding::write_paging_request()), do a proper osmo_mobile_identity_encode().
Since this may return errors, add an rc check for the caller of
write_paging_request(), gprs_rlcmac_paging_request().
A side effect is stricter validation of the Mobile Identity passing through the
Paging code path. Before, invalid MI might have passed through unnoticed.
Change-Id: Iad845acb0096b75dc453105c9c16b2252879b4ca
We have same kind of object splitted into two layers, in coding_scheme
and gprs_coding_scheme. Let's merge them together and get rid of the
class, which is not really useful because it's only a set of functions
operating on one enum value.
This change also fixes gcc 10.1.0 error about memseting a complex type
in rlc.h init().
Change-Id: Ie9ce2144ba9e8dbba9704d4e0000a2929e3e41df
Original file from wireshark.git (packet-gsm_csn1.c) is being built and
maintained as a C file. There's no real need for us to maintain it as a
C++, and doing so will make both files derive over time (as already
happened). Let's keep it as a C compiler (which btw seems to be more
strict) to make it easier to port patches back and forth wireshark.git.
Take the chance to move some declarations we added to csn1.h to be able
to build it out of wireshark. Let's keep those in a separate header file
to ease looking for differences.
Change-Id: I818a8ae947f002d35142f9f5473454cfd80e1830
P-TMSI is optional IE, but IE is mandatory and hence always available.
Since the encoding is actually a Mobile Identity, the IMSI is used in
case P-TMSI is not available.
Change-Id: I4dbf8db04e81f98352a42ce34a5d91326be9bfd1
* move window size encoding and writing into separate functions
* introduce necessary TBF wrappers to avoid direct m_window access
This is part of preparation work to move to separate UL/DL windows.
Related: OS#1759
Change-Id: I60184d5049bc7d7b119df5a9eb82d1c4b788c840
When PDAN/EPDAN with channel description is received, PCU will generate the
packet access reject if no resources are present. The encoding is done
based on section 7.1.3.2.1 and 8.1.2.5 of 44.060 version 7.27.0 Release 7.
This patch also includes the test case to validate the generated
packet access reject message.
This patch is integration tested on Osmo-trx setup with Ettus B210 board
and LG F70 MS with some simulation code changes in Osmo-pcu.
Change-Id: I096a3bb44a65533b9e9b091925dd5f70a8696d6
When RACH is received, PCU will generate the Immediate assignment reject
message if no resources are present. The encoding is done based on section
9.1.20 of 44.018 version 11.7.0 Release 11. This patch also includes the
test case to validate the generated Immediate assignment reject message.
This patch is integration tested on Osmo-trx setup with Ettus B210 board
and LG F70 MS with some simulation code changes in Osmo-pcu.
Change-Id: I3d33e2b9746fa4f338fad0e6b63b1c5f07de6f9b
Encode the EGPRS fields of immediate assignment message in uplink
when EGPRS PACKET CHANNEL REQUEST (11 bit RACH) is received.
The series of patches for 11 bit RACH are dependent on libosmocore
and osmo-bts patches for 11 bit RACH.
Change-Id: Ie5e309156e5dbbb6add74a1b4d257c4ee2332e52
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 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 the GPRS data block encoding is applied to every
coding scheme, even if an MCS is selected.
This commit renames the actual encoding function to
rlc_data_to_dl_append_gprs (not exported) and puts
selection code into Encoding::rlc_data_to_dl_append. This
requires an additional cs argument.
Sponsored-by: On-Waves ehf
This function appends a single chunk to an RLC downlink data block.
The implementation is basically taken from the
gprs_rlcmac_dl_tbf::create_new_bsn method without the TBF related
functionality and any side effects.
Note that it still only supports GRPS.
Sponsored-by: On-Waves ehf
Currently the (GPRS) RLC block encoding is done by setting the
header fields directly in gprs_rlcmac_dl_tbf::create_new_bsn.
This is much more complex with EGPRS, since the data fields are
not byte aligned, the header formats depend on the header type,
and the mapping of bits to bytes is LSB first.
This commit adds Encoding::rlc_write_dl_data_header which writes
the header according to the given gprs_rlc_data_header structure.
Encoding::rlc_copy_from_aligned_buffer is also added to copy
byte sequences into the message.
Note that the actual encoding of data units is not yet present.
Sponsored-by: On-Waves ehf
Add an use_egprs parameter to write_packet_downlink_assignment
and add the EGPRS related fields if it is set to true. The
window size is fixed at 64 blocks, link quality measurement
reports have been disabled, and the other optional fields are not
present.
Sponsored-by: On-Waves ehf
The current write_packet_uplink_ack implementation is based on the
CSN.1 encoder which makes it difficult to do the bitmap encoding for
EGPRS.
Add a new implementation based on bitvec functions to create the
PACKET UPLINK ACK/NACK messages.
Sponsored-by: On-Waves ehf
Currently the Encoding::write_packet_uplink_assignment method only
supports the GPRS variant of the message.
This commit adds the missing EGPRS variant to the encoder.
Sponsored-by: On-Waves ehf
encode_rbb() and write_packet_uplink_assignment are only called with UL
TBFs so change the function signature to reflect that.
Ticket: SYS#389
Sponsored by: On-Waves ehf
Pau Espin
Vadim Yanitskiy
Neels Hofmeyr
Daniel Willmann