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
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
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 window size is fixed to 64 even for EGPRS.
Support dynamic window sizes depending on the number of PDCH. The
WS can be set to b + f * N_PDCH. If the result is not valid according
to TS 44.060, Table 9.1.9.2.1, the value will be corrected to use the
next lower valid value (or 64).
The following VTY commands are added (config-pcu node):
window-size <0-1024> set base (b) value and leave f unchanged
window-size <0-1024> <0-256> set base (b) and factor (f)
Sponsored-by: On-Waves ehf
Currently only GPRS data block encoding is supported.
This commit adds rlc_data_to_dl_append_egprs which does the EGPRS
specific extension and chunk handling. It extends
Encoding::rlc_data_to_dl_append to use that function for MCS coding
schemes.
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
Currently the TBF and MS object use a plain integer value
(current_cs) to manage the coding scheme. This makes it difficult to
support the MCS schemes. GprsCodingScheme supports a partial ordering
of these values (CS and MCS) and provides safe increment and
decrement methods.
Use the GprsCodingScheme type instead of integer for cs fields and
variables. Add a 'mode' to GprsMs which can be set to either GPRS,
EGPRS, or EGPRS_GMSK which also set the initial values of
current_cs_ul/dl. Select the mode based on max_mcs_ul and max_mcs_dl.
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 there is only a mod_sns() method which is being used in
expression like bsn_expr & win.mod_sns(). This only works, because
it is known that mod_sns() is (sns() - 1) where sns() in turn is
always 2^n. This is error prone, hard to read, and relies on window
specifics that should be kept inside the respective module.
This commit adds a mod_sns(uint bsn) method to gprs_rlc_ul_window and
gprs_rlc_dl_window, that encapsulates and hides this optimized
computation.
Sponsored-by: On-Waves ehf
This commit adds EGPRS UL Ack/Nack encoding based on the CSN1 code.
Note that the bitmap encoding is still broken and not easy to fix
with the CSN1 framework, especially w.r.t. the length field.
Therefore this implementation will be abandoned and replaced by a
bitvec based one.
Sponsored-by: On-Waves ehf
Currently the same selector chain is used several times in the same
function.
This commit adds a pointer to Packet_Uplink_Ack_Nack and uses that
instead.
Sponsored-by: On-Waves ehf
Currently the Encoding::write_packet_uplink_ack function only
supports GPRS.
Split this function into a generic and a GPRS specific part.
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
Currently the current CS value is stored in the cs field of
gprs_rlcmac_tbf and initialised when it is used the first time.
This commit adds separate fields for UL and DL CS values to the
GprsMs class and provides corresponding getter methods for GprsMs and
gprs_rlcmac_tbf.
Ticket: #1739
Sponsored-by: On-Waves ehf
The TA value rather relates to an MS and not to a single TBF. So all
TBFs share the same TA value. Currently the TA value is stored per
TBF and eventually copied from an old TBF to a new one. It is in
general only passed with an RACH request when the TLLI and thus the
MS is not yet known.
This commit adds a TA member to the GprsMs class and uses that one
when the TBF is associated to an MS object. Since the TBF is not
always associated with an MS object (after RACH or when it has been
replaced by another TBF), the TA value is still stored in each TBF
and that value is used as long as no MS object is being associated.
Sponsored-by: On-Waves ehf
There is no need for the union/struct anymore. Make the variable members
of the UL/DL class.
As a result gprs_rlc_dl_window gets a reset() method because
memset(&dir.dl, 0, sizeof(dir.dl)) doesn't work anymore in reuse_tbf().
Ticket: SYS#389
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
The current code does not properly distinguish between DL assignments to
reuse a tbf (after it was put in state WAIT_RELEASE) and DL assignments
for an active tbf to change the allocation of the PDCH timeslots.
This patch introduces a new variable was_releasing which remembers if
trigger_dl_ass() was called with a tbf in state WAIT_RELEASE. In that
case we have to set the CONTROL_ACK field in the download assignment.
This should allow us to send DL assignments to change PDCH TS allocation
of a tbf before we enter FLOW state.
The code has an internal optimization to only use window_size
space. This means that the caller needed to know that only half
of the size was used. Change the API to work on the BSN and do
the mapping internally. The compiler should have plenty of
opportunity to propagate the constant(s) but this has not been
verified.
The send and receive window is now managed by an external object.
There are some issues that can only be solved with C++11 but it
is progres and removes some of the spaghetti code. For GPRS the
sns and ws is hardcoded. Move that into the window code.
All logging code that used tbf->tfi is now using tbf_name to
print the the TBF. External code is now using tfi() which is
inlined and should result in the same code being generated as
before (+debug code that can be stripped).
Now all updates to the tlli/tlli_valid are in one place. If we
implement the policy to update the matching/linked TBF we can
now to do it in a single place. Add a todo item for that as I
am waiting for feedback from the mailinglist.
TLLIs got printed as TBF. Fix that but also rename things to
TFI. The TFI is not required to be unique per BTS but it is
the indicator we use right now.
The list belongs to the BTS. This makes cleaning this up more easy
and establishes a hierachy of resources that start from the BTS. The
debug_diagram code is now broken.
Jacob Erlbeck
Daniel Willmann