Currently the RLC message length that is obtained from the DSP is
reduced by 1 if the last byte of the buffer includes spare bits.
While this worked well with GPRS, these bits are being used to
encode RLC blocks in EGPRS mode. Thus this last byte must not be
chopped off. The functionality of the code is not affected by this,
since the modified length value is not used.
This commit adds GprsCodingScheme::usedSizeDL/UL to return
the number of bytes needed to encode the message block. If there are
single bits at the end that are to be used (EGPRS), the functions
return the number of full bytes plus 1 (which is the buffer size
reported by the DSP and returned by sizeUL/sizeDL). The commit also
removes the len parameter from rcv_data_block_acknowledged.
Sponsored-by: On-Waves ehf
These struct names are more specific than necessary. They are used
for GPRS (uplink) already. In downlink direction, only a few fields
will be added to the header struct. Add addition,
gprs_rlc_ul_header_egprs does not map directly to an encoded
header, like many other 'header' structs do.
Change the names to fit both modes and both directions:
gprs_rlc_ul_header_egprs -> gprs_rlc_data_info
gprs_rlc_ul_data_block_info -> gprs_rlc_data_block_info
Sponsored-by: On-Waves ehf
The EGPRS multi-slot class need to be parsed from the CSN.1 RA
capability (see gprs_bssgp_pcu_rx_dl_ud).
This commit adds a workaround to get the EGPRS MS class from the MS
object if that is present.
Sponsored-by: On-Waves ehf
Currently GPRS is always used for downlink, which violates TS 44.060
(concurrent TBF must have the same mode).
Enable EGPRS mode for downlink if the EGPRS MS class is != 0 and
EGRPS has been enabled.
Note that EGPRS Ack/Nack handling is not yet implemented, so enabling
EGPRS will not work still. But we will now get EGPRS DL ACK/NACK
messages now from the MS.
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
Provide the initial MCS values for EGPRS data blocks. They are set
to 1 (MCS-1) for each direction and there is no support to change
these configuration values yet (the automatic adaption still works,
so there is probably no need to set these values).
Sponsored-by: On-Waves ehf
This sets the maximum MCS encoding used for EGPRS RLC data blocks
in either direction.
The following VTY command are added to node config-pcu:
- mcs max <1-9> set maximum for both, uplink and downlink
- mcs max <1-9> <1-9> set maximum for downlink and uplink (in that
order)
- no mcs max do not limit
Note that using a value of 4 or below for each direction implies
that a GMSK-only TBF may be assumed, which for instance would allow
the use of the GPRS MS class instead of the possibly more restrictive
EGPRS MS class.
Sponsored-by: On-Waves ehf
LListHead does basically the same like llist_pods, but more C++ish
and with type safety.
This commit turns the former list field of gprs_rlcmac_tbf into a
private field, provides accessors, moves the related code from
pcu_vty.c to pcu_vty_functions.cpp, and removes the llist_pods
type and related code.
Sponsored-by: On-Waves ehf
This function is similar to the show_ms function already present in
the target file. Since the TBF lists will be turned into LListHead
based lists, they will get an iteration function in
pcu_vty_functions.cpp, too.
Sponsored-by: On-Waves ehf
Currently casts from gprs_rlcmac_tbf to gprs_rlcmac_ul_tbf and
gprs_rlcmac_dl_tbf are done by using static_cast. This doesn't provide
protection against converting a gprs_rlcmac_ul_tbf pointer to a
gprs_rlcmac_dl_tbf pointer and vice versa.
This commit provides two functions as_ul_tbf and as_dl_tbf, that
behave similar like dynamic_cast but use the direction field instead
of RTTI.
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 msg data is accessed and index 0 assuming the msg is
not empty. While this should be always the case, the msg can be
empty if there are software errors in the message creation functions.
This commit adds an assertion to catch this kind of bugs.
Sponsored-by: On-Waves ehf
Currently the GPRS parameters are used, which is ok for the WS but
not for the SNS.
This commit uses RLC_EGPRS_SNS and RLC_EGPRS_MIN_WS for the window
configuration.
Sponsored-by: On-Waves ehf
Currently the EGPRS mode is enabled in setup_tbf depending on the
values of egprs_ms_class and bts->egprs_enabled (both must be != 0).
This makes it difficult to set different values (like window
parameters) depending on the direction.
This commit moved the initialisation part to tbf_alloc_ul_tbf und
just leaves the setting of the ms_class to setup_tbf.
Sponsored-by: On-Waves ehf
Currently the values for WS and SNS are fixed to 64 (WS) and 128
(SNS) which are the only values that can be used with GPRS. On the
other hand, EGPRS requires an SNS of 2014 and a WS in the range of
64 to 1024.
This commit adds member variables and setters to both window
classes. By default, the GPRS values are being used.
Sponsored-by: On-Waves ehf
Currently the gprs_rlc_dl_window and gprs_rlc_ul_window do not have
constructors, but need to get initialized explicitly.
This commit adds constructors to both classes and removes explicit
external initialization code.
Sponsored-by: On-Waves ehf
Currently in some places uint8_t is being used to encode BSNs and
SSNs. This is inconsistent and (even worse) not enough for EPGRS
which uses an SNS of 2014.
This commit changes these to uint16_t.
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
ASAN has found improper deletion of objects. These only occur
on shutdown but makes it impossible to run the test cases with
full ASAN support.
This commit fixes some of them and deactivates the freeing of the_pcu.bctx
which may cause a corruption in BTS::~BTS() later on.
Note that the latter is only a work-aound and should be fixed
properly. It will leak bctx objects, but this is currently not
critical, since gprs_bssgp_destroy is only called once, immediately
before a call to exit().
Ticket: OW#1572
Sponsored-by: On-Waves ehf
Use a signed integer instead of an unsigned one for num_chunks
which can set to a negative value on error.
Ensure that chunks is not dereferenced if it is NULL. In fact
that will not happen currently, since num_chunks is now always
<= 0 if chunks == NULL.
Fixes: Coverity CID 1347433, 1347434, 1347435
Sponsored-by: On-Waves ehf
Currently the control block scheduler does not seem to be fair in all
cases. At least it happend while testing the EGPRS code, that a
Uplink Ack/Nack message got never be sent, because a Downlink
assignment took over all the times.
This commit changes the round robin code to always increment the
priority offset by 1 instead of (i + 1). The former definitely
ensures that every message type gets the highest priority after some
steps. The latter might be more fair in some situations, but that and
its correctness are not proven.
Sponsored-by: On-Waves ehf
This commit removes the code that is no longer used due to the commit
"Use a single PDCH rcv_data_block method for GPRS and EGPRS".
Sponsored-by: On-Waves ehf
Currently GPRS is handled by the old code path while EGPRS already
uses the unified functions. The rcv_block_egprs is basically not
specific to EGPRS and just needs minor modifications to handle GPRS.
This commit turns gprs_rlcmac_pdch::rcv_block_egprs into a unified
rcv_data_block method and uses it for GPRS, too.
Note that the logging messages of the new parser are different.
Sponsored-by: On-Waves ehf
This commit replaces the stub by a method that decodes the block
first, and passes it to the TBF object associated with the TFI.
Sponsored-by: On-Waves ehf
The current rcv_data_block_acknowledged_gprs method is tightly
coupled to GPRS.
This commit adds variants of the involved methods that support
EGPRS and GPRS RLC encodings likewise.
Sponsored-by: On-Waves ehf
Currently gprs_rlcmac_tbf::extract_tlli takes care of decoding and
the TBF update. These are really different things and doing the
decoding in extract_tlli makes EGPRS support more complex.
This commit moves the TBF state related part into a new method
gprs_rlcmac_tbf::set_tlli_from_ul.
Sponsored-by: On-Waves ehf
Currently the coding scene is stored as number N, where there scheme
is CS-N.
This commit replaces this by a GprsCodingScheme type cs value. The
gprs_rlcmac_cs table is no longer needed and thus removed.
Sponsored-by: On-Waves ehf
These methods will be needed for EGPRS decoding.
The is_received method returns true iff a block with the given BSN
has already been received in the current window. A call to
invalidate_bsn marks the block as not received.
Sponsored-by: On-Waves ehf
Currently gprs_rlc_ul_window::receive_bsn calls raise_v_q and returns
the number of RLC data blocks that can be taken from the queue. This
does not fit the EGPRS feature to put 2 independant data blocks in a
single RLC block.
This commit removes raise_v_q from receive_bsn, hence it must be
called explicitely to get the number of processable data blocks.
Sponsored-by: On-Waves ehf
This commit adds new RLC block decoder functions that support both
GPRS and EGPRS. The code path is selected based on the value of the
GprsCodingScheme cs object.
- rlc_parse_ul_data_header
parses the header of an RLC data block including the E and FBI/TI
flags (currently supported CS-1 - CS-4, MCS-1 - MCS-4).
- rlc_copy_to_aligned_buffer
copies an RLC data unit to a byte aligned buffer and returns
the unit's length.
- rlc_get_data_aligned
is a convenience wrapper around rlc_copy_to_aligned_buffer
that avoids copying if the data unit is already byte aligned.
Sponsored-by: On-Waves ehf
This commit adds the methods maxDataBlockBytes and numDataBlocks
which provide information about the data areas within RLC messages.
In these areas, the extension bytes, TLLI, and the LLC data are
stored.
Sponsored-by: On-Waves ehf
Currently the declarations of rlc_ul_header, rlc_dl_header, and
rlc_li_field silently assume that a gcc for a little endian platform
is being used.
This commit adds '#if OSMO_IS_LITTLE_ENDIAN' the ensure the correct
byte ordering.
Sponsored-by: On-Waves ehf
The header type depends on the coding scheme, for GPRS there is a
single data header type per direction, for EGPRS there are 3 per
direction. In addition, control block header types are used with CS-1
only, so there is one of the per direction altogether for GRPS and
EGPRS.
This commit adds the header type enum and two methods headerTypeData
and headerTypeControl.
Sponsored-by: On-Waves ehf
This commit renames rcv_data_block_acknowledged to
rcv_data_block_acknowledged_gprs to separate it from EGPRS data block
decoding.
Sponsored-by: On-Waves ehf
Jacob Erlbeck