Currently the old TBF (either uplink or downlink) is passed around at
TBF allocation mainly to get information about the MS. To implement
more complex allocation algorithms, the MS object itself will be
needed anyway.
This commit replaces the old_tbf arguments by MS object arguments.
Sponsored-by: On-Waves ehf
This method does not do anything anymore, it's functionality has been
taken over by update_ms.
This commit removes gprs_rlcmac_tbf::update_tlli completely.
Sponsored-by: On-Waves ehf
The I_LEVEL values that are obtained now look suspicious. They do not
seem to be contained in messages recorded via gsmtab.
To help debugging this issue, this commit adds related debug messages
that are generated while the encoded values are taken from the
RLC/MAC messages.
Sponsored-by: On-Waves ehf
This commit extends the pcu_l1_meas structure by MS side measurement
values which are transmitted by PACKET DOWNLINK ACK/NACK and
PACKET RESOURCE REQUEST messages. The encoded values are remapped to
dB respectively % values. The values are stored in the corresponding
MS object (if there is one).
Note that the values are store as (rounded) integers, so some
different encodings are mapped to the same decoded value.
Sponsored-by: On-Waves ehf
Currently only the RSSI value is passed to the upper layers. Other
values like TA and BER which are needed for TA update respectively CS
selection are not propagated.
This commit introduces and passes a struct that contains a set of
measurement values.
Sponsored-by: On-Waves ehf
Since more functionality will be moved to the GprsMs class, a pointer
to the current BTS object is added to allow access to configuration
data and other methods.
Sponsored-by: On-Waves ehf
The ms_class value is a property of the MS and thus belongs to the
GprsMs class. Nevertheless the MS object is created after the TLLI
gets known, so the value still has to be stored in the TBF initially.
This commit add the ms_class value to the GprsMs class and introduces
TBF accessor functions which either access that object or, if that is
not available, the value stored locally.
Ticket: #1674
Sponsored-by: On-Waves ehf
Currently the TA storage stores up to 30 TLLI->TA mappings, if more
entries are created the oldest one is dropped. In theory this can
lead to missing TA information if many MS are present.
This commit removes the TimingAdvance class completely, since the TA
value is now stored in the GprsMs objects.
Note that the GprsMs objects are currently not kept after the TBFs
have detached from them, so the TA values are now kept for a shorter
time than before.
Ticket: #1674
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
These tests cover the message exchange from receiving from the first
RACH request to the first data block when establishing an uplink TBF.
This will be used to check, whether TA and other values are passed to
an MS object correctly.
In addition, the RX RACH log message in rcv_rach is extended to
contain the single block fn.
Sponsored-by: On-Waves ehf
Currently a new TBF is chained to an existing older one, either of
the other direction (active or releasing) or of the same direction
(releasing). This does not work properly work if and uplink and a
downlink TBF are being established at the same time while an old TBF
is being released. In that case, one of them is thrown away and the
pending procedure is cancelled.
The chaining is no longer necessary since the GprsMs objects have
been introduced which keep track of the active TBFs.
This commit removes the TBF members m_new_tbf and m_old_tbf and the
related methods and code paths.
Note that a new TBF can replace an older TBF entry of the same
direction within an MS object when it is associated with an MS (e.g.
by TLLI or because it is assigned via another, already associated
TBF). In that case, the old TBF is no longer associated with an MS
object.
Ticket: #1674
Sponsored-by: On-Waves ehf
Currently the BTS::trigger_dl_ass() method assigns the IMSI to the MS
object. This should be (and is already) done earlier where the MS
object is retrieved/created.
This commit removes the corresponding code along with the 'imsi'
parameter from trigger_dl_ass.
Sponsored-by: On-Waves ehf
Currently the TLLI is stored in each TBF. Since each MS is now
represented by a GprsMs object which takes care of TLLI updating,
and each TBF that has been associated with an TLLI also contains a
reference to a GprsMs object, per TBF TLLI handling is no longer
needed. Keeping all TBF m_tlli members up to date is complex and
doesn't currently work correctly in all circumstances.
This commit removes m_tlli and related members from the TBF class and
the tbf_by_tlli functions from the BTS class.
Ticket: #1674
Sponsored-by: On-Waves ehf
The type of the TBF update_ms() is being called on does not always
reflect whether the TLLI has been signaled by the MS or the SGSN.
This commit adds an additional parameter to tell the method, in which
direction the TLLI has been passed.
Sponsored-by: On-Waves ehf
Use the MS storage to find a MS object for a given TLLI instead of
searching the TBF lists. The TBFs are then taken from the MS object,
if one has been found. If all TBF might be temporarily detached from
the MS object, a GprsMs::Guard is added to prevent the deletion of
the object, in case another TBF gets attached later on in the scope.
Ticket: #1674
Sponsored-by: On-Waves ehf
This commit adds MS object creation and cleanup to the TBF related
code. MS objects are created when a TBF that has been "anonymous" so
far gets associated with a TLLI. When a TBF is replaced by another,
the old TBF is detached and the new one is attached to the MS. When
all TBFs have been detached, the MS object gets deleted.
The TBF related code should not call attach_tbf/detach_tbf directly
but use set_ms instead to make sure, that the references are updated
properly. GprsMs::detach_tbf also calls set_ms(NULL) on the detached
TBF object.
The MS object is not really used yet, the focus is still on object
creation, TBF association, and cleanup.
Ticket: #1674
Sponsored-by: On-Waves ehf
These fixes do not affect the semantics of the code. They either help
gcc by providing default values that won't be used ("may be
uninitialised"), remove unused variables, or change signed to
unsigned variables to avoid comparison warnings.
Addresses:
bts.cpp:494:32: warning: 'tbf' may be used uninitialized in this
function
emu/test_replay_gprs_attach.cpp:81:27: warning: comparison between
signed and unsigned integer expressions
emu/test_pdp_activation.cpp:95:23: warning: unused variable ‘budh’
emu/test_pdp_activation.cpp:97:6: warning: variable ‘rc’ set but
not used
emu/pcu_emu.cpp:109:26: warning: unused variable ‘bts’
alloc/AllocTest.cpp:74:27: warning: unused variable ‘tbf’
osmocom/core/utils.h:13:50: warning: comparison between signed and
unsigned integer expressions
types/TypesTest.cpp:319:7: warning: unused variable ‘count’
types/TypesTest.cpp:320:11: warning: unused variable ‘rbb’
alloc/AllocTest.cpp:74:27: warning: unused variable ‘tbf’
alloc/AllocTest.cpp:132:11: warning: unused variable ‘ts_no’
Currently two DL TBF objects with the same TLLI exist after reuse_tbf
which make the result of tbf_by_tlli undefined. This leads to several
DL TBFs belonging to the same TLLI.
This commit extends tbf_by_tlli to check the m_tlli_valid flag for
DL, too. That flag is set to 0 in reuse_tbf to mark the 'old' DL TBF
as invalid after its LLC data has been copied to the new one.
Sponsored-by: On-Waves ehf
There are a couple of possibilities where one TBF is used to assign a
new one:
1. Assign a DL TBF from a UL TBF
2. Assign a UL TBF from a DL TBF
3. Assign a DL TBF from a DL TBF which is in wait-release state (T3193 is
running)
In these cases the assignment is sent on the existing TBF and triggers
the assignement of the new TBF (with different TFI/direction).
The current code detects these situations by looking at dl/ul_ass_state
and then chosing the TBF with the opposite direction (DL/UL) that has
the same TLLI. This does not work in the case 3 above where a new DL TBF
is triggered for a DL TBF. The current code reuses the old TBF (and
TFI), but this violates the spec.
This patch introduces a m_new_tbf member which is set to the new TBF to
be assigned. When receiving a control ack the code looks up the
n_new_tbf member of the tbf that requested the control ack and completes
the ul/dl assignment. If the old TBF was in the wait release state
(T3193 is running) it is released.
From 3GPP TS 04.60 9.3.2.6:
"""
If the network has received the PACKET DOWNLINK ACK/NACK message with
the Final Ack Indicator bit set to '1' and has new data to transmit for
the mobile station, the network may establish a new downlink TBF for the
mobile station by sending the PACKET DOWNLINK ASSIGNMENT or PACKET
TIMESLOT RECONFIGURE message with the Control Ack bit set to '1' on
PACCH. In case the network establishes a new downlink TBF for the mobile
station, the network shall stop timer T3193.
"""
reuse_tbf() is modified to allocate a new TBF with a new TFI and trigger
a dl assignment for that TBF on the old TBF. All pending data is moved
to the new TBF.
Ticket: SYS#382
Sponsored-by: On-Waves ehf
All the function did was add debug output and call the set_state method.
Move the debugging into the method and remove the function.
Ticket: SYS#389
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
This method is only userul for DL TBFs so move it. As a result
gprs_rlcmac_pdch::rcv_control_ack needs to work with dl_tbfs.
Ticket: SYS#389
Sponsored-by: On-Waves ehf
llist_add is called on the TBF lists in tbf_alloc_ul/dl_tbf or in
rotate_in_list. All three places check the direction/add the new TBF to
the correct list so an ASSERT on entry is not needed.
Ticket: SYS#389
Sponsored-by: On-Waves ehf
The PODS struct has a back pointer to access the actual object.
llist_pods_for_each_entry traverses the list of struct llist_pods and
makes the entry available (through the back pointer).
Ticket: SYS#389
Sponsored-by: On-Waves ehf
UL and DL tbfs are used in very separate parts and are not the same
thing so split the alloc function and use the UL/DL version throughout
the code.
Ticket: SYS#389
Sponsored-by: On-Waves ehf
Many functions only ever deal with or return a UL or a DL TBF.
Explicitly change the type to reflect which TBF is used where.
Ticket: SYS#389
Sponsored-by: On-Waves ehf
rcv_control_dl_ack_nack is only meaningful for dl tbf while
rcv_control_ack can be sent in response to a dl or ul tbf. So
rcv_control_ack still needs to check for ul and dl tbfs.
Ticket: SYS#389
Sponsored-by: On-Waves ehf
The current code keeps a reference to all tbfs in the bts and another
reference in the pdch. This allows for the possibility of both lists to
go out of sync.
This patch removes the pdch-specific list of ul and dl tbfs and uses the
lists in the bts to lookup tbfs everywhere.
Performance for going through the global list is not an issue yet. We
can optimize this later and in a better way.
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.
This approach is somehow flawed. We need/want to debug problems on
systems with real traffic and re-compiling it with debug_diagram
is not an option. All internal logging needs to be expressive enough
so we can understand what is going on (e.g. create a script to
post-process the output).
This does not mean that they have been successfully transferred
to the SGSN/MS but at least that they have reached a certain point
in the message flow.
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.
This is like gsm_lchan_name and should be used in log statements.
This way we can easily change the information that is printed and
we know how to search things. The other part is that direct use
of tfi/tlli is removed which will allow us to make them private
and at the same time start to resolve the "tlli" updated in many
places.
Not old log statements are changed yet. This will done whenever
a bad log statement is seen on the console...
The TLLI can change when a new P-TMSI is assigned to the phone,
e.g. during a (periodic) routing area update. When the TLLI
changes we need to update all TBFs and maybe even register the
timing advance for the new TLLI..
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 timer is used for various timeouts and there is still external
client code that is calling it. In a perfect world the client code
would indicate that an event has happened and the internal timer
will be stopped. The best compromise is the "stop_t3191" method. It
allows to add semantic verification that the timer has been running.
Move the method into the PDCH. Extract the finding of TLLI into a
new class called Decoding. Move the assemble and forward LLC frames
into the TBF as it is poking in the internals of the TBF.
All dispatching will go through the PDCH. This will clean a lot
of the look-ups inside the gprs_rlcmac_data.c and continue with
adding structure to the pcu code.
Simplify the reset code now that the PDCH can know where it is
located. Rename the variables in the sba to trx_no and ts_no as
it stores the number and not the actual thing.
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.
The PollController is a friend of the SBAController and is allowed
to access the internal list. The list is hidden from everyone else.
This is done because the calculation of timeout should belong into
the PollController and not into the SBAController.
Only the gprs_rlcmac_pdch will manipulate the paging list now. There
can be various more refactorings of the code but they can be done
later. E.g. on memory allocation failure we can continue instead
of leaving the code, we should also set any_tbf only after things
have been paged.
Rely on packet_paging_request returning NULL in case the queue
is empty. We should move the write_packet_paging_request into
a separate file/object as well.
When a PDCH is disabled all resources should be freed. This is
currently not possible as the PDCH does not know where it belongs
to. On top of that the list (and other resources) should be
properly initialized on construction so that disable() is idempotent
and does not check if it was disabled. During the re-factoring I
noticed that during a sysmobts re-start some resources are not
freed. I left a warning in the code to resolve this issue later.
The current_frame is an attribute of the BTS. Move it from the
pcu_l1_if.cpp into the BTS. As the next step we can trigger
actions depending on the change of the frame.
Compared to the previous code there will be a branch to get the
global pointer so the code will be slightly slower than the previous
version but it allows us to start creating objects but still use
the code from C. It is best approach I have found so far.
One downside of C++ is that by default talloc will not be used
(unless we override the new operator to use talloc. Right now
we need to memset the C data structure by hand. The benefit of
enforcing a better structure should is more important though.
Jacob Erlbeck
Daniel Willmann