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.
Currently all of these messages are discarded if they are assumend to
be caused by noise. But even in these cases, the FN and TN values
which are added by the DSP are valid. So these can be used to update
the current_frame value.
The osmo-bts sets the fBFILevel of a physical channel to -200dB if it
is used for PDTCH or PACCH which is the case for all PDCH. This way
a data_ind or ra_ind message is already send at least once per block
period (4 frames) per PDCH. These messages are passed to either
handle_ph_data_ind or handle_ph_ra_ind even if they contain garbage
data.
The ra_ind messages are sometimes sent a few frames earlier than
data_ind messages using the same frame.
This commit adds calls to update the current_frame value based on all
of these messages before they are discarded. The FN taken from ra_ind
are passed with an increased max_delay (5) to compensate for early
ra_ind messages.
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
The current code tries to recover from dropped connections and resets the
pcu state so it can keep running. However, this never worked correctly
which is why the -e option is used. This option exits the pcu as soon as
the internal state needs to be reset.
This patch removes this option and makes this behaviour default.
Ticket: SYS#390
Sponsored-by: On-Waves ehf
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.
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.
Remove the global state from gprs_rlcmac_trigger_downlink_assignment
and walk up to the pcu_l1_if.cpp where I find the timeout handling
that should be part of the SBA and TBF functionality. In terms of
hierachies things start to be more clear.
There should be the BTS object. That holds the SBA and TBF Controllers
that can allocate TBFs and SBAs and will handle the timeout polling
for a BTS.
This is the begin of a long march of turning tbf into a C++ class
and properly hiding the secrets inside this implementation instead
of having it spread across various different files.
For mocking/unit-testing/emulation (and a dual trx-systems) having
global state is quite bad. Cut back on the usage of the global
struct gprs_rlcmac_bts. It also makes the complexity of certain
routines more clear.
The PCU does not properly re-set the state when the connection to the
BTS is lost (and the SGSN potentially is re-started during that). This
results in the BSSGP BVCI > 1 remaining blocked and no data will be
accepted by the SGSN.
Add the '-e' option and exit the PCU when the BSSGP/NS are getting
destroyed.
The timing advance of any TBF is stored when it ends. Whenever a new TBF
with the same TLLI is created (downlink TBF), the stored TA is recalled.
This algorithm assumes that the mobile does not move too fast during
transfer. Also the mobile must start a connection in order to get correct
initial timing advance.
This algorithm does not implement the timing advance procedure as defined
in TS 04.60. To implement the standard timing advance procedure, the BTS
must decode RACH on certain bursts, the mobile is expected to send them.
This requires much more complexity to a transceiver like USRP/UmTRX or
Calypso BTS.
The algorithm was tested at TA >= 8 and works quite well.
If not compiled with this support, the closing function does not exists,
so it must not be called.
Removed a "#warning", because closing is already supported.
In order to use this feature, sysmoBTS requires option "-M", otherwise
the traffic is forwarded through socket interface.
This is essential, if PCU runs on processor of sysmoBTS. The reaction
time and delay of PDTCH frames could heavily degrade proper packet flow.
Original code: c7e7f6868b
(The code was committed earlier, but got lost somehow.)
I added IMSI, so the paging request is sent in correct paging group.
Also I excluded rest octets from pseudo length.
It is tested and it work.
It is mandatory to support it because MS may request a single block.
In this case the network must assign a single block.
It is possible to force single block allocation for all uplink requests
on RACH. (VTY option)
The new data structure is required to define slot/TFI assigment for MS
with multislot capability.
Now there are two lists for TBFs: uplink and downlink. It is possible to
have different TBFs with same TFI in the same direction, as long as they
are assigned on different timeslots.
See tbf.txt for description.
Note: This does not implement any multislot support. It defines the new
data structure. Currently only the first slot is assigned.
The signal handler will end the main loop, so clean exit is performed.
The allocated memory is dumped in order to detect memory leaks.
All talloc functions use tall_pcu_ctx context instead of NULL, to track
memory leaks.
Merge is based on jolly_new branch with two modifications.
1. Modified PCU L1 interface.
pcu_l1_if.cpp - common functions for tx and rx messages on L1 interface.
sysmo_sock.cpp - SYSMO-PCU socket functions.
openbts_sock.cpp - OpenBTS-PCU socket functions.
pcuif_proto.h - L1 interface's primitives.
2. Modified encoding of RLC/MAC Control messages, now we use structures and encode_gsm_rlcmac_downlink() function for encode control blocks (without hand-coding).
Max
Daniel Willmann
Harald Welte