So far, all BTS we have interfaced had one OML link per BTS, independent of the
number of TRX. In Ericsson RBS 2000, there is an OML link for the DXU/IXU,
and one additional OML link for each TRX/TRU.
bsc_init.c was a big mess even only for two supported BTS models,
so before adding more BTS types, this needs a cleanup.
All the BTS specific code from bsc_init.c has now moved into
bts_{siemens_bs11,ipaccess_nanobts}.c
This has required that input_event() and nm_state_event() get both
converted to proper libosmocore signals instead of referencing external
symbols.
So far, OpenBSC simply assumed that all BTS's configured in openbsc.cfg are
neighbors of each other. While this is true for small site installations,
it is definitely not true in most real world cases. We now have the
following new commands at the 'configure bts' level:
'neighbor-list mode (auto|manual)' for selecting the mode
'neighbor-list (add|del) arfcn <0-1024>'
for adding/deleting ARFCN in manual mode
Remember if this channel got opened due a paging response and in
that case when we close it down we will call subscr_put_channel
that will try to page the subscriber again. This highlights the
lack of a good subscriber management in the MSC code.
The SMSqueue will be responsible of sending to the user. It will
do so in a loop and will also try not to overload the BTS. This
means the throughput of SMS will be limited.
Start counting the attempts of each paging request and call
the callback with the PAGING_BUSY type when the paging request
timed out but the subscriber was not paged at all. This can
only happen with a huge paging backlog.
In case the system has so many pending paging
This is implemented by not freeing the subscriber when the
reference count becomes smaller than zero. We hope that this
will save many database accesses during the congres.
Instead of sending many messages we will queue the OML
messages and wait for the ACK/NACK before sending the
next message from the queue. We tag the msgb to remember
if we need to wait for an ack or not.
We keep the order of all messages, on ACKs and similiar
occassions we will drown the queue until we reach a message
that needs to be acked and then wait for that ack again.
Possible breakage can appear when we send an OML (e.g.
BS11 specific message) msg which does not need to be acked
through the abis_nm_sendmsg call. The fix will be to use
the _direct version of this method.
Re-Enable as it might have fixed something... who knows.
Conflicts:
openbsc/include/openbsc/abis_nm.h
openbsc/include/openbsc/gsm_data.h
openbsc/src/abis_nm.c
openbsc/src/gsm_data.c
The default values are those where the parameters are encoded
as '0' and they're not output in the config file if that case
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
In case of a inflexible network it is better to hardcode
the rtp payload to a given type. E.g. when using AMR5.9 on
a TCH/F and TCH/H having the same payload is helpful. For
now this will be only used by the osmo-bsc.
Only page if we have a load that is acceptable for paging. This
option is off by default, and can be enabled per bts. The idea
is that when we have no resources right now we will not page as
it will only create more RACHs and increase the load.
By default we are keeping the old behavior to always page and
only by changing a setting one is using the new behavior.
It might be that we run down to zero available slots but the BTS
might not send us a load indication. This can happen if we think
we send paging requests and the BTS disagrees and considers them
as errors and does not count the paging message.
When we drop to zero we will start a credit timer to give us extra
credit after six seconds, if we get a CCCH load indication before
we will stop the timer.
It is possible that the MSC is not sending the channel type it
needs for the operations it wants to do. Add a configuration option
to assign a TCH in case of paging any requests. It can be a good
idea to leave SDCCHs free for location updating requests and use
the TCH for SMS-MT and CC-MT.
Store the mapping from request to channel type in the GSM Network
struct as there is some policy involved with handling the request.
E.g. in a half rate network we don't want emergy calls to be getting
a TCH/F, or we want to have a different policy for early/late assignment
of phone calls. Update the table when creating the network and when
the neci is changed.
Allow the MS to use uplink discontinous transmission by
setting the right bit in the SystemInformation and set
DTXd/DTXu on the RSL channel commands.
This is configurable via dtx-used (0|1) on the network
level and still considered as experimental.
Currently every SAPI release indication will trigger the channel. It
was possible that we had SAPI=3 and SAPI=0 allocated and we tried to
release the channel by sending a RF Channel Release, the BTS answered
with a RF Channel Release ACK but also sent the SAPI Release Indication
which triggered a channel release here. So it was possible that we
would have released a newly allocated channel because of the SAPI
release of the old connection.
This code now works by releasing all SAPIs from highest to lowest,
then sending a SACH Deactivate and finally releasing the channel. This
approach is in use on the on-waves/bsc-master.
Also, we now re-start the network listen test after it has finished,
so if you run a test from ipaccess-find, the test will get re-started
and re-started all the time.
* We should create the transaction for SMS, CC on the CM Service Request
but for now we will use a band aid and create a dummy operarion to wait
five seconds for the transaction to be opened.
The transaction should not know on which lchan we are operating
as this can change due handover. Add untested code to share the
subscriber connection of the new and old lchan and move the pointer
in case of success/failure. Also on a clear command we will free
any resources allocated...
This code is not tested and needs to be debugged, but it should
have the right structure. I am going to fix a potential memleak
in the next commit.
A channel will be released in case of
* Errors via the clear_request callback...
* no more transactions and operations are going on.
This means that if we do something without a transaction
the channel might be closed down right away. The bug fix
will be to create a transaction/operation.
This is a big change to the way we use the subscriber
connection. From now on it is is dynamically allocated
and we will slowly move from a 1:1 lchan to conn to
having more than one lchan per connection.
This is the first commit, the subscr_con* methods will
move to gsm_data once the use_count is removed from the
connection, the freeing of the connection will also change.
The Channel Activate might be sent to a different TRX than the
Immediate Assignment. So we need to make sure that the channel
is activated before we send the immediate assignment for the RACH.
Another reason for that is according to GSM 08.58 we should take
the frame number from the activate and use it for the starting
time inside the immediate assignment message. We obviously do not
do this yet.
The code assumes that the BTS will either respond with a CHAN ACK
or a CHAN NACK if not the lchan will remain in the request state.
Also, make sure the bit ordering in the pre-computed MA is correct,
as well as the cell channel description of the target cell being
present in the HO CMD.
We now compute the Cell Channel Description for SI 1 by bit-wise
OR of the ARFCN bitmask of each timeslot on all the TRX of the BTS.
Also, support generating a GSM 04.08 Channel Description IE for
the hopping case (with HSN/MAIO instead of ARFCN).
What's still missing now: Sending the 04.08 Mobile Allocation IE
Allow to set the TOS field via the VTY interface. The
SO_PRIORITY was not used as it has no effect on the
packets being sent (in contrast to the documentation).
When submitting a DTAP message, the BSC API will attempt to
establish the RLL layer and then send the message or send an
SAPI n REJECT. This will be used by the SMS code.
Harald Welte
Holger Hans Peter Freyther
Sylvain Munaut