The BTS layer needs to inform the handover code when an access
burst has been received. In turn the handover layer will ask the
bts to modify the channel, it will schedule the physical information
inform the BSC with the HANDOVER DETECTION and waits for the BTS
layer to inform it about the first received frame to stop a timer.
Currently, the AGCH queue length is not limited. This can lead to
large delays and network malfunction if there are many IMM.ASS.REJ
messages.
This patch adds two features:
- Don't accept msgs from the RSL layer when the queue is way too
full (safety measure, mainly if bts_ccch_copy_msg() is not being
called by the L1 layer, currently hard coded to 1000 messages)
- Selectively drop IMM.ASS.REJ from the queue output depending on the
queue length
Ticket: SYS#224
Sponsored-by: On-Waves ehf
This patch extends paging_gen_msg() by adding an output parameter
is_empty that is true, if only a paging message with dummy entries
has been placed into buffer. This feature is then used by
bts_ccch_copy_msg() to insert an AGCH message if is_empty is true.
Ticket: SYS#224
Sponsored-by: On-Waves ehf
Counters are added for the following events (use VTY show to query):
- Dropped IMMEDIATE ASSIGN REJECT messages
- Merged IMMEDIATE ASSIGN REJECT messages
- Rejected AGCH messages
- Use of PCH (non-reserved) for AGCH messages
- Use of AGCH (reserved) for AGCH messages
Sponsored-by: On-Waves ehf
This patch adds a function bts_update_agch_max_queue_length()
to compute a limit of the AGCH queue. This is based on the idea,
that the AGCH queue has a limited drain rate and that CHANNEL
REQUESTs must be answered within a certain time frame, given
by the minimum value of T3126 (see GSM 04.08). When the AGCH queue
reaches that limit, the last message would be delivered in time if
there were no other delays involved (which is not the case).
The calculation is based on the ratio of the number RACH slots and
CCCH blocks per time:
Lmax = (T + 2*S) / R_RACH * R_CCCH
where
T3126_min = (T + 2*S) / R_RACH
R_RACH is the RACH slot rate (e.g. RACHs per multiframe)
R_CCCH is the CCCH block rate (same time base like R_RACH)
The value depends control_channel_desc.ccch_conf and
rach_control.tx_integer (both from SYSINFO_TYPE_3) and should
therefore by called at least each time after one of these is changed.
For this reason, a signal callback is registered under
SS_GLOBAL/S_NEW_SYSINFO which invokes bts_update_agch_max_queue_length().
Sponsored-by: On-Waves ehf
Based-On: "bts: Calculate length of agch queue" by Ivan Kluchnikov
<kluchnikovi@gmail.com>
This patch adds a common function bts_ccch_copy_msg() that provides
and schedules AGCH and PCH messages. It is basically a frontend to
paging_gen_msg() and bts_agch_dequeue() and contains refactored code
from l1_if.c.
Sponsored-by: On-Waves ehf
Use the lchan->rel_act_kind field for the BCCH activatiob by OML.
The lchan's should be marked as active but no event should be sent to
the BSC. This is mostly like the PCU. We can now remove the secnd
argument from lchan_activate.
Nicolas ended up with linker issues due abis_rsl_sendmsg being
defined twice. Rename our version of the function and update the
code.
Patched with:
@i@
expression E;
@@
- abis_rsl_sendmsg(E)
+ abis_bts_rsl_sendmsg(E)
Currently the LEDs are being accessed directly from within the
l1_if.c file. So the handling of rf mute and activate/deactivate both
access LED_RF_ACTIVE directly. This may lead to an inconsistent LED
status.
This patch replaces these calls to sysmobts_led_set() by an abstract
equivalent bts_update_status(), that uses a set of independant status
ids. The associated values can than be combined into a visible LED
status. Currently LED_RF_ACTIVE is on iff BTS_STATUS_RF_ACTIVE is set
and BTS_STATUS_RF_MUTE is not set.
Sponsored-by: On-Waves ehf
Currently a Change Administrative State Request is just applied
unconditionally to the object's state object and then acknowledged.
This patch implements the special handling of setting the Radio
Carriers state to LOCK or UNLOCK. This is done by passing the
appropriate mute command to the L1 layer. Always all radio channels
are affected, it is not possible to lock single radio channels.
On success, an ACK is sent back to the bsc with the new state (based
on the state passed in the callback by the L1 layer). If something
went wrong or the firmware doesn't support RF mute, a NACK
(REQ_NOT_GRANTED) is sent instead.
Note that a NACK for such a request hasn't been sent by the BTS to
the BSC yet, so (albeit it's spec conformant to do so) the BSC must
be prepared to handle this correctly.
Ticket: OW#976
Sponsored-by: On-Waves ehf
This adds a new function
l1if_mute_rf(femtol1_hdl, ch_mute[8])
to set the mute state for each radio channel. On completion and iff
l1if_mute_rf() returned 0 the callback
oml_mo_rf_lock_chg(mo, ch_mute_state[8], success)
is invoked when the response from the superfemto DSP is received.
Ticket: OW#976
Sponsored-by: On-Waves ehf
The PCU is forcing the activation of a PDCH. Currently the BSC
will receive a channel act ack for a channel that was not
activated at all. Use the "release_reason" flag of the lchan
to see if we have requested a normal activation or a silent
one.
It feels a bit odd to do it in the TX function but it is the
most easy solution right now. I have added logging so it will
not be totally silent.
This introduces a new get_signlink_remote_ip() function whcih we also
use in the RSL code to determine the RTP remote address if the CRCX/MDCX
contains no remote IP address IE.
libosmoabis has a BTS-side implementation of the IPA protocol for years,
and osmo-bts should have used that all the time. Unfortunately it had
its own local hack, this patch is migrating to the libosmocore
implementation.
Instead of calling oml_mo_state_chg() [which transmits OML STATE CHG]
during bts_init(), we use a new oml_mo_state_init() function which
simply sets the state.
During development one switches from GSM900 to GSM1800 and GSM850 to
GSM1900. This commit attempts to make this switch more easy.
GSM1800 and GSM1900 have overlapping ARFCNs. This means that the
mapping from bands to arfcn is not injective. Because of that I
removed the code to deduce the band from the ARFCN. This was done
in commit 8c3d807b3f. The auto-band
option allows to move between GSM900/GSM1800 and GSM850/GSM1900.
Add a simple testcase with these auto-band configurations.
Chapter 5.2 applies to MS procedure, but 5.3 (BSS procedure) defines no
exact criterion, so I decided to use the procedure equivalent to MS.
The criterion is based on a counter S, which is initialized to a preset
RADIO_LINK_TIMEOUT, which can be configured via VTY. Whenever a received
SACCH block is bad, S is counted down by one. If SACCH block is
successfully decoded, S is counted up by two, but never above initial
RADIO_LINK_TIMEOUT value. If S reaches 0, an RSL Connection Failure
Indication with cause RF Radio Link Failure is sent to BSC, which then
aborts channel.
Use link timeout value from BSC via OML attribute.
How to test:
- Set "debug" for "meas" logging.
- Start silent call to an attached mobile.
- Remove battery from mobile or shield mobile.
- Watch S count down.
Issue the RfDeactivate.REQ before sending the MphClose.REQ. Ideally
we would issue MphClose.REQ after the RfDeactivate.CNF but this is
not possible right now.
The current approach makes the following warning of the DSP go away
on shutdown. This was tested with my E71 and an active silent-call
using a SDCCH.
DSP Warning:
[ERROR] : DeviceMng_ValidateL1Handle() => Invalid layer 1 handle
Instead of explicitly having to specify the local IP address for RTP
sockets in the BTS, we just use "0.0.0.0" instead, which gets
translated to INADDR_ANY.
We still accept the configuration directive in old config files, but
when we write, the line will no longer be re-written to the file.
TODO: IMHO, the IPA RSL CRCX/MDCX actually permit the BSC to specify the
IP address on the BTS side, and we probably simply ignore this at this
point.
These attributes are saved in paging_state, we don't need to save them a
second time in struct gsm_bts_role_bts. Add get and set methods for
these attributes and use them consitently in the VTY code.
This was found and debugged by Sylvain. The BTS will always support
A5/0 so we do not keep track of that, the first bit of the flags is
used for A5/1, second for A5/2... but for RSL there is an offset to
go from RSL to A5(x). Add a testcase and change the code.
* Comment out the osmo-bts-bb/Makefile as we have removed it from
the SUBDIRS and are not packaging the code right now
* Add missing include files for the build
Right now osmo-bts requires access to one OpenBSC header file and
this requires that openbsc and osmo-bts git are in the same directory.
Begin with making the location of the OpenBSC sourcecode configurable.
This approach will allow to build osmo-bts on our Jenkins installation
but now has the risk of more code including the openbsc/*.h header files.
This may be adding bells and whistles that nobody wants to touch, but at
least for current analysis/optimiziation they are useful to have. Later
on they should probably be removed again and/or obsoleted by OML
messages for configuration of paging behaviour by the BSC.
We now count the total number of RACH slots, the number with rx level
above the busy threshold, and the number of valid access bursts.
This data is used to generate RSL CCCH LOAD INDICATION for the RACH.
We now implement the fairly complex rules for schedulign of
SI 2bis/2ter/2quater, 13 and 9 on TC=4 and TC=5 of the BCCH Norm.
The patch is currently untested.
Andreas Eversberg
Harald Welte