This introducecs the new VTY command "neighbor-list mode manual-si5"
in combination with "si5 neighbor-list (add|del) arfcn <0-1024>",
which allows you to (optionally) have neighbor channel lists that
differ in SI5 and in SI2.
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
The reason for this is quite simple: We want to make sure anyone
running a customized version of OpenBSC to operate a network will
have to release all custom modifiations to the source code.
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
Sending this as the RTP_PAYLOAD2 will produce a MDCX NACK
as we send the RTP_PAYLOAD in the CRCX. It does not seem to
be necessary to send anything != 0 for the RTP_PAYLOAD2.
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.
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.
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
When we issue a RF Channel Release in case of a failure we receive
RLL release indications after the channel was tearn down and we
issue another RF Channel Release as a result. The channel allocator
might have already allocated this channel and we release the channel
again with another MS on it.
Make rsl_rf_chan_release take an error argument and make it set
a new state in case of an error and change the RF Channel Release
ack to not set the state back to none in case of an error but wait
for a timeout that is a bit higher than T3111.
I tested this with removing the battery during a phonecall and
waiting for the channel failure. With this test we only send the
release once.
Be able to tune the RACH settings of the BTS via the vty interface,
by default they are initialized to -1 which means we will use the
content of the static array (BTS default) and can be changed via
the VTY interface. I have verified the setting on the nanoBTS with
wireshark and I have tested writing the config file.
This new gprs-conf branch is intended to contain everything needed
to configure GPRS in the nanoBTS, but without implementing the SGSN/GGSN
functionality.
The SGSN/GGSN development will happen in a branch based on this branch
called "gprs-sgsn"
This library is intended to collect all generic/common funcitionality
of all Osmocom.org projects, including OpenBSC but also OsmocomBB
The library currently includes the following modules:
bitvec, comp128, gsm_utils, msgb, select, signal, statistics, talloc, timer,
tlv_parse, linuxlist
msgb allocation error debugging had to be temporarily disabled as it depends on
'debug.c' functionality which at the moment remains in OpenBSC
In 39315c4798 we introduced
per-bts OML attribute parser definitions and disallowed
a BTS of type unknown.
However, the VTY code first allocates a BTS with unknown type.
Some NM attributes are defined differently depending on
the BTS type. Having one big nm_att_tlvdef[] table for
all BTS types is no longer sufficient. This patch
* introduces 'struct gsm_bts_model' to describe a BTS model
* adds definitions of gsm_bts_model for BS-11 and nanoBTS
* changes the abis_nm_tlv_parse() function: include a bts pointer
Currently starting with the opencfg.cfg.nanobts and writing it out
and then trying to start again will not work. The network reject_cause
is initialized to 0 which is not a valid reject reason and when writing
this to the config file and trying to parse it will fail.
Pick roaming not allowed as a harmless option to those phones
accidently trying to connect to the BTS.
* On start the vty code will call the abis_nm method and this
will set the administrative state to unlock/lock
* During startup the BTS will report its state as well and would
possible overwrite the set administrative. We are only going
to update the administrative if it was 0 before. This appears
to work on all of my tests. In case this will not be the case
for others we will have to split the administrative into two
sets one for the BTS and one for the BSC.
In many cases we actually want a name / unique ID for the lchan,
not just for the on-air timeslot... especially in SDCCH/8 case,
where 8 SDCCHs share one timeslot...
This has the advantage that counters can be added all over the code
very easily, while having only one routine that stores all of the
current counter values to the database. The counters are synced
every 60 seconds, providing relatively fine grained statistics
about the network usage as time passes by.
Tweaking theses can be useful especially tx-integer that influence
both the spread of rach attemps and the delay between two attemps.
Looking up GSM 04.08 3.3.1.1.2 & 10.5.2.29 can help determine good
values. The default are choosed with a wide spacing between attemps
(tx integer = 9 -> T=12 & S=217 (non-combined CCCH/SDCCH) or 115 (for
combined CCCH/SDCCH)). This alleviates the problem of responding to
several RACH attempts by a same MS, allocating several RF channels when
only 1 is needed.
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
This implements the handover algorithm (and associated parameters)
as described in Chapter 8 of the book "Performance Enhancements in
a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen
Wigard.
The parameters such as averaging windows are configured in struct
gsm_network. We keep some state to trakc up to 10 neighbors as
they are being reported from the MS.
This has so far only been tested in a network with two BTS that
have each other as neighbor. Networks with morge neighbors might
encounter bugs.
Harald Welte
Holger Hans Peter Freyther
Sylvain Munaut