This code simply enables the channel allocator to understand the
dynamic TCH/F / PDCH channel type as used by ip.access nanoBTS.
It does not actually try to switch the dynamic mode, but instead
sends signals to a (not yet present) dynamic switching algorithm.
This returns true if the gsm_nm_state can be considered 'running'.
Note that we also accept availability==0xff (which is a code for
no value) because according to 12.21 it is perfectly valid.
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
When we allocate a channel, we send the RSL CHAN ACT REQ and wait until we get
a CHAN ACT ACK. Only the ACK will change the state, so there is a race where
we allocate that same channel to a different channel request before we get
the ACT ACK.
Introducing a new ACT_REQ state resolves this issue.
In case we have multiple TRX configured, but not all of them are
actually active/operational, we should not try to allocate channels
from such transceivers.
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.
If a RF channel is assigned but no response is ever heard from
the phone, we will receive a CONNECTION FAIL from the BTS,
triggering a RF release freeing the channel. Then sometime later,
T3101 will expire as well and free the channel again ...
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
This introduces a new LOGP() macro together with LOGL_* definition to
support multiple log levels (severities) throughout the codebase.
Please note that the actual logging system does not use them yet,
in this patch we simply introduce the new macros at the caller site.
The rationale is as following:
If we have NECI=1, then the phone will request a channel with CHREQ
"0100xxxx Originating speech call from dual-rate mobile station when TCH/H is
sufficient and supported by the MS for speech calls", then we will try to
allocate a TCH/H [as it is sufficient].
However, if there are no free TCH/H slots on the BTS, we abandon and can't
handle the MO call at all :(
Both GSM 04.08 RR and GSM 08.58 RSL need the multirate config
in the channel modify. Place the config in the lchan, change
the gsm48 methods to not take the argument, change the RSL
implementation to make use of it with the right IE.
The other code should use the t(l)v_put routines as well but
were left untouched for now.
Keep track of which SAPIs have been established either by the
BTS (from the MS) or by us. This can be used by the on-waves
BSC code to figure out if a new request should be made.
The channel allocator can be set in ascending or descending order.
Ascnending means we first try to allocate channels on TRX0, then TRX1, etc.
Descending means we first try to allocate cahnnels on TRXn, then n-1 down to 0.
So far, we immediately disable the RF channel without following a proper
RLL RELEASE procedure. This patch changes this.
If we locally terminate the connection, the channel allocator now triggers a
RLL RELEASE REQuest, which is responsed by the MS with a RLL RELEASE CONFirm,
based on which we send the RF CHANnel RELease to the BTS.
If the MS terminates the connection, we receive a RLL RELEASE INDication,
based on which we trigger RF CHANnel RELease to the BTS.
This is Harald's reworked MNCC base, slowly heading towards integration
into master. The key changes are:
* provide much more structure to the data in gsm_mncc
* encode_* and decode_* functions now take a structure rather than tons
of individual arguments (whose order nobody can remember)
* make sure we don't have copies of the same code everywhere by introducing
mncc_set_cause() and mncc_release_ind()
* save horizontal screen space if possible
* make sure we break lines > 80 characters
Harald Welte
Holger Hans Peter Freyther
Sylvain Munaut