The support has been implemented for an old model, we were told that
newer versions would be made incompatible with OpenBSC. Ther are
various warnings in the code and coverity has found some new ones.
Just remove the code as we don't know of anyone using this code.
Inside the SI1 rest_octets we will need to indicate if the ARFCN
is band 1800 or 1900. If the BTS is either 850 or 1900 we assume
we are running a PCS network, otherwise it is a DCS network.
The band indicator is not documented in GSM 04.08 but it is in the
GSM 05.14 version 6.1.0 Release 1997.
For PCS1900 the SI1 does not contain the ARFCN of the serving cell.
This is because the arfcn2band method will return GSM_BAND_1800 and
not GSM_BAND_1900. The academic fix would be to set the ARFCN_PCS bit
but this would require increasing the bitvector sizes from 1024/8 to
(0x8000 + 1024) / 8. This would increase the storage size for each
bitvector by three.
It is not possible to have DCS1800 and PCS1900 in one network so we
can avoid increasing the memory usage and check if the ARFCN resolved
to 1800 and then check if the BTS is a 1900 BTS and then claim that
this is compatible.
I saw the old copy of the "Appendix J" code too late and I have
discovered some quirks and I am more familar with my implementation.
Most noticable 'w' only needs to be as big as the input arfcn but
requires the 'w' to be initialized. The power_of_2 implementation
differs as well (mine matches the output of wirehsark).
The f0 could be chosen in a better way but right now picking
the lower bound is the easiest. It is not clear if to use
modulo if the range is chosen in the middle. This can be improved
in the future. Right now I have no bit fiddling for range128, 256
and 1024 as I was running out of time.
alpha=0 (the new value) doesn't reduce MS transmission power during GPRS
as much as we did with alpha=10. This is to optimize for coverage and
to keep GPRS working at all cost, and not care about MS battery life
time or uplink interference in surrounding cells.
FIXME: This should be made configurable via the VTY and the normal
default (unless configured otherwise by vty/config file) should be '6'.
In order to keep mobile at PACCH as long as possible the timer T3192 is
set to 1500ms. This reduces the probablity of long lasting assignment
process on CCCH for subsequent downlink TBFs.
so far, osmo-bts/sysmobts used to be entered as "sysmobts" type in the
configuration file. However, there are some differences in the
protocol/behaviour and we should reflect that by a new BTS plugin (with
lots of code reuse from the nanobts driver).
In addition to SI 2 and SI 5, the SI 2ter and 2bis is generated, if
neighbour cells in other bands exist. Also it is indicated in the rest
octets of SI3, that SI 2ter is used. If no neighbour cell in a different
band exists, the SI 2ter and SI 5ter is omitted.
A special case is P-GSM range (channels 1-124). To be compatible with
older phones, SI 2bis and SI 5bis is used. If the BCCH lays inside the
P-GSM band, only neighbour cells of the P-GSM range are included in
SI 2 and SI 5. If neighbour cells exist in the same band (900), but lay
outside the P-GSM range, the SI 2bis and SI 5bis is used to extend the
list of neighbour cells. The extension is also indicated in SI 2 and
SI 5. If the BCCH lays inside the P-GSM range, but no neighbour cell
exists in the same band outside the P-GSM range, the SI 2bis ans SI 5bis
are omitted.
libosmogsm is a new library that is distributed in the libosmocore.
Now, openbsc depends on it. This patch gets openbsc with this
change.
This patch also rewrites all include path to the new
osmocom/[gsm|core]
Signed-off-by: Pablo Neira Ayuso <pablo@gnumonks.org>
The HSL Femtocell seems to be a poor man implementation of the
ip.access Abis/IP protocol, but cutting corners wherever possible.
We try to workaround those corners wherever possible...
Holger Hans Peter Freyther
Harald Welte
Sylvain Munaut
Dieter Spaar