Installing a OsmoTRX based GSM network from scratch¶
- Table of contents
- Installing a OsmoTRX based GSM network from scratch
DISCLAIMER¶
This page is user-contributed information, and not official documentation by the Osmocom project. It might be outdated or inaccurate.
Please help by improving this document, or reporting any issues to the relevant mailing list.
This document is outdated by now and only applies if you would like to use hardware based on OsmoTRX!
THE CONFIG FILES ON THIS PAGE ARE PROBABLY OUTDATED. You may try the examples found in git, e.g. here and here.
This document describes how to install, configure and run OsmoTRX, OsmoBTS, OsmoNITB and LCR.
In order to use this quick howto, you must have basic knowledge about GIT and be familiar with compiling packages from source.
Prerequisite¶
These packages may be available from you distribution. If not, install them by hand as follows.
opencore-amr (optional, for LCR only)¶
This package installs GSM adaptive multirate codecs and the EFR codec. The Full-Rate codec is included in LCR's repository.
tar xvzf opencore-amr-x.x.x.tar.gz cd opencore-amr-x.x.x ./configure make make install ldconfig cd ..
Sip-Sofia (optional, for LCR only)¶
This package installs the open source SIP stack of Nokia Research Center.
It can be downloaded at http://sourceforge.net/projects/sofia-sip/files/sofia-sip/":http://sourceforge.net/projects/opencore-amr/files/opencore-amr/
tar xvzf sofia-sip-x.xx.xx.tar.gz cd sofia-sip-x.xx.xx ./configure make make install ldconfig cd ..
oRTP¶
This package installs the open source RTP protocol required for libosmo-abis.
tar xvzf ortp-x.xx.x.tar.gz cd ortp-x.xx.x ./configure make make install ldconfig cd ..
others¶
sqlite3, libdbi, dbd-sqlite3 (driver) should should be available from your distribution.
Building and installing¶
Build the following projects according to Build from source:
- libosmocore
- libosmo-abis
- openbsc
- osmobts with
./configure --enable-trx - osmotrx
Additional information related to OsmoTRX is available at OsmoTRX.
Linux-Call-Router (LCR) (optional)¶
This package installs the open source PBX software to bridge ISDN (DSS1) / SIP / GSM (MNCC protocol)
The latest version can downloaded via git:
git clone http://git.eversberg.eu/lcr.git
Now configure, as described here:
cd lcr autoreconf -i ./configure --with-sip --with-gsm-bs --with-gsm-ms
I strongly suggest not to use the Half-Rate codec (--enable-gsmhr) except for testing, because this codec is so slow, that only one or two calls may occupy CPU completely.
Sometimes it is necessary to point to different pkgconfig path, because your distribution may use other pkgconfig path than the default path of the packages above. Use the following prefix:
PKG_CONFIG_PATH=/usr/local/lib/pkgconfig/ ./configure .....
The configure result should include:
configure: Compiled with GSM network side support configure: Compiled with GSM mobile side support configure: Compiled with GSM half rate codec support configure: Compiled with GSM AMR codec support configure: Compiled with SIP support
Finish the installation:
make make install ldconfig cd ..
Configuration examples¶
OsmoBTS¶
mkdir ~/.osmocom edit ~/.osmocom/osmo-bts.cfg
bts 0 band DCS1800 ipa unit-id 1801 0 oml remote-ip 127.0.0.1 rtp bind-ip 127.0.0.1 rtp jitter-buffer 0 paging lifetime 0 gsmtap-sapi bcch gsmtap-sapi ccch gsmtap-sapi rach gsmtap-sapi agch gsmtap-sapi pch gsmtap-sapi sdcch gsmtap-sapi pacch gsmtap-sapi pdtch gsmtap-sapi sacch fn-advance 20 ms-power-loop -10 timing-advance-loop trx 0 rxgain 0 power 0
OpenBSC¶
mkdir ~/.osmocom edit ~/.osmocom/open-bsc.cfg
Be sure to change 'arfcn' to a frequency you have license for!
e1_input
e1_line 0 driver ipa
e1_line 0 port 0
network
network country code 262
mobile network code 42
short name [[OpenBSC]]
long name [[OpenBSC]]
auth policy accept-all
location updating reject cause 13
encryption a5 0
neci 1
paging any use tch 0
rrlp mode ms-based
mm info 1
handover 0
handover window rxlev averaging 10
handover window rxqual averaging 1
handover window rxlev neighbor averaging 10
handover power budget interval 6
handover power budget hysteresis 3
handover maximum distance 9999
timer t3101 10
timer t3113 60
timer t3122 10
dtx-used 0
subscriber-keep-in-ram 0
bts 0
type sysmobts
band DCS1800
cell_identity 0
location_area_code 1
training_sequence_code 7
base_station_id_code 63
ms max power 0
cell reselection hysteresis 4
rxlev access min 0
periodic location update 30
channel allocator descending
rach tx integer 9
rach max transmission 7
channel-descrption attach 1
channel-descrption bs-pa-mfrms 5
channel-descrption bs-ag-blks-res 1
ip.access unit_id 1801 0
oml ip.access stream_id 255 line 0
neighbor-list mode automatic
trx 0
rf_locked 0
arfcn 869
nominal power 0
max_power_red 0
rsl e1 tei 0
timeslot 0
phys_chan_config CCCH+SDCCH4
hopping enabled 0
timeslot 1
phys_chan_config TCH/F
hopping enabled 0
timeslot 2
phys_chan_config TCH/F
hopping enabled 0
timeslot 3
phys_chan_config TCH/F
hopping enabled 0
timeslot 4
phys_chan_config TCH/F
hopping enabled 0
timeslot 5
phys_chan_config TCH/F
hopping enabled 0
timeslot 6
phys_chan_config TCH/F
hopping enabled 0
timeslot 7
phys_chan_config TCH/F
hopping enabled 0
Linux-Call-Router (LCR) (optional)¶
options.conf¶
edit /usr/local/etc/lcr/options.conf
Add a line to show logging to the console:
debug 0x100000
interface.conf¶
The simplest configuration uses only the GSM interface. It allows LCR to forward calls from GSM to GSM or from GSM to a call test feature.
edit /usr/local/etc/lcr/interface.conf
You can remove (or comment out) everything and just add this interface:
[gsm] gsm-bs tones yes earlyb no extern
routing.conf¶
edit /usr/local/etc/lcr/routing.conf
You can remove (or comment out) everything and just add these rulesets:
[main]
interface=gsm : goto ruleset=gsm
: disconnect cause=31
[gsm]
dialing=99 : test
: extern interfaces=gsm
Look at the main rule set. All calls from interface 'gsm' are forwarded to rule set 'gsm'.
Look at the gsm rule set. All calls that dial '99' prefix, will be test calls. All other calls will be forwarded back to 'gsm' interface.
Running¶
I suggest to have one shell for every process to run, rather than stating all processes as damon from one shell. Not starting as deamon allows to easily see the debugging output.
OpenBSC¶
Open a shell and start OpenBSC:
osmo-nitb -c ~/.osmocom/open-bsc.cfg -l ~/.osmocom/hlr.sqlite3 -P -C --debug=DRLL:DCC:DMM:DRR:DRSL:DNM
OpenBSC runs as a stand-alone network with given config file and data base. In order to use LCR, add '-m' option. In this case the LCR replaces the built-in call control.
osmo-nitb -c ~/.osmocom/open-bsc.cfg -l ~/.osmocom/hlr.sqlite3 -P -m -C --debug=DRLL:DCC:DMM:DRR:DRSL:DNM
Very important is the option '-C'. On certain machines, osmo-nitb will halt from time to time while writing counters to database. This Without this option, audio might interrupt several seconds from time to time.
The debugging is usefull for early tests, because you will quickly see what happens if a mobile requests something.
<0005> bsc_init.c:422 WARNING: You are running an 'accept-all' network on a BTS that is not barred. This configuration is likely to interfere with production GSM networks and should only be used in a RF shielded environment such as a faraday cage! <0019> input/ipaccess.c:925 enabling ipaccess BSC mode DB: Database initialized. DB: Database prepared. <001d> sms_queue.c:220 Attempting to send 20 SMS
OsmoBTS¶
Open a shell and start OsmoBTS:
osmobts-trx -c ~/.osmocom/osmo-bts.cfg
((*)) | / \ [[OsmoBTS]] Using MAC address of eth0: 'xx:xx:xx:xx:xx:xx' ... <000a> trx_if.c:176 No response from tranceiver <000a> trx_if.c:176 No response from tranceiver <000a> trx_if.c:176 No response from tranceiver
OsmoTRX¶
Refer to the OsmoTRX page on how to run OsmoTRX.
UmTRX¶
The installation/setup/calibration of UmTRX is beyond the scope of this document. Please refer to:
- https://github.com/fairwaves
- http://files.ettus.com/uhd_docs/manual/html/build.html
- http://wush.net/trac/rangepublic/wiki/BuildInstallRun
calypso-BTS¶
Building Osmocom-BB with arm-elf toolchain is also beyond the scope of this document. If you managed to compile and run Osmocom-BB you should be able to run the transceiver too.
The latest version can downloaded via git:
git clone https://gitea.osmocom.org/sdr/libosmo-dsp git clone https://gitea.osmocom.org/phone-side/osmocom-bb
In order to compile Osmocom-BB with transceiver support, do the following:
cd libosmo-dsp autoreconf -i ./configure (sometimes it is necessary to point to different .../lib/pkgconfig/ path: PKG_CONFIG_PATH=/usr/local/lib/pkgconfig/ ./configure .....) make make install cd .. cd osmocom-bb # change branch: git checkout -b jolly/testing origin/jolly/testing cd src make # after it compiles, just enable transceiver support cd host/layer23 ./configure --enable-transceiver make
NOTE: "ms-power-loop" at osmo-bts.cfg should be set to -65, in order to prevent saturating the input. Also if the phone is only one or few meters away, "ms max power" should be set to 0. In case of long distance test it can be set to 30 (DCS) or 33 (GSM 900).
Now you should start with a single phone for one timeslot only. If it works, you can try two phones to serve two timeslots. Since you have only one slot, you will only be able to transmit broadcast, do location updating and send/receive SMS. Here is the "osmo-bts.cfg" for a single timeslot:
bts 0 band DCS1800 ipa unit-id 1801 0 oml remote-ip 127.0.0.1 rtp jitter-buffer 0 paging queue-size 200 paging lifetime 0 fn-advance 30 ms-power-loop -60 timing-advance-loop settsc setbsic trx 0 rxgain 0 power 0 slotmask 1 0 0 0 0 0 0 0
Run osmocon and transceiver application in separate shells:
# Please refer to Osmocom-BB wiki for compiling and running own firmware on compal phones... osmocon -p /dev/ttyUSB0 -m c123xor -c path_to/trx.highram.bin -r 99
transceiver -e 5 -r 99
When using two phones, two timeslots can be served. I suggest to configure second timeslot (TS 1) as TCH/H at openbsc.cnf. This way it is possible to allow two traffic channels on a single timeslot. If you do a call from one phone to another, you will need one channel for each phone. In order to use two phones, you need to change the alot map of osmo-bts.cnf:
slotmask 1 1 0 0 0 0 0 0
Run two osmocon and transceiver application in separate shells:
osmocon -p /dev/ttyUSB0 -m c123xor -c path_to/trx.highram.bin -r 99
# This osmocon connects to the serial interface of the second phone. # Note: "/tmp/osmocom_l2.2" is the second socket to which the transceiver will connect. osmocon -p /dev/ttyUSB1 -s /tmp/osmocom_l2.2 -m c123xor -c path_to/trx.highram.bin -r 99
transceiver -e 5 -r 99 -2
Linux-Call-Router (LCR) (optional)¶
Run LCR with debugging output.
lcr start
** LCR Version 1.14 LCR 1.14 started, waiting for calls...
Test¶
Location Updating¶
Switch on the phone.
If you have a SIM card for your network 262 42, you can use it and do automatic network search. If not, do a manual network and select this network. You should see debugging output on OpenBSC like this:
... <0002> gsm_04_08.c:424 -> LOCATION UPDATE ACCEPT ...
Call the music (LCR required)¶
Now enter phone number 995 to select the test function 5 of LCR. This test function just plays the hold music.
Echo and BFI test (LCR required)¶
Enter phone number 993 to select the test function 3 of LCR. This test function echoes back everything that is received. Note that it will re-transcode the speech data, so the audio from your voice is compressed and decompressed twice until you can hear a fraction of a second later.
You may experience short beeps. These beeps represent all bad frames that could not be decoded or got lost over the air. (Without this test, the missing frames will be extrapolated from previous frame, so some loss rate will not be recognized by the remote end.)
See also¶
- Multi-BTS with handover -- NITB plus two dual channel BTS (based on OsmoBTS) with handover support
Updated by laforge 21 days ago · 48 revisions
