Cellular Network Infrastructure

[[PageOutline]]

= Installing a GSM network from scratch =

This document describes how to install, configure and run BTS transceiver, OsmoBTS, OpenBSC 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 ==

=== opencore-amr ===

This package installs GSM adaptive multirate codecs

It can downloaded at [http://sourceforge.net/projects/opencore-amr/files/opencore-amr/]

{{{

tar xvzf opencore-amr-x.x.x.tar.gz

cd opencore-amr-x.x.x

./configure

make

make install

ldconfig

cd ..

}}}

=== Sip-Sofia ===

This package installs the open source SIP stack of Nokia Research Center.

It can downloaded at [http://sourceforge.net/projects/sofia-sip/files/sofia-sip/].

{{{

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.

It can downloaded at [http://download.savannah.gnu.org/releases/linphone/ortp/sources/].

{{{

tar xvzf ortp-x.xx.x.tar.gz

cd ortp-x.xx.x

./configure

make

make install

ldconfig

cd ..

}}}

=== others ===

sqlite3 and libdbi should be available from your distribution.

== Installing  ==

=== Linux-Call-Router (LCR) ===

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 git://git.misdn.eu/lcr.git/

}}}

Now configure, as described here:

{{{

cd lcr

autoreconf -i

./configure --with-sip --with-gsm-bs --with-gsm-ms --enable-gsm-hr

}}}

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 ..

}}}

=== libosmocore ===

This package installs the core utility library for various Osmocom projects.

The latest version can downloaded via git:

{{{

git clone git://git.osmocom.org/libosmocore.git

}}}

Finish the installation:

{{{

cd libosmocore

git checkout -b

autoreconf -i

./configure

make

make install

ldconfig

cd ..

}}}

=== libosmo-abis ===

This package installs the core utility library for various Osmocom projects.

The latest version can downloaded via git:

{{{

git clone git://git.osmocom.org/libosmo-abis.git

}}}

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 .....

}}}

Finish the installation:

{{{

cd libosmo-abis

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

ldconfig

cd ..

}}}

=== OpenBSC ===

This package installs the open source base station controller.

The latest version can downloaded via git:

{{{

git clone git://git.osmocom.org/openbsc.git

}}}

Finish the installation:

{{{

cd openbsc/openbsc/

change repository: git checkout -b jolly/testing origin/jolly/testing

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 ../..

}}}

=== OsmoBTS ===

osmo-bts: (BTS software)

This package installs the open source base transceiver station.

The latest version can downloaded via git:

{{{

git clone git://git.osmocom.org/osmo-bts.git

}}}

Finish the installation:

{{{

cd osmo-bts

change repository: git checkout -b jolly/trx origin/jolly/trx

autoreconf -i

./configure --enable-trx

(sometimes it is necessary to point to different .../lib/pkgconfig/ path: PKG_CONFIG_PATH=/usr/local/lib/pkgconfig/ ./configure .....)

make

make install

cd ..

}}}

== Configuration examples ==

=== OpenBTS ===

{{{

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

 radio-link-timeout 32

 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

}}}

{{{

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 t3103 0

 timer t3105 0

 timer t3107 0

 timer t3109 0

 timer t3111 0

 timer t3113 60

 timer t3115 0

 timer t3117 0

 timer t3119 0

 timer t3122 10

 timer t3141 0

 dtx-used 0

 subscriber-keep-in-ram 0

 bts 0

  type nanobts

  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

  codec-support fr hr efr afs ahs

  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

=== LCR ===

==== 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.