Cellular Network Infrastructure » cni-legacy » OpenBSC

[[PageOutline]]

'''OpenBSC''' is the current name for a software program that started with the name bs11-abis.

== What is OpenBSC ==

It is a [wiki:BSC] (Base Station Controller) side implementation of the A-bis protocol, as implemented in the GSM Technical Specification 08.5x and 12.21.  It implements a minimal subset of the [wiki:BSC], [wiki:MSC] and [wiki:HLR].  It does not implement ant of the interfaces (like the A and B interfaces) between the higher-order GSM network components.

The goal of the project is to

 * provide a basis for experimentation and security research with GSM from the network side

 * document, publicized and point out any security related issues that we find as part of that

 * learn more about GSM networks on a lower level, particularly the practical aspects with real-world equipment

We '''are not interested''' in

 * building a stable/reliable BSC/MSC for deployment in actual networks

 * building something that follows the GSM spec to the last detail

 * disrupting actual commercial GSM network

== Requirements ==

While OpenBSC is mainly written in portable C99 code, there are some non-portable parts:

 * The E1 input driver requires a Linux kernel with mISDN support and an [wiki:E1] interface card compatible with [wiki:mISDN]

To opertate a GSM network, you not only need OpenBSC but of course also some kind of GSM [wiki:BTS].  The only currently tested configurations are with a

 * Siemens [wiki:BS11 BS-11] microBTS

 * [wiki:nanoBTS ip.access nanoBTS]

== Source code ==

=== Releases ===

As we're a mostly research oriented project, we don't really have any releases yet.  This will likely change soon.

=== Development Version ===

You can check out the source code via

{{{

git clone git://openbsc.gnumonks.org/openbsc.git

}}}

or browse it at http://openbsc.gnumonks.org/trac/browser

== Mailing list ==

There's a developer mailing list called openbsc@lists.gnumonks.org

Subscription is available at [http://lists.gnumonks.org/mailman/listinfo/openbsc/]

== IRC (Internet Relay Chat) ==

We have an IRC channel where some developers and users hang out.  You can find it at:

irc.freenode.net/#openbsc

== Project status ==

=== Things that work ===

 * Housekeeping

  * [wiki:OML] Initialization of the BTS

  * [wiki:RSL] bringup, channel allocation, Channel required / Immediate Assign

 * Mobility Management

  * Very simplistic [wiki:HLR] implemented as sqlite database

  * Non-secure Authentication using [wiki:IMEI]/[wiki:IMSI] and regular SIM cards.

  * [wiki:IMEI]/[wiki:IMSI] skimming of all phones that try to register with OpenBSC

  * Transmission of MM INFO packets with operator name and local time / timezone

  * paging of mobiles that are registered to the BTS

  * keeping track of which location area a phone has last performed location updating

  * in-call handover between multiple cells inside one BSC

 * SMS Support

  * [wiki:SMS] reception and [wiki:SMS] sending, including routing between subscribers

  * Sending of SMS from OpenBSC commandline

  * Sending of SMS from external applications by writing to the SQL tables

 * Voice Call Support

  * MO (Mobile Originated) and MT (Mobile Terminated) calls

  * TCH/F support with FR and EFR codec

  * TCH/H support with AMR codec (in BSC-only configuration)

 * E1 support

  * demultiplex of the four 16k sub-channels with voice data contained in one [wiki:E1] timeslot

  * support for multiple [wiki:TRX] in one [wiki:BTS]

  * support for multiple [wiki:BTS] connected to the same E1 link (multi-loop configuration)

 * Abis/IP support

  * Abis/IP protocol for nanoBTS

  * RTP gateway to interoperate E1 based BTS and nanoBTS on one BSC and switch calls between them

 * GPRS/EDGE support

  * configuring the nanoBTS OML objects/attributes for GPRS and EDGE

  * setting SYSTEM INFORMATION 13 via RSL

  * configurable RAID/CGI/NSVCI/NSEI/BVCI

  * have the BTS interoperate a SGSN with Gb (NS-over-IP) interface

=== Things that are implemented but don't work yet or aren't tested yet ===

 * GPRS support (SGSN + GGSN inside OpenBSC)

 * Support the use of A3/A8 and A5/1 (we need SIM cards with known Ki, e.g. simulated SIM cards)

=== Things being worked at ===

 *  GPS/DCF77 disciplined quartz reference for the HFC-E1 card (via HS-Esslingen, Student Research Project)

=== Things that are missing ===

 * Cell Broadcast

 * transcoding of voice data

 * TCH/H voice calls (in standalone config)

 * [wiki:CSD] calls

 * emergency call handling

 * Discontinuous TX and RX ([wiki:DTX] / [wiki:DRX]) support

== Authors ==

OpenBSC was mainly developed by [http://laforge.gnumonks.org/ Harald Welte]. Contributions by Holger Freyther, Stefan Schmidt, Daniel Willmann, Jan Luebbe, Thomas Seiler and Andreas Eversberg.

Special thanks to Dieter Spaar for [wiki:BS11-Init] and tons of feedback and comments, without which we would not have been able to make progress as quickly as we did.