OsmoBTS¶

OsmoBTS is a software implementation of a GSM BTS.

It implements the follwing protocols/interfaces:

• LAPDm (GSM 04.06)
• RTP
• A-bis/IP in IPA multiplex
• OML (GSM TS 12.21)
• RSL (GSM TS 08.58)

OsmoBTS is building up on work done previosuly for OpenBSC (e.g. RSL, OML, RTP) and OsmocomBB (e.g. LAPDm). The Abis/IP protocol staking is inspired by ip.access A-bis/IP, sometimes called IPA multiplex.

OsmoBTS in the Osmocom architecture¶

OsmoBTS in a GSM + GPRS/EDGE network using OsmoNITB¶

OsmoBTS in a GSM + GPRS/EDGE network using OsmoBSC and OsmoMSC¶

Backends / Hardware support¶

OsmoBTS is modular and has support for multiple back-ends. A back-end talks to a specific L1/PHY implementation of the respective BTS hardware. Based on this architecture, it should be relatively easy to add a new back-end to support so-far unsupported GSM PHY/L1 and associated hardware.

So far OsmoBTS has been integrated with several different L1/PHY and hardware systems. The backends are:

• osmo-bts-sysmo
  • Multiple indoor and outdoor BTS products called sysmoBTS by sysmocom
• osmo-bts-sysmo-remote
  • Allows forwarding over UDP of the Layer1 to the sysmoBTS hardware, while running osmo-bts-sysmo-remote on (for example) x86 hardware.
• osmo-bts-trx
  • Wideband SDR transceiver hardware supported by OpenBTS transceiver or OsmoTRX PHY layer software, including the UmTRX, the USRP family, etc.
  • Multiple indoor and outdoor fairwaves BTSs, like UmDESK and UmSITE
• osmo-bts-litecell15
• osmo-bts-octphy
• osmo-bts-bb
  • A pretty crazy experimental BTS hardware based on two OsmocomBB phones had originally been supported, but needs to be re-integrated with core code changes.

Binary Packages¶

Osmocom provides binary packages for several flavors of Debian and Ubuntu GNU/Linux on a variety of architectures (i586, x86_64, armhf, armv7l). Unless you are a software developer interested in developing on Osmocom, it is recommended you use those packages instead of building from source.

For more details see Binary_Packages

Manuals¶

• OsmoBTS User Manual
• OsmoBTS VTY Reference: osmo-bts-lc15, osmo-bts-oc2g, osmo-bts-octphy, osmo-bts-sysmo, osmo-bts-trx, osmo-bts-virtual
• OsmoBTS Abis Protocol Manual

GPRS support¶

In the GSM architecture, the BTS is an element in the circuit-switched domain only.

For packet-switched support, OsmoBTS provides a socket interface towards OsmoPCU. This adds GPRS and EDGE support to it.

Source code¶

The source code is available from git.osmocom.org (module osmo-bts).

Public read-only access is available via

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

You can browse it via cgit: https://git.osmocom.org/osmo-bts/

Test Suite¶

We have a TTCN-3 test suite for OsmoBTS as part of our Titan_TTCN3_Testsuites

• source code: http://git.osmocom.org/osmo-ttcn3-hacks/tree/bts
• results: https://jenkins.osmocom.org/jenkins/view/TTCN3/job/ttcn3-bts-test/

Authors / Credits¶

OsmoBTS was originally developed in 2011 by Andreas Eversberg and Harald Welte.

Today it is mostly maintained by Harald Welte and his team at sysmocom.

Commercial Support¶

Commercial support as well as development, system integration and training services for this project are available from sysmocom