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gerrit.osmocom.org / libosmocore / 9e713f382897fe341ada39bf6a0a4d6027d1f26d
commit9e713f382897fe341ada39bf6a0a4d6027d1f26d[log] [tgz]
authorVadim Yanitskiy <axilirator@gmail.com>Tue Mar 31 19:40:09 2020 +0700
committerVadim Yanitskiy <axilirator@gmail.com>Wed Apr 01 01:09:31 2020 +0700
tree5f9c402a97c31247f5926b3a6cece20d11be6514
parent41ce6753bc0e5ed449df9906ba181aa2b3602e93 [diff]
coding: fix bit ordering in 11-bit RACH coding functions

According to 3GPP TS 44.004, figure 7.4a.b, the format of 11-bit
RACH uplink / Uplink access burst block is as defined follows:

  <---------------------------------------------------

      8     7     6     5     4     3     2     1
  +--------------------------------------------------+
  |  11 bit RACH uplink / Uplink access burst block  | OCT1
  +--------------------------------------------------+
                                 |                   | OCT2
                                 +-------------------+

As was (correctly) assumed in [1], the bit ordering in 11-bit RACH
coding functions is wrong. The problem is that neither of generic
functions from bit16gen.h can be used to load / store the RA11
value (regardless of the endianness), because they assume that
the payload is 16 bit long.

With this patch applied, RA11 values from [1] look correct:

  < EGPRS Packet channel request message content > ::=
    < Signalling : 110011  < RandomBits : 00111 > > |
    < Signalling : 110011  < RandomBits : 00110 > > |
    < Signalling : 110011  < RandomBits : 01111 > > |
    < Signalling : 110011  < RandomBits : 01100 > > |
    < Signalling : 110011  < RandomBits : 00111 > > |
    < Signalling : 110011  < RandomBits : 10110 > > ;

[1] Id80e471d252b9416217b56f4c8c0a8f5f1289fee

Change-Id: I43d30611dd69f77f2b3b46f4b56056a8891d3c24
Related: OS#1548
2 files changed
tree: 5f9c402a97c31247f5926b3a6cece20d11be6514
  1. contrib/
  2. debian/
  3. doc/
  4. include/
  5. m4/
  6. src/
  7. tests/
  8. utils/
  9. .gitignore
  10. .gitreview
  11. .mailmap
  12. configure.ac
  13. COPYING
  14. Doxyfile.codec.in
  15. Doxyfile.coding.in
  16. Doxyfile.core.in
  17. Doxyfile.ctrl.in
  18. Doxyfile.gb.in
  19. Doxyfile.gsm.in
  20. Doxyfile.vty.in
  21. git-version-gen
  22. libosmocodec.pc.in
  23. libosmocoding.pc.in
  24. libosmocore.pc.in
  25. libosmoctrl.pc.in
  26. libosmogb.pc.in
  27. libosmogsm.pc.in
  28. libosmosim.pc.in
  29. libosmousb.pc.in
  30. libosmovty.pc.in
  31. Makefile.am
  32. osmo-release.mk
  33. osmo-release.sh
  34. README.md
  35. TODO-RELEASE
README.md

libosmocore - set of Osmocom core libraries

This repository contains a set of C-language libraries that form the core infrastructure of many Osmocom Open Source Mobile Communications projects.

Historically, a lot of this code was developed as part of the OpenBSC project, but which are of a more generic nature and thus useful to (at least) other programs that we develop in the sphere of Free Software / Open Source mobile communications.

There is no clear scope of it. We simply move all shared code between the various Osmocom projects in this library to avoid code duplication.

The libosmcoore.git repository build multiple libraries:

  • libosmocore contains some general-purpose functions like select-loop abstraction, message buffers, timers, linked lists
  • libosmovty contains routines related to the interactive command-line interface called VTY
  • libosmogsm contains definitions and helper code related to GSM protocols
  • libosmoctrl contains a shared implementation of the Osmocom control interface
  • libosmogb contains an implementation of the Gb interface with its NS/BSSGP protocols
  • libosmocodec contains an implementation of GSM voice codecs
  • libosmocoding contains an implementation of GSM channel coding
  • libosmosim contains infrastructure to interface SIM/UICC/USIM cards
  • libosmotrau contains encoding/decoding functions for A-bis TRAU frames

Homepage

The official homepage of the project is https://osmocom.org/projects/libosmocore/wiki/Libosmocore

GIT Repository

You can clone from the official libosmocore.git repository using

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

There is a cgit interface at http://git.osmocom.org/libosmocore/

Documentation

Doxygen-generated API documentation is generated during the build process, but also available online for each of the sub-libraries at http://ftp.osmocom.org/api/latest/libosmocore/

Mailing List

Discussions related to libosmocore are happening on the openbsc@lists.osmocom.org mailing list, please see https://lists.osmocom.org/mailman/listinfo/openbsc for subscription options and the list archive.

Please observe the Osmocom Mailing List Rules when posting.

Contributing

Our coding standards are described at https://osmocom.org/projects/cellular-infrastructure/wiki/Coding_standards

We us a gerrit based patch submission/review process for managing contributions. Please see https://osmocom.org/projects/cellular-infrastructure/wiki/Gerrit for more details

The current patch queue for libosmocore can be seen at https://gerrit.osmocom.org/#/q/project:libosmocore+status:open