osmocom-bb

History

Vadim Yanitskiy 5516b42336 trxcon/scheduler: fix handling of PTCCH logical channel According to 3GPP TS 45.010, section 5.6.2, for packet-switched channels the BTS shall monitor the delay of the Access Bursts sent by the MS on PTCCH and respond with timing advance values for all MS performing the procedure on that PDCH. According to 3GPP TS 45.002, section 3.3.4.2, PTCCH (Packet Timing advance control channel) is a packet dedicated channel, that is used for continuous Timing Advance control (mentioned above). There are two sub-types of that logical channel: - PTCCH/U (Uplink): used to transmit random Access Bursts to allow estimation of the Timing Advance for one MS in packet transfer mode. - PTCCH/D (Downlink): used by the network to transmit Timing Advance updates for several MS. As per 3GPP TS 45.003, section 5.2, the coding scheme used for PTCCH/U is the same as for PRACH as specified in subclause 5.3, while the coding scheme used for PTCCH/D is the same as for CS-1 as specified in subclause 5.1.1. The way we used to handle both PTCCH/U and PTCCH/D is absolutely wrong - it has nothing to do with xCCH coding. Instead, we need to use rx_pdtch_fn() for Downlink and tx_rach_fn() for Uplink. Also, since we only have a shared RSL channel number for PDCH (Osmocom-specific RSL_CHAN_OSMO_PDCH), there should be a way to distinguish both PDTCH and PTCCH logical channels. Let's introduce TRX_CH_LID_PTCCH for that. Change-Id: I2d1e9b8a66f027047f8d7bdc3f82ff9d8ebcc25e		2019-09-30 20:50:28 +07:00
..
host	trxcon/scheduler: fix handling of PTCCH logical channel	2019-09-30 20:50:28 +07:00
shared	vty: skip installing cmds now always installed by default	2017-11-09 01:14:49 +00:00
target	trx_toolkit/data_msg.py: enrich some ValueError messages	2019-08-29 18:02:04 +02:00
target_dsp	target_dsp/bin2cfile.py: make it compatible with python3	2019-07-11 16:10:43 +02:00
Makefile	Merge 'fixeria/trx' into master	2018-04-07 19:35:24 +02:00
README.building	README.building: cosmetic: correct wiki links	2018-05-20 15:34:16 +03:00
README.development	README.development: add brief info about the TRX Toolkit	2018-05-20 15:46:20 +03:00

README.development

= Contributing to OsmocomBB development =

Feel free to help us by extending the code.  Always make sure to
send back all your patches to Gerrit (recommended) or to the
baseband-devel@lists.osmocom.org mailing list - Free Software
is all about sharing. For details, see:

https://osmocom.org/projects/cellular-infrastructure/wiki/Gerrit
https://gerrit.osmocom.org/

== Coding Style ==

Like all C language Osmocom projects, we use the Linux Kernel coding
style, you can find it in the Documentation/CodingStyle subdirectory
of any Linux Kernel source. For details, see:

https://osmocom.org/projects/cellular-infrastructure/wiki/Coding_standards

== More Information ==

Please consult the https://osmocom.org/projects/baseband/wiki/.

If you have any technical questions regarding the code, don't hesitate
to ask the baseband-devel@lists.osmocom.org mailing list.

== subdirectories containing libraries and code ==

=== src/shared/libosmocore ===

This is a library of various utility routines, including linked lists,
message buffers, bit-vectors, memory allocator, signals, select loop
handling, timers - as well as some more specifically GSM related things
like a TLV parser, a Comp128V1 implementation and utility functions for
RSL (TS 08.58) and CC/MM/RR (TS 04.08).

libosmocore is maintained in git://git.osmocom.org/libosmocore.git, so

	DO NOT DIRECTLY COMMIT TO libosmocore IN THIS REPOSITORY!

We simply maintain a copy (synchronized by git-subtree) in this
repository for the ease of building and to make sure everyone is using
the proper/compatible version of libosmocore

Please note, whatever you add to libosmocore will need to build as a
Linux userspace program (using glibc) just as well as on the OsmocomBB
embedded target without OS.  So please refrain from using fancy
functions.


=== src/target/firmware ===

The firmware is what we build for the actual target (phone).  It was
written with some idea of modularity in mind, i.e. we have

 * Ti Calypso specific code in calypso/
 * Analog Baseband code in abb/
 * RF Mixer code in rf/
 * Layer1 code in layer1/
 * NOR flash handling in flash/
 * LCD display handling in display/
 * minimal C-Library code in lib/
 * communications utility routines in comm/
 * Board (phone model/family) specific code in board/
   * board/compal_e88 is the Motorola C115-C124 family
   * board/compal_e99 is the Motorola C155 family
 * Applications (each app builds one firmware image) in apps/

=== src/target/trx_toolkit ===

A set of tools in Python for debugging TRX interface and creating
a virtual Um-interface between OsmocomBB and OsmoBTS. For details,
please refer:

https://osmocom.org/projects/baseband/wiki/TRX_Interface
https://osmocom.org/projects/baseband/wiki/FakeTRX
target/trx_toolkit/README

=== src/target_dsp/calypso ===

This is where we keep some (assembly) code that we wrote for
the DSP that is part of the Calypso DBB.

=== src/host/layer23 ===

The Layer2 (LAPDm / TS 04.06) and Layer3 (CC/MM/RR / TS 04.08)
implementations, as they are growing.