FreeCalypso > hg > gsm-net-reveng

annotate tfo-ut/README @ 100:a1868d31ce7f default tip

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
tfo-ut: add README
author Mychaela Falconia <falcon@freecalypso.org>
date Wed, 19 Mar 2025 01:39:57 +0000
parents
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
100
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1 Each of the 3 tfo-*.bin files in this directory is an extract from an MSC-side
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
2 E1 timeslot recording in a Nokia TCSM2 TFO session involving a cross-connect
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
3 between two TRAU channels. The extracts have been chosen to begin at the point
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
4 where the TRAU starts emitting TFO frames, thereby beginning with a series of
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
5 TFO frames that contain an embedded TFO_TRANS message. In each experiment, one
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
6 of the two cross-connected TRAU channels emitted two "plain" TFO frames (not
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
7 containing embedded TFO messages) in between the initial embedded TFO_TRANS and
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
8 the subsequent embedded TFO_REQ_L; this channel was chosen for the present
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
9 extracts. Each extract is thus 2560 PCM samples, containing 16 aligned TFO
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
10 frames: 5 carrying TFO_TRANS, 2 plain, 9 carrying TFO_REQ_L.
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
11
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
12 In each of the three TCSM2 sessions from which these TFO frame extracts were
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
13 taken, the Ater UL input was fed with a stream of good DHFs (decoder homing
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
14 frames) for the respective codec, hence the TFO frame content is nothing but
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
15 these DHFs. In the case of FR and EFR captures, one of the 16 consecutive
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
16 frames also exhibits TAF=1. OTOH, the same does not hold for HR: the TRAU-8k
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
17 frame format used in TFO and in most Abis implementations carries TAF only for
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
18 BFIs and invalid SID, but not for good speech or valid SID frames.
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
19
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
20 The tfo-*.hex files that are generated from tfo-*.bin by the Makefile in this
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
21 directory are intended to serve as unit tests for TFO frame extraction functions
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
22 that are currently being implemented in libosmotrau. The lack of frame content
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
23 diversity (nothing but DHF) is not seen as a problem: the objective here is to
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
24 test TFO frame extraction functions; the higher-level logic of TRAU frame
a1868d31ce7f tfo-ut: add README
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
25 decoding has its own unit tests.