FreeCalypso > hg > gsm-net-reveng

annotate pathloss/fsl.c @ 94:f9ef582c199c

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
tfo-ut: check in tfo-fr.bin and tfo-efr.bin Each of these binary files is an extract from MSC-side E1 timeslot recording in a Nokia TCSM2 TFO session involving a cross-connect between two TRAU channels. The extracts have been chosen to begin at the point where the TRAU starts emitting TFO frames, thereby beginning with a series of TFO frames that contain an embedded TFO_TRANS message. In each experiment, one of the two cross-connected TRAU channels emitted two "plain" TFO frames (not containing embedded TFO messages) in between the initial embedded TFO_TRANS and the subsequent embedded TFO_REQ_L; this channel was chosen for the present extracts. Each extract is thus 2560 PCM samples, containing 16 aligned TFO frames: 5 carrying TFO_TRANS, 2 plain, 9 carrying TFO_REQ_L.
author Mychaela Falconia <falcon@freecalypso.org>
date Tue, 18 Mar 2025 22:56:23 +0000
parents 599fac1b882d
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
66
599fac1b882d pathloss: implement FSL
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1 /*
599fac1b882d pathloss: implement FSL
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
2 * Free Space Loss calculation
599fac1b882d pathloss: implement FSL
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
3 */
599fac1b882d pathloss: implement FSL
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
4
599fac1b882d pathloss: implement FSL
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
5 #define _GNU_SOURCE
599fac1b882d pathloss: implement FSL
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
6 #include <math.h>
599fac1b882d pathloss: implement FSL
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
7 #include "range_func.h"
599fac1b882d pathloss: implement FSL
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
8
599fac1b882d pathloss: implement FSL
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
9 #define PI_f ((float) M_PI)
599fac1b882d pathloss: implement FSL
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
10
599fac1b882d pathloss: implement FSL
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
11 float rf_range_freespace(float freq_mhz, float path_loss)
599fac1b882d pathloss: implement FSL
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
12 {
599fac1b882d pathloss: implement FSL
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
13 float wavelen = 300.0f / freq_mhz;
599fac1b882d pathloss: implement FSL
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
14
599fac1b882d pathloss: implement FSL
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
15 return (wavelen / pow10f(path_loss / -20.0f)) / (PI_f * 4.0f);
599fac1b882d pathloss: implement FSL
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
16 }