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Feature #4396

Circuit Switched Data (CSD) Support

Added by laforge about 1 year ago. Updated 6 months ago.

Status:
New
Priority:
Low
Assignee:
-
Category:
-
Target version:
-
Start date:
02/13/2020
Due date:
% Done:

0%

Resolution:
Spec Reference:
Tags:
CSD

Description

This would primarily entail:
  • permitting the related bearer types on the 04.08 CC side
  • configuring the DSP correctly to perform the 45.003 interleaving / coding for the respective bearer type
  • implementing the various rate adaptation functions to get to the individual sync/async characters. AFAIR there even was a hardware accelerator (maybe that was only MTK, not TI?). In any case, we want a software implementation on the host PC side, we don't care about an efficient implementation on the baseband chip.

Test/development could be done against Racal 6103, which supports both data + fax calls


Related issues

Related to OsmoBTS - Feature #1572: Circuit Switched Data (CSD) SupportNew02/23/2016

History

#1 Updated by laforge about 1 year ago

  • Tags set to CSD

#2 Updated by laforge about 1 year ago

  • Related to Feature #1572: Circuit Switched Data (CSD) Support added

#3 Updated by fixeria 6 months ago

configuring the DSP correctly to perform the 45.003 interleaving / coding for the respective bearer type

JFYI, here is an extract from include/calypso/l1_environment.h:

/* Channel mode definitions for DEDICATED mode */
#define SIG_ONLY_MODE      0    // signalling only
#define TCH_FS_MODE        1    // speech full rate
#define TCH_HS_MODE        2    // speech half rate
#define TCH_96_MODE        3    // data 9,6 kb/s
#define TCH_48F_MODE       4    // data 4,8 kb/s full rate
#define TCH_48H_MODE       5    // data 4,8 kb/s half rate
#define TCH_24F_MODE       6    // data 2,4 kb/s full rate
#define TCH_24H_MODE       7    // data 2,4 kb/s half rate
#define TCH_EFR_MODE       8    // enhanced full rate
#define TCH_144_MODE       9    // data 14,4 kb/s half rate

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