==== This product offering is discontinued =====

FAX/Data Relay Control Software

Software Overview 

Communication systems using advanced voice compression techniques require special on-line signal handling to pass FAX/Data traffic in the available channel bandwidth, typically 16Kb/s or 8Kb/s. Relay systems automatically recognize and demodulate the FAX/Data signal to recover the "baseband" data stream, ranging from 2.4Kb/s to 14.4 Kb/s. This data is then formatted and passed through the link for re-modulation at the remote end.

ILLICO's Relay control software provides modem control, data formatting, and end-to-end protocol for real-time communications control. The software is written in C-language for compilation to either floating point (TMS320C3x) or fixed point (TMS320C5x/C54x/C55x) assembly language. Combined with ILLICO's assembly language FAX and Data modems, the Relay Control software creates a complete relay capability in a single Digital Signal Processor. 

The modem standards supported are:

  • Group 3 FAX: V.17, V.29, V.27ter, V.21
  • Data: V.32bis, V.22bis, Bell212A, V.21, Bell103

Both T.38 and enhanced proprietary protocols are available to support various types of TDM and Packet networks including satellite, wireless, IP, Frame relay or ATM.

Features and Benefits 

  • Relay software is written in 'C' for ease of support and customization. 
  • Support for rates up to 14.4Kb/s (V.17 FAX and V.32bis data). 
  • Optional forcing of the transactions to a lower bit rate for low bandwidth systems. 
  • PCM or linear interface with fixed 8KHz sampling rates. 
  • Direct interface with ILLICO C5x, C54x, C55x or C3x assembly language modem modules.
  • Group 3 signal classification by protocol analysis (the relevant T.30 control bits are extracted to learn the data rate and modem standard used for image transmission). 

Program Memory Requirements 

The following two examples show typical TMS320 DSP memory requirements for relay applications (control software plus modems). The first example is a full FAX/data application; the second example is a limited FAX-only application. The program memory figures include both the assembly language modem and relay control software. 

Example 1 (FAX and data relay). 
FAX modes supported: V.21, V27ter, V.29, V.17 
Data modes supported: V.21, B103, B212A, V.22, V.22bis, V.32, V.32bis. 
---Program memory required:  25K 

Example 2  (low speed FAX relay only) 
FAX modes supported: V.21, V27ter, V.29 
---Program memory required: 12K


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