ZyXEL Communications 56K

User's Guide for ZyXEL Omni 56K USB Modem

3-14

4-bit Voice Data Compression

The main issue in the digitized voice mode is the amount of storage required. A relatively

simple ADPCM algorithm can reduce the speech data rate to half the rate and maintain about

the same voice quality. This algorithm can also be used to reduce the speech data rate to 1/3 or

1/4 of the original rate, but with voice quality degradation. Only 4-bit ADPCM is used in the

Omni 56K USB.

Contents

Main ZyXEL ZyXEL Omni 56K USB Modem Page Page Limited Warranty ZyXEL Omni 56K USB Modem Become a Registered Owner User's Guide for ZyXEL Omni 56K USB Modem vi Customer Support Table of Contents Page List of Tables Page Page Page Preface Page Chapter 1 Introduction 1.1 Main Features Page Chapter 2 2.1.2 Back Panel Page Page Chapter 3 Specifications and Functional Description 3.1 Specifications 3.1.1 Hardware Specification 3-2 3.1.2 Firmware Specification Table 4. Firmware Specifications 3.2 Protocol Support n Data Physical Layer For more information on detailed command sets, please refer to Chapter 5. . n Fax Physical Layer 3.3 Omni 56K USB Capability The data/fax/voice feature of the Omni 56K USB is described in the following table: Table 5. Data/Fax/Voice Feature Description 3.3.1 Data Function Physical Layer Capability Page Page Page Page Page Page 3.3.2 Security Function Page 3.3.3 Fax Function 3.3.4 Voice Function Page Chapter 4 Result Codes 4.1 Result Codes Page Page Page 5-1 Chapter 5 Command Sets 5.1 Data Command Sets 5.1.1 Basic AT Command Sets Table 10. Basic AT Command Sets 5-2 5-3 5-4 5.1.2 Extended AT& Command Sets Table 12. Extended AT& Command Set 5-5 5-6 5-7 5-8 5.1.3 Extended AT* Command Sets Table 13. Extended AT* Command Sets 5-9 5.1.4 Extended AT# Command Sets 5-11 5.2 Fax Command Sets 5.2.1 Service Class 1 Commands Table 15. Service Class 1 Commands 5-12 Table 17. Command Syntax Table 18. Supported Commands (per TIA PN2388 dated 8/20/1990) 5-13 5-14 Table 19. Class 2 Command Responses 5-15 Class 2 Flow Control 5-16 5.2.3 Service Class 2.0 Commands Table 20. Service Class 2.0 Commands 5-17 User's Guide for ZyXEL Omni 56K USB Modem 5-18 5-19 5.2.4 Voice AT Commands Table 21. Voice AT Commands 5-20 5-21 5.2.5 Voice Shielded DTE Commands Table 22. Voice Shielded DTE Commands 5.2.6 Voice Shielded DTE Responses Table 23. Voice Shielded DTE Responses 5-22 5.3 S-Register Descriptions 5.3.1 Basic S-Registers "ATSn=x" Table 24. Basic S-Registers ATSn=x Table 25. Extended S-Registers "ATSn=x" 5-23 5-24 5-25 5-26 5-27 5-28 5-29 Page Chapter 6 Firmware Upgrade 6.1.1 Upgrading by Software (for Windows 98/NT/2000) 6.1.2 Upgrading by Using a Terminal Program A Glossary AT prefix (ATtention). To send an AT B C D E F G H I J K L Index