INTRODUCTION This addendum is being published to describe an additional data service that is available on a cdma2000 spread spectrum system complying with TIA/EIA/IS-2000-A, and to revise chapters included in addendum 1 consistent with enhanced capabilities provided in TIA/EIA/IS-2000-A. Complete chapters included in this addendum are: TIA/EIA/IS-707-A-2.10 Data Service Options for Spread Spectrum Systems: Radio Link Protocol Type 3 TIA/EIA/IS-707-A-2.12 Data Service Options for Spread Spectrum Systems: cdma2000 High Speed Packet Data Service Option 33 TIA/EIA/IS-707-A-2.13 Data Service Options for Spread Spectrum Systems: cdma2000 ISDN Interworking Service Option 37 Chapter 10 in this addendum replaces TIA/EIA/IS-707-A-1.10, and chapter 12 in this addendum replaces TIA/EIA/IS-707-A-1.12. In addition, an enhancement to chapter 3 to support TTY/TDD applications is provided.