In addition to the air interface techniques described in the previous section on CDMA2000 1X, the following high-speed packet data transmission enhancements are incorporated into CDMA2000 1xEV-DO Rel 0:

• High-Speed Packet-Switched Downlink Channelization Structure: bundling downlink resources into a packet data channel to enable high-speed data rate transmissions by combining all of the available Walsh codes and power
• Fast and Adaptive Modulation and Coding Schemes: to optimize the delivery of packets based on changes in the radio environment
• Fast and Adaptive Packet Data Scheduling: to rapidly adapt to changes in the radio link
• Fast Hybrid ARQ: to acknowledge correct receipt of data and retransmit erroneous data
• Incremental Redundancy Feedback in the Downlink: to increase the effective data rate in the uplink by terminating the transmission of a packet early if it is decoded earlier than expected
• Fast Downlink Rate Control: to rapidly adjust to changes in the radio environment
• Uplink Rate Control: to efficiently control the transmission of mobile devices
• Downlink Multiple User Separation: to efficiently assign the downlink channel to users
• Downlink Transmission Signaling: to indicate the downlink modulation and coding
• Closed Loop Downlink Power Control: to reduce power used by the base station
• Uplink Rate Detection: to enable correct decoding of uplink data traffic
• Short Transmission Time Intervals (TTI): to accelerate the transmission of packets