These changes included the introduction of several new forward link data rates that increase the maximum burst rate from 2.45 Mbit/s to 3.1 Mbit/s. Also included were protocols that would decrease connection establishment time (called enhanced access channel MAC), the ability for more than one mobile to share the same timeslot (multi-user packets) and the introduction of QoS flags. All of these were put in place to allow for low latency, low bit rate communications such as VoIP.
In the United States, Verizon Wireless and Sprint Nextel have migrated 100% of their EV-DO Rev.0 networks to EV-DO Rev. A.
The additional forward rates for EV-DO Rev. A are:
| DRC Index | Data rate in kbit/s | Slots scheduled | Payload size (bits) | Code Rate | Modulation |
|---|---|---|---|---|---|
| 13 | 1536 | 2 | 5120 | 5/12 | 16-QAM |
| 14 | 3072 | 1 | 5120 | 5/6 | 16-QAM |
In addition to the changes on the forward link, the reverse link was enhanced to support higher complexity modulation (and thus higher bit rates). An optional secondary pilot was added, which is activated by the mobile when it tries to achieve enhanced data rates. To combat reverse link congestion and noise rise, the protocol calls for each mobile to be given an interference allowance which is replenished by the network when the reverse link conditions allow it. The reverse link has a maximum rate of 1.8 Mbit/s, but under normal conditions users experience a rate of approximately 500-1000kbit/s but with more latency than cable and dsl.
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