 mode enables multicarrier operation using aggregation of 1xEV-DO channel cards. If the access network hardware supports the basic asymmetric mode of operation, ter- minals would be set up in asymmetric mode for applications such as file download that require more bandwidth on the forward link than the reverse link. The asymmetric mode of operation results in reduced reverse link overhead since the pilot channels for the additional reverse link carriers are not transmitted. The enhanced asymmetric multicarrier mode is similar to the basic asymmetric mul- ticarrier mode with the exception that feedback channels for up to four forward CDMA channels are transmitted on a single reverse link using the same long code. Therefore, a 16-carrier forward link may be supported using a reverse link carrier with basic asymmetric mode by using 16 unique user long codes or with enhanced asymmetric mode by using 4 unique user long codes. Selective Deployment: Rev. B can be deployed in high capacity areas with multiple carriers. Since Rev. B is backward compatible to Rev. A, Rev. B can be gradually rolled-out across 4 Transmission Target is defined as the number of slots of transmission required to achieve a certain PER (packet error rate), usually 1%. Next Generation Mobile Communications Ecosystem EVDO Rev 0 EVDO Rev 0 EVDO Rev 0 EVDO Rev 0 EVDO Rev 0 EVDO Rev A EVDO Rev A EVDO Rev 0 EVDO Rev A EVDO Rev B EVDO Rev B EVDO Rev B Figure 5.8 Rev. B deployment scenario (each carrier is of 1.25 MHz; not drawn according to a scale) a network. Figure 5.8 shows an example of a site which is transitioning from a lower data capacity to a data hot spot. 5.3.3 Rev. B Performance Rev. B will improve the performance of all Rev. A data applications and most importantly VoIP. Rev. B enables higher streaming rates for video and audio; faster upload of pictures, videos, and audio files; and faster mobile broadband for laptops. Figure 5.9 shows the improvement in VoIP capacity with Rev. B as compared to Rev. A [4]. This improvement is augmented wit