An upgrade for WCDMA / UMTS / HSDPA networks that applies HSDPA-like enhancements to the uplink side of the connection, allowing peak upload data rates of up to 5.8 Mbit/s (million bits per second).
HSUPA is both a compliment and a successor to HSDPA, which offers very fast data rates, but only for the downlink / download side. Together, HSDPA and HSUPA are somtimes referred to as HSPA.
HSUPA devices and networks include WCDMA and HSDPA technology and are backward-compatible with devices and networks supporting only those technologies.
HSUPA is expected to be standardized by the 3GPP in UMTS Release 6.
In terms of data speed and general technology evolution, the closest equivalent to HSUPA for CDMA networks would be EVDO Rev. A.