High Speed Packet Access (HSPA) is a wireless access technology designed for increasing the capacity of Internet connectivity from 3G mobile terminals; UMTS and WCDMA based networks. HSPA refers to improvements made in both the downlink or High Speed Downlink Packet Access (HSDPA) and to the uplink or High Speed Uplink Packet Access (HSUPA).
HSPA+ was introduced in 3GPP Rel.7 and is a combination of HSDPA (3GPP Rel.5) and HSUPA (3GPP Rel.6).
HSPA+ is a further enhancement of HSPA that introduces higher-order modulation and MIMO, CPC, carrier aggregation, Layer-2 enhancements, architecture improvements in the uplink and downlink.
With each new 3GPP release, the improvements and new features added to HSPA+ improve the uplink and downlink speed, reduce the latency and increase number of simultaneous data connections that can be supported.