HSDPA
HSDPA aim to reach high data rates (14.4 Mbit/s) in the DL first. These data rate should be compatible with the DSL standards at that time. In R5 high data rate in UL was not as important as in DL. Key features have been fast scheduling and the introduction of 16-QAM.
HSPA
In R6 HSUPA was added to reach data rates of more than 5 Mbit/s in UL. With the possibility to exchange both signaling and data in both UL and DL on HSPA the first step towards all PS services has been made for limited QoS.
LTE
LTE R8 is the standard of the 4th generation and offers extremely high performance: Data rates in the order of hundreds of Mbit/s, an architecture designed for AIPN and all PS services (no CS possible any more) from the start, and most low latency times for the user plane and the control plane. MIMO and higher order modulation schemes (64-QAM) are extensively used for LTE. With LTE R9 the data rates will be further extended.
HSPA+
HSPA+ has been planed while the work on LTE was already ongoing and thus has to follow the benchmark set by LTE. R7 not only doubles the data rates of HSPA but also introduced feature like CPC allowing the UE always in all RRC states (also CELL_FACH and XXX_PCH) to fully rely on HSDPA services R7 HSPA+ introduces MIMO and 64-QAM as in LTE. In R8 64-QAM will be combined with MIMO in order to enhance the DL data rate by 50%. As well DL interference cancellation is introduced in R8.
