In the past few years, a considerable increase in number of users as well as offered traffic per user has been experienced
in HSPA networks, both in the downlink and in the uplink.
In response to this, several features have been standardized in 3GPP. These include multi-carrier HSPA, downlink and
uplink CELL_FACH state enhancements, and introduction of downlink and uplink MIMO. However, much of the focus
has been on improving downlink performance and further enhancements are needed for the uplink to handle increasing
traffic load as well as new traffic types.