Introducing heterogeneous networks in HSPA

In heterogeneous networks, low power nodes may be deployed within macro cells for coverage and capacity improvement. Due to transmit power difference between low power nodes and macro cells, downlink (DL) and uplink (UL) coverage of the low power nodes can be very different. This DL-UL coverage difference could negatively affect system performance on both the DL and the UL. We describe a few techniques to alleviate this problem in HSPA. We present simulation results to show the effectiveness of these techniques as well as the system performance improvement of heterogeneous networks over traditional macro cell only deployments in HSPA.