Mario Mark Scipione

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.

Performance of VoIP services over 3GPP WCDMA networks

We analyze the performance of voice services over 3GPP WCDMA networks for Release 99 and Release 7 deployments. We show, by using simulations, that the system capacity of Release 7 VoIP is significantly higher than the Release 99 circuit-switched voice under similar system conditions and voice quality. These results are obtained under the 3GPP simulation assumptions where uplink and downlink constraints for power, code and interference are considered. Both AMR 12.2 and 5.9 as well as different types of mobile receivers (Rake and equalizer, single and dual receive antennas) are considered. We also show that the capacity and performance can be increased significantly further by using uplink interference cancellation at the base station. The performance of best effort traffic in the presence of voice users is also analyzed.

System performance of Inter-NodeB MF-HSDPA with RLC and MAC enhancements

In this paper, we study the feature of Multi-Flow HSDPA (MF-HSDPA), which allows simultaneous transmission of separate data packets from two or more serving cells (across different sectors or NodeBs) to a UE. This new feature brings challenges for system design, especially for the Inter-NodeB case, in which the serving cells reside in different NodeBs. To address these challenges, we propose enhancements to the Radio Link Control (RLC) layer and Media Access Control (MAC) layer. Simulation results show significant performance gain can be achieved by the MF-HSDPA feature.

Performance analysis of HSPA Multi-carrier heterogeneous networks

Heterogeneous networks (HetNets), consisting of Macro NodeBs (macros) and low power Pico NodeBs (picos), can increase system capacity by offloading some users to the picos. However, this offloading may be limited due to intercell interference from macros to picos that reduces their coverage. HSPA Multi-carrier HetNets allow the use of range expansion techniques to achieve more offloading, such as power reduction from the macros on one carrier. This paper provides a system level analysis of the gain provided by power reduction on one carrier of the macros in a HetNet environment. As the interference from the macros is reduced, more capacity offloading to picos occurs and higher system capacity can be achieved. By considering cell biasing in serving cell selection, further gains can be observed.