Link Adaptation Performance Analysis and Design for HSUPA

HSUPA is to the UMTS uplink what HSDPA is to its downlink. The work done in this project will participate in the definition of HSUPA, as it is still under the 3GPP standardisation process. The evolution aims at achieving higher performance levels in terms of higher reachable bit rates with an increased availability. Furthermore, packets delays needs to be reduced to allow among other the working of new emerging applications like Voice over IP. The all-IP UMTS, evolution from circuit switched to packet switched where all traffic will be managed by the Packet Scheduler, is the ultimate goal. To achieve those results, a simulation tool will be built and upgraded along with the project. At first, new Packet Scheduling schemes will be considered that take into account the new channel structure where DCH and E-DCH (corresponding to normal UMTS and HSUPA) will be separately scheduled, DCH in the RNC and E-DCH at the NodeB. A scheduler closer to the UEs, allows a more dynamic and accurate management of the available resources. This will contribute to the increase of high bit rate availability. Furthermore, HARQ schemes that allow fast Layer-1 retransmissions, to combat fast changes in the channel quality that would normally trigger a RLC retransmission (slow) or even a TCP retransmission (even slower), will be considered and their interaction with the rest of the system evaluated. In this context, the performance of scheduling per HARQ process will be investigated. Those techniques are expected to significantly reduce the existing packet transmission delays. On top of that, new traffic models taking into account the evolution of the users? needs and their real usage will be considered to allow a better evaluation of the system performance. The Quality of Service is also thought of in this project where available tools (RESPECT) will be upgraded so as to allow the real time evaluation of HSUPA. (Malek Boussif, Preben E. Mogensen, Jeroen Wigard, Nokia Networks & Nina Madsen, Nokia Networks)