Impact of Inter-cell Interference on Flow Level Performance of Scheduling Schemes for the UMTS EUL

The UMTS enhanced uplink (EUL) is expected to provide higher capacity, increased data rates, and smaller latency on the communication link from users towards the network. A key mechanism in EUL traffic handling is the packet scheduler, for which a number of basic schemes can be identified (one-by-one, partial parallel, and full parallel). In this paper we analyze the interaction between the EUL scheduling scheme deployed in the network and the inter-cell interference. On the one hand, different scheduling schemes cause different inter-cell interference patterns on neighbouring cells. On the other hand, the different schemes are affected by inter-cell interference in different ways. The scheduling schemes are evaluated and compared under different approaches for reserving part of the allowed noise rise at the base station for inter-cell interference. For our analysis, we have developed a hybrid analytical/simulation approach allowing for fast evaluation of performance measures such as the mean flow transfer time and fairness expressing how the performance depends on the user´s location. This approach takes into account both the packet-level characteristics and the flow-level dynamics due to the random user behaviour.