Impact of relaying on inter-cell interference in mobile cellular networks

Incorporating relay nodes in cellular networks, e.g. UMTS/ HSPA, is beneficial for extending coverage as well as for service enhancement. In this paper we study the inter-cell interference generated by a relay-enabled cell and how this influences the performance of mobile users. The performance measures of interest are the inter-cell interference distribution, realized rates and flow throughput. Our investigations show that not only relaying reduces interference but as result of this decrease all users experience an additional performance improvement, independently whether they use a relay or not. The effect is even stronger when flow throughputs are evaluated. The consideration of flow dynamics is a strong and distinctive aspect of our analysis methodology. We show that the evaluation on flow level contributes significantly to better understanding of the effects of relaying. Special attention is also given to the applied scheduling scheme.