QoS-aware resource management for LTE-Advanced relay-enhanced network

Relaying is one of the major innovative concepts proposed in the recent years for cellular radio communication systems. It is a perfect solution for dealing with the issue of high variability of performance in cellular networks. By coordinated deployment at cell-edge or in shadowed areas, relay nodes can extend network coverage and increase the low end-user performance. Considering the advantages, relaying is recently being included in the standards of the fourth generation systems such as the LTE-Advanced and the WiMAX. However, one major problem of relaying is still to be resolved. Specifically, there are no concrete concepts for quality-of-service provisioning for relayed transmissions. This paper investigates the case of packet delivery times over multi-hop links in relay-enhanced networks. The discussion is specifically based on relaying implementation in the LTE-Advanced system. The quality-of-service satisfaction and its fairness for the base station and relay-node-connected users are analyzed in the framework of the utility theory. For the purpose of this analysis, utility functions are proposed for real-time traffic with minimum data rate and/or maximum packet delivery time requirements. Furthermore, several optimization concepts are proposed for managing multi-hop transmissions in a quality-of-service aware manner. The included analysis based on the LTE-Advanced system level simulations shows that the proposed optimizations have the potential to improve the overall quality-of-service satisfaction in a relay-enhanced system.