A New Discontinuous Reception (DRX) Scheme for LTE-Advanced Carrier Aggregation Systems with Multiple Services

In order to achieve higher bandwidth and higher throughput, the carrier aggregation (CA) technique has been adopted by the specifications of 3GPP Release 10 for Long Term Evolution (LTE) advanced systems, where the user equipment (UE) may operate over up to 5 component carriers (CCs). On the other hand, 3GPP specifications also define a mechanism named discontinuous reception (DRX) in order to save the energy consumption of UE operation, where a UE is allowed to stop monitoring Physical Downlink Control CHannel (PDCCH) during some period of the operation time. Obviously, the duration and the frequency of these non-monitoring periods are important parameters which significantly impact the energy saving (ES) efficiency and the system performance. The conventional UE-specific DRX scheme is not efficient since all CCs are applied with the same DRX operation. Moreover, multiple services with different delay requirements may operate simultaneously for the same UE in the realistic communication systems. Hence, the mechanism of applying identical DRX configuration over all CCs is not optimal and will cause large energy waste. In this paper, we propose a new efficient DRX scheme for LTE-A systems with multiple services, where some important parameters are further optimized according to the characteristics of multi-CC and multi-service systems. Simulation results demonstrate that the proposed DRX scheme can improve the energy saving efficiency significantly compared with the existing no-DRX scheme and the conventional UE-specific DRX scheme, even with 10% retransmission probability.