Energy-Efficient DRX Scheduling for Multicast Transmissions in 3GPP LTE-Advanced Wireless Networks

• Main Authors: Hsieh, Po-Chung, 謝博鈞
• Other Authors: Tseng, Yu-Chee
• Format: Others
• Language: en_US
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/56299854571295384695

碩士 === 國立交通大學 === 資訊科學與工程研究所 === 101 === The 3GPP LTE-A (Long Term Evolution-Advanced) is the most promising technology for the next-generation wireless communications. It provides high transmission rates up to 1 Gbps and supports various broadband multimedia services, such as IPTV and Voice/Video-over-IP services. To reduce the energy consumption of user equipments (UEs), the LTE-A standard defines the Discontinuous Reception Mechanism (DRX) to allow UEs to turn off their radio interfaces and go to sleep when no data needs to be received. However, how to optimally configure DRX for UEs is still left as an open issue. In this paper, we address the DRX optimization problem for multicast services. This problem asks how to guarantee the quality of service (QoS) of the multicast streams under the Evolved Node B (eNB) while minimizing the UEs’ wake-up time. We prove this problem to be NP-complete and propose an energy-efficient heuristic. This heuristic consists of two phases. The first phase tries to aggregate the required bandwidth of the multicast streams for UEs to reduce their wake-up periods. The second phase further minimizes UEs’ unnecessary wake-up periods by optimizing their DRX configurations. Extensive simulation results show that our scheduling is close to the optimum in most cases.