Adaptive DRX Mechanism To Improve Energy Effciency And To Reduce Page Delay For VoWiFi Devices

Voice over Wi-Fi (VoWiFi) provides telephony services using voice over IP on Wi-Fi. Many service providers in world deployed their infrastructure with VoWiFi services to extend their coverage without costly Radio Access Network (RAN) infrastructure. Dual SIM Dual Standby (DSDS) devices support VoWiFi and are popular in market. DSDS Mobile Devices equipped with a single Radio Frequency Integrated Circuit (RFIC) to reduce device cost by Original Equipment Manufacturer (OEM) and serve the dual SIM functionality with efficient RF arbitration algorithm. When device connected to Wireless Fidelity (Wi-Fi), while in idle mode, mobile device listens to paging channel in Discontinuous Reception (DRX) mode periodically to monitor paging message on cellular network and also listens to beacon signals on Wireless Local Area Network (WLAN) network simultaneously resulting additional power consumption at mobile device. In dual SIM environment, single RF used to listen paging channel on both SIM operators. In paging collision scenario, with RF resource provided to one SIM, other SIM suffers in paging reception causing delayed paging or paging failure. To improve paging performance of DSDS devices and to reduce power consumption, we propose two novel algorithm called Priority Weighted Round Robin (PWRR), which prioritize non-VoWiFi SIM for RF sharing and Adaptive idle mode DRX mechanism using eDRX (Extended Discontinuous Reception) feature when Mobile Device register with IMS over Wi-Fi. Simulation results indicate that Key Performance Indicators of call setup time (CST) and call success ratio (CSR) of the new RF sharing mechanism compared with traditional mechanism shows reduction in delayed paging and paging failures by ~50% and ~ 3.3% respectively in conflicting trials. Also, there is a potential scope to improve Mobile Device's power consumption and efficient radio resource utilization at network by keeping cellular modem in longer sleep when Mobile Device registered over Wi-Fi using eDRX and provided evaluation results of 5 to 15% that shows the improvement in system.