Efficient Power Saving and Zero Network Flooding Protocol for VoWiFi Registration
Imran Mohammed, Debabrata Das · 2019
In Voice over WiFi (VoWiFi), user equipments (UEs) like mobile phones, tablets, etc., starts scanning of WiFi network signal strength and send Virtual Private Network (VPN) tunnel requests to evolved Packet Data Gateway (ePDG) server to establish VoWiFi sessions. This VPN tunnel requests eventually fails, if network does not have VoWiFi capability, which causes flooding of packets in cellular operator network. Additionally, the above unnecessary scanning of the WiFi network signal strength by UE drains battery power. To solve these challenges, we have proposed a novel idea to the cellular operator's core network to introduce a VoWiFi capability indication bit to notify UE of VoWiFi capability of the network. Moreover, we have also proposed new initiation and termination of VoWiFi registration process in UE, based on received VoWiFi capability indication bit. With the proposed idea, the experimental results reveal that, mobile phones battery current consumption has reduced drastically from 86.9mA to 18.69mA. In addition, VPN tunnel requests to ePDG server are reduced from 83 packets to zero packets as VPN tunnel requests are stopped on receiving VoWiFi capability indication bit as VoWiFi unsupported from network. The above observations are for an experiment set up duration of 10 minutes and with VoWiFi registration retry timer of 30 seconds.