Reliable Control Message Exchange in Wireless Real-World Multi-Path Deployments

Modern User Equipments (UEs) like mobile phones, are having multiple network interfaces such as LTE and WiFi. Additionally, solutions like Multipath-TCP (MPTCP), Multipath-UDP (MPUDP), Multipath-QUIC (MPQUIC), etc. are focused on utilising multiple network interfaces in parallel to give enhanced performance. In recent past, MPTCP solution itself is deployed by many Mobile Network Operators (MNOs) under various commercial names (GigaLTE in South Korea, NextG in Thailand, etc.). However these solutions are deployed as an operator feature, in a controlled environment and are having DNS resolution followed by control message-exchange-sequence for enabling the MPTCP feature. For these control messages, one fixed network interface is used, which is either 4G LTE, 5G New Radio or WiFi. When that particular network interface has poor signal condition, the enabling of MPTCP feature fails. Even though MPTCP has load balancing within itself to handle the network interface in poor condition, it never gets the chance to do so due to above challenge of fixed network interface for control message. We considered this limitation and proposed an innovative idea in this paper, which consists of novel controller elements and control flow. This idea enhances the reliability of UEs which are dealing with network interfaces having poor condition, in controlled MPTCP environments. We have successfully implemented this idea in Samsung Galaxy Note9 and S9 variants for regions where it has MPTCP feature deployed. With our new idea we are able to achieve around 8% improvement in reliability of control signal while dealing with poor network conditions for LTE and WiFi.