A Fault Tolerant Mechanism for UE Authentication in 5G Networks

Generally, the 5th Generation (5G) network will be soon available in the near future. It will be one with the feature that some of its network functions are handled by Virtual Machines (VMs), rather than by a dedicated one (like that in the 4th generation (4G) networks). Basically, VMs of a specific network function are managed by their own Software Defined Networking (SDN) Controller, which makes the management and operation of these VMs and OpenvSwitches become easier. On the other hand, the connection between Internet of Things (IoT) devices and a network is often intermittent. Consequently, Authentication Server Function (AUSF) has to frequently authenticate these devices. This is also one of the reasons why a 5G network will prepare an AUSF Pool to distribute its authentication burden, particularly when a huge number of user equipment (UEs) and IoT devices are connected to it. Next, when a VM fails, how do other AUSFs take over for the failed to continue the authentication tasks? This is not completely defined in 5G specifications. In this study, we propose a fault tolerant mechanism for 5G end-device authentication, named Fault Tolerant 5G Authentication Scheme (FT5AS), in which a machine, named Mediator, is added to manage and keep track of authentication steps for end devices. The purpose is that when a VM fails, other AUSFs can successfully take over its authentication tasks on UEs. Also, the FT5AS can detect this failure immediately and react properly, aiming to increase the Quality of Service (QoS) that an UE can receive from 5G networks. Our simulation results indicate that the FT5AS is feasible and its performance is not lower than that of tested schemes.