Bi-group pre-handover authentication model solving signaling congestion of subway LiFi network

Abstract

In the metro scenario, massive users will switch from the platform network to the subway network simultaneously. The resulting huge and burst authentication traffic could cause signaling congestion in the subway light fidelity (LiFi) network. In this paper, a bi-group pre-handover authentication model (BGPHA) is developed to solve this problem by analyzing the characteristics of LiFi networks and the mobility of metro users. Specifically, a bi-group authentication mechanism is created in the BGPHA based on the ultra-dense deployment characteristic of LiFi networks. Next, a re-authentication mechanism is created in the BGPHA based on the link vulnerability characteristic of LiFi networks. Besides, a quick rejoin mechanism is created in the BGPHA based on the random mobility of metro users. Finally, the effectiveness of BGPHA is demonstrated by numerical and simulation analysis. Numerical analysis indicates that BGPHA has a lower authentication overhead growth with the number of users compared to the conventional single-group authentication scheme. Simulation analysis demonstrates that BGPHA can significantly decrease the handover latency in the presence of light path blockages. Furthermore, the handover failure rate can be effectively reduced by up to 6 times with the BGPHA.