A Safe and Stable Timing Method over Air Interface Based on Multi-Base Station Cooperation

Abstract

Absolute time synchronization plays an important role in 5G vertical industry applications such as the Industrial Internet of Things. To meet the emerging wireless time synchronization demand in those scenarios, method named TAP is proposed by taking PHY layer signals into account. Although TAP can achieve sub-microsecond level timing accuracy over the air interface, it can also be easily affected by forward spoofing, replay attack, etc. due to its broadcasting mechanism. This paper proposes an improved timing method based on TAP aiming to expand its practicality. First, a timing structure with multiple base stations is proposed to fight against timing deception. Second, the PHY layer signal PRS is applied for realtime monitoring of channel delay, which is usually related to timing deception. Third, a triple-step judgement model is proposed to further identify effective timing information. Simulations show that the proposed method is more robust in terms of stability and security compared to TAP.