On the Information Freshness Under Random Jamming Attacks

In this letter, we study a timely status update wireless system, where the transmitter suffers from jamming. The jammer attacks the system by inserting malicious updates, which use a higher transmission SNR to block the transmission of source updates. For the first time, we obtain the closed-form expressions of the average AoI under two jamming attacks, i.e., high-power and low-power jamming. Under the high-power jamming, we prove the convexity of average AoI in the jamming SNR and propose a simple anti-jamming technique based on the convexity. Under the low-power jamming, we numerically validate that the average AoI increases approximately linearly in the jamming SNR. We also observe that an increase in jamming rate causes a larger increase in average AoI under high-power jamming compared to that under the low-power case.