  This work studies the information freshness of the vehicle-to-infrastructure
status updating in Internet of vehicles, which is modeled as a multi-source
Ber/Geo/1/1 preemptive queueing system with heterogeneous service time. We pay
attention to both the distribution and average of AoI. To fully track the
per-source AoI evolution, a Markov two-dimensional (2D) age process is
introduced. The first element of the 2D age process stands for the
instantaneous per-source AoI, while the second represents whether an update of
the concerned source is being served and its current age. A complete framework
and detailed analyses on the per-source AoI are presented based on the
Markovity of the 2D age process. By studying the state transition
probabilities, stationary equations, and stationary distribution of the 2D age
process, analytical expressions of the probability mass function and average of
per-source AoI are derived. Numerical results validate the accuracy of the
theoretical analyses.
