  Age of Information (AoI), defined as the time elapsed since the generation of
the latest received update, is a promising performance metric to measure data
freshness for real-time status monitoring. In many applications, status
information needs to be extracted through computing, which can be processed at
an edge server enabled by mobile edge computing (MEC). In this paper, we aim to
minimize the average AoI within a given deadline by jointly scheduling the
transmissions and computations of a series of update packets with deterministic
transmission and computing times. The main analytical results are summarized as
follows. Firstly, the minimum deadline to guarantee the successful transmission
and computing of all packets is given. Secondly, a \emph{no-wait computing}
policy which intuitively attains the minimum AoI is introduced, and the
feasibility condition of the policy is derived. Finally, a closed-form optimal
scheduling policy is obtained on the condition that the deadline exceeds a
certain threshold. The behavior of the optimal transmission and computing
policy is illustrated by numerical results with different values of the
deadline, which validates the analytical results.
