Goal-oriented Communication for Status Updating over Random Delay Channel

With the proliferation of communication demand, goal-oriented communication goes beyond traditional bit-level communications, which emphasizes the significance of information and its relevance to a specific goal. This paper studies the goal-oriented status updating problem over a random delay channel. For detecting the occurrences of status change, Age of Changed Information (AoCI), which considers both the timeliness and content of the update, is applied as a goal-oriented metric. In this paper, we aim to study the goal-oriented status updating policy that minimizes the weighted sum of AoCI and transmission cost. The investigated problem is formulated as a semi-Markov decision process (SMDP) and solved by reformulating it into a multi-variances optimization problem. We prove that the optimal updating policy is of threshold type, and a nearly closed expression of the optimal threshold is derived. A bisection searching algorithm is derived to obtain the optimal threshold. Simulation results including the performance comparisons of different policies with different parameters are given, which shows the generality of our proposed algorithm.