We consider a system where the updates from independent sources are disseminated via a publish-subscribe mechanism. The sources are the publishers and a decision process (DP), acting as a subscriber, derives decision updates from the source data. We derive the stationary expected age of information (AoI) of decision updates delivered to a monitor. We show that a lazy computation policy in which the DP may sit idle before computing its next decision update can reduce the average AoI at the monitor even though the DP exerts no control over the generation of source updates. This AoI reduction is shown to occur because lazy computation can offset the negative effect of high variance in the computation time.

翻译：我们考虑一个系统，其中来自独立源的更新通过发布-订阅机制进行传播。源作为发布者，而一个充当订阅者的决策过程（DP）从源数据中推导出决策更新。我们推导出传递给监视器的决策更新的稳态预期信息年龄（AoI）。研究表明，一种惰性计算策略——即DP在计算下一次决策更新前可能处于空闲状态——能够降低监视器的平均AoI，即使DP对源更新的生成没有控制权。这种AoI降低被证明是由于惰性计算可以抵消计算时间高方差带来的负面影响。