In this work, we investigate the issue of semantics in non real-time communication scenarios, that is, without stringent information delivery constraints. While semantics has been widely used in the context of communications, the definition of the semantic metrics has been limited to the real-time applications. We thus revise the basic concepts of the timeliness and the accuracy and propose their formal definitions in the case of non real-time applications characterized by a possibility of non-causal signal reconstruction at the destination. In particular, we link the concept of accuracy to the canonical first-order auto-regressive model of the signal, while the timeliness is defined by the time difference to reference samples of the signal. We compare the proposed semantic metrics in the case of different buffer management strategies and using numerical examples we show that the optimality of the transmission strategy changes when the real-time or non real-time applications are considered.

中文翻译：

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非实时应用程序的语义度量


在这项工作中，我们研究非实时通信场景中的语义问题，即没有严格的信息传递约束。虽然语义已广泛应用于通信领域，但语义度量的定义仅限于实时应用程序。因此，我们修改了及时性和准确性的基本概念，并在非实时应用的情况下提出了它们的正式定义，其特点是在目的地进行非因果信号重建的可能性。特别是，我们将准确性的概念与信号的规范一阶自回归模型联系起来，而及时性则由信号参考样本的时间差来定义。我们比较了不同缓冲区管理策略情况下提出的语义度量，并使用数值示例表明，当考虑实时或非实时应用时，传输策略的最优性会发生变化。