This paper considers a cooperative status update system with a source aiming to send randomly generated status updates to a designated destination as timely as possible with the help of a relay. We adopt a recently proposed concept, Age of Information (AoI), to characterize the timeliness of the status updates. We propose an age-oriented opportunistic relaying (AoR) protocol to reduce the AoI of the considered system. Specifically, the relay opportunistically replaces the source to retransmit the successfully received status updates that have not been correctly delivered to the destination, but the retransmission of the relay can be preempted by the arrival of a new status update at the source. By carefully analyzing the evolution of AoI, we derive a closed-form expression of the average AoI for the proposed AoR protocol. We further minimize the average AoI by optimizing the generation probability of the status updates at the source. Simulation results validate our theoretical analysis and demonstrate that the average AoI performance of the proposed AoR protocol is superior to that of the non-cooperative system.

中文翻译：

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具有随机到达的合作状态更新系统中面向年龄的机会中继

本文考虑了一个协作状态更新系统，其目标是在中继的帮助下尽可能及时地将随机生成的状态更新发送到指定的目的地。我们采用最近提出的概念，即信息时代 (AoI)，来表征状态更新的及时性。我们提出了一种面向年龄的机会中继 (AoR) 协议，以减少所考虑系统的 AoI。具体来说，中继机会性地替换源来重传成功接收的尚未正确传递到目的地的状态更新，但是中继的重传可以被源处的新状态更新的到达抢占。通过仔细分析 AoI 的演变，我们得出了所提议的 AoR 协议的平均 AoI 的封闭形式表达式。我们通过优化源头状态更新的生成概率进一步最小化平均 AoI。仿真结果验证了我们的理论分析，并证明所提出的 AoR 协议的平均 AoI 性能优于非合作系统。