In applications of remote sensing, estimation, and control, timely communication is critical but not always ensured by high-rate communication. This work proposes decentralized age-efficient transmission policies for random access channels with MM transmitters. We propose the notion of age-gain of a packet to quantify how much the packet will reduce the instantaneous age of information at the receiver side upon successful delivery. We then utilize this notion to propose a transmission policy in which transmitters act in a decentralized manner based on the age-gain of their available packets. In particular, each transmitter sends its latest packet only if its corresponding age-gain is beyond a certain threshold which could be computed adaptively using the collision feedback or found as a fixed value analytically in advance. Both methods improve age of information significantly compared to the state of the art. In the limit of large MM , we prove that when the arrival rate is small (below 1eM\frac {1}{eM} ), slotted ALOHA-type algorithms are order optimal. As the arrival rate increases beyond 1eM\frac {1}{eM} , while age increases under slotted ALOHA, it decreases significantly under the proposed age-based policies. For arrival rates θ\theta , θ=1o(M)\theta =\frac {1}{o(M)} , the proposed algorithms provide a multiplicative gain of at least two compared to the minimum age under slotted ALOHA (minimum over all arrival rates). We conclude that it is beneficial to increase the sampling rate (and hence the arrival rate) and transmit packets selectively based on their age-gain. This is surprising and contrary to common practice where the arrival rate is optimized to attain the minimum AoI. We further extend our results to other random access technologies such as Carrier-sense multiple access (CSMA).

中文翻译：

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随机接入信道中的信息时代


在遥感、估计和控制应用中，及时通信至关重要，但高速通信并不总是能保证这一点。这项工作提出了使用 MM 发射机的随机接入信道的分散式有效传输策略。我们提出了数据包年龄增益的概念，以量化数据包在成功传送后将在接收端减少多少信息的瞬时年龄。然后，我们利用这个概念提出一种传输策略，其中发射机根据其可用数据包的年龄增长以分散的方式进行操作。特别地，每个发射机仅当其相应的年龄增益超过某个阈值时才发送其最新的分组，该阈值可以使用冲突反馈自适应地计算或者预先分析为固定值。与现有技术相比，这两种方法都显着提高了信息的时效性。在大 MM 的限制下，我们证明当到达率较小时（低于 1eM\frac {1}{eM} ），时隙 ALOHA 型算法是阶次最优的。随着到达率增加超过 1eM\frac {1}{eM} ，而在时隙 ALOHA 下年龄增加，在提出的基于年龄的政策下，它显着下降。对于到达率 θ\theta ， θ=1o(M)\theta =\frac {1}{o(M)} ，与时隙 ALOHA 下的最小年龄（最小超过所有到达率）。我们的结论是，提高采样率（从而提高到达率）并根据数据包的年龄增长选择性地传输数据包是有益的。这是令人惊讶的，并且与优化到达率以获得最小 AoI 的常见做法相反。 我们进一步将我们的结果扩展到其他随机接入技术，例如载波侦听多路访问（CSMA）。