Age of Information in Random Access Channels
Age of Information in Random Access Channels
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DOI：
10.1109/tit.2022.3180965
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发表时间：
2019-12
影响因子：
2.5
通讯作者：
Xingran Chen;Konstantinos Gatsis;Hamed Hassani;S. S. Bidokhti-S.
中科院分区：
文献类型：
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作者：
Xingran Chen;Konstantinos Gatsis;Hamed Hassani;S. S. Bidokhti-S.
在遥感、估计和控制应用中，及时的通信是至关重要的，但高速通信并不总是保证的。该工作针对具有$M$发射机的随机接入信道提出了分散的年龄有效的传输策略。我们提出了分组年龄增益的概念来量化分组在成功传递后将在接收方减少信息的瞬时年龄的程度。然后，我们利用这一概念提出了一种传输策略，在该策略中，发送器基于其可用分组的年龄增益以分散的方式行动。具体地，每个发射机仅在其对应的年龄增益超过某一阈值时才发送其最新分组，该阈值可以使用冲突反馈自适应地计算或预先分析地发现为固定值。与最先进的技术相比，这两种方法都显著地改善了信息的年龄。在大$M$的极限下，证明了当到达速率较小时(小于$FRAC{1}{em}$)，时隙ALOHA型算法是阶数最优的。随着到达率增加到超过$FRAC{1}{em}$，而在时隙ALOHA下年龄增加，在拟议的基于年龄的政策下显著下降。对于到达率$\theta$，$\theta=\FRAC{1}{o(M)}$，与时隙ALOHA下的最小年龄(对所有到达率最小)相比，所提出的算法提供至少2倍的乘法增益。我们的结论是，提高采样率(从而提高到达率)并基于分组的年龄增益选择性地传输分组是有益的。这令人惊讶，而且与通常的做法相反，在这种做法下，到达率被优化以达到最小的AOI。我们进一步将我们的结果推广到其他随机接入技术，如载波侦听多址(CSMA)。
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 $M$ 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 $M$ , we prove that when the arrival rate is small (below $\frac {1}{eM}$ ), slotted ALOHA-type algorithms are order optimal. As the arrival rate increases beyond $\frac {1}{eM}$ , while age increases under slotted ALOHA, it decreases significantly under the proposed age-based policies. For arrival rates $\theta $ , $\theta =\frac {1}{o(M)}$ , 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).