|Age of Information in Random Access Channels
|Xingran Chen, Konstantinos Gatsis, Hamed Hassani, Shirin Saeedi Bidokhti, University of Pennsylvania, United States
|N.7: Age of Information II
|Networking and Network Coding
|Click here to download the manuscript
|Click here to watch in the Virtual Symposium
|In applications of remote sensing, estimation, and control, timely communication is not always ensured by high-rate communication. Oftentimes, it is observed that as the capacity of a system is approached, delay increases significantly and so does age of information – a metric recently proposed to capture freshness and timeliness of information. This work proposes distributed age-efficient transmission policies for random access channels with M transmitters and provides asymptotic results for the age of information as M → ∞. Slotted Aloha-type algorithms are shown to be asymptotically age-optimal for arrival rates below 1/eM and far from optimal for larger arrival rates. For larger arrival rates, novel distributed age-based policies are proposed that benefit from the availability of fresh packets to reduce age of information. For arrival rates θ, θ =1/o(M), the proposed algorithms provide a multiplicative gain factor of at least two compared to the state-of-the-art schemes. We conclude that, as opposed to the common practice, it is beneficial to increase the sampling rate (and hence the arrival rate) and transmit packets selectively based on their “age-gains”, a notion defined in the paper.