Delay and Peak-Age Violation Probability in Short-Packet Transmissions


Devassy R., Durisi G., Ferrante G. C. , Simeone O., UYSAL BIYIKOĞLU E.

IEEE International Symposium on Information Theory (ISIT), Colorado, United States Of America, 17 - 22 June 2018, pp.2471-2475 identifier

  • Publication Type: Conference Paper / Full Text
  • City: Colorado
  • Country: United States Of America
  • Page Numbers: pp.2471-2475
  • Keywords: Delay, finite blocklength, age of information, queuing, FINITE BLOCKLENGTH, FADING CHANNELS, NETWORKS
  • Middle East Technical University Affiliated: Yes

Abstract

This paper investigates the distribution of delay and peak age of information in a communication system where packets, generated according to an independent and identically distributed Bernoulli process, are placed in a single-server queue with first-come first-served discipline and transmitted over an additive white Gaussian noise (AWGN) channel. When a packet is correctly decoded, the sender receives an instantaneous error-free positive acknowledgment, upon which it removes the packet from the buffer. In the case of negative acknowledgment, the packet is retransmitted. By leveraging finite-blocklength results for the AWGN channel, we characterize the delay violation and the peak-age violation probability without resorting to approximations based on large deviation theory as in previous literature. Our analysis reveals that there exists an optimum blocklength that minimizes the delay violation and the peak-age violation probabilities. We also show that one can find two blocklength values that result in very similar average delay but significantly different delay violation probabilities. This highlights the importance of focusing on violation probabilities rather than on averages.