Sending Information Through Status Updates

TL;DR

This paper explores how an energy harvesting transmitter can encode messages into status update timings, balancing information rate and freshness of updates, and compares different schemes for optimizing this tradeoff.

Contribution

It introduces a novel framework where status updates carry independent messages encoded in their timings, analyzing the tradeoff with age of information.

Findings

Proposes multiple schemes for encoding messages in update timings.

Analyzes the rate-AoI tradeoff for different encoding strategies.

Provides performance comparisons of the proposed schemes.

Abstract

We consider an energy harvesting transmitter sending status updates regarding a physical phenomenon it observes to a receiver. Different from the existing literature, we consider a scenario where the status updates carry information about an independent message. The transmitter encodes this message into the timings of the status updates. The receiver needs to extract this encoded information, as well as update the status of the observed phenomenon. The timings of the status updates, therefore, determine both the age of information (AoI) and the message rate (rate). We study the tradeoff between the achievable message rate and the achievable average AoI. We propose several achievable schemes and compare their rate-AoI performances.