Enabling Agile Ambient IoT Networking via a Parameterized Hybrid Radio

TL;DR

Janus is a hybrid radio platform that unifies passive and active modes, enabling agile, low-power Ambient IoT networking and rapid protocol prototyping with comparable performance to dedicated radios.

Contribution

The paper introduces Janus, a configurable hybrid radio architecture that simplifies physical layer control for Ambient IoT, facilitating faster prototyping and standardization.

Findings

Janus achieves comparable communication performance to dedicated radios.

It significantly reduces configuration overhead.

The prototype supports diverse protocols like 3GPP A-IoT, IEEE 802.11 AMP, and Bluetooth.

Abstract

The emergence of Ambient IoT signals a paradigm shift toward massive batteryless networking. However, the absence of an agile physical layer substrate remains a fundamental barrier to research and standardization. Current testbeds are hindered by decoupled radio paths, high static power, and cumbersome control methods, which stifle rapid protocol prototyping. In this paper, we present Janus, the first hybrid active-passive configurable radio architected for agile Ambient IoT networking. Janus introduces a parameterized architecture that unifies passive and active transmission into a single RF front end, abstracting complex physical layer behaviors into concise parameters. This design enables a system-level control plane for dynamic mode transitions and an energy management plane for fine-grained harvesting across multiple sources. We implement a compact PCB prototype and evaluate its performance across diverse protocol landscapes, including 3GPP A-IoT, IEEE 802.11 AMP, and Bluetooth SIG. Our experimental results demonstrate that Janus achieves communication performance on par with dedicated radios while significantly reducing configuration overhead. Ultimately, Janus serves as a versatile enabler for validating emerging protocols and accelerating the standardization of next-generation low-power networks.