Tuning into the Web: Low-Cost Internet Access via FM Radio

Overview

Over 2.6 billion people remain without access to the Internet in 2025. This phenomenon is especially pronounced in developing regions, where cost and infrastructure limitations are major barriers to connectivity. In response, we design Sonic, a low-cost, scalable data delivery system that builds on existing infrastructures: FM radio for downlink broadcasting, and SMS for personalized uplink. Sonic is motivated by the widespread availability of FM radio and SMS infrastructure in developing regions, along with embedded FM radio tuners in affordable mobile phones. Sonic offers several innovations to effectively transmit Web content over sound over FM radio, in a reliable and compressed form. For example, we transmit pre-rendered webpages and leverage pixel interpolation to recover errors at the receiver. We further modify Android to offer a simpler deployment pipeline, supporting a wide range of devices. We deployed Sonic at an FM radio station in Cameroon for six weeks with 30 participants. Our results demonstrate a sustained downlink throughput of 10~kbps, less than 20% loss for a majority of transmissions with signal strength above -90~dbM, and a strong user engagement across both Web browsing and ChatGPT interactions.

WebFM Deployment Results

Key Capabilities

  • Delivers simplified web content via FM radio in image form
  • Supports SMS-based interaction with LLMs like ChatGPT
  • Works on low-end Android phones with FM receivers
  • Operates offline with no need for traditional internet
  • Robust under lossy conditions with pixel interpolation and FEC
WebFM Architecture Diagram

Highlights

  • Real-world deployment in Cameroon with 30 users over 6 weeks
  • Achieved 10 kbps throughput with >70% decoding accuracy
  • Broadcast web pages and AI responses with no internet access
  • FM-capable phones available under local income thresholds
  • Scalable architecture using existing broadcast infrastructure
WebFM Mobile App Interface

Figure: A prototype of this system where a webpage is encoded as audio on the server and sent to the transmitter to broadcast. The client receives the audio transmission and decodes it back into the original image.

Paper

Read the paper: SONIC: Connect the Unconnected via FM Radio & SMS

Collaborators

  • Ayush Pandey (NYUAD)
  • Matteo Varvello (Bell Labs)
  • Khalid Mengal (NYUAD)
  • Jean Louis K. E. Fendji (University of Ngaoundéré)
  • Yasir Zaki (Advisor, NYU Abu Dhabi)