Overview
ISO/IEC 17417:2011 defines the physical layer (PHY) and medium access control (MAC) for Short Distance Visible Light Communication (SDVLC). The standard targets very short-range optical links (up to 10 cm) using visible light (wavelengths 380–780 nm) and specifies modulation, encoding, frame formats and user-visible brightness control that is independent of data modulation. SDVLC is designed primarily for systems where LEDs used for illumination also carry data or where visible status and data transfer are combined (the standard notes mobile-to-mobile as a representative application).
Key technical topics and requirements
- Range & spectrum: Communication specified for up to 10 cm using visible light in the 380–780 nm band.
- Modulation: Mandatory On-Off Keying (OOK) with a mandatory modulation frequency of 120 MHz; timing/jitter constraints are defined to ensure reliable demodulation.
- Encodings: 8B/10B encoding is required (for maximum throughput); 2B/4B is optional to allow variable optical duty cycles (25%, 50%, 75%) and visible-brightness trade-offs.
- PHY electrical/optical requirements: Transmitter and receiver optical performance, rise/fall times (≤ 3.0 ns), and off-state irradiance limits are specified to guarantee interoperability and visible-light safety/visibility.
- MAC and framing: Data Frame and Visible Frame structures, MAC PDU formats, CRCs, start/control headers, bit order (LSB first), and link management messages (association, disassociation, acknowledge, burst modes) are defined.
- Human-visible control: The standard mandates human-detectable brightness control separate from data modulation so devices can indicate link status or user-visible signals without affecting data integrity.
- Interoperability rules: Conformance clauses enumerate required elements (transmitter + receiver, mandatory encoding and modulation frequency, etc.).
Practical applications and target users
- Device manufacturers of consumer electronics, mobile devices, wearables, and IoT gadgets that want short-range, line-of-sight data exchange using LEDs.
- Use cases include secure proximity pairing, device-to-device transfers, status signaling combined with data, and experimental short-range high-speed links where RF is undesirable.
- System integrators and test labs implementing PHY/MAC stacks for visible light prototypes or products benefiting from visible status indicators tied to data channels.
- Researchers developing VLC modulation, encoding, and human-factors integration for combined illumination/data systems.
Related standards
ISO/IEC 17417 references several relevant documents for interoperability and protocol design, including:
ISO/IEC 17417:2011 is essential reading for anyone implementing short-distance visible light links where LED illumination and data exchange must coexist reliably and visibly.