Overview
ISO/IEC 15149-3:2016 specifies the relay protocol for extended range in Magnetic Field Area Networks (MFAN). As part of the ISO/IEC 15149 family, this standard defines how MFAN devices (coordinator, nodes, repeaters) operate together to extend effective network coverage using low-frequency magnetic-field communication. It covers addressing, request/response codes, time-division management and MAC-layer relay functions to connect out-of-boundary nodes via MFAN repeaters (MFAN-R).
Keywords: ISO/IEC 15149-3, MFAN, magnetic field area network, relay protocol, extended range, TDMA, MFAN repeater
Key Topics and Technical Requirements
- Network architecture and elements
- Defines device roles: MFAN-C (coordinator), MFAN-N (node), MFAN-R (repeater).
- Single MFAN-C per network; nodes and repeaters associate to it.
- Time-domain management (TDMA)
- Superframe structure divided into request period, response period, and spontaneous period.
- MFAN-C allocates request time slots; response period is divided by device count. Repeaters may subdivide their slots to create nested superframes for out-of-range nodes.
- Relay and addressing
- Addressing scheme and request/response codes are defined to manage relay behavior and association/disassociation.
- Repeater setup procedures and message types (e.g., RSRq, RSRs, RSRA) are specified for forming relay links.
- MAC layer
- Frame formats and frame types are defined, including request frames, response frames, response confirmation frames and blocks.
- MAC functions include repeater set-up, data transmission timing and network status management.
- Physical/air interface characteristics
- MFAN uses low carrier frequencies (30 kHz–300 kHz), simple robust modulation (e.g., BPSK), and coding techniques (Manchester or NRZ‑L) to provide several kbps over several meters in harsh environments.
Applications
- Extending wireless communication coverage in environments where RF propagation is poor: around metal, underground, underwater-adjacent or soil-rich settings.
- Enabling reliable short-range telemetry and control in industrial, mining, agricultural, and underground infrastructure.
- Supporting systems that combine wireless communication and wireless power transfer (WPT) where magnetic-field links are preferred.
- Implementing robust IoT and sensor networks in harsh or metallic environments that require repeaters to reach remote nodes.
Who should use this standard
- Device manufacturers and system integrators designing MFAN hardware (coordinators, nodes, repeaters).
- Firmware and protocol developers implementing MAC/relay functions and TDMA scheduling.
- Test labs and certification bodies validating MFAN interoperability and extended-range relay behavior.
- Architects of industrial and infrastructure communications seeking standards-based magnetic-field networking solutions.
Related standards
This standard is essential for anyone implementing or deploying MFAN relay networks intended to extend coverage reliably in harsh environments.