Overview
ISO 21216:2012 defines the physical (PHY) air interface for millimetre‑wave communications used in Intelligent Transport Systems (ITS) under the CALM (Communications Access for Land Mobiles) framework. Often called CALM MM or the millimetre wave air interface, the standard specifies PHY‑level parameters for systems operating in the 57 GHz–66 GHz range (commonly referenced around the 60 GHz band) to support medium‑range, medium‑to‑high speed wireless links for vehicle‑to‑vehicle (V2V), vehicle‑to‑infrastructure (V2I) and related ITS applications.
Key topics and requirements
- PHY scope and architecture
- Specifies OSI Layer 1 parameters and interfaces to the CALM architecture (compliant with ISO 21217 and ISO 21218).
- Frequency range
- Global capable radio part: 57 GHz to 66 GHz; regional deployment may be limited (e.g., Europe 63–64 GHz).
- Regulatory and regional variations
- Emission limits, channelization and allowed bands vary by ITU region; equipment must comply with local rules and may support automatic, secure re‑configuration when moving between jurisdictions.
- Transmitter power and directivity
- Maximum Tx power and antenna directivity are governed by national/regional regulations; power control must be implemented and not user‑overridable.
- Mobility support
- PHY implementations must support vehicle speeds up to 220 km/h (mobile systems).
- Modulation and data rates
- Modulation schemes follow regional regulations; adaptive modulation must include a basic negotiation header. Supports schemes referenced (e.g., BPSK, 4QAM, and applicability of IEEE 802.11a in certain profiles).
- PHY–CALM interface parameters (MM‑PHY‑CI)
- Required CI parameters include: Rx sensitivity, Tx power, DataRate, DataRateNW, DataRatesNW, Directivity, CommRangeRef, CommProfil, Medium, RegulatoryInformation, TXpowMax.
- Out of scope
- Over‑the‑air transaction protocols are not defined by ISO 21216 and are left to regional or higher‑layer standards.
Practical applications and users
- Applications
- High‑throughput ITS uses: safety messaging, collision avoidance, roadside telemetry updates, probe data collection, video/image transfer, infotainment, traffic management, and enforcement.
- Who uses this standard
- Automotive OEMs, telematics and ITS equipment manufacturers, RSU/OBU designers, wireless chipset and antenna vendors, regulators and standards bodies, and system integrators deploying 60 GHz ITS links.
- Why it matters
- Provides a common PHY specification enabling interoperable medium‑range, high‑capacity ITS communications while accommodating regional regulatory constraints.
Related standards
- ISO 21217 - CALM architecture
- ISO 21218 - CALM medium service access points and MM‑PHY‑CI mapping
- ISO 24102 - CALM application management (upper layers)
- Regional references: ITU‑R M.1452‑1, ECC/ERC recommendations, FCC Part 15 and national regulations (Japan, Korea)
Keywords: ISO 21216:2012, CALM MM, millimetre wave air interface, 60 GHz band, ITS PHY layer, V2V, V2I, OBU, RSU, regulatory compliance.