ISO 18185-5:2007

Overview - ISO 18185-5:2007 (Physical layer for electronic seals)

ISO 18185-5:2007 specifies the air interface (physical layer) between electronic container seals (eSeals) and Reader/Interrogators. It is part of the ISO 18185 series for freight containers - electronic seals, defining radio and low-frequency links used to localize, identify and report container status. The standard ensures interoperability for RFID-based eSeals across global supply chains by referencing established RFID air‑interface standards.

Key topics and technical requirements

• System components: eSeal, LF (low-frequency) transmitter, and Reader. The system uses dual-frequency operation (long-range and short-range).
• Two physical layer types:
  • Type A: 433.92 MHz long-range link (LRL) with anti-collision slot-based collection protocol (aligned to ISO/IEC 18000‑7) plus an LF OOK short-range link (123–125 kHz) for localization.
  • Type B: 2.4 GHz long-range link (LRL) using BPSK with Direct Sequence Spread Spectrum (DSSS) and FSK short-range link characteristics aligned to ISO/IEC 24730‑2.
• LF short-range link (Type A):
  • OOK modulation, Manchester encoding, approximately 1 600 bps.
  • One-way transmission from LF transmitter to eSeal; preamble and packet framing are defined to mark packet boundaries.
• 2.4 GHz link parameters (Type B) - selected examples:
  • Operating range 2 400–2 483.5 MHz, centre frequency 2 441.75 MHz, occupied bandwidth 60 MHz.
  • Modulation BPSK DSSS, data bit rate 59.7 kb/s, PN chip rate ~30.52 MHz, CRC definitions and blink/telemetry timing parameters.
• Collision handling: Type A uses slot-based anti-collision; Type B eSeals do not require an anti-collision protocol.
• Scope of application: eSeals for freight containers covered by ISO 668, ISO 1496 (parts 1–5) and ISO 830.

Applications and who uses it

ISO 18185-5 is practical for:

• eSeal manufacturers designing radio and LF modules for tamper-evident container seals.
• RFID system integrators and Reader/Interrogator vendors ensuring interoperable air-interface implementations.
• Logistics providers, ports, customs and terminal operators deploying electronic seals for real‑time container identification, tamper detection and tracking.
• Regulatory bodies and standards committees harmonizing supply‑chain security and RFID deployment.

Related standards

• ISO 18185 series (Parts 1–4: communication protocol, application requirements, environmental characteristics, data protection)
• ISO/IEC 18000‑7 (433 MHz RFID parameters)
• ISO/IEC 24730‑2 (2.4 GHz air interface)
• ISO 17363, ISO 10374 (Freight container RFID identification)
• ISO 17712 (mechanical seals) and container standards ISO 668, ISO 1496, ISO 830

Keywords: ISO 18185-5, electronic seals, freight containers, physical layer, RFID, 433 MHz, 2.4 GHz, LF OOK, DSSS, eSeal.