Technical Specification for Cellular Mobile Terminals (IMDA TS CMT)

Scope and Impact

This technical specification, IMDA TS CMT (Issue 1 Rev 4), defines the minimum requirements for Cellular Mobile Terminals (CMTs) intended for use in Singapore’s Public Mobile Radio Communication Systems. The regulation applies to handheld, portable, and vehicle-mounted equipment, as well as RF interface cards and modems. It encompasses devices utilizing the following technologies:

• ITU IMT-2000 (E-UTRA FDD / LTE)
• ITU IMT-Advanced (LTE-Advanced and LTE-Advanced Pro)
• ITU IMT-2020 (5G NR, including FR1 and FR2)

Permitted Radio Bands and Technical Parameters

CMTs must operate within the designated frequency ranges specified for E-UTRAN and 5G NR bands. Key operating parameters include:

• Band 1 / n1: Transmit (1920 – 1980 MHz), Receive (2110 – 2170 MHz)
• Band 3 / n3: Transmit (1710 – 1785 MHz), Receive (1805 – 1880 MHz)
• Band 7 / n7: Transmit (2500 – 2570 MHz), Receive (2620 – 2690 MHz)
• Band 8 / n8: Transmit (880 – 915 MHz), Receive (925 – 960 MHz)
• Band 26 / n26: Transmit (814 – 849 MHz), Receive (859 – 894 MHz)
• Band 28 / n28: Transmit (703 – 748 MHz), Receive (758 – 803 MHz)
• Band 38 / n38: TDD (2570 – 2620 MHz)
• Band 40 / n40: TDD (2300 – 2400 MHz)
• n77: 3300 – 4200 MHz
• n78: 3300 – 3800 MHz
• n257: 26500 – 29500 MHz
• n258: 24250 – 27500 MHz
• n261: 27500 – 28350 MHz

Specific Restrictions and Mandated Requirements

• 2G Connectivity: 2G capabilities must be disabled by factory default. Connection to 2G networks must require deliberate user action (e.g., via a settings menu).
• Voice-Over-LTE (VoLTE): Devices designed for voice calling must support VoLTE per 3GPP specifications. VoLTE must be enabled by default and compatible with all Singaporean mobile network operators.
• Emergency Cell Broadcast (CBS): Mandatory support for "SG Alert" and "Test Alert" notifications. Devices must prioritize these messages, support lengths up to 1395 characters, and follow specific audio patterns (e.g., 853 Hz and 960 Hz for polyphonic devices) and vibration cadences.
• IMEI Security: Every CMT must be allocated a unique IMEI/PEI. Manufacturers must implement security measures to prevent duplication or unauthorized removal of the identity.

Testing and Conformity Assessment Procedures

Compliance must be demonstrated through testing against international standards. Manufacturers are required to provide a Supplier’s Declaration of Conformity (SDoC) based on the following:

• RF EMF Safety (SAR and Power Density): Compliance with ICNIRP guidelines is mandatory. Relevant standards include CENELEC EN 50360, EN 50566, and IEC/IEEE 62209-1528. Note: Standards IEC/EN 62209-1 and 62209-2 are not accepted after 1 October 2025.
• Electromagnetic Compatibility (EMC): Testing is required based on ETSI EN 301 489-1 and ETSI EN 301 489-52. Vehicular equipment must also meet requirements regarding electrical transients (ISO 7637-2).
• Radio Interface: LTE devices must comply with ETSI EN 301 908-13. 5G NR devices must comply with ETSI EN 301 908-25 and ETSI TS 138 521-1/-2. Band 26 devices must meet FCC Part 22 or Part 90S requirements.
• Equipment Safety: Devices must meet IEC 62368-1 (Minimum Edition 2). Lithium batteries must comply with UL 1642, IEC 62133, or IEC 60086-4.

Labeling and User Information

While the regulation primarily focuses on technical parameters, it specifies requirements for user-facing information:

• Safety Documentation: Suppliers must provide SAR and/or power density information in printed form within the user guide or a dedicated leaflet in the equipment package.
• Advisory Information: Packages must include advisory information regarding electrical safety and non-ionizing radiation hazards for operation in potentially hazardous areas (e.g., fuel depots, aircraft).
• Keypad: Any alphanumeric keypad must comply with ITU-T Recommendation E.161.

Regulatory Replacement and Modifications

This document, IMDA TS CMT Issue 1 Rev 4 (March 2026), replaces the previous IMDA TS CMT Issue 1 Rev 3 (December 2024). Significant updates in this revision include the addition of IEC 60086-4 for lithium battery safety, mandated disabling of 2G connectivity by default, and clarified requirements for emergency cell broadcast configurations.