The Infocomm Media Development Authority (IMDA) in Singapore has published Technical Specification for Short Range Devices (SRD) Issue 1 Revision 2 on August 21, 2021.

The Technical Specification defines the minimum requirement for Short Range Device (SRD) to operate in one of the authorized frequency bands or frequencies, and transmit within the corresponding output power levels and restricted conditions.

The definition of SRD is as follows:

SRDs may be fixed, mobile or portable stations that come with a radio frequency output connector and dedicated antenna or an       integral antenna. Applications include alarms, identification systems, radio detection, vehicle radar systems, wireless local area         networks, remote controls, telecommand, telemetry and on-site paging systems. These devices may employ different types of           modulation and may have speech applications.

There are changes for frequency bands in Technical Specification SRD 2021.

• 6-150kHz, 150-5000kHz, and 6765-6795kHz – Included in in ‘Wireless power transfer’ as application type
• 26.96-27.28MHz – Included ‘Non specific SRD’ as application type
• 169.40-175MHz – Included ‘Meter Reading’ as application type
• 433.05-434.79MHz – Included ‘Intermittent/Periodic transmission of control signals’ as application type; added FCC Part 15 and 15.231 as reference standard
• 433.05-434.79MHz – Included ‘RFID for commercial shipping containers, limited to areas such as ports, rail terminals and warehouses’ as application type; added FCC Part 15 and 15.240 as reference standard
• 920-925MHz – Included ‘Non specific SRD’ as application type
• 5.725-5.875GHz – Included ‘Wireless Industrial Applications (WIA)’ as application type
• 24-24.25Ghz – Included ‘Tank level probing radar’ as application type
• 24-24.25GHz – Included ‘Non specific SRD’ as application type
• 57-64GHz – Included ‘Tank level probing radar’ as application type
• 57-64GHz – Included ‘Non specific SRD’ as application type

EMC and Safety requirements for all communication products need to comply to EMC Class B requirement.

The changes of adding new functionality for the existing frequency is to cater wider variety of SRD applications especially new technologies.

• 16-5000kHz is to cater Wireless Charging (Wireless Power Transfer) which is previously not clearly stated in the Technical Specification
• 920-925Mhz is to cater for LORA / Zwave and other new technologies in this range
• 57-64Ghz is to cater for all sensor technologies using this range