5G Repeater Classification and Technical Standards

I. Characteristics of Repeaters

In mobile communication systems, a repeater (Mobile Repeater), also known as a signal amplifier (repeater) or mobile signal booster, is a device that amplifies existing mobile phone signals to improve signal strength in weak areas. Its working principle involves using an external antenna to receive weak signals, transmitting them to a signal amplifier for amplification, and then rebroadcasting the enhanced signal through an internal antenna. This improves mobile phone connectivity within its effective range, making it particularly suitable for rural areas, large concrete and metal structures, or vehicles.

II. Repeater Standards

Signal boosters used in 5G (NR) systems are classified into: Repeaters, NCRs (Network Control Repeaters), and auxiliary equipment; among them, NCRs are further divided into NCR-Fwd and NCR-MT. The applicable requirements, procedures, test conditions, performance evaluation, and performance standards for different types of base stations in wireless networks are as follows:

• NR repeaters equipped with antenna connectors that can be terminated during EMC testing meet the RF requirements for type 1-C repeaters in TS 38.106[2] and demonstrate compliance with TS 38.115-1[3].
• NR repeaters without antenna connectors, i.e., antenna elements do not radiate during EMC testing, meet the RF requirements for type 2-O repeaters in TS 38.106[2] and demonstrate compliance with TS 38.115-2[4].
• NCRs equipped with antennas or TAB connectors that can be terminated during EMC testing meet the RF requirements for NCR-Fwd/MT type 1-C and type 1-H in TS 38.106[2] and demonstrate compliance with TS 38.115-1[3].
• The NCR is not equipped with an antenna connector, meaning that the antenna element was not radiated during EMC testing, which complies with the NCR-Fwd/MT 2-O type RF requirements in TS 38.106 [2] and demonstrates its compliance by conforming to TS38.115-2 [4].

The repeater usage environment classification refers to the residential, commercial, and light industrial environment classifications used in IEC 61000-6-1 [6], IEC 61000-6-3 [7], and IEC 61000-6-8 [24]. These EMC requirements were chosen to ensure that the equipment is sufficiently compatible in residential, commercial, and light industrial environments. However, these levels do not cover extreme situations that may occur in any location but with a low probability.