5G 28GHz In-Building RF Relay AIR-28G The AIR-28G is a system that supports 5G NR mobile communication service by distributing 28GHz 5G signal through the air interface and distributing it within the in-building. Currently commercially operated on SK Telecom test network.


  • 28GHz Active In-building RF Relay
  • 28GHz 5G NR service-enabled building antenna integral optical distribution RF relay system
  • mmwave 5G MIMO signals are distributed over the wireless interface and in-building optical distribution system to expand service coverage
  • Enable Analog optical distribution and support 800 MHz 2T2R MIMO service
  • Active RF Relay system to address issues of shaded areas and degradation in In-building that can be caused by high path-loss due to 28GHz ultra-high frequency characteristics and by Penetration Loss due to building structures.
  • Wireless optical distribution system to remove shaded areas and increase capacity in the building
  • 2x2 MIMO support for 28GHz 5G NR Throughput increase
  • Support for mmwave radio interface interworking and TDD synchronous detection
AIR-28G is a member of the cost-effective and highly scalable Mobile Access


  • Features

    • Supportable frequency

       - 28 GHz: mmwave 5G NR

    • Optic Interface : Analog Optic (DL 1λ, UL 4λ)
    • Baseband Interface: Air interface (mmwave)
    • Support for 2x2 MIMO services through Cross Polarization
    • Wideband analog light distribution, Ultra low-latency realization 
    • Outdoor DONOR for 5G base station and LOS link configuration
    • 5G signal TDD synchronous detection and TDD switching signal transmission/control
    • 28GHz DL Input AGC and Path Control, UL Gain balance capability provided
    • Application of tilting structure for application of various building environments
    • Remote surveillance via IRCS servers
  • Applications

    • Mobile Access (Inbuild Optic Distributed Active Antenna) Service
    • 28GHz mmwave 5G NR Frequency Service
    • System that can be built/opened quickly to remove shaded areas in the building


    OAM and Maintainability

    • IRCS Protocol
    • Analog optics, Frequency Modulation Control & Management Protocol

5G 28GHz In-Building RF Relay AIR-28G Applications


Parameter AIR-28G
Frequency 27.525 - 28.325 GHz (IBW 800 MHz)
MIMO/Interface 2T2R (cross polarization) / Air (mmwave)
Optical transmission distance (MU-OSU-RU) Lower than 2 km (9 dBo)
Used Optical Transmission (DL) 1 wavelength (UL) 4 wavelength
Input Power -40 - -65 dBm/Total
Output Power 27 dBm/EIRP

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