Home/Glossary/6G Glossary/Simultaneously Transmitting and Reflecting RIS (STAR-RIS)
6G • RAN

Simultaneously Transmitting and Reflecting RIS (STAR-RIS)

Omnidirectional Simultaneously Transmitting and Reflecting Metasurface

Advanced metasurface that splits incident radio waves into reflected and transmitted beams, delivering 360-degree full-space wireless coverage.

Technical Explanation

Conventional Reconfigurable Intelligent Surfaces (RIS) can only reflect signals back into the same half-space (180° coverage), leaving the opposite side of the wall in a dead zone. STAR-RIS (or omni-surface) introduces independent magnetic and electric surface impedances on sub-wavelength meta-atoms. This allows the surface to simultaneously transmit a portion of the electromagnetic energy through the partition into an adjacent room while reflecting the remainder into the primary room, achieving seamless 360-degree full-space coverage.

Key Functions

  • Splits incident signals simultaneously into transmitted and reflected wavefronts
  • Eliminates half-space blind zones inherent in legacy reflecting-only metasurfaces
  • Controls amplitude and phase independently on both sides of physical room partitions
  • Operates under energy splitting, mode switching, or time-switching protocols
Specifications
ETSI ISG RIS 002, IEEE Communications Surveys & Tutorials STAR-RIS
Interfaces
STAR-RIS Controller BusSub-6G/Sub-THz Front-HaulUu-RIS

Related 6G Concepts

Want to memorize 6G concepts like this one?
Study it with SuperMemo SM-2 spaced repetition flashcards.
Practice 6G Flashcards