Wireless connectivity has become essential for communication, education, transport, healthcare, industry and many other services. Future sixth-generation (6G) networks are expected to accommodate rapidly increasing data traffic, connected devices and intelligent applications while providing high reliability, broad coverage, low latency and improved energy and spectrum efficiency. However, conventional wireless systems mainly adapt the transmitter and receiver, while the propagation environment itself remains largely uncontrolled.
Reconfigurable intelligent surfaces offer a promising way to make the wireless environment programmable. Most conventional surfaces can only reflect signals and therefore mainly serve users located on one side of the surface. Simultaneously transmitting and reflecting intelligent omni-surfaces can serve users on both sides, potentially providing more flexible and nearly full-space wireless coverage. Nevertheless, many existing studies rely on idealised models that do not sufficiently account for physical constraints, spatial correlation, propagation effects, imperfect surface control and the dependence between transmission and reflection characteristics. This can lead to unrealistic performance predictions and limit the practical design of these technologies.
ENIOS aimed to establish realistic foundations for intelligent omni-surface-assisted communication beyond 5G and towards 6G. Its first objective was to develop physically motivated mathematical and statistical channel models that capture relevant propagation conditions, implementation constraints and dependence structures. Its second objective was to create analytical tools for evaluating system performance, including reliability, achievable rate, coverage, multiple access and secure communication. Its third objective was to investigate new adaptive architectures combining intelligent surfaces with spatially reconfigurable and fluid antenna concepts.
The project’s pathway to impact is based on translating physical characteristics into tractable models, using these models to derive and validate communication performance results, and making the resulting knowledge available to the research community. In the short term, these outcomes provide researchers and engineers with more reliable tools for comparing and designing emerging 6G technologies. In the longer term, they can support further simulation, experimental validation, standardisation and technology development. ENIOS therefore contributes to the European ambition of developing secure, sustainable and energy efficient digital connectivity and may ultimately support more reliable wireless services for citizens, industry and connected infrastructure.
