Have you ever encountered situations like these: losing cell service suddenly in a city filled with skyscrapers; being unable to use navigation in an underground parking garage; or struggling to make an emergency call in a remote mountainous area? These seemingly ordinary issues actually reveal the deep-seated limitations of existing mobile communication technologies.

Although 5G has been widely deployed, significant coverage gaps still exist. Data shows that 5G dead zones in urban densely populated areas remain as high as 30%, while underground spaces and remote areas exceed 50%. Furthermore, 5G base stations consume three times more power than 4G, and persistently high operational costs limit network expansion.

As we enter the 6G era, communication demands are growing exponentially: holographic communication requires speeds exceeding 100 Gbps, metaverse applications demand millisecond-level latency, and intelligent transportation requires 99.999% reliability. These new demands pose unprecedented challenges to communication technology.

At the same time, 6G will utilize millimeter-wave and terahertz high-frequency bands for transmission. However, high-frequency signals have poor penetration and are easily blocked. To achieve comprehensive coverage, traditional architectures require a large number of base stations, which are not only costly but may also lead to electromagnetic pollution.

Ⅰ. Intelligent Metasurfaces (RIS): Making Communication as Effortless as Sunlight

An Intelligent Metasurface (Reconfigurable Intelligent Surface, RIS) is a two-dimensional metasurface composed of programmable electromagnetic units that can dynamically control the amplitude and phase of wireless signals to achieve intelligent signal reflection and optimization.

Simply put, RIS acts like an “intelligent mirror” that can:

l Directional Reflection: Precisely transmit base station signals to target users

• Signal enhancement: Achieve in-phase superposition through phase control
• Interference suppression: Eliminate unwanted signals via out-of-phase superposition
• Path optimization: Select the optimal propagation path

Compared to traditional equipment, RIS offers significant advantages:

Low cost: No complex RF links required; hardware costs can be reduced by over 50%

Low power consumption: Relying on passive reflection, power consumption is only 1% of that of a base station

Easy deployment: Slim, lightweight devices that can be mounted on walls, light poles, etc.

Intelligent control: Combines AI algorithms to dynamically optimize beamforming

RIS marks a shift from “passively adapting to the environment” to “actively shaping the environment.” Its workflow includes:

1. Environment sensing: AI algorithms locate users and determine channel conditions
2. Intelligent control: Calculates optimal reflection phases
3. Dynamic optimization: Real-time adjustment of each unit’s reflection characteristics

This active control capability allows every user to enjoy a customized communication environment, significantly enhancing communication quality and system capacity.

Ⅱ. Multi-Base Station, Multi-RIS Networking: A Revolutionary Breakthrough for 6G

In October 2025, China Telecom completed the first 6G multi-base station, multi-RIS networking trial in Yanqing, Beijing, marking the transition of RIS technology from the laboratory to practical application.

This network architecture includes:

Multiple base stations (BS): Providing multi-source transmission to enhance spatial diversity

Multiple RIS: Deployed at key locations such as building facades, roadside areas, and tunnel entrances

Edge AI control layer: Coordinating signal strategies among RIS and base stations

User terminals: Receiving enhanced signals synthesized from multiple paths

The trial results include:

Overcoming single-station coverage limitations: Through the collaboration of multiple base stations and RIS units, data rates in areas with weak coverage were increased by more than five times

Resolving handover interruptions: Beamforming adaptive technology enables seamless handover, supporting continuous services such as AR, live streaming, and smart inspections

Advantages of multi-station, multi-RIS networking:

Expanded coverage: Dead zones reduced by approximately 60%

Signal enhancement: Received signal strength increased by three times, and data rates in areas with weak coverage increased by five times

Reduced interference: Multi-user interference reduced by 40%

50% improvement in spectral efficiency

30% reduction in energy consumption; based on existing base stations, the annual power savings could meet the needs of a medium-sized city

Ⅲ. Key Technological Breakthroughs

1. Elimination of dead zones: RIS constructs virtual line-of-sight paths; multipath synthesis combined with AI-powered intelligent tracking boosts signal strength in areas with weak coverage by 3 times (approximately 5 dB).
2. Interference Suppression and Beamforming: Block-based RIS, TTD mechanisms, and cascaded channel decoupling reduce multi-user interference by 40%, improve signal consistency by 80%, and increase beamforming accuracy by 30%.
3. AI-Driven Intelligent Control: Reinforcement learning, federated learning, and hierarchical optimization algorithms enable RIS to perceive environmental changes in real time and dynamically optimize reflection configurations.

Ⅳ. Application Scenarios and Commercial Value

• Smart Cities: Solves coverage blind spots in urban canyons, underground spaces, and indoor environments
• Industrial Internet: Optimizes workshop communications and ensures low latency and high reliability; for example, reducing communication latency in welding workshops from 15 milliseconds to 2 milliseconds
• Intelligent Transportation: Vehicle-to-infrastructure coordination, autonomous driving support, and traffic flow optimization
• Remote Areas: Low-cost coverage; RIS replaces some base stations, reducing hardware and deployment costs by 50%–70% and extending the lifespan of passive terminals to 10 years

Ⅴ. Industry Development and Future Outlook

R&D Progress: China leads globally in RIS R&D, having completed live-network verification in the 3.5 GHz band, with signal strength in weak coverage areas increased by 3 times.

Corporate Initiatives: Telecommunications giants such as Huawei and ZTE have established dedicated teams, and the RIS Technology Alliance (RISTA) now has over 30 members.

Standardization: The IMT-2030 (6G) Promotion Group has included RIS in its research on key technologies, and 3GPP Rel-19 has launched a research project.

Commercial Timeline:

2025–2027: Technology validation and small-scale pilot projects

2027: 6G standardization

2030: Large-scale commercial deployment, achieving connection densities in the tens of millions and data rates of 10 Gbps

Future Development Directions: Multi-band integration, convergence of communication, sensing, computing, and intelligence, and an open ecosystem to drive high-quality communication across all scenarios.

Intelligent metasurface technology marks a shift in communication systems from “adapting to the environment” to “actively shaping the environment.” RIS not only resolves existing communication bottlenecks but also reshapes the design paradigm of communication systems.

As the technology matures, 6G will realize the vision of “communication as ubiquitous as sunlight,” making the intelligent interconnection of all things a reality. All these innovations begin with a “thinking mirror”—the intelligent metasurface.