ZTE Dynamic RIS: Towards Cost-Efficient and Sustainable 5G-Advanced and Beyond

Challenges Facing 5G-Advanced and Beyond

As 5G commercialization gains momentum, active exploration of 5G-Advanced and 6G communication systems is underway. Nevertheless, the industry faces challenges on this evolutionary journey. Traditional network deployment proves inadequate for seamless coverage due to the assumption of an uncontrollable wireless environment, and the construction cost and energy consumption remain notably high. The advent of 5G-Advanced and future communication systems introduces new and demanding services, such as high-speed, low-latency applications (e.g., mixed reality, holographic rendering, sensing, and wireless medical services), creating a notable contradiction between service capacity requirements and limited spectrum resources.

While 5G continues to dominate headlines, the telecom industry is already focusing on technological advancements beyond the 5G era. Reconfigurable intelligent surface (RIS) has emerged as a robust contender for 5G-Advanced and 6G mobile networks, gaining global attention from academia and industry stakeholders.

RIS: A Novel Form of Antennas for Next-Generation Networks

RIS stands out as a cutting-edge and promising technology, poised for commercial success in 5G-Advanced and 6G. This innovation offers enhanced performance, cost-effectiveness, easy deployment, and low-carbon networks, playing a pivotal role in the cost-efficient and sustainable evolution of 5G-Advanced and beyond. The fundamental principle of RIS lies in creating an intelligent and adaptable environment through digital programming, manipulating the electromagnetic properties of metamaterials for unparalleled flexibility.

In contrast to conventional materials following Snell’s Law, which dictates that the angles of reflection and incidence signals remain equal and unalterable, RIS leverages electromagnetic (EM) metamaterials to precisely control the direction, width, and quantity of EM waves, facilitating accurate reflection or penetration.

ZTE Leading RIS Application in 5G Networks for Ecosystem Growth

ZTE has long been committed to R&D and commercial trials in the field of RIS. Leveraging advanced algorithms, a diverse range of product offerings and extensive partnerships, ZTE continues to drive the development of the RIS ecosystem.

• Diverse Portfolio

ZTE has launched a diverse RIS product portfolio including reflective RIS and refractive RIS, tailored to different use cases and environments.

Reflective RIS is primarily used for on-demand signal reflection in base stations. When obstacles between the base station and the user affect signal quality and user experience, reflective RIS can be deployed to reflect the signal to the user’s location, thereby enhancing the signal there. This technology can be strategically placed in accessible areas like poles, billboards and walls, offering cost-effective deployment options.

At the June 2023 Shanghai exhibition, ZTE unveiled its second-generation dynamic reflective RIS, named D-RIS 2.0. This device boasts an 80% reduction in power consumption compared to its predecessor, thanks to advancements in new materials and architecture. It also supports IP65 for outdoor long-term deployment, offering waterproof and dustproof capabilities.

Refractive RIS is primarily applied to glass surfaces, such as windows in buildings or carriage windows, to achieve outdoor coverage indoors or enhance coverage in high-speed train carriages. To avoid impacting indoor brightness, refractive RIS is typically designed in a transparent form and is therefore also referred to as transparent RIS.

• Advanced Algorithm

In the early stages of RIS research, the typical approach was static RIS. However, the performance of static RIS is severely constrained due to the inability to dynamically adjust the antenna beam direction in response to changes in the environment and terminal positions. ZTE has developed D-RIS to address this challenge. D-RIS uses dynamic beamforming to automatically track devices in real-time as they move within the coverage area, connecting them to the strongest available link. This greatly expands the base station’s coverage and ensures an optimal user experience. To reduce the processing complexity of RIS and maintain its cost and power consumption at extremely low levels, ZTE’s D-RIS relies on the channel estimation capability of base stations. The base station guides the D-RIS through a beam sweeping process to determine the user’s location. As users engage in services, the base station signals the D-RIS through an in-band air interface to adopt the optimal beam direction towards the user. Additionally, this implementation preserves the interface protocols between base stations and terminals, allowing 5G commercial terminals to access the network through RIS without modifications. This enables operators to deploy RIS in their 5G networks well before its widespread introduction in 6G.

ZTE Leads Commercial RIS Trials in the Fields

ZTE leads multiple commercial RIS trials, demonstrating that D-RIS can address operators’ growing coverage and performance needs while reducing their CAPEX and OPEX.

In September 2023, the 19th Asian Games were held in Hangzhou, China. During the event, China Telecom and ZTE showcased cutting-edge 5G-Advanced technologies and implemented several smart projects. Notably, D-RIS emerged as a key technology, delivering cost-effective and energy-efficient features. It played a significant role in ensuring ubiquitous 5G-Advanced coverage across sports venues and the Asian Games Village.

In the vicinity of the Hangzhou Asian Games venues, numerous high-rise buildings posed challenges to indoor 5G signal coverage due to non-line-of-sight (NLOS) conditions. To overcome this, RIS was rapidly deployed to expand the coverage of base station within living areas, shops and parking garages. This cost-effective and eco-friendly solution ensures comprehensive indoor coverage, delivering consistently high data rates for users.

In sports venues, the demand for network capacity surged, particularly with the introduction of HD 8K sports broadcasts. 5G-Advanced technology facilitated seamless HD streaming of Asian Games events, providing continuous high-speed services for multiple devices. Despite ample bandwidth from high-frequency bands, coverage challenges existed. The combination of AAU with RIS at the Hangzhou Asian Games achieved full coverage within the competition venues, substantially reducing deployment costs and speeding up the deployment process.

It is imperative to embrace RIS to sustain high-capacity performance in as many indoor and outdoor venues as possible. Imagine enjoying streaming videos or making calls over a 1 Gbps connection from a millimeter-wave outdoor base station, then seamlessly moving indoors without any disruption—this is the true power of RIS.