Looking at how AI will shape future wireless networks including 5G Advanced and 6G.
The AI revolution is here. With the release of AI applications like ChatGPT, we are seeing firsthand the power and potential of deep neural networks (DNNs) and machine learning (ML). While ChatGPT is a language model that is trained to generate human-like text, the same underlying concept will change all aspects of technology during the next decade. For example, one of the biggest appeals of AI is its ability to optimize complex scenarios with large amounts of data. Wireless systems have also been growing in complexity for the last decade and struggle to process the vast amount of data that is produced, making them an ideal candidate for AI and ML.
AI in 5G networks
As 5G matures, AI and ML are already being introduced for study by the 3rd Generation Partnership Project (3GPP), the standardization body that maintains cellular specifications. Applications of AI under consideration are primarily in the air interface, including network energy saving, load balancing, and mobility optimization. Potential use cases in the air interface are so numerous that a small subset has been selected for study in the upcoming 3GPP Release 18, including channel state information (CSI) feedback, beam management, and positioning. It is important to note that 3GPP is not developing AI / ML models. Rather it seeks to create common frameworks and evaluation methods for AI/ML models being added into different air interface functions .
Outside of the 3GPP and the air interface, O-RAN ALLIANCE is exploring how AI/ML can be used to improve network orchestration. For example, the O-RAN ALLIANCE has a unique feature in its architecture called the RAN Intelligent Controller (RIC) that is designed to host AI/ML optimization applications (Figure 1). The RIC can host xApps, which run in near-real-time, and rApps, which run in non-real-time. The xApps for improving spectral efficiency and energy efficiency and, rApps for network orchestration, that leverage AI already exist today. More xApps/rApps and applications using AI /ML in the RIC will become available as the O-RAN ecosystem grows and matures.
Figure 1 An illustration of the O-RAN network architecture with the RIC that hosts AI/ML optimization applications that can either run in near-real-time or non-real-time. Source: Keysight
AI-native 6G networks
6G is in its infancy, but it is already clear that AI/ML will be a fundamental part of all aspects of future wireless systems. On the network side, the term “AI native” is used widely in the industry despite not being officially defined. One way of looking at these AI-native networks is to extrapolate from the diagram above (Figure 1) based on current trends of virtualization and disaggregation of the Radio Access Network (RAN). Each block of the network is likely to contain AI/ML models that will vary from vendor to vendor and application to application (Figure 2).
Figure 2 A basic diagram of the O-RAN 6G network where each block in that system incorporates AI models that might vary based on vendor or application. Source: Keysight
AI-native networks can also mean networks that were built to natively run AI/ML models. Consider the design flow below (Figure 3). In traditional 5G networks, the air interface is made up of different processing blocks, each designed by humans. In 5G Advanced, each block will leverage ML to optimize a specific function. In 6G, it’s possible that AI will design the entire air interface using DNNs.
Figure 3 A design flow showing the progression from AI infused to AI native networks. Source: Keysight
AI/ML power consumption optimization
Building on the idea that AI/ML can be used to improve network management orchestration, 6G looks to leverage AI/ML to solve optimization challenges. For example, AI could be used to optimize the power consumption of the network by turning on and off components based on real-time operating conditions. Today, xApps and rApps accomplish this at a base station level by turning on and off power-hungry components like power amplifiers when they are not in use. However, the ability of AI to quickly solve challenging compute problems and analyze large amounts of data opens the possibility of optimizing our networks at a larger, city-wide, or national scale. Entire base stations could be turned off during low use and cells could be reconfigured to service real-time demand in an energy optimized way using the least possible resources. It is not possible to reconfigure base stations and city-wide networks in this way today—it takes days or weeks to reconfigure and test any changes made to network configurations. Though, advances in different AI techniques remain promising and are top of mind for infrastructure providers.
Reshaping cellular networks with AI
Wireless networks will not wait for 6G to start leveraging the power of AI. Active research is happening across the entire ecosystem to develop new models and integrate them into the wireless systems of both today and tomorrow.
However, these models are still new and need to be evaluated for rigor and reliability. Properly training AI models on diverse data sets, quantifying their improvement over traditional techniques, and defining new test methodology for AI enabled modules are critical steps that must be taken as this new tech is adopted. As AI models and testing best practices mature, there is no doubt that AI will revolutionize wireless communications in the next 5-10 years.
This article was originally published on EDN.
Sarah LaSelva is the director of 6G marketing at Keysight Technologies and has a background in microwave and millimeter wave technology. She has over a decade of experience in test and measurement concentrating on wireless communications, both studying and promoting the latest wireless technologies.