5G has been part of our lives and the market for several years, while the industry is already looking ahead to its successor, 6G. But can we say it is fully implemented?
An international team led by Northeastern University, with participation from IMDEA Networks, TU Berlin, University of Porto, University of Oslo, Politecnico di Torino, Technical University of Denmark, and Hewlett Packard Labs, sought the answer. Over the course of a year, they measured performance in several cities across Europe and North America. The conclusion: 5G is widely deployed in major urban centers, but its benefits do not always translate into a better experience than 4G.
"We collected controlled and crowdsourced data in eight cities [Berlin, Turin, Oslo, Porto, Madrid, Vancouver, Boston, and the Bay Area] and found a striking geographic and operator-level variation: some networks offer excellent 5G uplink performance, while others show little or no improvement compared to LTE," explains Imran Khan, a predoctoral researcher at Northeastern University and the study's first author.
Claudio Fiandrino, Research Assistant Professor at IMDEA Networks, summarizes: "5G deployment in major cities has stabilized, but this stability has not yet translated into consistent latency advantages over 4G/LTE; the reality is more varied than marketing suggests."
The study combines large-scale crowdsourced measurements with a controlled millimeter-wave campaign, providing both breadth and depth to the findings. The picture that emerges is uneven: in many places, 5G does not offer clear latency benefits over LTE. The differences are less about the "5G" label and more about operator decisions, such as spectrum band, deployment density, and the use of cloud and edge infrastructure.
Beyond the technical results, the study highlights what this means for users, policy makers and operators: "For many users and real-world applications, switching to 5G will not automatically guarantee lower latency or better responsiveness. Some 5G cells offer lower latency, but in others performance may be similar or even worse than LTE, depending on the operator and location. Decisions regarding latency-sensitive services should therefore be based on actual measurements, not just the technology generation," explains Fiandrino.
The researchers also warn about the risks of moving prematurely to 6G. "There is a risk of wasted investment and unmet public expectations; misallocation of resources toward promoted features instead of addressing operational issues (coverage gaps, backhaul/edge location, spectrum fragmentation); and potential policy and market decisions based on optimistic promises rather than tangible reality. This could also undermine trust if future generations (6G) are promoted prematurely," cautions the IMDEA Networks researcher.
The solution, the authors emphasize, lies in large-scale, forward-looking measurement. The focus must be on the real user experience before advancing, and operational and implementation issues should be resolved before moving to the next generation. Policies and 6G investments should be guided by transparent and reproducible results.
The study finds that while 5G rollout and stability look mature in many urban areas, performance advantages (particularly latency) are still uneven. As Fiandrino stresses: "In terms of coverage and deployment stability, 5G seems mature in major cities, but full maturity has not yet been reached regarding reliability, clear performance advantages, and user experience compared to 4G, especially in latency. Therefore, maturity is conditional: deployed, yes; consistently superior performance, not yet."
