6G Symposium Recap – Spectrum Sharing in 6G Systems
If you missed the 6G Symposium, check out our blog for a full overview of Day 1 highlights, a review of Day 2’s keynote speech by National Science Foundation's Dr. Thyaga Nandagopal and fireside chat with NIST Director Dr. Walter G. Copan, and recaps of the Symposium’s most thoughtful panels. Recordings of the sessions will be available soon.
The second day of the 6G Symposium continued the discussion around the challenges posed by spectrum, but with a specific focus on spectrum sharing. The panel's moderator, Monica Paolini, founder and president of wireless consulting firm Senza Fili, began the session with a baseline question for all panelists: What is the best way to share spectrum efficiently that brings everyone on board?
5G is currently being rolled out and delivering 1.5 GBps in certain cities in the U.S., a country that leads the world in high-band spectrum allocation. "When we talk about spectrum sharing, we need to talk about adjacent channel users too, not just co-channel users," said FCC CTO Monisha Ghosh. She illustrated this point by addressing the passive users in higher bands like weather satellites as well. "In mid-bands, around 8-10 GHz and below, where it's still best for wide area cellular use, the picture is different,” she added. “There it's more about sharing with incumbents. And unlicensed services have to protect primary users."
The 6G, or the “Next G” will face many of the same issues as 5G. Ghosh pointed out that with the convergence and proliferation of unlicensed spectrum usage for cellular, the hope is that industry can begin designing systems that enable those running on licensed and unlicensed spectrum to work together. In short, it is clear that 6G will require better spectrum sharing modalities than we have today.
To punctuate this discussion, the panelists discussed the rollout of the CBRS system in the 3.5 GHz band earlier this year. This band had previously been allocated exclusively to the U.S. Department of Defense to be used for radar systems, but is now being shared with commercial systems. This shared model system has been operational since January 2020. Panelists indicated that the system is exceeding expectations. "There have been no interference complaints so far," said Andrew Clegg, Spectrum Engineering Lead for Google. "We are due for some innovation in the propagation model world," he added, describing that the propagation models for CBRS date back to the 1960s. "That's closer to Marconi than it is to today." Google, he said, is aiding this research by using its massive database of geodata to build new propagation models.
Echoing the call for propagation model research was Sheryl Genco, director of NTIA's Institute for Telecommunications Sciences (ITS). "Our data science group is just beginning to take a whole nation approach to build a propagation model for the whole world," she said. "We are also looking toward real-time spectrum management, which could really help prevent interference to incumbents." She encouraged industry participation in this research effort, reminding audiences that NTIA has an open data policy and open use policy, meaning their propagation models are open and available for anyone to use.
Tom Rondeau, Program Manager for DARPA, offered the Department of Defense perspective on spectrum sharing. "Maxwell's equations haven't changed, but the way we interact with them has evolved," he said. "We don't just share spectrum; we share the knowledge of how we use it." Rondeau described how DARPA is doing advanced research around phased arrays, spread spectrum, and software defined radio systems. The biggest challenges, he says, are often around computational power. Network slicing is one way they have found to help reduce that computational power requirement.
Simply put, 6G is about significantly increasing performance, in all aspects, over 5G. Masoud Olfat, Senior Director of Technology Development for Federated Wireless, discussed that the overall goal is to make spectrum sharing more efficient, and to discover new ways to exploit spectrum sharing. "We are looking at open RAN, computational edge networks, network slicing models and NFV," he said. "We need to learn how we can use spectrum sharing to improve overall performance of the wireless network and people's lives."
To recap more of the key take-aways and thought-provoking presentations from the 6G Symposium, please join us for a 6G Symposium Sync Up webinar on Thursday, November 5 at 1:00 p.m. ET, hosted with Fierce Wireless. Symposium organizers Doug Castor from InterDigital and Tommaso Melodia from Northeastern University will join industry experts to digest and make sense of the event’s varying perspectives on the 6G roadmap, the role of AI and Machine Learning in 6G networks, spectrum sharing approaches, public-private research partnerships, and much more.
You may register here.