The FCC’s Technological Advisory Council (TAC) met in the last week of August to update its progress. While some topics the TAC’s 6G working group raised showed an industry trend, others sounded like creative approaches.
Among the most recurring themes was video, which has been regarded as a strong 6G use case since the beginning. According to Brian Daly, Assistant VP at AT&T and co-chair of the working group, questions about enabling enhanced XR and VR capabilities need a further look.
“How will 5G and 6G networks support the massive volume of mobile, IoT, and XR devices? Many of these devices require low latency and seamless connectivity as they support both near- and non-real-time services. And many are trending toward real-time applications,” he pointed out.
Manu Gosain, Senior Director at Northeastern University and co-chair, added that the working group is paying attention to the developments the research community is making, especially in the standardisation area.
“This community is very active, and there are 3GPP enhancements that have been looked at and have been standardised starting from release 15 around enabling low power modes,” he said. “We’re going to continue to follow the evolution of this community.”
Gosain also explained that the industry is tracking motion to render to photon latency as the key metric to meet the requirements of a mobile network communication system to enable full XR and VR capabilities.
“This metric can be found by calculating the latencies across the edge processing, the 5G round trip time over the air, and then the device processing on the user device or whatever form factor that device is going to take,” Gosain explained.
Full Duplex: Questions Without Answers
The working group also addressed full duplex, one of the technologies regarded as fundamental for unlocking 6G’s potential.
According to Gosain, one crucial challenge remains without a clear solution today: self-interference of the signal.
“There are certain approaches being studied for cancelling and suppressing this self-interference, and some of the issues that we’re looking at are now with the proliferation of massive MIMO antenna arrays,” he observed.
“Some of the cancellation techniques in the analogue domain don’t necessarily scale for the large arrays that we have in 5G, and probably we’ll see more and more elements come as we move towards 6G,” the director added.
Borrowing from the Neighbour
While XR and full duplex have been common topics in telecommunications in recent years, the working group presented an alternative solution for an old problem: heavy network usage.
The answer? Use ATSC 3.0, a new television broadcast standard that the FCC adopted in November 2017 that helps enable a convergence with broadband streaming.
“What is of particular interest is datacasting on ATSC 3.0. It can enable a low latency push of information, more of a broadcast push of information to devices in a metro area or regional coverage area by the ATSC 3.0 station,” Daly argued.
“It will allow for reliable time-sensitive communications across regional areas, especially in congested environments,” the AT&T executive added.
According to him, AT&T and other companies are looking at providing a dongle that can be used for the datacasting services rather than incorporating the ATSC within the mobile device itself. The dongle would be connected via Bluetooth or Wi-Fi to an external device such as a mobile phone.
“Some of the datacasting use cases envisioned are IoT to download information to a large number of IoT devices, software updates to devices, firmware updates, map updates for connected cars, digital signage, and also some of the agriculture use cases,” Daly pointed out.
Next Steps
For the next quarter, the 6G working group will look at additional topic areas, more specifically:
- mmWave and Terahertz
- Positioning and Timing
- Integrated Sensing and Communication
