With 6G gaining more visibility, naturally, there is a discussion on a new air interface, and, particularly, on the use of millimetre wave frequencies. It’s almost like 6G is synonymous with millimetre waves and the air interface is the starting point. Traditionally, Radio Access has dominated the development of the next G, as we’ve travelled from 2G to 5G.
That should not be the case for 6G.
The purpose of 6G should be the enablement of widest possible access, by all people across the world, to digital services and voice, and that a novel Intelligent Core Network should be the key feature of 6G which facilitates access to multiple radio access technologies including existing 2G-5G plus the new 6G radio as well as LEO satellite and WiFi whilst also catering for interworking with Private Networks.
In effect, with its overarching Intelligent Core, 6G would be a “Network of Networks”, maximising access to wireless connectivity, leveraging all existing infrastructures as well as new ones.
The Intelligent Core should be the starting point in 6G, followed by Semi-Autonomous Devices and finally, the Multiple and Diverse Access Media. In the latter, that the spectrum is no longer exclusively assigned to a given G should be the norm, (rather than the exception, as in re-farming).
If one starts with the purpose of 6G being the enablement of widest possible access, by all people across the world, to digital services including those provided by “things” (such as IOT, robots, drones, autonomous vehicles, virtual reality and similar), and in particular, provided or supported increasingly by AI, voice taken for granted, of course, then one arrives at 6G being a “facility” which:
- Leverages existing 3GPP platforms, 2-5G, making sure coverage of remote areas and people is not compromised
- Caters for a multiplicity of diverse access media where geographically small but high-spec 6G islands coexist with wide-area 4G-5G common access layers, along with more localised Private Networks
- Includes extensive use of Private Networks, whether offered as slices by large MNOs or truly private deployments including shared frequencies and different protocols such as CBRS.
- Embraces WiFi, LEO Satellite,
- Embraces Fibre and FWA as intrinsic parts of the concept,
- Exploits new frequency bands through a new air interface but not exclusively, so that 4G and 5G technologies also utilise those frequencies where appropriate,
- Caters for coexistence of mmw frequencies in use for cellular as well as PTP, PTMP backhaul and FWA in shared fashion.
- Considers Fibre an intrinsic part of the 6G concept and caters for it to be designed in from the outset, for example, when deploying 6G hotspots which could be connected by dedicated mmw or fibre backhaul with super speeds and latency,
- Empowers devices for Authentication and Mobility Management across above diverse landscape of wireless networks,
In this heterogenous environment, the 6G Intelligent Core and the “empowered” Devices perform overall Authentication and Mobility Management. The 6G Intelligent Core enables the Device with the knowledge of specific protocols of the networks the Device is about to access.
Needless to say, one no longer has devices restricted to given operators network(s); instead, they enjoy an extensive use of National Roaming which is administered by the 6G Intelligent Core, most probably, making good use of e-SIM functionality as part of that overall control or mediation.
Given the diversity of protocols (6xGs, WiFi, LEO Satellite, CBRS etc) and the range of frequency bands in use, it will, probably, be necessary to make some sacrifices in seamless mobility and even in the frequency bands/types of networks accessible by a given device type.
As mentioned at the beginning, the 6G Intelligent Core is a critical and central part of this vision. It has overarching reach, has the ability to translate, mediate for the different protocols of the diverse network technologies it enables the devices to access.
In technical media, there is currently, a debate on whether the development of 6G should be through an Evolutionary or a Revolutionary approach. Given above conceptual functionality of 6G, such distinction is not actually appropriate. It is a new concept which has Revolutionary and Evolutionary aspects.
Leveraging existing Gs is obviously evolutionary yet the above idea of 6G Intelligent Core is revolutionary. Extending the life of existing 4/5G networks reduces or delays capital investments, and it can be argued to be better environmentally.
Moving up the frequency bands to millimetrewaves is evolutionary. The new 6G air interface not backwardly compatible with 4/5G would be revolutionary, yet the proposed operation of the 6G Intelligent Core and the Semi-Autonomous Devices might make 6G New Radio look evolutionary. That Security in 6G needs fresh thinking and a revolutionary approach is discussed in another Azenby blog https://azenby.com/archives/3081
That spectrum should not be assigned to 6G exclusively may appear revolutionary but is it really? With Spectrum Aggregation and Dynamic Spectrum Sharing already in use in 4/5G, that is a natural development.
Another aspect of the ITU spectrum strategy and the national Regulators’ policies in the 6G world should be to support network sharing, spectrum sharing/trading, including the availability of more spectrum for shared use, especially given the extremely short re-use distances of millimetre waves and the highly likely small area deployment of 6G New Radios. Some might argue, given the advances in semiconductor technology, that re-use even within a room might be feasible using super-MIMO beam steering. {ref another future Azenby blog}
Naturally, this vision of 6G has many challenges. Such versatility and intelligence in the 6G Intelligent Core and the enablement of Devices for self-management in the management of authentication and mobility is a tall order, not to mention the range of frequencies those devices would have to cope with; but the prize is worth the effort. Given the never-ending advances in semiconductor technology and AI in the service of telecoms, anything is possible.
This vision of 6G has a very significant side benefit, too, since the Emergency Services of the country would not be constrained to one network provider (as is the case, normally) but instead they would have automatic access to all the networks in the country and use the best network available at the specific time and location where they need it.
Our industry has done a great job in giving mobile communications to the masses over the last 3+ decades. Now, we have an opportunity to excel. Let’s go for it!