Q&A led by Ravi Veerasubrananian

What is the current and roadmap device (UE) support for 1 x NR plus 5 x LTE Carriers?

Andy Sutton  – The initial 5G new radio devices are designed with support of carry aggregation. because this ENDC mode of operation (non stand-alone mode) outlined earlier in the session, when you connect to a 5G network today, you actually connect over the 4G signalling network, because it’s a wide area coverage. Today we use 5G as a speed boost to maintain and enhance the mobile broadband experience. From release 15, when we introduced 5G devices, those devices would support new radio and up to 5 x 20 MHz LTE carriers, from the specification from 3G BP. We do see that usage on the network in devices used today. Clearly it depends how many carriers and operators are deployed to the base station as to whether 5 are actually available, depending on the strategy and the spectrum holding and investment the operator makes. Certainly on the EE network there are 5 carriers deployed in parallel with new radio. This also depends on the amount of traffic consumed by the user, if it cannot be dealt with by NR, additional carriers are bought into play. This mode of operation will ensure 4G and 5G radio can work together and that is how 5G operates on most networks.

What are the EMF challenges and solutions (ICNIRP) for rolling out M-MIMO?

Phil Sheppard – There is regulation in place that specifies safe level of radio that can be transmitted. Typically, you have to calculate the radiation and power, and limit both, to ensure there is no damage to people. M-MIMO has the beam forming capability which allows you to focus and concentrates power to a narrower area than a traditional antenna – the way this has been dealt with so far is to take a cautious approach and reduce the amount of energy being transmitted being output. This means you cannot extract the full value and benefit from the antenna. What’s being worked on is what is the statistical power that can be delivered and can the antenna be managed and limit the power in any one direction to safely use the full range of it. If you look at actual power levels being transmitted at any one site, there is a very low percentage of the safe limit being emitted.

For BT/EE, who have announced the Nokia decision, will Open RAN play a part in the access network any time soon?

Andy Sutton - Open RAN has been developed by the Open RAN alliance; BT is an active member of this – contributing to the developments of the specifications to allow Open RAN architecture. This is looking to functionally decompose the radio access network into a number of subcomponents. Taking the radio unit and then taking the digital section and decomposing this into different further sections to achieve different levels of optimisation. The open aspect comes into play as the target is that you can buy each component from a different vendor, plug them together and they will work perfectly, which isn’t the case today. It’s believed this will drive innovation, commercial benefits and open up the market to specialist vendors who may not want to play in the end to end space. The rollout with Nokia that has just been announced will be a traditional radio access network in the macro cell network, which is where the technology is today.

It’s thought that the first Opportunity for Open RAN in building deployments, where it will start to grow. Beyond that, small cells in the external network and then macro cells across networks. This is a journey which could take is 5-10 years, in reality. 

The UK Govt. (Dept. for Digital, Culture, Media and Sport), launched a task force to address UK's limited diversity in vendor ecosystem, now Huawei are restricted, and Nokia/Ericsson are dominant - what alternatives do the panel see as viable?

Alastair Masson - The challenge is bigger than just diversity in the eco system, following the news surrounding Huawei. Due to the fact that for so many operators the bidding tactics and levels for spectrum are driven by cost of investment in network infrastructure. The problem is more fundamental than just diversity and the problems lie in the business models and weighing up if the economics still work.

The truth is, this is going to be more expensive which needs to be met somehow. It’s unsure where the government stand on this. The buyers of the service will be paying for the rollout. The Open RAN architecture is the alternative as business involves. There are operators trailing Open RAN, we are working with businesses and we are seeing a lot of Open RAN technologies maturing to private campus 5G networks. 

Has government green lighted 5G funding or is it left to industry? Can you outline how UK Govt. are enabling 5G? Dept. Digital, Culture, Media and Sport and Ofcom how do they interact and who is lead 5G Minister and Shadow?

Abhaya Sumanasena – The UK government is under pressure to deploy 5G fast. The UK government has done a lot of work to make 5G happen in the UK. For example, the test and trial process; there are 6 regions in the UK where there has been investment and 5G has been used. Use cases have been tested to put us ahead and on par with other countries. Ofcom and the government do interact; Ofcom is independent body with responsibility to manage the UK spectrum, minimise interference and optimise use. Loads of spectrum used by government, where Ofcom is also involved, and they are working together to make sure spectrum bands are available. When speaking on spectrum, it’s important to talk about harmonisation – other countries identify the same spectrum bands for the same purpose – which has resulted in European level harmonisation which Ofcom has had a contribution to. There are also initiatives in place to improve connections in rural areas.

Phil Sheppard - The government don’t intervene in direct investments in 5G in commercial situations – there are a few things that have been noticed; there is barrier busting work group around planning and commissions to make an easier and more fluid deployment of 5G. There is also a programme called 5G Create which investigates trials for new apps coming to the market. Where coverage is an issue in low economic areas, they are investing in the shared rule network. 

How important will small cell deployment be for 5G? Is network sharing of small cells a potential mechanism to make small cells cost effective?

Abhaya Sumanasena - Small cells are important and haven’t really taken off until now. Not due to the technology but to the business case and the cost economics of deploying a small cell. Planning permissions is required to deploy any new site. There are many governments working on making these things easier, which will hopefully help to deploy small cells to give local capacity.

5G is a massive development. Is 6G being thought of, what lies beyond?

Andy Sutton – There’s certainly early conversations about 6G, there is question to whether the G is even relevant anymore as the technology continues to evolve and is spread across a wider set of use cases. 6G as a term is good for marketing and academic funding so we will see the term used, but it may not be relevant anymore. What is the deployment of 6G trying to solve? There is a long roadmap of 5G, which needs to be carried out and deployment continued. It’s very early days but conversations are starting, and BT will be a part of the dialogue. 

Where does Elon Musk's Starlink project fit in?

Alastair Masson - This is to do with Satellite. Stepping back from Elon Musk, and thinking about SatComms in general; it is a struggle to see how it fits within the mass market piece, Satellites are more related to maritime, aviation and extreme remote. High economics are required for a project like this and therefore it probably won’t reach penetration into the market. 

Andy Sutton – BT are looking at satellite for rural areas as a use case where terrestrial transmission cannot be delivered. This involves employing satellite-based resilience to terrestrial transmission. For example, EE delivers the network for Emergency Services in the UK; in order to deliver high performance requirements there needs to be a high level of availability. Delivering resilience at a terrestrial level is challenging, however delivering that resilience through a space-based component is advantageous. BT are interested in projects such as Starlink, as operators there is opportunity there to help critical industries.

To what extent will 2G, 3G, 4G and 5G radio access networks be rationalised and the spectrum refarmed?

Abhaya Sumanasena – Having worked with an operator, it’s very expensive to run parallel networks of 2G, 3G, 4G and 5G – it’s important to weigh up what is most economical to do. Refarming will happen at some point because cost economics don’t work and it’s not optimum to run parallel networks. Real Wireless have published a study surrounding the switch off of 2G which can be found here.

Andy Sutton – There are new techniques coming to the market to help with refamring. Previously an entire block of spectrum had to be taken and moved from one technology to another. Now we are seeing a dynamic spectrum sharing between 4G and 5G. You may lose capacity, but it does mean you can have a 20mdhz carrier serving LTE and 5G new radio customers. As the percentage of handsets that support 5G increases, you’ll see customers migrating to new radio utilisation. Over time you’ll lock that carrier to new radio. This gives you a smoother order of granularity in terms of reframing spectrum from one radio access technology to another.   

Phil Sutton – It’s time to start retiring some old technology, specifically 3G. 2G still fixes networks in for a little while longer, but 5G and 4G work nicely together over time and we can gradually move across those. We may look to move to merging these technologies in the future which would become a form of 6G. 

How significant will AI/ML be for planning and managing complex, virtualised 5G networks?

Andy Sutton – There is a huge number of parameters that need to be optimised, not just in mobile but in the internet itself. There’s a huge diverse range of traffic types which react in different ways. Machine learning and automation are a clear direction of strategy and will be critical. BT is investing heavily in both.