In case you missed it, a Deutsche Telekom-backed 5G sky-network is gearing up for launch – offering country-wide 5G coverage for a decently-sized European country with just 60 masts – and no site rentals to speak of. As covered over on RCR Wireless last week, the venture proposes a high-altitude platform (HAP), on unmanned hydrogen-powered aircraft, will carry a new breed of wireless antenna to provide blanket 5G coverage from 20,000 metres up.
The parties involved – UK-based startup Stratospheric Platforms Limited (SPL), in which Deutsche Telekom has a 38 percent stake, and UK-based innovation house Cambridge Consultants, which Capgemini acquired in April – hailed the new 5G antenna, announced on a press call last week, as “unlike anything seen before” and a “remarkable technical achievement”. An LTE-based prototype has been tested already with Deutsche Telekom in southern Germany; the new antenna will take to the skies in 2022, and the whole thing is scheduled to launch in 2024.
Richard Deakin, chief executive at SPL, commented: “This single mega cell tower in the stratosphere will provide coverage that is equal to the combined efforts of hundreds of terrestrial cellular masts, rewriting the economics of mobile broadband.” Some numbers were provided, for comparison: an airborne antenna array mounted on 60 aircraft could cover all of the UK; 67 would do for Germany. The UK will require another 400,000 masts to provide national 5G coverage, by contrast, calculate SLP and Cambridge Consultants.
So could 5G networks in the future be fixed in the sky, aboard fleets of aircraft, instead of being fixed to masts and buildings with expensive rents? And how, exactly? Speaking with Enterprise IoT Insights (see Q&A below), the trio said they expect other operators to get involved, and suggested any sky-bound 5G network may yet be operated as a neutral host setup, affording a chance for national operators to share access to the infrastructure to in-fill black-spots and not-spots, and to close the digital divide around broadband access.
They also said sky-based 5G could, in complement with terrestrial infrastructure, provide coverage beyond straight consumer connectivity, to support massive-scale IoT, including for industrial private cellular, as the business and technical cases justified. In terms of ‘verticals’, Tim Fowler, chief sales officer at Cambridge Consultants, pointed to the value of airborne 5G, offering sharper coverage, in the transportation sector, in the rollout of autonomous vehicles and drones, and in out-of-reach connectivity for smart agriculture.
Fowler said: “Unlike the terrestrial cells sites we see on the ground, the HAP phased array antenna provides uniform coverage of high performance 5G – with significantly lower degradation of signal quality over the coverage area – together with the ability to ‘paint’ connectivity over highly targeted areas. These enable a whole host of 5G use cases to be realised, from consumer connectivity to innovative industrial IoT applications.” His comments are available in full in the Q&A section, below.
The new antenna from Cambridge Consultants is designed to be both powerful and low-energy, and also both huge (three meters square) and lightweight (120kg). It will be the “world’s largest commercial airborne communications antenna”, when it finally launches in 2024, the firm said. It called the prototype, even at one eighth of the intended size of the commercial model, one of its “crowning achievements”.
Fowler said: “Advanced calibration across the four tiles of the prototype deliver beams with astonishing accuracy, maintaining laser-like performance during flight motion and paving the way for the huge 32-tile commercial array to now be developed. Each antenna produces 480 individual, steerable beams, creating patterns that can be ‘painted’ onto the ground to cover specific areas such as roads, railway lines or shipping lanes.
“The ability to produce hundreds of beams enables the antenna to reuse spectrum ensuring fast and even coverage across the entire covered area. A unique, wholly digital beamforming capability gives massive flexibility in how services are deployed, allowing in-flight reconfiguration to deliver services beyond the reach of conventional fixed terrestrial networks. This includes following mobile users, including trains and autonomous vehicles, and providing coverage exactly where required, for example ending at national borders.”
The hydrogen-powered aircraft, as the other piece of the innovation, is designed to fly at an altitude of 20,000 metres for around eight days, before coming down for refueling. It offers a low environmental impact, said SPL, with low noise, zero CO2 and zero NOx emissions.
A single HAP will provide coverage over an area of up to 140 kilometres in diameter – “equivalent to hundreds of today’s terrestrial masts,” said SPL and Cambridge Consultants in a statement. A fleet of around 60 HAPs over the UK would provide blanket 5G connectivity with peak 5G speeds in excess of 100 Gbps “in aggregate”, the pair said. This proposed flying-5G network will be a “fraction of the cost of building and maintaining terrestrial infrastructure”, they claimed.
They said: “With radically cheaper costs, this new platform has the potential to connect the unconnected in the developing world, to fill gaps in coverage across the developed world and to ensure rural areas aren’t left behind anywhere across the globe.”
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Note, the below Q&A is with Deutsche Telekom (DT), and Richard Deakin and Tim Fowler from Stratospheric Platforms Limited (SPL) and Cambridge Consultants Limited (CCL), respectively.
How much is this project a proof-of-concept, and how much is it a real commercial endeavour?
DT: “At this point of time the project is a successful proof of concept. It has shown that ‘airborne towers’ can be a realistic and economical addition to our existing terrestrial network in the future.”
SPL: “The project is a commercial endeavour and has been running since 2016, with the first services due for launch by Deutsche Telekom in Germany in 2024. The latest milestone has been for Cambridge Consultants to complete a proof of concept 5G antenna, which has overcome the key technical challenges within simulated flight conditions and proven its unique modular design can scale seamlessly to the future development of the full scale model which is needed for commercial flight.”
How does the prospect of airborne 5G antennas impact operators’ national terrestrial rollout plans for 5G – in Germany with DT, and elsewhere?
DT: “Our current national terrestrial rollout plans for 5G are not affected by the successful trial. Deutsche Telekom is closely following the current technology development and is looking forward to the current prototype development, which is expected to be completed in 2022. Whilst actual usage will be based on the available data and planned production ramp-up at the time, Deutsche Telekom is interested in employing the SPL’s technology.”
CCL: “The high-altitude platform (HAP) is designed to work in complement with terrestrial networks. In major cities and suburban areas, where the demand and revenues are the greatest, I expect terrestrial ground-based networks to remain a key strategy. However, the HAPs provide a vastly more attractive business case to roll out high performance 5G in remote and rural areas and could certainly play a major role in operator deployment strategies.”
SPL: “Delivering 5G and 4G services from the stratosphere is significantly cheaper than providing the service by terrestrial masts. Each aircraft can replace the need for at least 200 terrestrial towers and provides significantly better quality coverage over wide areas than is possible with a terrestrial solution. The airborne service can also be deployed much faster compared to lengthy, costly and complex terrestrial tower installation programmes.”
Will this innovation be used – after 2024 – to in-fill coverage in remote areas, or will it be used in place of terrestrial 5G in urban and suburban areas?
DT: “We see the use of ‘airborne towers’ as a useful addition to its existing network – in both rural and urban areas.”
SPL: “Delivering telecoms services from the stratosphere is complementary to existing terrestrial networks as the un-manned aircraft essentially serves as a mast at 60,000-feet and the systems can be integrated easily, as has already been trialled by Deutsche Telekom. The aircraft will not compete with the high density 4G and 5G services in the centre of cities but as you move into less populated areas, the service is capable of providing significantly better data rates to users over very wide areas compared to anything in service or planned today for most countries.”
Do you expect other operators to sign up?
SPL: “Absolutely. Deutsche Telecom is the launch customer, but the HAPs are open to other carriers.”
Is this innovation more about 6G than 5G?
DT: “The field tests were carried out with LTE technology.”
CCL: “The antenna has been designed to support all mobile standards. It can support LTE and 5G today, and be re-banded for 6G in the future”
What spectrum will be used, and how will this interplay with the other spectrum in Germany?
DT: “Current frequency selections are determined by regulatory requirements and WRC allocations. We are currently using mm-wave backhaul (48GHz) into the telco network from the aircraft and 2.1GHz fronthaul from the aircraft to the user equipment. At present, it is not yet possible to make any statements about the spectrum that can be used in the future.”
Does this new airborne 5G connectivity have specific applications?
DT:”The trial was focused on coverage, not on applications.”
Will airborne 5G be used mostly for consumer connectivity, or will it be used for IoT connectivity?
CCL: “Unlike the terrestrial cells sites we see on the ground, the HAP phased array antenna provides uniform coverage of high performance 5G – with significantly lower degradation of signal quality over the coverage area – together with the ability to ‘paint’ connectivity over highly targeted areas. These enable a whole host of 5G use cases to be realised, from consumer connectivity to innovative industrial IoT applications.
“Let’s take transportation as an example, the HAPs can beam connectivity to specific routes or track individual vehicles. This could enable many IoT applications related to smart infrastructure and autonomous vehicles, whether by road, rail, or sea. Another example is smart agriculture. If you consider a single HAP can provide coverage equal to 200 terrestrial base stations, it’s a vastly more attractive business case to cover rural and agricultural areas where there are huge benefits to be gained from the IoT.
“Importantly, the system also has a very low latency of about 1ms. This is significantly better than other wide area coverage systems – such as satellites, which have typical latencies of 25ms-30ms – and are subsequently unable to be used for the safety-critical systems needed for real time computation in autonomous vehicles and drones for example. The system keeps the capability for operators to make planning choices regarding diversity and redundancy, should they wish to deliver higher levels of availability needed for some mission critical applications.”
Will airborne infrastructure complement operators’ private ‘campus’ network propositions for industry?
DT: “If the deployment is an economically and technically sensible addition to our campus networks, then this option will be considered in the future.”
SPL: “This really comes down to economics and carrier-choices. If a HAP is more cost effective to provide the targeted coverage needed for campus connectivity compared to terrestrial infrastructure, then it’s a real possibility.”
Will these airborne masts work as neutral host infrastructure? Will the likes of DT share this new infrastructure with other national operators in Germany?
DT: “Assuming technical feasibility, such a decision would be the result of individual cooperation agreements.”
SPL: “Yes. It could be that a shared infrastructure model emerges whereby more than one carrier transmits from a single HAP, or fleet of HAPs, much like the shared tower infrastructure we see on the ground today. We are in active discussions with a rage of telcos around the world.”
Will a third party operator run this instead of operators? Who will manage the fleet of aircraft? Will operators be involved?
SPL: “SPL and its operating partners will run the HAPs with one or more carriers granted licenses to operate their networks from the aircraft. It’s important to note that from the carrier’s perspective this is essentially reconfigurable infrastructure. You can move your base stations as and when you need to – you are not tied to terrestrial planning regulations for tower construction and the density of coverage can follow demand. I expect it to be a really attractive option.”
DT: “Currently, Deutsche Telekom is not planning to enter the aviation industry.”
Will this change how mobile networks are deployed? Will terrestrial masts become a thing of the past?
CCL: “When we were first approached by SPL four years ago it was with a highly ambitious vision: to revolutionise the telecoms experience by beaming connectivity from the sky. The HAPs are certainly set to achieve this, working hard to complement terrestrial masts, which will always have a home in urban areas that experience consistent high demand and where the economics stack up.
“For everywhere else, the HAPs make an outstanding business case to connect the world to high performance 5G. Our role, to design and build this ‘mega cell tower in the stratosphere’, has seen us make breakthrough after breakthrough and we’re excited to build on these innovations with SPL, on the path to commercial deployment.”
