Stratospheric Drones & Low Earth Satellites: Revolutionizing Terrestrial Rural Broadband from the Skies?

Posted on January 15, 2024 by Dr. Kim

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“From an economic and customer experience standpoint, deploying stratospheric drones may be significantly more cost effective than establishing extra terrestrial infrastructures”.

This article, in a different and somewhat shorter format, has also been published by New Street Research under the title “Stratospheric drones: A game changer for rural networks?”. You will need to register with New Street Research to get access.

As a mobile cellular industry expert and a techno-economist, the first time I was presented with the concept of stratospheric drones, I feel the butterflies in my belly. That tingling feeling that I was seeing something that could be a huge disruptor of how mobile cellular networks are being designed and built. Imagine getting rid of the profitability-challenged rural cellular networks (i.e., the towers, the energy consumption, the capital infrastructure investments), and, at the same time, offering much better quality to customers in rural areas than is possible with the existing cellular network we have deployed there. A technology that could fundamentally change the industry’s mobile cellular cost structure for the better at a quantum leap in quality and, in general, provide economical broadband services to the unconnected at a fraction of the cost of our traditional ways of building terrestrial cellular coverage.

Back in 2015, I got involved with Deutsche Telekom AG Group Technology, under the leadership of Bruno Jacobfeuerborn, in working out the detailed operational plans, deployment strategies, and, of course, the business case as well as general economics of building a stratospheric cellular coverage platform from scratch with the UK-based Stratospheric Platform Ltd [2] in which Deutsche Telekom is an investor. The investment thesis was really in the way we expected the stratospheric high-altitude platform to make a large part of mobile operators’ terrestrial rural cellular networks obsolete and how it might strengthen mobile operator footprints in countries where rural and remote coverage was either very weak or non-existing (e.g., The USA, an important market for Deutsche Telekom AG).

At the time, our thoughts were to have an operational stratospheric coverage platform operationally by 2025, 10 years after kicking off the program, with more than 100 high-altitude platforms covering a major Western European country serving rural areas. As it so often is, reality is unforgiving, as it often is with genuinely disruptive ideas. Getting to a stage of deployment and operation at scale of a high-altitude platform is still some years out due to the lack of maturity of the flight platform, including regulatory approvals for operating a HAP network at scale, increasing the operating window of the flight platform, fueling, technology challenges with the advanced antenna system, being allowed to deployed terrestrial-based cellular spectrum above terra firma, etc. Many of these challenges are progressing well, although slowly.

Globally, various companies are actively working on developing stratospheric drones to enhance cellular coverage. These include aerospace and defense giants like Airbus, advancing its Zephyr drone, and BAE Systems, collaborating with Prismatic for their PHASA-35 UAV. One of the most exciting HAPS companies focusing on developing world-leading high-altitude aircraft that I have come across during my planning work on how to operationalize a Stratospheric cellular coverage platform is the German company Leichtwerk AG, which has their hydrogen-fueled StratoStreamer as well as a solar-powered platform under development with the their StratoStreamer being close to production-ready. Telecom companies like Deutsche Telekom AG and BT Group are experimenting with hydrogen-powered drones in partnership with Stratospheric Platforms Limited. Through its subsidiary HAPSMobile, SoftBank is also a significant player with its Sunglider project. Additionally, entities like China Aerospace Science and Technology Corporation and Cambridge Consultants contribute to this field by co-developing enabling technologies (e.g., advanced phased-array antenna, fuel technologies, material science, …) critical for the success and deployability of high-altitude platforms at scale, aiming to improve connectivity in rural, remote, and underserved areas.

The work on integrating High Altitude Platform (HAP) networks with terrestrial cellular systems involves significant coordination with international regulatory bodies like the International Telecommunication Union Radiocommunication Sector (ITU-R) and the World Radiocommunication Conference (WRC). This process is crucial for securing permission to reuse terrestrial cellular spectrum in the stratosphere. Key focus areas include negotiating the allocation and management of frequency bands for HAP systems, ensuring they don’t interfere with terrestrial networks. These efforts are vital for successfully deploying and operating HAP systems, enabling them to provide enhanced connectivity globally, especially in rural areas where terrestrial cellular frequencies are already in use and remote and underserved regions. At the latest WRC-2023 conference, Softbank successfully gained approval within the Asia-Pacific region to use mobile spectrum bands for stratospheric drone-based mobile broadband cellular services.

Most mobile operators have at least 50% of their cellular network infrastructure assets in rural areas. While necessary for providing the coverage that mobile customers have come to expect everywhere, these sites carry only a fraction of the total mobile traffic. Individually, rural sites have poor financial returns due to their proportional operational and capital expenses.

In general, the Opex of the cellular network takes up between 50% and 60% of the Technology Opex, and at least 50% of that can be attributed to maintaining and operating the rural part of the radio access network. Capex is more cyclical than Opex due to, for example, the modernization of radio access technology. Nevertheless, over a typical modernization cycle (5 to 7 years), the rural network demands a little bit less but a similar share of Capex overall as for Opex. Typically, the Opex share of the rural cellular network may be around 10% of the corporate Opex, and its associated total cost is between 12% and 15% of the total expenses.

The global telecom towers market size in 2023 is estimated at ca. 26+ billion euros, ca. 2.5% of total telecom turnover, with a projected growth of CAGR 3.3% from now to 2030. The top 10 Tower management companies manage close to 1 million towers worldwide for mobile CSPs. Although many mobile operators have chosen to spin off their passive site infrastructure, there are still some remaining that may yet to spin off their cellular infrastructure to one of many Tower management companies, captive or independent, such as American Tower (224,019+ towers), Cellnex Telecom (112,737+ towers), Vantage Towers (46,100+ towers), GD Towers (+41,600 towers), etc…

IMAGINE.

Focusing on the low- or no-profitable rural cellular coverage.

Imagine an alternative coverage technology to the normal cellular one all mobile operators are using that would allow them to do without the costly and low-profitable rural cellular network they have today to satisfy their customers’ expectations of high-quality ubiquitous cellular coverage.

For the alternative technology to be attractive, it would need to deliver at least the same quality and capacity as the existing terrestrial-based cellular coverage for substantially better economics.

If a mobile operator with a 40% EBITDA margin did not need its rural cellular network, it could improve its margin by a sustainable 5% and increase its cash generation in relative terms by 50% (i.e., from 0.2×Revenue to 0.3×Revenue), assuming a capex-to-revenue ratio of 20% before implementing the technology being reduced to 15% after due to avoiding modernization and capacity investments in the rural areas.

Imagine that the alternative technology would provide a better cellular quality to the consumer for a quantum leap reduction of the associated cost structure compared to today’s cellular networks.

Such an alternative coverage technology might also impact the global tower companies’ absolute level of sustainable tower revenues, with a substantial proportion of revenue related to rural site infrastructure being at risk.

**Figure 1** An example of an unmanned autonomous stratospheric coverage platform. **Source:** Cambridge Consultants presentation (see reference [2]) based on their work with Stratospheric Platforms Ltd (SPL) and SPL’s innovative high-altitude coverage platform.

TERRESTRIAL CELLULAR RURAL COVERAGE – A MATTER OF POOR ECONOMICS.

When considering the quality we experience in a terrestrial cellular network, a comprehensive understanding of various environmental and physical factors is crucial to predicting the signal quality accurately. All these factors generally work against cellular signal propagation regarding how far the signal can reach from the transmitting cellular tower and the achievable quality (e.g., signal strength) that a customer can experience from a cellular service.

Firstly, the terrain plays a significant role. Rural landscapes often include varied topographies such as hills, valleys, and flat plains, each affecting signal reach differently. For instance, hilly or mountainous areas may cause signal shadowing and reflection, while flat terrains might offer less obstruction, enabling signals to travel further.

At higher frequencies (i.e., above 1 GHz), vegetation becomes an increasingly critical factor to consider. Trees, forests, and other dense foliage can absorb and scatter radio waves, attenuating signals. The type and density of vegetation, along with seasonal changes like foliage density in summer versus winter, can significantly impact signal strength.

The height and placement of transmitting and receiving antennas are also vital considerations. In rural areas, where there are fewer tall buildings, the height of the antenna can have a pronounced effect on the line of sight and, consequently, on the signal coverage and quality. Elevated antennas mitigate the impact of terrain and vegetation to some extent.

Furthermore, the lower density of buildings in rural areas means fewer reflections and less multipath interference than in urban environments. However, larger structures, such as farm buildings or industrial facilities, must be factored in, as they can obstruct or reflect signals.

Finally, the distance between the transmitter and receiver is fundamental to signal propagation. With typically fewer cell towers spread over larger distances, understanding how signal strength diminishes with distance is critical to ensuring reliable coverage at a high quality, such as high cellular throughput, as the mobile customer expects.

The typical way for a cellular operator to mitigate the environmental and physical factors that inevitably result in loss of signal strength and reduced cellular quality (i.e., sub-standard cellular speed) is to build more sites and thus incur increasing Capex and Opex in areas that in general will have poor economical payback associated with any cellular assets. Thus, such investments make an already poor economic situation even worse as the rural cellular network generally would have very low utilization.

**Figure 2** Cellular capacity or quality measured by the unit or total throughput is approximately driven by the amount of spectrum (in MHz) times the effective spectral efficiency (in Mbps/MHz/units) times the number of cells or capacity units deployed. When considering the effective spectral efficiency, one needs to consider the possible “boost” that a higher order MiMo or Advanced Antenna System will bring over and above the Single In Single Out (SISO) antenna would result in.

As our alternative technology also would need to provide at least the same quality and capacity it is worth exploring what can be expected in terms of rural terrestrial capacity. In general, we have that the cellular capacity (and quality) can be written as (also shown in Figure 2 above):

Throughput (in Mbps) =
Spectral Bandwidth in MHz ×
Effective Spectral Efficiency in Mbps/MHz/Cell ×
Number of Cells

We need to keep in mind that an additional important factor when considering quality and capacity is that the higher the operational frequency, the lower the radius (all else being equal). Typically, we can improve the radius at higher frequencies by utilizing advanced antenna beam forming, that is, concentrate the radiated power per unit coverage area, which is why you will often hear that the 3.6 GHz downlink coverage radius is similar to that of 1800 MHz (or PCS). This 3.6 GHz vs. 1.8 GHz coverage radius comparison is made when not all else is equal. Comparing a situation where the 1800 MHz (or PCS) radiated power is spread out over the whole coverage area compared to a coverage situation where the 3.6 GHz (or C-band in general) solution makes use of beamforming, where the transmitted energy density is high, allowing to reach the customer at a range that would not be possible if the 3.6 GHz radiated power would have been spread out over the cell like the example of the 1800 MHz.

As an example, take an average Western European rural 5G site with all cellular bands between 700 and 2100 MHz activated. The site will have a total of 85 MHz DL and 75 MHz UL, with a 10 MHz difference between DL and UL due to band 38 Supplementary Downlink SDL) operational on the site. In our example, we will be optimistic and assume that the effective spectral efficiency is 2 Mbps per MHz per cell (average over all bands and antenna configurations), which would indicate a fair amount of 4×4 and 8×8 MiMo antenna systems deployed. Thus, the unit throughput we would expect to be supplied by the terrestrial rural cell would be 170 Mbps (i.e., 85 MHz × 2.0 Mbps/MHz/Cell). With a rural cell coverage radius between 2 and 3 km, we then have an average throughput per square kilometer of 9 Mbps/km2. Due to the low demand and high-frequency bandwidth per active customer, DL speeds exceeding 100+ Mbps should be relatively easy to sustain with 5G standalone, with uplink speeds being more compromised due to larger coverage areas. Obviously, the rural quality can be improved further by deploying advanced antenna systems and increasing the share of higher-order MiMo antennas in general, as well as increasing the rural site density. However, as already pointed out, this would not be an economically reasonable approach.

THE ADVANTAGE OF SEEING FROM ABOVE.

**Figure 3** illustrates the difference between terrestrial cellular coverage from a cell tower and that of a stratospheric drone or high-altitude platform (“Antenna-in-the-Sky”). The benefit of seeing the world from above is that environmental and physical factors have substantially less impact on signal propagation and quality primarily being impacted by distance as it approximates free space propagation. This situation is very different for a terrestrial-based cellular tower with its radiated signal being substantially impacted by the environment as well as physical factors.

It may sound silly to talk about an alternative coverage technology that could replace the need for the cellular tower infrastructure that today is critical for providing mobile broadband coverage to, for example, rural areas. What alternative coverage technologies should we consider?

If, instead of relying on terrestrial-based tower infrastructure, we could move the cellular antenna and possibly the radio node itself to the sky, we would have a situation where most points of the ground would be in the line of sight to the “antenna-in-the-sky.” The antenna in the sky idea is a game changer in terms of coverage itself compared to conventional terrestrial cellular coverage, where environmental and physical factors dramatically reduce signal propagation and signal quality.

The key advantage of an antenna in the sky (AIS) is that the likelihood of a line-of-sight to a point on the ground is very high compared to establishing a line-of-sight for terrestrial cellular coverage that, in general, would be very low. In other words, the cellular signal propagation from an AIS closely approximates that of free space. Thus, all the various environmental signal loss factors we must consider for a standard terrestrial-based mobile network do not apply to our antenna in the sky.

Over the last ten years, we have gotten several technology candidates for our antenna-in-the-sky solution, aiming to provide terrestrial broadband services as a substitute, or enhancement, for terrestrial mobile and fixed broadband services. In the following, I will describe two distinct types of antenna-in-the-sky solutions: (a) Low Earth Orbit (LEO) satellites, operating between 500 to 2000 km above Earth, that provide terrestrial broadband services such as we know from Starlink (SpaceX), OneWeb (Eutelsat Group), and Kuiper (Amazon), and (b) So-called, High Altitude Platforms (HAPS), operating at altitudes between 15 to 30 km (i.e., in the stratosphere). Such platforms are still in the research and trial stages but are very promising technologies to substitute or enhance rural network broadband services. The HAP is supposed to be unmanned, highly autonomous, and ultimately operational in the stratosphere for an extended period (weeks to months), fueled by green hydrogen and possibly solar. The high-altitude platform is thus also an unmanned aerial vehicle (UAV), although I will use the term stratospheric drone and HAP interchangeably in the following.

Low Earth Orbit (LEO) satellites and High Altitude Platforms (HAPs) represent two distinct approaches to providing high-altitude communication and observation services. LEO satellites, operating between 500 km and 2,000 km above the Earth, orbit the planet, offering broad global coverage. The LEO satellite platform is ideal for applications like satellite broadband internet, Earth observation, and global positioning systems. However, deploying and maintaining these satellites involves complex, costly space missions and sophisticated ground control. Although, as SpaceX has demonstrated with the Starlink LEO satellite fixed broadband platform, the unitary economics of their satellites significantly improve by scale when the launch cost is also considered (i.e., number of satellites).

Figure 4 illustrates a non-terrestrial network architecture consisting of a Low Earth Orbit (LEO) satellite constellation providing fixed broadband services to terrestrial users. Each hexagon represents a satellite beam inside the larger satellite coverage area. Note that, in general, there will be some coverage overlap between individual satellites, ensuring a continuous service including interconnected satellites. The user terminal (UT) dynamically aligns itself, aiming at the best quality connection provided by the satellites within the UT field of vision.

**Figure 4** Illustrating a Non-Terrestrial Network consisting of a Low Earth Orbit (LEO) satellite constellation providing fixed broadband services to terrestrial users (e.g., Starlink, Kuiper, OneWeb,…). Each hexagon represents a satellite beam inside the larger satellite coverage area. Note that, in general, there will be some coverage overlap between individual satellites, ensuring a continuous service. The operating altitude of a LEO satellite constellation is between 300 and 2,000 km. It is assumed that the satellites are interconnected, e.g., laser links. The User Terminal antenna (UT) is dynamically orienting itself after the best line-of-sight (in terms of signal quality) to a satellite within UT’s field-of-view (FoV). The FoV has not been shown in the picture above so as not to overcomplicate the illustration. It should be noted just like with the drone it is possible to integrate the complete gNB on the LEO satellite. There might even be applications (e.g., defense, natural & unnatural disaster situations, …) where a standalone 5G SA core is integrated.

On the other hand, HAPs, such as unmanned (autonomous) stratospheric drones, operate at altitudes of approximately 15 km to 30 km in the stratosphere. Unlike LEO satellites, the stratospheric drone can hover or move slowly over specific areas, often geostationary relative to the Earth’s surface. This characteristic makes them more suitable for localized coverage tasks like regional broadband, surveillance, and environmental monitoring. The deployment and maintenance of the stratospheric drones are managed from the Earth’s surface and do not require space launch capabilities. Furthermore, enhancing and upgrading the HAPs is straightforward, as they will regularly be on the ground for fueling and maintenance. Upgrades are not possible with an operational LEO satellite solution where any upgrade would have to wait on a subsequent generation and new launch.

Figure 5 illustrates the high-level network architecture of an unmanned autonomous stratospheric drone-based constellation providing terrestrial cellular broadband services to terrestrial mobile users delivered to their normal 5G terminal equipment. Each hexagon represents a beam arising from the phased-array antenna integrated into the drone’s wingspan. To deliver very high-availability services to a rural area, one could assign three HAPs to cover a given area. The drone-based non-terrestrial network is drawn consistent with the architectural radio access network (RAN) elements from Open RAN, e.g., Radio Unit (RU), Distributed Unit (DU), and Central Unit (CU). It should be noted that the whole 5G gNB (the 5G NodeB), including the CU, could be integrated into the stratospheric drone, and in fact, so could the 5G standalone (SA) packet core, enabling full private mobile 5G networks for defense and disaster scenarios or providing coverage in very remote areas with little possibility of ground-based infrastructure (e.g., the arctic region, or desert and mountainous areas).

**Figure 5** illustrates a Non-Terrestrial Network consisting of a stratospheric High Altitude Platform (HAP) drone-based constellation providing terrestrial Cellular broadband services to terrestrial mobile users delivered to their normal 5G terminal equipment. Each hexagon represents a beam inside the larger coverage area of the stratospheric drone. To deliver very high-availability services to a rural area, one could assign three HAPs to cover a given area. The operating altitude of a HAP constellation is between 10 to 50 km with an optimum of around 20 km. It is assumed that there is inter-HAP connectivity, e.g., via laser links. Of course, it is also possible to contemplate having the gNB (full 5G radio node) in the stratospheric drone entirely, which would allow easier integration with LEO satellite backhauls, for example. There might even be applications (e.g., defense, natural & unnatural disaster situations, …) where a standalone 5G SA core is integrated.

The unique advantage of the HAP operating in the stratosphere is (1) The altitude is advantageous for providing wider-area cellular coverage with a near-ideal quality above and beyond what is possible with conventional terrestrial-based cellular coverage because of very high line-of-sight likelihood due to less environment and physical issues that substantially reduces the signal propagation and quality of a terrestrial coverage solution, and (2) More stable atmospheric conditions characterize the stratosphere compared to the troposphere below it. This stability allows the stratospheric drone to maintain a consistent position and altitude with less energy expenditure. The stratosphere offers more consistent and direct sunlight exposure for a solar-powered HAP with less atmospheric attenuation. Moreover, due to the thinner atmosphere at stratospheric altitudes, the stratospheric drone will experience a lower air resistance (drag), increasing the energy efficiency and, therefore, increasing the operational airtime.

**Figure 6** illustrates Leichtwerk AG’s StratoStreamer HAP design that is near-production ready. Leichtwerk AG works closely together with AESA towards the type certificate that would make it possible to operationalize a drone constellation in Europe. The StratoStreamer has a wingspan of 65 meter and can carry a payload of 100+ kg. **Courtesy:** Leichtwerk AG.

Each of these solutions has its unique advantages and limitations. LEO satellites provide extensive coverage but come with higher operational complexities and costs. HAPs offer more focused coverage and are easier to manage, but they need the global reach of LEO satellites. The choice between these two depends on the specific requirements of the intended application, including coverage area, budget, and infrastructure capabilities.

In an era where digital connectivity is indispensable, stratospheric drones could emerge as a game-changing technology. These unmanned (autonomous) drones, operating in the stratosphere, offer unique operational and economic advantages over terrestrial networks and are even seen as competitive alternatives to low earth orbit (LEO) satellite networks like Starlink or OneWeb.

STRATOSPHERIC DRONES VS TERRESTRIAL NETWORKS.

Stratospheric drones positioned much closer to the Earth’s surface than satellites, provide distinct signal strength and latency benefits. The HAP’s vantage point in the stratosphere (around 20 km above the Earth) ensures a high probability of line-of-sight with terrestrial user devices, mitigating the adverse effects of terrain obstacles that frequently challenge ground-based networks. This capability is particularly beneficial in rural areas in general and mountainous or densely forested areas, where conventional cellular towers struggle to provide consistent coverage.

Why the stratosphere? The stratosphere is the layer of Earth’s atmosphere located above the troposphere, which is the layer where weather occurs. The stratosphere is generally characterized by stable, dry conditions with very little water vapor and minimal horizontal winds. It is also home to the ozone layer, which absorbs and filters out most of the Sun’s harmful ultraviolet radiation. It is also above the altitude of commercial air traffic, which typically flies at altitudes ranging from approximately 9 to 12 kilometers (30,000 to 40,000 feet). These conditions (in addition to those mentioned above) make operating a stratospheric platform very advantageous.

Figure 6 illustrates the coverage fundamentals of (a) a terrestrial cellular radio network with the signal strength and quality degrading increasingly as one moves away from the antenna and (b) the terrestrial coverage from a stratospheric drone (antenna in the sky) flying at an altitude of 15 to 30 km. The stratospheric drone, also called a High-Altitude Platform (HAP), provides near-ideal signal strength and quality due to direct line-of-sight (LoS) with the ground, compared to the signal and quality from a terrestrial cellular site that is influenced by its environment and physical factors and the fact that LoS is much less likely in a conventional terrestrial cellular network. It is worth keeping in mind that the coverage scenarios where a stratospheric drone and a low earth satellite may excel in particular are in rural areas and outdoor coverage in more dense urban areas. In urban areas, the clutter, or environmental features and objects, will make line-of-site more challenging, impacting the strength and quality of the radio signals.

**Figure 6** The chart above illustrates the coverage fundamentals of (a) a terrestrial cellular radio network with the signal strength and quality degrading increasingly as one moves away from the antenna and (b) the terrestrial coverage from a stratospheric drone (antenna in the sky) flying at an altitude of 15 to 30 km. The stratospheric drone, also called a High Altitude Platform (HAP), provides near-ideal signal strength and quality due to direct line-of-sight (LoS) with the ground, compared to the signal & quality from a terrestrial cellular site that is influenced by its environment and physical factors and the fact that LoS is much less likely in a conventional terrestrial cellular network.

From an economic and customer experience standpoint, deploying stratospheric drones may be significantly more cost-effective than establishing extensive terrestrial infrastructure, especially in remote or rural areas. The setup and operational costs of cellular towers, including land acquisition, construction, and maintenance, are substantially higher compared to the deployment of stratospheric drones. These aerial platforms, once airborne, can cover vast geographical areas, potentially rendering numerous terrestrial towers redundant. At an operating height of 20 km, one would expect a coverage radius ranging from 20 km up to 500 km, depending on the antenna system, application, and business model (e.g., terrestrial broadband services, surveillance, environmental monitoring, …).

The stratospheric drone-based coverage platform, and by platform, I mean the complete infrastructure that will replace the terrestrial cellular network, will consist of unmanned autonomous drones with a considerable wingspan (e.g., 747-like of ca. 69 meters). For example, European (German) Leichtwerk’s StratoStreamer has a wingspan of 65 meters and a wing area of 197 square meters with a payload of 120+ kg (note: in comparison a Boing 747 has ca. 500+ m2 wing area but its payload is obviously much much higher and in the range of 50 to 60 metric tons). Leichtwerk AG work closely together with AESA in order to achieve the European Union Aviation Safety Agency (EASA) type certificate that would allow the HAPS to integrate into civil airspace (see refs. [34] for what that means).

An advanced antenna system is positioned under the wings (or the belly) of the drone. I will assume that the coverage radius provided by a single drone is 50 km, but it can dynamically be made smaller or larger depending on the coverage scenario and use case. The drone-based advanced antenna system breaks up the coverage area (ca. six thousand five hundred plus square kilometers) into 400 patches (i.e., a number that can be increased substantially), averaging approx. 16 km2 per patch and a radius of ca. 2.5 km. Due to its near-ideal cellular link budget, the effective spectral efficiency is expected to be initially around 6 Mbps per MHz per cell. Additionally, the drone does not have the same spectrum limitations as a rural terrestrial site and would be able to support frequency bands in the downlink from ~900 MHz up to 3.9 GHz (and possibly higher, although likely with different antenna designs). Due to the HAP altitude, the Earth-to-HAP uplink signal will be limited to a lower frequency spectrum to ensure good signal quality is being received at the stratospheric antenna. It is prudent to assume a limit of 2.1 GHz to possibly 2.6 GHz. All under the assumption that the stratospheric drone operator has achieved regulatory approval for operating the terrestrial cellular spectrum from their coverage platform. It should be noted that today, cellular frequency spectrum approved for terrestrial use cannot be used at an altitude unless regulatory permission has been given (more on this later).

Let’s look at an example. We would need ca. 46 drones to cover the whole of Germany with the above-assumed specifications. Furthermore, if we take the average spectrum portfolio of the 3 main German operators, this will imply that the stratospheric drone could be functioning with up to 145 MHz in downlink and at least 55 MHz uplink (i.e., limiting UL to include 2.1 GHz). Using the HAP DL spectral efficiency and coverage area we get a throughput density of 70+ Mbps/km2 and an effective rural cell throughput of 870 Mbps. In terrestrial-based cellular coverage, the contribution to quality at higher frequencies is rapidly degrading as a function of the distance to the antenna. This is not the case for HAP-based coverage due to its near-ideal signal propagation.

In comparison, the three incumbent German operators have on average ca. 30±4k sites per operator with an average terrestrial coverage area of 12 km2 and a coverage radius of ca. 2.0 km (i.e., smaller in cities, ~1.3 km, larger in rural areas, ~2.7 km). Assume that the average cost of ownership related only to the passive part of the site is 20+ thousand euros and that 50% of the 30k sites (expect a higher number) would be redundant as the rural coverage would be replaced by stratospheric drones. Such a site reduction quantum conservatively would lead to a minimum gross monetary reduction of 300 million euros annually (not considering the cost of the alternative technology coverage solution).

In our example, the question is whether we can operate a stratospheric drone-based platform covering rural Germany for less than 300 million euros yearly. Let’s examine this question. Say the stratospheric drone price is 1 million euros per piece (similar to the current Starlink satellite price, excluding the launch cost, which would add another 1.1 million euros to the satellite cost). For redundancy and availability purposes, we assume we need 100 stratospheric drones to cover rural Germany, allowing me to decommission in the radius of 15 thousand rural terrestrial sites. The decommissioning cost and economical right timing of tower contract termination need to be considered. Due to the standard long-term contracts may be 5 (optimistic) to 10+ years (realistic) year before the rural network termination could be completed. Many Telecom businesses that have spun out their passive site infrastructure have done so in mutual captivity with the Tower management company and may have committed to very “sticky” contracts that have very little flexibility in terms of site termination at scale (e.g., 2% annually allowed over total portfolio).

We have a capital expense of 100 million for the stratospheric drones. We also have to establish the support infrastructure (e.g., ground stations, airfield suitability rework, development, …), and consider operational expenses. The ballpark figure for this cost would be around 100 million euros for Capex for establishing the supporting infrastructure and another 30 million euros in annual operational expenses. In terms of steady-state Capex, it should be at most 20 million per year. In our example, the terrestrial rural network would have cost 3 billion euros, mainly Opex, over ten years compared to 700 million euros, a little less than half as Opex, for the stratospheric drone-based platform (not considering inflation).

The economical requirements of a stratospheric unmanned and autonomous drone-based coverage platform should be superior compared to the current cellular terrestrial coverage platform. As the stratospheric coverage platform scales and increasingly more stratospheric drones are deployed, the unit price is also likely to reduce accordingly.

Spectrum usage rights yet another critical piece.

It should be emphasized that the deployment of cellular frequency spectrum in stratospheric and LEO satellite contexts is governed by a combination of technical feasibility, regulatory frameworks, coordination to prevent interference, and operational needs. The ITU, along with national regulatory bodies, plays a central role in deciding the operational possibilities and balancing the needs and concerns of various stakeholders, including satellite operators, terrestrial network providers, and other spectrum users. Today, there are many restrictions and direct regulatory prohibitions in repurposing terrestrially assigned cellular frequencies for non-terrestrial purposes.

The role of the World Radiocommunications Conference (WRC) role is pivotal in managing the global radio-frequency spectrum and satellite orbits. Its decisions directly impact the development and deployment of various radiocommunication services worldwide, ensuring their efficient operation and preventing interference across borders. The WRC’s work is fundamental to the smooth functioning of global communication networks, from television and radio broadcasting to cellular networks and satellite-based services. The WRC is typically held every three to four years, with the latest one, WRC-23, held in Dubai at the end of 2023, reference [13] provides the provisional final acts of WRC-23 (December 2023). In landmark recommendation, WRC-23 relaxed the terrestrial-only conditions for the 698 to 960 MHz and 1,71 to 2.17 GHz, and 2.5 to 2.69 GHz frequency bands to also apply for high-altitude platform stations (HAPS) base stations (“Antennas-in -Sky”). It should be noted that there are slightly different frequency band ranges and conditions, depending on which of the three ITU-R regions (as well as exceptions for particular countries within a region) the system will be deployed in. Also the HAPS systems do not enjoy protection or priority over existing use of those frequency bands terrestrially. It is important to note that the WRC-23 recommendation only apply to coverage platforms (i.e., HAPS) in the range from 20 to 50 km altitude. These WRC-23 frequency-bands relaxation does not apply to satellite operation. With the recognized importance of non-terrestrial networks and the current standardization efforts (e.g., towards 6G), it is expected that the fairly restrictive regime on terrestrial cellular spectrum may be relaxed further to also allow mobile terrestrial spectrum to be used in “Antenna-in-the-Sky” coverage platforms. Nevertheless, HAPS and terrestrial use of cellular frequency spectrum will have to be coordinated to avoid interference and resulting capacity and quality degradation.

SoftBank announced recently (i.e., 28 December 2023 [11]), after deliberations at the WRC-23, that they had successfully gained approval within the Asia-Pacific region (i.e., ITU-R region 3) to use mobile spectrum bands, namely 700-900MHz, 1.7GHz, and 2.5GHz, for stratospheric drone-based mobile broadband cellular services (see also refs. [13]). As a result of this decision, operators in different countries and regions will be able to choose a spectrum with greater flexibility when they introduce HAPS-based mobile broadband communication services, thereby enabling seamless usage with existing smartphones and other devices.

Another example of re-using terrestrial licensed cellular spectrum above ground is SpaceX direct-to-cell capable 2^nd generation Starlink satellites.

On January 2^nd, 2024, SpaceX launched their new generation of Starlink satellites with direct-to-cell capabilities to close a connection to a regular mobile cellular phone (e.g., smartphone). The new direct-to-cell Starlink satellites use T-Mobile US terrestrial licensed cellular frequency band (i.e., 2×5 MHz Band 25, PCS G-block) and will work, according to T-Mobile US, with most of their existing mobile phones. The initial direct-to-cell commercial plans will only support low-bandwidth text messaging and no voice or more bandwidth-heavy applications (e.g., streaming). Expectations are that the direct-to-cell system would deliver up to 18.3 Mbps (3.66 Mbps/MHz/cell) downlink and up to 7.2 Mbps (1.44 Mbps/MHz/cell) uplink over a channel bandwidth of 5 MHz (maximum).

Given that terrestrial 4G LTE systems struggle with such performance, it will be super interesting to see what the actual performance of the direct-to-cell satellite constellation will be.

COMPARISON WITH LEO SATELLITE BROADBAND NETWORKS.

When juxtaposed with LEO satellite networks such as Starlink (SpaceX), OneWeb (Eutelsat Group), or Kuiper (Amazon), stratospheric drones offer several advantages. Firstly, the proximity to the Earth’s surface (i.e., 300 – 2,000 km) results in lower latency, a critical factor for real-time applications. While LEO satellites, like those used by Starlink, have reduced latency (ca. 3 ms round-trip-time) compared to traditional geostationary satellites (ca. 240 ms round-trip-time), stratospheric drones can provide even quicker response times (one-tenth of an ms in round-trip-time), making the stratospheric drone substantially more beneficial for applications such as emergency services, telemedicine, and high-speed internet services.

A stratospheric platform operating at 20 km altitude and targeting surveillance, all else being equal, would be 25 times better at distinguishing objects apart than an LEO satellite operating at 500 km altitude. The global aerial imaging market is expected to exceed 7 billion euros by 2030, with a CAGR of 14.2% from 2021. The flexibility of the stratospheric drone platform allows for combining cellular broadband services and a wide range of advanced aerial imaging services. Again, it is advantageous that the stratospheric drone regularly returns to Earth for fueling, maintenance, and technology upgrades and enhancements. This is not possible with an LEO satellite platform.

Moreover, the deployment and maintenance of stratospheric drones are, in theory, less complex and costly than launching and maintaining a constellation of satellites. While Starlink and similar projects require significant upfront investment for satellite manufacturing and rocket launches, stratospheric drones can be deployed at a fraction of the cost, making them a more economically viable option for many applications.

The Starlink LEO satellite constellation currently is the most comprehensive satellite (fixed) broadband coverage service. As of November 2023, Starlink had more than 5,000 satellites in low orbit (i.e., ca. 550 km altitude), and an additional 7,000+ are planned to be deployed, with a total target of 12+ thousand satellites. The current generation of Starlink satellites has three downlink phased-array antennas and one uplink phase-array antenna. This specification translates into 48 beams downlink (satellite to ground) and 16 beams uplink (ground to satellite). Each Starlink beam covers approx. 2,800 km2 with a coverage range of ca. 30 km, over which a 250 MHz downlink channel (in the Ku band) has been assigned. According to Portillo et al. [14], the spectral efficiency is estimated to be 2.7 Mbps per MHz, providing a total throughput of a maximum of 675 Mbps in the coverage area or a throughput density of ca. 0.24 Mbps per km2.

According to the latest Q2-2023 Ookla speed test it is found that “among the 27 European countries that were surveyed, Starlink had median download speeds greater than 100 Mbps in 14 countries, greater than 90 Mbps in 20 countries, and greater than 80 in 24 countries, with only three countries failing to reach 70 Mbps” (see reference [18]). Of course, the actual customer experience will depend on the number of concurrent users demanding resources from the LEO satellite as well as weather conditions, proximity of other users, etc. Starlink themselves seem to have set an upper limit of 220 Mbps download speed for their so-called priority service plan or otherwise 100 Mbps (see [19] below). Quite impressive performance if there are no other broadband alternatives available.

According to Elon Musk, SpaceX aims to reduce each Starlink satellite’s cost to less than one million euros. However, according to Elon Musk, the unit price will depend on the design, capabilities, and production volume. The launch cost using the SpaceX Falcon 9 launch vehicle starts at around 57 million euros, and thus, the 50 satellites would add a launch cost of ca. 1.1 million euros per satellite. SpaceX operates, as of September 2023, 150 ground stations (“Starlink Gateways”) globally that continue to connect the satellite network with the internet and ground operations. At Starlink’s operational altitude, the estimated satellite lifetime is between 5 and 7 years due to orbital decay, fuel and propulsion system exhaustion, and component durability. Thus, a LEO satellite business must plan for satellite replacement cycles. This situation differs greatly from the stratospheric drone-based operation, where the vehicles can be continuously maintained and upgraded. Thus, they are significantly more durable, with an expected useful lifetime exceeding ten years and possibly even 20 years of operational use.

Let’s consider our example of Germany and what it would take to provide LEO satellite coverage service targeting rural areas. It is important to understand that a LEO satellite travels at very high speeds (e.g., upwards of 30 thousand km per hour) and thus completes an orbit around Earth in between 90 to 120 minutes (depending on the satellite’s altitude). It is even more important to remember that Earth rotates on its axis (i.e., 24 hours for a full rotation), and the targeted coverage area will have moved compared to a given satellite orbit (this can easily be several hundreds to thousands of kilometers). Thus, to ensure continuous satellite broadband coverage of the same area on Earth, we need a certain number of satellites in a particular orbit and several orbits to ensure continuous coverage at a target area on Earth. We would need at least 210 satellites to provide continuous coverage of Germany. Most of the time, most satellites would not cover Germany, and the operational satellite utilization will be very low unless other areas outside Germany are also being serviced.

Economically, using the Starlink numbers above as a guide, we incur a capital expense of upwards of 450 million euros to realize a satellite constellation that could cover Germany. Let’s also assume that the LEO satellite broadband operator (e.g., Starlink) must build and launch 20 satellites annually to maintain its constellation and thus incur an additional Capex of ca. 40+ million euros annually. This amount does not account for the Capex required to build the ground network and the operations center. Let’s say all the rest requires an additional 10 million euros Capex to realize and for miscellaneous going forward. The technology-related operational expenses should be low, at most 30 million euros annually (this is a guesstimate!) and likely less. So, covering Germany with an LEO broadband satellite platform over ten years would cost ca. 1.3 billion euros. Although substantially more costly than our stratospheric drone platform, it is still less costly than running a rural terrestrial mobile broadband network.

Despite being favorable compared in economic to the terrestrial cellular network, it is highly unlikely to make any operational and economic sense for a single operator to finance such a network, and it would probably only make sense if shared between telecom operators in a country and even more so over multiple countries or states (e.g., European Union, United States, PRC, …).

Despite the implied silliness of a single mobile operator deploying a satellite constellation for a single Western European country (irrespective of it being fairly large), the above example serves two purposes; (1) To illustrates how economically in-efficient rural mobile networks are that a fairly expansive satellite constellation could be more favorable. Keep in mind that most countries have 3 or 4 of them, and (2) It also shows that the for operators to share the economics of a LEO satellite constellation over larger areal footprint may make such a strategy very attractive economically,

Due to the path loss at 550 km (LEO) being substantially higher than at 20 km (stratosphere), all else being equal, the signal quality of the stratospheric broadband drone would be significantly better than that of the LEO satellite. However, designing the LEO satellite with more powerful transmitters and sensitive receivers can compensate for the factor of almost 30 in altitude difference to a certain extent. Clearly, the latency performance of the LEO satellite constellation would be inferior to that of the stratospheric drone-based platform due to the significantly higher operating altitude.

It is, however, the capacity rather than shared cost could be the stumbling block for LEOs: For a rural cellular network or stratospheric drone platform, we see the MNOs effectively having “control” over the capex costs of the network, whether it be the RAN element for a terrestrial network, or the cost of whole drone network (even if it in the future, this might be able to become a shared cost).

However, for the LEO constellation, we think the economics of a single MNO building a LEO constellation even for their own market is almost entirely out of the question (ie multiple €bn capex outlay). Hence, in this situation, the MNOs will rely on a global LEO provider (ie Starlink, or AST Space Mobile) and will “lend” their spectrum to their in their respective geography in order to provide service. Like the HAPs, this will also require further regulatory approvals in order to free up terrestrial spectrum for satellites in rural areas.

We do not yet have the visibility of the payments the LEOs will require, so there is the potential that this could be a lower cost alternative again to rural networks, but as we show below, we think the real limitation for LEOs might not be the shared capacity rental cost, but that there simply won’t be enough capacity available to replicate what a terrestrial network can offer today.

However, the stratospheric drone-based platform provides a near-ideal cellular performance to the consumer, close to the theoretical peak performance of a terrestrial cellular network. It should be emphasized that the theoretical peak cellular performance is typically only experienced, if at all, by consumers if they are very near the terrestrial cellular antenna and in a near free-space propagation environment. This situation is a very rare occurrence for the vast majority of mobile consumers.

Figure 7 summarizes the above comparison between a rural terrestrial cellular network with the non-terrestrial cellular networks such as LEO satellites and Stratospheric drones.

**Figure 7** Illustrating a comparison between terrestrial cellular coverage with stratospheric drone-based (“Antenna-in-the-sky”) cellular coverage and Low Earth Orbit (LEO) satellite coverage options.

While the majority of the 5,500+ Starlink constellation is 13 GHz (Ku-band), at the beginning of 2024, Space X launched a few 2nd generation Starlink satellites that support direct connections from the satellite to a normal cellular device (e.g., smartphone), using 5 MHz of T-Mobile USA’s PCS band (1900 MHz). The targeted consumer service, as expressed by T-Mobile USA, is providing texting capabilities over areas with no or poor existing cellular coverage across the USA. This is fairly similar to services at similar cellular coverage areas presently offered by, for example, AST SpaceMobile, OmniSpace, and Lynk Global LEO satellite services with reported maximum speed approaching 20 Mbps. The so-called Direct-2-Device, where the device is a normal smartphone without satellite connectivity functionality, is expected to develop rapidly over the next 10 years and continue to increase the supported user speeds (i.e., utilized terrestrial cellular spectrum) and system capacity in terms of smaller coverage areas and higher number of satellite beams.

Table 1 below provides an overview of the top 10 LEO satellite constellations targeting (fixed) internet services (e.g., Ku band), IoT and M2M services, and Direct-to-Device (or direct-to-cell) services. The data has been compiled from the NewSpace Index website, which should be with data as of 31st of December 2023. The Top-10 satellite constellation rank has been based on the number of launched satellites until the end of 2023. Two additional Direct-2-Cell (D2C or Direct-to-Device, D2D) LEO satellite constellations are planned for 2024-2025. One is SpaceX Starlink 2nd generation, which launched at the beginning of 2024, using T-Mobile USA’s PCS Band to connect (D2D) to normal terrestrial cellular handsets. The other D2D (D2C) service is Inmarsat’s Orchestra satellite constellation based on L-band (for mobile terrestrial services) and Ka for fixed broadband services. One new constellation (Mangata Networks) targeting 5G services. With two 5G constellations already launched, i.e., Galaxy Space (Yinhe) launched 8 LEO satellites, 1,000 planned using Q- and V-bands (i.e., not a D2D cellular 5G service), and OmniSpace launched two satellites and have planned 200 in total. Moreover, currently, there is one planned constellation targeting 6G by the South Korean Hanwha Group (a bit premature, but interesting nevertheless) with 2,000 6G LEO Satellites planned. Most currently launched and planned satellite constellations offering (or plan to provide) Direct-2-Cell services, including IoT and M2M, are designed for low-frequency bandwidth services that are unlikely to compete with terrestrial cellular networks’ quality of service where reasonable good coverage (or better) exists.

In Table 1 below, we then show 5 different services with the key input variables as cell radius, spectral efficiency and downlink spectrum. From this we can derive what the “average” capacity could be per square kilometer of rural coverage.

We focus on this metric as the best measure of capacity available once multiple users are on the service the spectrum available is shared. This is different from “peak” speeds which are only relevant in the case of very few users per cell.

We start with terrestrial cellular today for bands up to 2.1GHz and show that assuming a 2.5km cell radius, the average capacity is equivalent to 11Mbps per sq.km.

For a LEO service using Ku-band, i.e., with 250MHz to an FWA dish, the capacity could be ca. 2Mbps per sq.km.

For a LEO-based D2D device, what is unknown is what the ultimate spectrum allowance could be for satellite services with cellular spectrum bands, and spectral efficiency. Giving the benefit of the doubt on both, but assuming the beam radius is always going to be larger, we can get to an “optimistic” future target of 2Mbps per sq. km, i.e., 1/5^th of a rural terrestrial network.

Finally, we show for a stratospheric drone, that given similar cell radius to a rural cell today, but with higher downlink available and greater spectral efficiency, we can reach ca. 55Mbps per sq. km, i.e. 5x what a current rural network can offer.

INTEGRATING WITH 5G AND BEYOND.

The advent of 5G, and eventually 6G, technology brings another dimension to the utility of stratospheric drones delivering mobile broadband services. The high-altitude platform’s ability to seamlessly integrate with existing 5G networks makes them an attractive option for expanding coverage and enhancing network capacity at superior economics, particularly in rural areas where the economics for terrestrial-based cellular coverage tend to be poor. Unlike terrestrial networks that require extensive groundwork for 5G rollout, the non-terrestrial network operator (NTNO) can rapidly deploy stratospheric drones to provide immediate 5G coverage over large areas. The high-altitude platform is also incredibly flexible compared to both LEO satellite constellations and conventional rural cellular network flexibility. The platform can easily be upgraded during its ground maintenance window and can be enhanced as the technology evolves. For example, upgrading to and operationalizing 6G would be far more economical with a stratospheric platform than having to visit thousands or more rural sites to modernize or upgrade the installed active infrastructure.

SUMMARY.

Stratospheric drones represent a significant advancement in the realm of wireless communication. Their strategic positioning in the stratosphere offers superior coverage and connectivity compared to terrestrial networks and low-earth satellite solutions. At the same time, their economic efficiency makes them an attractive alternative to ground-based infrastructures and LEO satellite systems. As technology continues to evolve, these high-altitude platforms (HAPs) are poised to play a crucial role in shaping the future of global broadband connectivity and ultra-high availability connectivity solutions, complementing the burgeoning 5G networks and paving the way for next-generation three-dimensional communication solutions. Moving away from today’s flat-earth terrestrial-locked communication platforms.

The strategic as well as the disruptive potential of the unmanned autonomous stratospheric terrestrial coverage platform is enormous, as shown in this article. It has the potential to make most of the rural (at least) cellular infrastructure redundant, resulting in substantial operational and economic benefits to existing mobile operators. At the same time, the HAPs could, in rural areas, provide much better service overall in terms of availability, improved coverage, and near-ideal speeds compared to what is the case in today’s cellular networks. It might also, at scale, become a serious competitive and economical threat to LEO satellite constellations, such as, for example, Starlink and Kuipers, that would struggle to compete on service quality and capacity compared to a stratospheric coverage platform.

Although the strategic, economic, as well as disruptive potential of the unmanned autonomous stratospheric terrestrial coverage platform is enormous, as shown in this article, the flight platform and advanced antenna technology are still in a relatively early development phase. Substantial regulatory work remains in terms of permitting the terrestrial cellular spectrum to be re-used above terra firma at the “Antenna-in-the-Sky. The latest developments out of WRC-23 for Asia Pacific appear very promising, showing that we are moving in the right direction of re-using terrestrial cellular spectrum in high-altitude coverage platforms. Last but not least, operating an unmanned (autonomous) stratospheric platform involves obtaining certifications as well as permissions and complying with various flight regulations at both national and international levels.

Terrestrial Mobile Broadband Network – takeaway:

It is the de facto practice for mobile cellular networks to cover nearly 100% geographically. The mobile consumer expects a high-quality, high-availability service everywhere.
A terrestrial mobile network has a relatively low area coverage per unit antenna with relatively high capacity and quality.
Mobile operators incur high and sustainable infrastructure costs, especially in rural areas with low or no return on that cost.
Physical obstructions and terrain limit performance (i.e., non-free space characteristics).
Well-established technology with high reliability.
The potential for high bandwidth and low latency in urban areas with high demand may become a limiting factor for LEO satellite constellations and stratospheric drone-based platforms. Thus, it is less likely to provide operational and economic benefits covering high-demand, dense urban, and urban areas.

LEO Satellite Network – takeaway:

The technology is operational and improving. There is currently some competition (e.g., Starlink, Kuiper, OneWeb, etc.) in this space, primarily targeting fixed broadband and satellite backhaul services. Increasingly, new LEO satellite-based business models are launched providing lower-bandwidth cellular-spectrum based direct-to-device (D2D) text, 4G and 5G services to regular consumer and IoT devices (i.e., Starlink, Lynk Global, AST SpaceMobile, OmniSpace, …).
Broader coverage, suitable for global reach. It may only make sense when the business model is viewed from a worldwide reach perspective (e.g., Starlink, OneWeb,…), resulting in much-increased satellite network utilization.
An LEO satellite broadband network can cover a vast area per satellite due to its high altitude. However, such systems are in nature capacity-limited, although beam-forming antenna technologies (e.g., phased array antennas) allow better capacity utilization.
The LEO satellite solutions are best suited for low-population areas with limited demand, such as rural and largely unpopulated areas (e.g., sea areas, deserts, coastlines, Greenland, polar areas, etc.).
Much higher latency compared to terrestrial and drone-based networks.
Less flexible once in orbit. Upgrades and modernization only via replacement.
The LEO satellite has a limited useful operational lifetime due to its lower orbital altitude (e.g., 5 to 7 years).
Lower infrastructure cost for rural coverage compared to terrestrial networks, but substantially higher than drones when targeting regional areas (e.g., Germany or individual countries in general).
Complementary to the existing mobile business model of communications service providers (CSPs) with a substantial business risk to CSPs in low-population areas where little to no capacity limitations may occur.
Requires regulatory permission (authorization) to operate terrestrial frequencies on the satellite platform over any given country. This process is overseen by national regulatory bodies in coordination with the International Telecommunication Union (ITU) as well as national regulators (e.g., FCC in the USA). Satellite operators must apply for frequency bands for uplink and downlink communications and coordinate with the ITU to avoid interference with other satellites and terrestrial systems. In recent years, however, there has been a trend towards more flexible spectrum regulations, allowing for innovative uses of the spectrum like integrating terrestrial and satellite services. This flexibility is crucial in accommodating new technologies and service models.
Operating a LEO satellite constellation requires a comprehensive set of permissions and certifications that encompass international and national space regulations, frequency allocation, launch authorization, adherence to space debris mitigation guidelines, and various liability and insurance requirements.
Both LEO and MEO satellites is likely going to be complementary or supplementary to stratospheric drone-based broadband cellular networks offering high-performing transport solutions and possible even acts as standalone or integrated (with terrestrial networks) 5G core networks or “clouds-in-the-sky”.

Stratospheric Drone-Based Network – takeaway:

It is an emerging technology with ongoing research, trials, and proof of concept.
A stratospheric drone-based broadband network will have lower deployment costs than terrestrial and LEO satellite broadband networks.
In rural areas, the stratospheric drone-based broadband network offers better economics and near-ideal quality than terrestrial mobile networks. In terms of cell size and capacity, it can easily match that of a rural mobile network.
The solution offers flexibility and versatility and can be geographically repositioned as needed. The versatility provides a much broader business model than “just” an alternative rural coverage solution (e.g., aerial imaging, surveillance, defense scenarios, disaster area support, etc.).
Reduced latency compared to LEO satellites.
Also ideal for targeted or temporary coverage needs.
Complementary to the existing mobile business model of communications service providers (CSPs) with additional B2B and public services business potential from its application versatility.
Potential substantial negative impact on the telecom tower business as the stratospheric drone-based broadband network would make (at least) rural terrestrial towers redundant.
May disrupt a substantial part of the LEO satellite business model due to better service quality and capacity leaving the LEO satellite constellations revenue pool to remote areas and specialized use cases.
Requires regulatory permission to operate terrestrial frequencies (i.e., frequency authorization) on the stratospheric drone platform (similar to LEO satellites). Big steps have are already been made at the latest WRC-23, where the frequency bands 698 to 960 MHz, 1710 to 2170 MHz, and 2500 to 2690 MHz has been relaxed to allow for use in HAPS operating at 20 to 50 km altitude (i.e., the stratosphere).
Operating a stratospheric platform in European airspace involves obtaining certifications as well as permissions and (of course) complying with various regulations at both national and international levels. This includes the European Union Aviation Safety Agency (EASA) type certification and the national civil aviation authorities in Europe.

ACKNOWLEDGEMENT.

I greatly acknowledge my wife, Eva Varadi, for her support, patience, and understanding during the creative process of writing this article.

I also owe a lot of gratitude to James Ratzer, Partner at New Street Research, for editorial suggestions, great discussions and challenges making the paper far better than it otherwise would have been. I would also like to thank Russel Waller, Pan European Telecoms and ESG Equity Analyst at New Street Research, for being supportive and insistent to get something written for NSR.

I also greatly appreciate my past collaboration and the many discussions on the topic of Stratospheric Drones in particular and advanced antenna designs and properties in general that I have had with Dr. Jaroslav Holis, Senior R&D Manager (Group Technology, Deutsche Telekom AG) over the last couple of years. When it comes to my early involvement in Stratospheric Drones activities with Group Technology Deutsche Telekom AG, I have to recognize my friend, mentor, and former boss, Dr. Bruno Jacobfeuerborn, former CTO Deutsche Telekom AG and Telekom Deutschland, for his passion and strong support for this activity since 2015. My friend and former colleague Rachid El Hattachi deserves the credit for “discovering” and believing in the opportunities that a cellular broadband-based stratospheric drone brings to the telecom industry.

Many thanks to CEO Dr. Reiner Kickert of Leichtwerk AG for providing some high resolution pictures of his beautiful StratoStreamer.

Thanks to my friend Amit Keren for suggesting a great quote that starts this article.

Any errors or unclarities are solely due to myself and not the collaborators and colleagues that have done their best to support this piece.

Telco energy consumption – a path to a greener future?

Posted on October 3, 2023 by Dr. Kim

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To my friend Rudolf van der Berg this story is not about how volumetric demand (bytes or bits) results in increased energy consumption (W·h). That notion is silly, as we both “violently” agree on ;-). I recommend that readers also check out Rudolf’s wonderful presentation, “Energy Consumption of the Internet (May 2023),” which he delivered at the RIPE86 student event this year in 2023.

Recently, I had the privilege to watch a presentation by a seasoned executive talk about what his telco company is doing for the environment regarding sustainability and CO2 reduction in general. I think the company is doing something innovative beyond compensating shortfalls with buying certificates and (mis)use of green energy resources.

They replace (reasonably) aggressively their copper infrastructure (country stat for 2022: ~90% of HH/~16% subscriptions) with green sustainable fiber (country stat for 2022: ~78%/~60%). This is an obvious strategy that results in a quantum leap in customer experience potential and helps reduce overall energy consumption resulting from operating the ancient copper network.

Missing a bit imo, was the consideration of and the opportunity to phase out the HFC network (country stat for 2022: ~70%/~60%) and reduce the current HFC+Fibre overbuild of 1.45 and, of course, reduce the energy consumption and operational costs (and complexity) of operating two fixed broadband technologies (3 if we include the copper). However, maybe understandably enough, substantial investments have been made in upgrading to Docsis 3.1. An investment that possibly still is somewhat removed from having been written off.

The “wtf-moment” (in an otherwise very pleasantly and agreeable session) came when the speaker alluded that as part of their sustainability and CO2 reduction strategy, the telco was busy migrating from 4G LTE to 5G with the reasoning that 5G is 90% more energy efficient compared to 4G.

Firstly, it is correct that 5G is (in apples-for-apples comparisons!) ca. 90% more efficient in delivering a single bit compared to 4G. The metric we use is Joules-per-bit or Watts-seconds-per-bit. It is also not uncommon at all to experience Telco executives hinting at the relative greenness of 5G (it is, in my opinion, decidedly not a green broadband communications technology … ).

Secondly, so what! Should we really care about relative energy consumption? After all, we pay for absolute energy consumption, not for whatever relativized measure of consumed energy.

I think I know the answer from the CFO and the in-the-know investors.

If the absolute energy consumption of 5G is higher than that of 4G, I will (most likely) have higher operational costs attributed to that increased power consumption with 5G. If I am not in an apples-for-apples situation, which rarely is the case, and I am anyway really not in, the 5G technology requires substantially more power to provide for new requirements and specifications. I will be worse off regarding the associated cost in absolute terms of money. Unless I also have a higher revenue associated with 5G, I am economically worse off than I was with the older technology.

Having higher information-related energy efficiency in cellular communications systems is a feature of the essential requirement of increasingly better spectral efficiency all else being equal. It does not guarantee that, in absolute monetary terms, a Telco will be better off … far from it!

THE ENERGY OF DELIVERING A BIT.

Energy, which I choose to represent in Joules, is equal to the Power (in Watt or W) that I need to consume per time-unit for a given output unit (e.g., a bit) times the unit of time (e.g., a second) it took to provide the unit.

Take a 4G LTE base station that consumes ca. 5.0kW to deliver a maximum throughput of 160 Mbps per sector (@ 80 MHz per sector). The information energy efficiency of the specific 4G LTE base station (e.g., W·s per bit) would be ca. 10 µJ/bit. The 4G LTE base station requires 10 micro (one millionth) Joules to deliver 1 bit (in 1 second).

In the 5G world, we would have a 5G SA base station, using the same frequency bands as 4G and with an additional 10 MHz @ 700MHz and 100 MHz @ 3.5 GHz included. The 3.5 GHz band is supported by an advanced antenna system (AAS) rather than a classical passive antenna system used for the other frequency bands. This configuration consumes 10 kW with ~40% attributed to the 3.5 GHz AAS, supporting ~1 Gbps per sector (@ 190 MHz per sector). This example’s 5G information energy efficiency would be ca. 0.3 µJ/bit.

In this non-apples-for-apples comparison, 5G is about 30 times more efficient in delivering a bit than 4G LTE (in the example above). Regarding what an operator actually pays for, 5G is twice as costly in energy consumption compared to 4G.

It should be noted that the power consumption is not driven by the volumetric demand but by the time that demand exists and the load per unit of time. Also, base stations will have a power consumption even when idle with the degree depending on the intelligence of the energy management system applied.

So, more formalistic, we have

E per bit = P (in W) · time (in sec) per bit, or in the basic units

J / bit = W·s / bit = W / (bit/s) = W / bps = W / [ MHz · Mbps/MHz/unit · unit-quantity ]

E per bit = P (in W) / [ Bandwidth (in MHz) · Spectral Efficiency (in Mbps/MHz/unit) · unit-quantity ]

It is important to remember that this is about the system spec information efficiency and that there is no direct relationship between the Power that you need and the outputted information your system will ultimately support bit-wise.

and

Thus, the relative efficiency between 4G and 5G is

Currently (i.e., 2023), the various components of the above are approximately within the following ranges.

The power consumption of a 5G RAT is higher than that of a 4G RAT. As we add higher frequency spectrum (e.g., C-band, 6GHz, 23GHz,…) to the 5G RAT, increasingly more spectral bandwidth (B) will be available compared to what was deployed for 4G. This will increase the bit-wise energy efficiency of 5G compared to 4G, although the power consumption is also expected to increase as higher frequencies are supported.

If the bandwidth and system power consumption is the same for both radio access technologies (RATs), then we have the relative information energy efficiency is

Depending on the relative difference in spectral efficiency. 5G is specified and designed to have at least ten times (10x) the spectral efficiency of 4G. If you do the math (assuming apples-to-apples applies), it is no surprise that 5G is specified to be 90% more efficient in delivering a bit (in a given unit of time) compared to 4G LTE.

And just to emphasize the obvious,

RAT refers to the radio access technology, BB is the baseband, freq the cellular frequencies, and idle to the situation where the system is not being utilized.

Volume in Bytes (or bits) does not directly relate to energy consumption. As frequency bands are added to a sector (of a base station), the overall power consumption will increase. Moreover, the more computing is required in the antenna, such as for advanced antenna systems, including massive MiMo antennas, the more power will be consumed in the base station. The more the frequency bands are being utilized in terms of time, the higher will the power consumption be.

Indirectly, as the cellular system is being used, customers consume bits and bytes (=8·bit) that will depend on the effective spectral efficiency (in bps/Hz), the amount of effective bandwidth (in Hz) experienced by the customers, e.g., many customers will be in a coverage situation where they may not benefit for example from higher frequency bands), and the effective time they make use of the cellular network resources. The observant reader will see that I like the term “effective.” The reason is that customers rarely enjoy the maximum possible spectral efficiency. Likely, not all the frequency spectrum covering customers is necessarily being applied to individual customers, depending on their coverage situation.

In the report “A Comparison of the Energy Consumption of Broadband Data Transfer Technologies (November 2021),” the authors show the energy and volumetric consumption of mobile networks in Finland over the period from 2010 to 2020. To be clear, I do not support the author’s assertion of causation between volumetric demand and energy consumption. As I have shown above, volumetric usage does not directly cause a given power consumption level. Over the 10-year period shown in the report, they observe a 70% increase in absolute power consumption (from 404 to 686 GWh, CAGR ~5.5%) and a factor of ~70 in traffic volume (~60 TB to ~4,000 TB, CAGR ~52%). Caution should be made in resisting the temptation to attribute the increase in energy over the period to be directly related to the data volume increase, however weak it is (i.e., note that the authors did not resist that temptation). Rudolf van der Berg has raised several issues with the approach of the above paper (as well as with many other related works) and indicated that the data and approach of the authors may not be reliable. Unfortunately, in this respect, it appears that systematic, reliable, and consistent data in the Telco industry is hard to come by (even if that data should be available to the individual telcos).

Technology change from 2G/3G to 4G, site densification, and more frequency bands can more than easily explain the increase in energy consumption (and all are far better explanations than data volume). It should be noted that there will also be reasons that decrease power consumption over time, such as more efficient electronics (e.g., via modernization), intelligent power management applications, and, last but not least, switching off of older radio access technologies.

The factors that drive a cell site’s absolute energy consumption is

Radio access technology with new technologies generally consumes more energy than older ones (even if the newer technologies have become increasingly more spectrally efficient).
The antenna type and configuration, including computing requirements for advanced signal processing and beamforming algorithms (that will improve the spectral efficiency at the expense of increased absolute energy consumption).
Equipment efficiency. In general, new generations of electronics and systems designs tend to be more energy-efficient for the same level of performance.
Intelligent energy management systems that allow for effective power management strategies will reduce energy consumption compared to what it would have been without such systems.
The network optimization goal policy. Is the cellular network planned and optimized for meeting the demands and needs of the customers (i.e., the economic design framework) or for providing the peak performance to as many customers as possible (i.e., the Umlaut/Ookla performance-driven framework)? The Umlaut/Ookla-optimized network, maxing out on base station configuration, will observe substantially higher energy consumption and associated costs.

The absolute cellular energy consumption has continued to rise as new radio access technologies (RAT) have been introduced irrespective of the leapfrog in those RATS spectral (bits per Hz) and information-related (Joules per bit) efficiencies.

WHY 5G IS NOT A GREEN TECHNOLOGY?

Let’s first re-acquaint ourselves with the 2015 vision of the 5G NGMN whitepaper;

“5G should support a 1,000 times traffic increase in the next ten years timeframe, with energy consumption by the whole network of only half that typically consumed by today’s networks. This leads to the requirement of an energy efficiency increase of x2000 in the next ten years timeframe.” (Section 4.2.2 Energy Efficiency, 5G White Paper by NGMN Alliance, February 2015).

The bold emphasis is my own and not in the paper itself. There is no doubt that the authors of the 5G vision paper had the ambition of making 5G a sustainable and greener cellular alternative than historically had been the case.

So, from the above statement, we have two performance figures that illustrate the ambition of 5G relative to 4G. Firstly, we have a requirement that the 5G energy efficiency should be 2000x higher than 4G (as it was back in the beginning of 2015).

Getting more spectrum bandwidth is relatively trivial as you go up in frequency and into, for example, the millimeter wave range (and beyond). However, getting 20+ GHz (e.g., 200+x100 MHz @ 4G) of additional practically usable spectrum bandwidth would be rather (=understatement) ambitious.

And that the absolute energy consumption of the whole 5G network should be half of what it was with 4G

If you think about this for a moment. Halfing the absolute energy consumption is an enormous challenge, even if it would have been with the same RAT. It requires innovation leapfrogs across the RAT electronic architecture, design, and material science underlying all of it. In other words, fundamental changes are required in the RF frontend (e.g., Power amplifiers, transceivers), baseband processing, DSP, DAC, ADC, cooling, control and management systems, algorithms, compute, etc…

But reality eats vision for breakfast … There really is no sign that the super-ambitious goal set by the NGMN Alliance in early 2015 is even remotely achievable even if we would give it another ten years (i.e., 2035). We are more than two orders of magnitude away from the visionary target of NGMN, and we are almost at the 10-year anniversary of the vision paper. We more or less get the benefit of the relative difference in spectral efficiency (x10), but no innovation beyond that has contributed very much to quantum leap cellular energy efficiency bit-wise.

I know many operators who will say that from a sustainability perspective, at least before the energy prices went through the roof, it really does not matter that 5G, in absolute terms, leads to substantial increases in energy consumption. They use green energy to supply the energy demand from 5G and pay off $CO_2$ deficits with certificates.

First of all, unless the increased cost can be recovered with the customers (e.g., price plan increase), it is a doubtful economic venue to pursue (and has a bit of a Titanic feel to it … going down together while the orchestra is playing).

Second, we should ask ourselves whether it is really okay for any industry to greedily consume sustainable and still relatively scarce green resources without being incentivized (or encouraged) to pursue alternatives and optimize across mobile and fixed broadband technologies. Particularly when fixed broadband technologies, such as fiber, are available, that would lead to a very sizable and substantial reduction in energy consumption … as customers increasingly adapt to fiber broadband.

Fiber is the greenest and most sustainable access technology we can deploy compared to cellular broadband technologies.

SO WHAT?

5G is a reality. Telcos are and will continue to invest substantially into 5G as they migrate their customers from 4G LTE to what ultimately will be 5G Standalone. The increase in customer experience and new capabilities or enablers are significant. By now, most Telcos will (i.e., 2023) have a very good idea of the operational expense associated with 5G (if not … you better do the math). Some will have been exploring investing in their own green power plants (e.g., solar, wind, hydrogen, etc.) to mitigate part of the energy surge arising from transitioning to 5G.

I suspect that as Telcos start reflecting on Open RAN as they pivot towards 6G (-> 2030+), above and beyond what 6G, as a RAT, may bring of additional operational expense pain, there will be new energy consumption and sustainability surprises to the cellular part of Telcos P&L. In general, breaking up an electronic system into individual (non-integrated) parts, as opposed to being integrated into a single unit, is likely to result in an increased power consumption. Some of the operational in-efficiencies that occur in breaking up a tightly integrated design can be mitigated by power management strategies. Though in order to get such power management strategies to work at the optimum may force a higher degree of supplier uniformity than the original intent of breaking up the tightly integrated system.

However, only Telcos that consider both their mobile and fixed broadband assets together, rather than two silos apart, will gain in value for customers and shareholders. Fixed-mobile (network) conversion should be taken seriously and may lead to very different considerations and strategies than 10+ years ago.

With increasing coverage of fiber and with Telcos stimulating aggressive uptake, it will allow those to redesign the mobile networks for what they were initially supposed to do … provide convenience and service where there is no fixed network present, such as when being mobile and in areas where the economics of a fixed broadband network makes it least likely to be available (e.g., rural areas) although LEO satellites (i.e., here today), maybe stratospheric drones (i.e., 2030+), may offer solid economic alternatives for those places. Interestingly, further simplifying the cellular networks supporting those areas today.

TAKE AWAY.

Volume in Bytes (or bits) does not directly relate to the energy consumption of the underlying communications networks that enable the usage.

The duration, the time scale, of the customer’s usage (i.e., the use of the network resources) does cause power consumption.

The bit-wise energy efficiency of 5G is superior to that of 4G LTE. It is designed that way via its spectral efficiency. Despite this, a 5G site configuration is likely to consume more energy than a 4G LTE site in the field and, thus, not a like-for-like in terms of number of bands and type of antennas deployed.

The absolute power consumption of a 5G configuration is a function of the number of bands deployed, the type of antennas deployed, intelligent energy management features, and the effective time 5G resources that customers have demanded.

Due to its optical foundation, Fiber is far more energy efficient in both bit-wise relative terms and absolute terms than any other legacy fixed (e.g., xDSL, HFC) or cellular broadband technology (e.g., 4G, 5G).

Looking forward and with the increasing challenges of remaining sustainable and contributing to CO2 reduction, it is paramount to consider an energy-optimized fixed and mobile converged network architecture as opposed to today’s approach of optimizing the fixed network separately from the cellular network. As a society, we should expect that the industry works hard to achieve an overall reduction in energy consumption, relaxing the demand on existing green energy infrastructures.

With 5G as of today, we are orders of magnitude from the original NGMN vision of energy consumption of only half of what was consumed by cellular networks ten years ago (i.e., 2014), requiring an overall energy efficiency increase of x2000.

Be aware that many Telcos and Infrastructure providers will use bit-wise energy efficiency when they report on energy consumption. They will generally report impressive gains over time in the energy that networks consume to deliver bits to their customers. This is the least one should expect.

Last but not least, the telco world is not static and is RAT-wise not very clean, as mobile networks will have several RATs deployed simultaneously (e.g., 2G, 4G, and 5G). As such, we rarely (if ever) have apples-to-apples comparisons on cellular energy consumption.

ACKNOWLEDGEMENT.

I greatly acknowledge my wife, Eva Varadi, for her support, patience, and understanding during the creative process of writing this article. I also greatly appreciate the discussion on this topic that I have had with Rudolf van der Berg over the last couple of years. I thank him for pointing out and reminding me (when I forget) of the shortfalls and poor quality of most of the academic work and lobbying activities done in this area.

PS

If you are aiming at a leapfrog in absolute energy reduction of your cellular network, above and beyond what you get with your infrastructure suppliers (e.g., Nokia, Ericsson, Huawei…), I really recommend you take a look at Opanga‘s machine learning-based Joule ML solution. The Joules ML has been proven to reduce RAN energy costs by 20% – 40% on top of what the RAT supplier’s (e.g., Ericsson, Nokia, Huawei, etc.) own energy management solutions may bring.

Disclosure: I am associated with Opanga and on their Industry Advisory Board.

5G Standalone – Network Slicing, a Bigger Slice of the Value Pie (Part II)

Posted on January 29, 2022 by Dr. Kim

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Full disclosure … when I was first introduced to the concept of Network Slicing, from one of the 5G fathers that I respect immensely (Rachid, it must have been back at the end of 2014), I thought that it was one of the most useless concepts that I had heard of. I did simply not see (or get) the point of introducing this level of complexity. It did not feel right. My thoughts were that taking the slicing concept to the limit might actually not make any difference to not having it, except for a tremendous amount of orchestration and management overhead (and, of course, besides the technological fun of developing it and getting it to work).

It felt a bit (a lot, actually) as a “let’s do it because we can” thinking. With the “We can” rationale based on the maturity of cloudification and softwarization frameworks, such as cloud-native, public-cloud scale, cloud computing (e.g., edge), software-defined networks (SDN), network-function virtualization (NFV), and the-one-that-is-always-named Artificial Intelligence (AI). I believed there could be other ways to offer the same variety of service experiences without this additional (what I perceived as an unnecessary) complexity. At the time, I had reservations about its impact on network planning, operations, and network efficiency. Not at all sure, it would be a development in the right economic direction.

Since then, I have softened to the concept of Network Slicing. Not (of course) that I have much choice, as slicing is an integral part of 5G standalone (5G) implementation that will be implemented and launched over the next couple of years across our industry. Who knows, I may very likely be proven very wrong, and then I learn something.

What is a network slice? We can see a network slice as an on-user-demand logical separated network partitioning, software-defined on-top of our common physical network infrastructure (wam … what a mouthful … test me out on this one next time you see me), slicing through our network technology stack and its layers. Thinking of a virtual private network (VPN) tunnel through a transport network is a reasonably good analogy. The network slice’s logical partitioning is isolated from other traffic streams (and slices) flowing through the 5G network. Apart from the slice logical isolation, it can have many different customizations, e.g., throughput, latency, scale, Quality of Service, availability, redundancy, security, etc… The user equipment initiates the slice request from a list of pre-defined slice categories. Assuming the network is capable of supporting its requirements, the chosen slice category is then created, orchestrated, and managed through the underlying physical infrastructure that makes up the network stack. The pre-defined slice categories are designed to match what our industry believe is the most essential use-cases, e.g., (a) enhanced mobile broadband use cases (eMBB), (b) ultra-reliable low-latency communications (uRLLC) use cases, (c) massive machine-type communication (MMTC) use cases, (d) Vehicular-to-anything (V2X) use-cases, etc… While the initial (early day) applications of network slicing are expected to be fairly static and configurationally relatively simple, infrastructure suppliers (e.g., Ericsson, Huawei, Nokia, …)expect network slices to become increasingly dynamic and rich in their configuration possibilities. While slicing is typically evoked for B2B and B2B2X, there is not really a reason why consumers could not benefit from network slicing as well (e.g., gaming/VR/AR, consumer smart homes, consumer vehicular applications, etc..).

Show me the money!

Ericsson and Arthur D. Little (ADL) have recently investigated the network slicing opportunities for communications service providers (CSP). Ericsson and ADL have analyzed more than 70 external market reports on the global digitalization of industries and critically reviewed more than 400 5G / digital use cases (see references in Further Readings below). They conclude that the demand from digitalization cannot be served by CSPs without Network Slicing, e.g., “Current network resources cannot match the increasing diversity of demands over time” and “Use cases will not function” (in a conventional mobile network). Thus, according to Ericsson and ADL, the industry can not “live” without Network Slicing (I guess it is good that it comes with 5G SA then). In fact, from their study, they conclude that 30% of the 5G use cases explored would require network slicing (oh joy and good luck that it will be in our networks soon).

Ericsson and ADL find globally a network slicing business potential of 200 Billion US dollars by 2030 for CSPs. With a robust CAGR (i.e., the potential will keep growing) between 23% to 36% by 2030 (i.e., CAGR estimate for period 2025 to 2030). They find that 6 Industries segments take 90+% of the slicing potential; (1) Healthcare (23%), (2) Government (17%), (3) Transportation (15%), (4) Energy & Utilities (14%), (5) Manufacturing (12%) and (6) Media & Entertainment (11%). For the keen observer, we see that the verticals are making up for most of the slicing opportunities, with only a relatively small part being related to the consumers. It should, of course, be noted that not all CSPs are necessarily also mobile network operators (MNOs), and there are also outside the strict domain of MNOs revenue potential for non-MNO CSPs (I assume).

Let us compare this slicing opportunity to global mobile industry revenue projections from 2020 to 2030. GSMA has issued a forecast for mobile revenues until 2025, expecting a total turnover of 1,140 Billion US$ in 2025 at a CAGR (2020 – 2025) of 1.26%. Assuming this compounded annual growth rate would continue to apply, we would expect a global mobile industry revenue of 1,213 Bn US$ by 2030. Our 5G deployments will contribute in the order of 621 Bn US$ (or 51% of the total). The incremental total mobile revenue between 2020 and 2030 would be ca. 140 Bn US$ (i.e., 13% over period). If we say that roughly 20% is attributed to mobile B2B business globally, we have that by 2030 we would expect a B2B turnover of 240+ Bn US$ (an increase of ca. 30 Bn US$ over 2020). So, Ericsson & ADL’s 200 Bn US$ network slicing potential is then ca. 16% of the total 2030 global mobile industry turnover or 30+% of the 5G 2030 turnover. Of course, this assumes that somehow the slicing business potential is simply embedded in the existing mobile turnover or attributed to non-MNO CSPs (monetizing the capabilities of the MNO 5G SA slicing enablers).

Of course, the Ericsson-ADL potential could also be an actual new revenue stream untapped by today’s network infrastructures due to the lack of slicing capabilities that 5G SA will bring in the following years. If so, we can look forward to a boost of the total turnover of 16% over the GSMA-based 2030 projection. Given ca. 90% of the slicing potential is related to B2B business, it may imply that B2B mobile business would almost double due to network slicing opportunities (hmmm).

Another recent study assessed that the global 5G network slicing market will reach approximately 18 Bn US$ by 2030 with a CAGR of ca. 41% over 2020-2030.

Irrespective of the slicing turnover quantum, it is unlikely that the new capabilities of 5G SA (including network slicing and much richer granular quality of service framework) will lead to new business opportunities and enable unexplored use cases. That, in turn, may indeed lead to enhanced monetization opportunities and new revenue streams between now (2022) and 2030 for our industry.

Most Western European markets will see 5G SA being launched over the next 2 to 3 years; as 5G penetration rapidly approaches 50% penetration, I expect network slicing use cases being to be tried out with CSP/MNOs, industry partners, and governmental institutions soon after 5G SA has been launched. It should be pointed out that already for some years, slicing concepts have been trialed out in various settings. Both in 4G as well as 5G NSA networks.

Prologue to Network Slicing.

5G comes with a lot of fundamental capabilities as shown in the picture below,

5G allows for (1) enhanced mobile broadband, (2) very low latency, (3) massive increase in device density handling, i.e., massive device scale-up, (4) ultra-higher network reliability and service availability, and (5) enhanced security (not shown in the above diagram) compared to previous Gs.

The service (and thus network) requirement combinations are very high. The illustration below shows two examples of mapped-out sub-set of service (and therefore also eventually slice) requirements mapped onto the major 5G capabilities. In addition, it is quite likely that businesses would have additional requirements related to slicing performance monitoring, for example, in real-time across the network stack.

and with all the various industrial or vertical use cases (see below) one could imagine (noting that there may be many many more outside our imagination), the “fathers” of 5G became (very) concerned with how such business-critical services could be orchestrated and managed within a traditional mobile network architecture as well as across various public land mobile networks (PLMN). Much of this also comes out of the wish that 5G should “conquer” (take a slice of) next-generation industries (i.e., Industry 4.0), providing additional value above and beyond “the dumb bit pipe.” Moreover, I do believe that in parallel with the wish of becoming much more relevant to Industry 4.0 (and the next generation of verticals requirements), what also played a role in the conception of network slicing is the deeply rooted engineering concept of “control being better than trust” and that “centralized control is better than decentralized” (I lost count on this debate of centralized control vs. distributed management a long time ago).

So, yes … The 5G world is about to get a lot more complex in terms of Industrial use cases that 5G should support. And yes, our consumers will expect much higher download speeds, real-time (whatever that will mean) gaming capabilities, and “autonomous” driving …

“… it’s clear that the one shared public network cannot meet the needs of emerging and advanced mobile connectivity use cases, which have a diverse array of technical operations and security requirements.” (quote from Ericsson and Arthur D. Little study, 2021).

“The diversity of requirements will only grow more disparate between use cases — the one-size-fits-all approach to wireless connectivity will no longer suffice.” (quote from Ericsson and Arthur D. Little study, 2021).

Being a naturalist (yes, I like “naked” networks), it does seem somewhat odd (to me) to say that next generation (e.g., 5G) networks cannot support all the industrious use cases that we may throw at it in its native form. Particular after having invested billions in such networks. By partitioning a network up in limiting (logically isolated), slice instances can all be supported (allegedly). I am still in the thinking phase on that one (but I don’t think the math adds up).

Now, whether one agrees (entirely) with the economic sentiment expressed by Ericsson and ADL or not. We need a richer granular way of orchestrating and managing all those diverse use-cases we expect our 5G network to support.

Network Slicing.

So, we have (or will get) network slicing with our 5G SA Core deployment. As a reminder, when we talk about a network slice, we mean;

“An on-user-demand logical separated network partitioning, software-defined, on-top of a common physical network infrastructure.”

So, the customer requested the network slice, typically via a predefined menu of slicing categories that may also have been pre-validated by the relevant network. Requested slices can also be Customized, by the requester, within the underlying 5G infrastructure capabilities and functionalities. If the network can provide the requested slicing requirements, the slice is (in theory) granted. The core network then orchestrates a logically separated network partitioning throughout the relevant infrastructure resources to comply with the requested requirements (e.g., speed, latency, device scale, coverage, security, etc…). The requested partitioning (i.e., the slice) is isolated from other slices to enable (at least on a logical level) independence of other live slices. Slice Isolation is an essential concept to network slicing. Slice Elasticity ensures that resources can be scaled up and down to ensure individual slice efficiency and an overall efficient operation of all operating slices. It is possible to have a single individual network slice or partition a slice into sub-slices with their individual requirements (that does not breach the overarching slice requirements). GSMA has issued roaming and inter-PLMN guidelines to ensure 5G network slicing inter-operability when a customer’s application finds itself outside its home -PLMN.

Today, and thanks to GSMA and ITU, there are some standard network slice services pre-defined, such as (a) eMBB – Enhanced Mobile Broadband, (b) mMTC – Massive machine-type communications, (c) URLLC – Ultra-reliable low-latency communications, (d) V2X – Vehicular-to-anything communications. These identified standard network slices are called Slice Service Types (SST). SSTs are not only limited to above mentioned 4 pre-defined slice service types. The SSTs are matched to what is called a Generic Slice Template (GST) that currently, we have 37 slicing attributes, allowing for quite a big span of combinations of requirements to be specified and validated against network capabilities and functionalities (maybe there is room for some AI/ML guidance here).

The user-requested network slice that has been set up end-2-end across the network stack, between the 5G Core and the user equipment, is called the network slice instance. The whole slice setup procedure is very well described in Chapter 12 of “5G NR and enhancements, from R15 to R16. The below illustration provides a high-level illustration of various network slices,

The 5G control function Access and Mobility management Function (AMF) is the focal point for the network slicing instances. This particular architectural choice does allow for other slicing control possibilities with a higher or lower degree of core network functionality sharing between slice instances. Again the technical details are explained well in some of the reading resources provided below. The takeaway from the above illustration is that the slice instance specifications are defined for each layer and respective physical infrastructure (e.g., routers, switches, gateways, transport device in general, etc…) of the network stack (e.g., Telco Core Cloud, Backbone, Edge Cloud, Fronthaul, New Radio, and its respective air-interface). Each telco stack layer that is part of a given network slice instance is supposed to adhere strictly to the slice requirements, enabling an End-2-End, from Core to New Radio through to the user equipment, slice of a given quality (e.g., speed, latency, jitter, security, availability, etc..).

And it may be good to keep in mind that although complex industrial use cases get a lot of attention, voice and mobile broadband could easily be set up with their own slice instances and respective quality-of-services.

Network slicing examples.

All the technical network slicing “stuff” is pretty much-taken care of by standardization and provided by the 5G infrastructure solution providers (e.g., Mavenir, Huawei, Ericsson, Nokia, etc..). Figuring the technical details of how these works require an engineering or technical background and a lot of reading.

As I see it, the challenge will be in figuring out, given a use-case, the slicing requirements and whether a single slice instance suffice or multiple are required to provide the appropriate operations and fulfillment. This, I expect, will be a challenge for both the mobile network operator as well as the business partner with the use case. This assumes that the economics will come out right for more complex (e.g., dynamic) and granular slice-instance use cases. For the operator as well as for businesses and public institutions.

The illustration below provides examples of a few (out of the 37) slicing attributes for different use cases, (a) Factories with time-critical, non-time-critical, and connected goods sub-use cases (e.g., sub-slice instances, QoS differentiated), (b) Automotive with autonomous, assisted and shared view sub-use cases, (c) Health use cases, and (d) Energy use cases.

One case that I have been studying is Networked Robotics use cases for the industrial segment. Think here about ad-hoc robotic swarms (for agricultural or security use cases) or industrial production or logistics sorting lines; below are some reflections around that.

End thoughts.

With the emergence of the 5G Core, we will also get the possibility to apply Network slicing to many diverse use cases. That there are interesting business opportunities with network slicing, I think, is clear. Whether it will add 16% to the global mobile topline by 2030, I don’t know and maybe also somewhat skeptical about (but hey, if it does … fantastic).

Today, the type of business opportunities that network slicing brings in the vertical segments is not a very big part of a mobile operator’s core competence. Mobile operators with 5G network slicing capabilities ultimately will need to build up such competence or (and!) team up with companies that have it.

That is, if the future use cases of network slicing, as envisioned by many suppliers, ultimately will get off the ground economically as well as operationally. I remain concerned that network slicing will not make operators’ operations less complex and thus will add cost (and possible failures) to their balance sheets. The “funny” thing (IMO) is that when our 5G networks are relatively unloaded, we would not have a problem delivering the use cases (obviously). Once our 5G networks are loaded, network slicing may not be the right remedy to manage traffic pressure situations or would make the quality we are providing to consumers progressively worse (and I am not sure that business and value-wise, this is a great thing to do). Of course, 6G may solve all those concerns 😉

Acknowledgement.

I greatly acknowledge my wife, Eva Varadi, for her support, patience, and understanding during the creative process of writing this Blog. Also, many of my Deutsche Telekom AG and Industry colleagues, in general, have in countless ways contributed to my thinking and ideas leading to this little Blog. Thank you!

5G Standalone – European Demand & Expectations (Part I).

Posted on January 29, 2022 by Dr. Kim

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By the end of 2020, according with Ericsson, it was estimated that there where ca. 7.6 million 5G subscriptions in Western Europe (~ 1%). Compare this to North America’s ca. 14 million (~4%) and 190 million (~11%) North East Asia (e.g, China, South Korea, Japan, …).

Maybe Western Europe is not doing that great, when it comes to 5G penetration, in comparison with other big regional markets around the world. To some extend the reason may be that 4G network’s across most of Western Europe are performing very well and to an extend more than servicing consumers demand. For example, in The Netherlands, consumers on T-Mobile’s 4G gets, on average, a download speed of 100+ Mbps. About 5× the speed you on average would get in USA with 4G.

From the October 2021 statistics of the Global mobile Suppliers Association (GSA), 180 operators worldwide (across 72 countries) have already launched 5G. With 37% of those operators actively marketing 5G-based Fixed Wireless Access (FWA) to consumers and businesses. There are two main 5G deployment flavors; (a) non-standalone (NSA) deployment piggybacking on top of 4G. This is currently the most common deployment model, and (b) as standalone (SA) deployment, independently from legacy 4G. The 5G SA deployment model is to be expected to become the most common over the next couple of years. As of October 2021, 15 operators have launched 5G SA. It should be noted that, operators with 5G SA launched are also likely to support 5G in NSA mode as well, to provide 5G to all customers with a 5G capable handset (e.g., at the moment only 58% of commercial 5G devices supports 5G SA). Only reason for not supporting both NSA and SA would be for a greenfield operator or that the operator don’t have any 4G network (none of that type comes to my mind tbh). Another 25 operators globally are expected to be near launching standalone 5G.

It should be evident, also from the illustration below, that mobile customers globally got or will get a lot of additional download speed with the introduction of 5G. As operators introduce 5G, in their mobile networks, they will leapfrog their available capacity, speed and quality for their customers. For Europe in 2021 you would, with 5G, get an average downlink (DL) speed of 154 ± 90 Mbps compared to 2019 4G DL speed of 26 ± 8 Mbps. Thus, with 5G, in Europe, we have gained a whooping 6× in DL speed transitioning from 4G to 5G. In Asia Pacific, the quality gain is even more impressive with a 10× in DL speed and somewhat less in North America with 4× in DL speed. In general, for 5G speeds exceeding 200 Mbps on average may imply that operators have deployed 5G in the C-band band (e.g., with the C-band covering 3.3 to 5.0 GHz).

The above DL speed benchmark (by Opensignal) gives a good teaser for what to come and to expect from 5G download speed, once a 5G network is near you. There is of course much more to 5G than downlink (and uplink) speed. Some caution should be taken in the above comparison between 4G (2019) and 5G (2021) speed measurements. There are still a fair amount of networks around the world without 5G or only started upgrading their networks to 5G. I would expect the 5G average speed to reduce a bit and the speed variance to narrow as well (i.e., performance becoming more consistent).

In a previous blog I describe what to realistically expect from 5G and criticized some of the visionary aspects of the the original 5G white paper paper published back in February 2015. Of course, the tech-world doesn’t stand still and since the original 5G visionary paper by El Hattachi and Erfanian. 5G has become a lot more tangible as operators deploy it or is near deployment. More and more operators have launched 5G on-top of their 4G networks and in the configuration we define as non-standalone (i.e., 5G NSA). Within the next couple of years, coinciding with the access to higher frequencies (>2.1 GHz) with substantial (unused or underutilized) spectrum bandwidths of 50+ MHz, 5G standalone (SA) will be launched. Already today many high-end handsets support 5G SA ensuring a leapfrog in customer experience above and beyond shear mobile broadband speeds.

The below chart illustrates what to expect from 5G SA, what we already have in the “pocket” with 5G NSA, and how that may compare to existing 4G network capabilities.

There cannot be much doubt that with the introduction of the 5G Core (5GC) enabling 5G SA, we will enrich our capability and service-enabler landscape. Whether all of this cool new-ish “stuff” we get with 5G SA will make much top-line sense for operators and convenience for consumers at large is a different story for a near-future blog (so stay tuned). Also, there should not be too much doubt that 5G NSA already provide most of what the majority of our consumers are looking for (more speed).

Overall, 5G SA brings benefits, above and beyond NSA, on (a) round-trip delay (latency) which will be substantially lower in SA, as 5G does not piggyback on the slower 4G, enabling the low latency in ultra-reliable low latency communications (uRLLC), (b) a factor of 250× improvement device density (1 Million devices per km2) that can be handled supporting massive machine type communication scenarios (mMTC), (c) supports communications services at higher vehicular speeds, (d) in theory should result in low device power consumption than 5G NSA, and (e) enables new and possible less costly ways to achieve higher network (and connection) availability (e.g., with uRLLC).

Compared to 4G, 5G SA brings with it a more flexible, scalable and richer set of quality of service enablers. A 5G user equipment (UE) can have up to 1,024 so called QoS flows versus a 4G UE that can support up to 8 QoS classes (tied into the evolved packet core bearer). The advantage of moving to 5G SA is a significant reduction of QoS driven signaling load and management processing overhead, in comparison to what is the case in a 4G network. In 4G, it has been clear that the QoS enablers did not really match the requirements of many present day applications (i.e., brutal truth maybe is that the 4G QoS was outdated before it went live). This changes with the introduction of 5G SA.

So, when is it a good idea to implement 5G Standalone for mobile operators?

There are maybe three main events that should trigger operators to prepare for and launch 5G SA;

Economical demand for what 5G SA offers.
Critical mass of 5G consumers.
Want to claim being the first to offer 5G SA.

with the 3rd point being the least serious but certainly not an unlikely factor in deploying 5G SA. Apart from potentially enriching consumers experience, there are several operational advantages of transitioning to a 5GC, such as more mature IT-like cloudification of our telecommunications networks (i.e., going telco-cloud native) leading to (if designed properly) a higher degree of automation and autonomous network operations. Further, it may also allow the braver parts of telco-land to move a larger part of its network infrastructure capabilities into the public-cloud domain operated by hyperscalers or network-cloud consortia’s (if such entities will appear). Another element of the 5G SA cloud nativification (a new word?) that is frequently not well considered, is that it will allow operators to start out (very) small and scale up as business and consumer demand increases. I would expect that particular with hyperscalers and of course the-not-so-unusual-telco-supplier-suspects (e.g., Ericsson, Nokia, Huawei, Samsung, etc…), operators could launch fairly economical minimum viable products based on a minimum set of 5G SA capabilities sufficient to provide new and cost-efficient services. This will allow early entry for business-to-business new types of QoS and (or) slice-based services based on our new 5G SA capabilities.

By end of 2021, it is expected that Western Europe would have in the order of 36 Million 5G connections, around a 5% 5G penetration. Increasing to 80 Million (11%) by end of 2022. By 2024 to 2025, it is expected that 50% of all mobile connections would be 5G based. As of October 2021 ca. 58% of commercial available mobile devices supports already 5G SA. This SA share is anticipated to grow rapidly over the next couple of years making 5G NSA increasingly unimportant.

Approaching 50% of all connections being 5G appears a very good time to aim having 5G standalone implemented and launched for operators. Also as this may coincide with substantial efforts to re-farming existing frequency spectrum from 4G to 5G as 5G data traffic exceeds that of 4G.

For Western Europe 2021, ca. 18% of the total mobile connections are business related. This number is expected to steadily increase to about 22% by 2030. With the introduction of new 5G SA capabilities, as briefly summarized above, it is to be expected that the 5G business connection share quickly will increase to the current level and that business would be able to directly monetize uRLLC, mMTC and the underlying QoS and network slicing enablers. For consumers 5G SA will bring some additional benefits but maybe less obvious new monetization possibilities, beyond the proportion of consumers caring about latency (e.g., gamers). Though, it appears likely that the new capabilities could bring operators efficiency opportunities leading to improved margin earned on consumers (for another article).

Recommendation:

Learn as much as possible from recent IT cloudification journeys (e.g., from monolithic to cloud, understand pros and cons with lift-and-shift strategies and the intricacies of operating cloud-native environments in public cloud domains).
Aim to have 5GC available for 5G SA launch latest by 2024.
Run 5GC minimum viable product poc’s with friendly (business) users prior to bigger launch.
As 5G is launched on C-band / 3.x GHz it may likewise be a good point in time to have 5G SA available. At least for B2B customers that may benefit from uRLLC, lower latency in general, mMTC, a much richer set of QoS, network slicing, etc…
Having a solid 4G to 5G spectrum re-farming strategy ready between now and 2024 (too late imo). This should map out 4G+NSA and SA supply dynamics as increasingly customers get 5G SA capabilities in their devices.

Western Europe mobile market expectations – traffic growth.

With the growth of 5G connections and the expectation that 5G would further boost the mobile data consumption, it is expected that by 2023 – 2024, 50% of all mobile data traffic in Western Europe would be attributed to 5G. This is particular driven by increased rollout of 3.x GHz across the Western European footprint and associated massive MiMo (mMiMo) antenna deployments with 32×32 seems to be the telco-lands choice. In blended mobile data consumption a CAGR of around 34% is expected between 2020 and 2030, with 2030 having about 26× more mobile data traffic than that of 2020. Though, I suspect that in Western Europe, aggressive fiberization of telecommunications consumer and business markets, over the same period, may ultimately slow the growth (and demand) on mobile networks.

A typical Western European operator would have between 80 – 100+ MHz of bandwidth available for 4G its downlink services. The bandwidth variation being determined by how much is required of residual 3G and 2G services and whether the operator have acquired 1500MHz SDL (supplementary downlink) spectrum. With an average 4G antenna configuration of 4×4 MiMo and effective spectral efficiency of 2.25 Mbps/MHz/sector one would expect an average 4G downlink speed of 300+ Mbps per sector (@ 90 MHz committed to 4G). For 5G SA scenario with 100 MHz of 3.x GHz and 2×10 MHz @ 700 MHz, we should expect an average downlink speed of 500+ Mbps per sector for a 32×32 massive MiMo deployment at same effective spectral efficiency as 4G. In this example, although naïve, quality of coverage is ignored. With 5G, we more than double the available throughput and capacity available to the operator. So the question is whether we remain naïve and don’t care too much about the coverage aspects of 3.x GHz, as beam-forming will save the day and all will remain cheesy for our customers (if something sounds too good to be true, it rarely is true).

In an urban environment it is anticipated that with beam-forming available in our mMiMo antenna solutions downlink coverage will be reasonably fine (i.e., on average) with 3.x GHz antennas over-layed on operators existing macro-cellular footprint with minor densification required (initially). In the situation that 3.x GHz uplink cannot reach the on-macro-site antenna, the uplink can be closed by 5G @ 700 MHz, or other lower cellular frequencies available to the operator and assigned to 5G (if in standalone mode). Some concerns have been expressed in literature that present advanced higher order antenna’s (e.g., 16×16 and above ) will on average provide a poorer average coverage quality over a macro cellular area than what consumers would be used to with lower order antennas (e.g., 4×4 or lower) and that the only practical (at least with today’s state of antennas) solution would be sectorization to make up for beam forming shortfalls. In rural and sub-urban areas advanced antennas would be more suitable although the demand would be a lot less than in a busy urban environment. Of course closing the 3.x GHz with existing rural macro-cellular footprint may be a bigger challenge than in an urban clutter. Thus, massive MiMo deployments in rural areas may be much less economical and business case friendly to deploy. As more and more operators deploy 3.x GHz higher-order mMiMo more field experience will become available. So stay tuned to this topic. Although I would reserve a lot more CapEx in my near-future budget plans for substantial more sectorization in urban clutter than what I am sure is currently in most operators plans. Maybe in rural and suburban areas the need for sectorizations would be much smaller but then densification may be needed in order to provide a decent 3.x GHz coverage in general.

Western Europe mobile market expectations – 5G RAN Capex.

That brings us to another important aspect of 5G deployment, the Radio Access Network (RAN) capital expenditures (CapEx). Using my own high-level (EU-based) forecast model based on technology deployment scenario per Western European country that in general considers 1 – 3% growth in new sites per anno until 2024, then from 2025 onwards, I assuming 2 – 5% growth due to densifications needs of 5G, driven by traffic growth and before mentioned coverage limitations of 3.x GHz. Exact timing and growth percentages depends on initial 5G commercial launch, timing of 3.x GHz deployment, traffic density (per site), and site density considering a country’s surface area.

According with Statista, Western Europe had in 2018 a cellular site base of 421 thousands. Further, Statista expected this base will grow with 2% per anno in the years after 2018. This gives an estimated number of cellular sites of 438k in 2020 that has been assumed as a starting point for 2020. The model estimates that by 2030, over the next 10 years, an additional 185k (+42%) sites will have been built in Western Europe to support 5G demand. 65% (120+k) of the site growth, over the next 10 years, will be in Germany, France, Italy, Spain and UK. All countries with relative larger geographical areas that are underserved with mobile broadband services today. Countries with incumbent mobile networks, originally based on 900 MHz GSM grids (of course densified since the good old GSM days), and thus having coarser cellular grids with higher degree of mismatching the higher 5G cellular frequencies (i.e., ≥ 2.5 GHz). In the model, I have not accounted for an increased demand of sectorizations to keep coverage quality upon higher order mMiMO deployments. This, may introduce some uncertainty in the Capex assessment. However, I anticipate that sectorization uncertainty may be covered in the accelerated site demand the last 5 years of the period.

In the illustration above, the RAN capital investment assumes all sites will eventually be fiberized by 2025. That may however be an optimistic assumption and for some countries, even in Western Europe, unrealistic and possibly highly uneconomical. New sites, in my model, are always fiberized (again possibly too optimistic). Miscellaneous (Misc.) accounts for any investments needed to support the RAN and Fiber investments (e.g., Core, Transport, Cap. Labor, etc..).

In the economical estimation price erosion has been taken into account. This erosion is a blended figure accounting for annual price reduction on equipment and increases in labor cost. I am assuming a 5-year replacement cycle with an associated 10% average price increase every 5 years (on the previous year’s eroded unit price). This accounts for higher capability equipment being deployed to support the increased traffic and service demand. The economical justification for the increase unit price being that otherwise even more new sites would be required than assumed in this model. In my RAN CapEx projection model, I am assuming rational deployment, that is demand driven deployment. Thus, operators investments are primarily demand driven, e.g., only deploying infrastructure required within a given financial recovery period (e.g., depreciation period). Thus, if an operator’s demand model indicate that it will need a given antenna configuration within the financial recovery period, it deploys that. Not a smaller configuration. Not a bigger configuration. Only the one required by demand within the financial recovery period. Of course, there may be operators with other deployment incentives than pure demand driven. Though on average I suspect this would have a neglectable effect on the scale of Western Europe (i.e., on average Western Europe Telco-land is assumed to be reasonable economically rational).

All in all, demand over the next 8 years leads to an 80+ Billion Euro RAN capital expenditure, required between 2022 and 2030. This, equivalent to a annual RAN investment level of a bit under 10 Billion Euro. The average RAN CapEx to Mobile Revenue over this period would be ca. 6.3%, which is not a shockingly high level (tbh), over a period that will see an intense rollout of 5G at increasingly higher frequencies and increasingly capable antenna configurations as demand picks up. Biggest threat to capital expenditures is poor demand models (or no demand models) and planning processes investing too much too early, ultimately resulting in buyers regret and cycled in-efficient investment levels over the next 10 years. And for the reader still awake and sharp, please do note that I have not mentioned the huge elephant in the room … The associated incremental operational expense (OpEx) that such investments will incur.

As mobile revenues are not expected to increase over the period 2022 to 2030, this leaves 5G investments main purpose to maintaining current business level dominated by consumer demand. I hope this scenario will not materialize. Given how much extra quality and service potential 5G will deliver over the next 10 years, it seems rather pessimistic to assume that our customers would not be willing to pay more for that service enhancement that 5G will brings with it. Alas, time will show.

Acknowledgement.

I greatly acknowledge my wife Eva Varadi for her support, patience and understanding during the creative process of writing this Blog. Petr Ledl, head of DTAG’s Research & Trials, and his team’s work has been a continuous inspiration to me (thank you so much for always picking up on that phone call Petr!). Also many of my Deutsche Telekom AG, T-Mobile NL & Industry colleagues in general have in countless of ways contributed to my thinking and ideas leading to this little Blog. Thank you!

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"It doesn't matter how beautiful your idea is, it doesn't matter how smart or important you are. If the idea doesn't agree with reality, it's wrong", Richard Feynman (paraphrased)

Category Archives: 5G Standalone

Stratospheric Drones & Low Earth Satellites: Revolutionizing Terrestrial Rural Broadband from the Skies?

IMAGINE.

TERRESTRIAL CELLULAR RURAL COVERAGE – A MATTER OF POOR ECONOMICS.

THE ADVANTAGE OF SEEING FROM ABOVE.

STRATOSPHERIC DRONES VS TERRESTRIAL NETWORKS.

Spectrum usage rights yet another critical piece.

COMPARISON WITH LEO SATELLITE BROADBAND NETWORKS.

INTEGRATING WITH 5G AND BEYOND.

SUMMARY.

Terrestrial Mobile Broadband Network – takeaway:

LEO Satellite Network – takeaway:

Stratospheric Drone-Based Network – takeaway:

FURTHER READING.

ACKNOWLEDGEMENT.

Telco energy consumption – a path to a greener future?

THE ENERGY OF DELIVERING A BIT.

WHY 5G IS NOT A GREEN TECHNOLOGY?

SO WHAT?

TAKE AWAY.

ACKNOWLEDGEMENT.

PS