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A Sobering Look at the Future Role of HTS Systems for 5G

July 24th, 2023
Picture of Tom Choi
Tom Choi

I’m pleased to be invited by Via Satellite to write an article that may provide contrarian perspectives to the popular beliefs that are pervasive in the market that somehow HTS GEO, MEO and NGSO systems will be having a material impact in the adoption and deployment of 5G from 2020 and beyond. 

The current FSS industry is now entering the third year of a down turn which we do not know if we will recover from. Above and beyond the over-built supply of FSS satellite capacity for regional and bent pipe wide-beam transponders, the industry is suffering from the ever-expanding competition from terrestrial expansion of fiber and 3G/4G systems which continues to eat into our revenue base as end users give up satellites in favor of lower cost terrestrial alternatives. Because the leaders in our industry continue to believe that HTS capacity is the savior of their respective businesses, the build out of these systems are eroding prices even before these systems launch. It is rare today to see end users committing to any long-term contracts now as they believe that pricing will be ever lower as new systems come on online. They would be wise to assume so, I am afraid.

Following the OneWeb and ViaSat 3 investments, SES has doubled down on O3b with their next-generation platform and Telesat has committed to the next generation of LEO Ka-band system. While these next-generation HTS systems offer more capacity and flexibility than the first generation HTS systems, they will not have sufficient capacity to make a meaningful contribution to the $1 trillion mobile broadband market, which will be launching their own next generation high throughput wireless platform called 5G. The reason is simple:

Broadband density is a terminology I recently came up with to describe how much total capacity can be delivered within a square kilometer to serve people with wireless broadband services. Broadband density can also be a metric to compare capacity available from different types of wireless systems. So, let’s begin.

The total surface area of the Earth is 510 million km2. Let’s assume that with 640 satellites with about 20Gbps per satellite, OneWeb has 13 Terabits per second (this is generous because over the artic circles most of the satellites haves to switch off beams due to interference) of total capacity over the globe. Then the broadband density of OneWeb is 0.025 Mbps, or 25 kbps/ km2. ViaSat 3 satellite with 1 Terabit of capacity from three positions would provide a broadband density of 0.006 Mbps/ km2, or 5. 9kbps/ km2. When thinking about broadband to places where people live, this doesn’t sound much. In fact, all the HTS systems combined would deliver less than 100 kbps/km2 of broadband density.

So, how does this compare to terrestrial alternatives? An LTE eNode typically will have 45 to 300 Mbps and will have an effective range of several kilometers. Assuming a eNode is covering a 5 km radius and is serving 100 Mbps, its broadband density is 1.27 Mbps/ km2. It’s obvious nowhere on Earth where LTE exists ViaSat 3, OneWeb nor any other HTS system has a chance to out-compete with this terrestrial wireless technology, which is now almost nine years old. Yet the on-coming 5G gNodes will deliver minimum 100 mbps to 1 Gbps to handhelds and will typically deliver 1 to 10 Gbps per installation. Since the implementation of 5G is planned for milimeterwave (Ka-band), the range of these systems will be a few hundred meters. Assuming that a 10 Gbps gNode serves a 1 km radius, its broadband density will be 3.1 Gbps/ km2. This is a meaningful amount of bandwidth which I believe will serve multiple broadband users where people live.

5G will be globally available in 2020 well ahead of the schedule of OneWeb, O3b mPower, ViaSat 3’s global deployment, and Telesat’s global LEO system. 3 Gbps/km2 from a single gNode versus not even 100 kbps/km2 for all of the planned HTS systems combined will give you an idea if satellites will have any meaningful role to play in 5G deployment. You can do the math.

To give you an idea what this means, France is 644,000 km2. All of the planned HTS systems combined will have about 64Gbps of capacity over France or sufficient bandwidth to serve 6 to 7 gNodes — pretty pathetic if you ask me. One may say that this is too simplistic and that 64 Gbps will be shared across thousands of 5G sites. I am afraid that the definition of broadband will change in the near future where the extremely fast speeds available from 5G towers will bring on a new round of applications and services the consumers will demand and will not be served by satellites due to their extremely low broadband density.

I am sure that some of these HTS systems will find some market niche and customer segments (e.g. maritime and aero where terrestrial systems don’t exist) but where people live and spend money, you will not find them being served by satellites. Satellites lost the battle for wireless broadband against 3G and the odds are progressively getting worse with each mobile wireless generation evolution. Unless we make a quantum leap forward (1,000 to 10,000 times improvement) in the amount of available capacity we can deliver to the ground (broadband density of 100 Mbps to 1 Gbps per km2 ) satellites will not play a meaningful role in 5G-like services. VS