The Latest Trends in the Space Business: Prospects for Direct Cellular Connectivity at One of the Largest Space Industry Conferences in the U.S.【Warpspace CSO Talks About SATELLITE 2024 Part Ⅲ】

Warpspace Inc.
5 min readApr 17, 2024

SATELLITE 2024, one of the world’s largest satellite industry conferences, was held March 18–21, 2024, in Washington, D.C. SATELLITE, organized by Via Satellite, a satellite-related information media company, has a history of over 40 years since 1981. It is one of the top three conference events in the U.S. space field, along with the Space Symposium held every April and the Smallsat Conference held every August.

SATELLITE brings together people from around the world involved in satellites, military and security, investment, transportation, telecommunications, media, etc. This year’s speakers included Diane Howard, Director of Commercial Space Policy at the White House National Space Council, and Jessica Rosenworcel, Chair of the Federal Communications Commission (FCC).

Attributes of SATELLITE conference participants (adapted from SATELLITE 2024 HP)

With the attention of operators around the world focused on this topic, a number of significant announcements were made at SATELLITE 2024. Warpspace CSO Hirokazu Mori also participated in a panel discussion, discussing the importance, benefits, and challenges of inter-satellite and satellite-to-ground optical communications. In this article, Mori focuses on a few of the news items presented at the conference, topics that were of particular interest to him,

1.SpaceX’s Starship Successfully Tested
2.SpaceX Begins Sales of Optical Communication Terminals
3. Direct Cell-Satellite Connection

We are pleased to present you with the following information.
(For a report on SATELLITE 2023, which Mori attended last year, click here.)

The third part of this report details “3. direct connection between cell phones and satellites”

(Click here for the first part and here for the second part.)

FCC Adopts Final Rules for Communications Framework

Mori said the most significant topic at Satellite this year was,

“The FCC (Federal Communications Commission) adopted a framework to make the radio waves used by terrestrial mobile terminals available to satellites.”

(*1【FCC】FCC approves direct-to-smartphone regulatory framework)

The FCC (Federal Communications Commission) is a federal agency that regulates telecommunications and radio frequencies and regulates wireless and electronic devices.

Federal Communications Commission (FCC) Chair Jessica Rosenworcel(*1)

Currently, radio waves are used in various places around us, such as television and radio broadcasting, but each application is assigned a radio frequency that can be used. In other words, the frequencies used by terrestrial terminals and satellites are different, making communication between the two impossible.

Familiar radio waves and their frequencies (based on figures from docomo “What is a radio wave? (*2)

The Supplemental Coverage from Space (SCS) regulatory framework, a communications framework for frequency band coordination by the FCC, was proposed to address this issue.

The adoption of the SCS framework will enable cooperation between wireless and satellite carriers. This is a significant milestone, as it will enable the provision of telecommunications services in areas that are inaccessible by radio waves or cables from base stations.

FCC Chair Jessica Rosenworcel said,

“When they work together, they will be able to provide communications services at all times. That means, for example, if a disaster strikes and our terrestrial systems are destroyed, we’ll be able to provide backup communications via satellite.”

This adoption is a very big step forward in the “direct-to-cell” industry, where mobile terminals on the ground are directly connected to communication satellites. At the same time, it is also a major step forward in resolving the situation where base stations cannot operate due to large-scale disasters, and we will be keeping a close eye on future developments.

(*2 [docomo] What is a radio wave?)

”Direct-to-cell” connection between a smartphone and a communications satellite

So what are the advantages of “direct-to-cell”?

Currently, there is a lot of interest in high-speed Internet services to the entire world using low-earth orbit mega-constellations such as Starlink, Amazon’s Project Kuiper, and Oneweb, but let’s take SpaceX’s Starlink for an example.

Starlink is a service that makes the Internet available by installing a dedicated antenna on the ground. The mobile terminal first connects to the Starlink satellite via a dedicated antenna, and the Starlink satellite then connects to the Internet through the ground antenna (*3).

How does Starlink work?(*4)

(*3 [SpaceX] HIGH-SPEED INTERNET Available almost anywhere on Earth.)

(*4 [Dgtl Infra] Elon Musk’s Starlink and Satellite Broadband)

Satellite-based Internet access services have existed for some time, but Starlink stands apart in terms of its high speed and low latency.

Until now, communication satellites have been located in Geostationary Orbit (GSO), which is an orbit that is geostationary relative to the ground. However, because GSO is far from the earth’s surface, satellite communications using GSO have suffered from problems such as insufficient communication latency and speed, as well as high satellite development costs due to the need for larger satellite systems (antennas and batteries) and high barriers to new entrants to the market.

The Falcon 9, a SpaceX rocket, has overcome these problems. The Falcon 9 is a thoroughly cost-effective rocket that can launch satellites into LEO (Low Earth Orbit), MEO (Medium Earth Orbit), and GSO at a much lower cost than similarly sized rockets of the same era. This has led to an increase in the number of new operators entering the commercial satellite market and a trend toward launching small satellites into LEO and MEO. (*5)

In other words, Starlink has succeeded in providing high-speed, low-latency services at low cost by positioning satellites in LEO at an altitude of about 550 km.

(*5 [Warpspace] Unstoppable march of New Space. New developments in the satellite communication business over MEO?

Dedicated Starlink antenna (*3)

On the other hand , “Direct to cell” is a service that enables communication through a direct connection between a smartphone and a satellite. This service is characterized by its ease of use: no hardware or firmware changes to the smartphone are required, and no special applications are needed.

Starlink satellite and direct communication mechanism (*6)

In Japan, KDDI will utilize SpaceX’s Starlink to realize direct connectivity, first supporting SMS in 2024, followed by voice and data communications(*6).

KDDI’s “Direct to cell” concept is to “connect anywhere in sight of the sky.

We will keep a close eye on this technology to see if it can be a game changer in telecommunications.

(*6 [KDDI] SpaceX successfully launched the first satellite capable of direct communication with smartphones)

( Author: Natsumi Kawaguchi )



Warpspace Inc.

Warpspace develops “WarpHub InterSat”, an optical inter-satellite data relay service. We will realize this service for LEO Sat operators by 2025.