T-Mobile And SpaceX’s Satellite Partnership Paves The Way For Real Use Of Satellite In 5G

Mobile & SpaceXT-MOBILE

The satellite communications space has been incredibly busy over the last year, with many companies discussing the possibility of satellite connectivity for consumer devices. Many players in the space, such as AST SpaceMobile and Omnispace, have already launched satellites and are in talks with various carriers around the world to roll out services. One of the leaders in satellite communications, SpaceX, however, has been conspicuously silent when it comes to potential carrier partnerships. Instead, it has mostly used its existing Starlink satellite constellation to service residential customers in rural areas where other providers are unavailable. All of that changed this week, though, with SpaceX’s announcement that it will partner with T-Mobile to deliver satellite coverage via T-Mobile’s PCS (1900 MHz) spectrum, which it has had since the 3G days.

The new network

Before diving into the partnership, let’s look at some additional context. SpaceX recently got clearance from the FCC to roll out Starlink to mobile users such as RVs and boats. These would primarily use SpaceX’s Starlink service while stationary but might move from one fixed location to another. In addition to this, the 3GPP, the industry body responsible for setting the 5G global standard, ratified Release 17 this past March. Release 17 includes the ability to incorporate non-terrestrial communications into the 5G network, ensuring interoperability across devices and networks. All these things are happening while T-Mobile continues to increase the footprint of its 5G network with the continued rollout of its 2.5 GHz Ultra Capacity and 600 MHz coverage bands. However, even T-Mobile recognizes that terrestrial networks are not enough to bring coverage everywhere. For that matter, the poor economics of covering rural areas make it unattractive to for-profit carriers, which is why things like the RDOF (Rural Digital Opportunity Fund) fund exist but still isn’t enough to cover the whole country.

All of which brings us to the partnership with SpaceX. T-Mobile plans to use 10 MHz of the G-Block of the PCS band of spectrum for the project, while SpaceX will add significantly larger antennas to its new Starlink v2 satellites. These satellites will have to be launched before this capability can be brought to T-Mobile’s customers and SpaceX will have to file a Part 25 with the FCC to have the ability to operate its satellites in this band. T-Mobile CEO Mike Sievert and SpaceX CEO Elon Musk both explained that these satellites will operate like cell towers in the sky. While considerably more challenging than installing terrestrial cell towers, this approach would result in significantly larger cells capable of providing services to much larger areas than terrestrial networks.

Public safety

The new satellite service will not only cover sparsely populated rural areas, but also add coverage in wilderness areas that traditionally have no connectivity, such as forests, deserts, seas and oceans. Generally, when it comes to satellite communications as long as you have a clear view of the sky, you will get signal. National parks, with their poor cell coverage and high visitation, could stand to benefit greatly. Satellite coverage would enable people to call for emergency services in remote areas of a national park without needing an expensive satellite phone or additional satellite service. Similarly, it could allow families to be in constant communication with loved ones that they might be worried about. While this may on some level ruin the solitude of going into nature, it will very likely save lives.

Services on the network

According to Elon Musk and T-Mobile CEO Mike Sievert, the service would first be utilized for messaging (though it will still be real-time in nature). Mike Sievert stated that T-Mobile will work with messaging partners to verify and test their services on the new network to ensure maximum compatibility and the best user experience. This would likely be along the lines of RCS services like Google Messenger, Apple iMessage, WhatsApp and Facebook Messenger. Next would be audio services for making phone calls, followed eventually by data services. Since the cells will purportedly be capable of speeds up to 1-2 MB/s, hundreds or thousands of users would share the same cell making high-bandwidth applications out of the question.

The new satellite network will operate just like another cellular network for users’ devices, since the 1900 MHz band is actually quite old and most of it was originally auctioned in the 90s. Conveniently, this means that users won’t need to get new devices to take advantage of the satellite coverage. While T-Mobile hasn’t necessarily said whether it considers this a 4G or 5G network, it’s worth considering that 5G NTN is part of 3GPP Rel. 17, which likely won’t make its way into devices or networks until next year at the earliest. In other words, it probably will not be marketed as 5G, at least not immediately. T-Mobile’s CEO Mike Sievert also stated that he does not expect to charge extra for the service; instead T-Mobile plans to make it available for free to its highest paying customers on the Magenta Max service. By increasing ARPU (average revenue per user), T-Mobile hopes to pay for this service without raising prices.

Open to partners

The CEOs of both companies have expressed interest in partnering with other operators around the world to expand the service and give access to their spectrum in the way that T-Mobile has. By making spectrum available they would enable the service and create the potential for global roaming agreements with each other to enable their customers to always be connected anywhere they go in the world. I could see someone like Deutsche Telekom participating in this, as it is one of the largest operators in the world and owns a considerable (48%) chunk of T-Mobile US. Other potential partners with available re-farmed spectrum include SK-Telecom, Vodafone or even Reliance Jio in India. The latter could benefit greatly from satellite’s improved coverage for such a huge country.

Final thoughts

T-Mobile demonstrated its 5G leadership early on, focusing first and foremost on coverage with the deployment of its ‘Long-Range’ 600 MHz 5G network. The company quickly followed that up with its ‘Ultra Capacity’ 5G (2.5 GHz) network, which added the capacity and performance that users had been expecting from the next generation network and devices. T-Mobile continues to invest in expanding those two networks and improving on its undisputed 5G network leadership by adding this new potential layer of coverage.

I believe the next generation of 5G networks will incorporate NTN to increase coverage and develop new 5G use cases (though public safety, regular messaging applications and voice calls alone are enough to justify NTN). NTN could enable low-data rate, geographically isolated IoT devices to connect to a 5G network—for example, sensors to detect illegal logging, fires, landslides, etc., in remote wilderness areas. It’s unclear whether T-Mobile’s partnership with SpaceX will bridge the gap between a proprietary solution and one that is standards-based, though I wouldn’t be surprised if T-Mobile goes that direction. Either way, it will be very exciting. I can’t wait to test the service out myself in a future visit to a National Park.