The mobile and satellite industries progressed along parallel path, rarely intersecting. This is because neither side could satisfy the value creation needs of the other side [see here]. However, there is a renaissance in satellite communications brought about by high-throughput satellites and improved launch economics. Entrepreneurs from outside the industry like Elon Musk and Jeff Bezos are planning terabit-sized low-earth orbit (LEO) constellations. On the other side, the economic promise of 5G made it central in a trade war between the US and China! Academia is already researching the intersection of satellite and mobile communications under the banner of 6G. So with these developments, what are the opportunities for mobile-satellite intersect in the short and medium terms?
Mobile-Satellite Application Intersect
The mobile-satellite intersect will require identifying applications that drive business revenue. The 3GPP made such an attempt in order to identify requirements and develop the standard towards meeting them. Unlike the past, satellite companies are actively participating in these proceedings. To understand the possibility of intersect, we analyzed the 12 use cases identified by 3GPP for the satellite-mobile intersect:
| Use case | Challenges to address |
|---|---|
| Roaming between terrestrial and satellite networks | Private networks including those based on non-3GPP provide an alternative that is highly competitive with 5G. Solution is feasible. |
| Broadcast and multicast with a satellite overlay | A user device would be burdened with additional cost to support satellite access raising the issue of lack of standardization in the satellite segment. |
| Internet of Things with a satellite network | Additional cost and power consumption on the user devices. Requirements for LEO network with NB-IoT and mMTC support requires careful analysis of the business case. |
| Temporary use of a satellite component | Satellites don’t support the 5G air interface so requiring user devices to support satellite air interface is a regulatory issue. Alternatives are available. |
| Optimal routing or steering over a satellite | Alternatives are available. Use case requires increasing cost of user device to support added functionality. |
| Satellite trans-border service continuity | Requires regulatory approvals. Additionally user device needs to support the satellite air interface which adds cost and is fragmented |
| Global satellite overlay | Requires connectivity among satellites which some planned constellations will provide. |
| Indirect connection through a 5G satellite access network | Raises issues related to roaming and charging as well as regulatory questions. Technology exists today. |
| 5G fixed backhaul between NR and the 5G Core | Price and availability of competitive options to satellite. |
| 5G moving platform backhaul | Satellite backhaul is a good fit for this application. |
| 5G to premises | Connecting the unconnected is a traditionally hard business case to rationalize. 5G + satellite will not solve it! |
| Off-shore wind farms | Alternative technologies are available. |
The Challenges
The identified mobile-satellite applications uncover a number of challenges:
- The satellite industry lacks standards. Unlike the mobile industry where technical specifications govern product development, the satellite industry does not have interoperable systems. This will work to gate the integration between the two industries.
- The mobile-satellite intersect will depend highly on the context of the use cases. There are competitive options for both sides which offer a better business case. Hence, the mobile-satellite intersect will need to demonstrate its competitive worthiness.
- Use cases requiring a satellite radio access technology similar to that of terrestrial 5G network place restrictions on satellite networks. These use cases lead to different deployment model than current planned or existing constellations.
- Use cases built on the integration of satellite technology into user handsets create challenges: cost, power consumption, business models and ecosystem support.
Our analysis shows that transport (backhaul) remains the main use case that will govern the interaction between the two industries in the short and medium terms. Transport over satellites will benefit from lower prices which consequently will benefit the deployment of cellular network and private wireless networks.
Additionally:
- Satellite transport will not help 5G deployments in urban areas where lower cost transport alternatives than satellite are available.
- Satellite offered capacity remains at the low-end of 5G mobile backhaul requirements. Mid-band (2.5 and 3.5 GHz) and millimeter wave (28 GHz) 5G spectrum features wide channels (100+ MHz) leading to high throughput.
- There is a need to integrate satellites with 4G networks which will remain serving billions of subscribers for years to come.
Collision Ground
As mobile spectrum allocations push into higher frequency bands, it will lead to greater collision between the two industries. This is not a new development. It traces to WRC07 when mobile operators unsuccessfully pushed for shared spectrum access in the C-band. In WRC15 mobile operators made a failed attempt at the 28 GHz spectrum. The standoff will continue at WRC19.
For additional information on what to expect from the deployment of LEO satellites see: The space internet race is dawning: Here’s what to expect.