Combining mobile and satellite networks

What are the main challenges in combining satellite and terrestrial networks?

This is a contributed article by Noemí de Hevia Méndez, Lead Telecoms Consultant at CGI UK

There are currently 8 billion mobile accounts globally, and data demand is increasing. With 5G commercially available, users expect to have the same quality of internet experience anytime, anywhere. As networks are rolled out, they will extend wireless connectivity beyond the people, to support the connectivity for everything that may benefit from being connected.

Until now, the only real option outside the coverage areas has been to use heavy, dedicated and expensive end-user satellite solutions. New developments in the satellite communications eco-system have overcome previous limitations, including (1) a new generation of Low Earth Orbit (LEO) constellations (dramatically reducing latency in satellite communications), (2) technical advances in Geostationary (GEO) satellite which provides high throughput with the same amount of allocated frequency on orbit, and (3) improvements in GEO satellites make them more robust than ever before. As a result, the gap between terrestrial and satellite has been closing. Satellite is increasingly considered as a cost-effective network communications alternative.

There has been a steady convergence between mobile and satellite networks. The satellite industry has historically tended to focus on improvements to backhaul, finding ways to integrate satellite technology into the prevalent standards and technologies. Today, 5G standards define common network architecture, "a network of networks", to which all access technologies can adhere.

In this context, satellite should no longer be seen as a separate, standalone network. Rather, satellite is increasingly being used as the most cost-effective backhaul alternative. There is increasing interest and participation from 3GPP into the satellite communication industry, with companies and organisations convinced of the market potential for an integrated satellite and terrestrial network infrastructure, in the context of 5G. The roles and benefits of satellites in 5G have been studied since 3GPP Release 14 in 2016, although the technical specifications are still yet to be released. It is expected that future versions will include new standardisation of satellite in mobile networks, starting from 3GPP Release 16 later this year.

CGI has been supporting the development of complex, mission-critical space solutions, enabling satellite navigation and communications as well as terrestrial telecommunications network management systems. The integration of 5G and satellite technologies is an opportunity for CGI to support the transformation of communications.

Typical scenarios for satellite in 5G

There are two main scenarios for delivering satellite and 5G: the satellite proves the backhaul connection for a local terrestrial 5G Radio Access Network (RAN) and the satellite provides a RAN with direct 5G links to mobile users, in this last arrangement satellite acts as a gNodeB.

Satellite backhaul offers unique characteristics in terms of its practically universal availability and rapid deployment times. In addition, off-loading traffic from the terrestrial system to the satellite opens up the possibility of improving resilience and security using the two networks.

Future 3GPP standard releases will include direct 5G connectivity to mobile users, offering a connectivity alternative to rural and hard to reach areas. Moreover, it is easier to cover mobile sites with satellite links, especially for aeroplanes, trains, boats and other vehicles that frequent regions of the planet traditionally beyond the reach of cellular companies. Another notable service where satellite has an advantage is multicast/broadcast, avoiding propagation latency issues with intelligent caching.


The integration of satellite components brings new requirements and challenges in deploying 5G systems. Starting with the competition for use of radio spectrum as well as the regulatory and technical requirements to help ensure smooth handovers between satellite and terrestrial networks and the device consequent feature support across the ecosystem.

Moving to the operational area, a unified management of hybrid terrestrial-satellite 5G networks it is required for monitoring and management of both terrestrial and satellite radio interfaces. Another notable requirement is traffic management and orchestration to achieve expected E2E performance with quality of service.

To achieve such goals, new planning, design and operation skills and tools need to be developed to integrate satellite-terrestrial 5G networks.

Some 5G enablers for satellites

Equally, new technology is emerging that will help to tackle these challenges. One of the main ones is the development of new LEO satellite constellations reducing satellite latency, for example, LeoSat, OneWeb and Starlink. Satellite network virtualization, via the introduction of techniques such as Software Defined Networks (SDN) and Network Function Virtualisation (NFV), simplifies network management and offers new flexible services to more customers. ‘Cloudification' of satellite management functionality using COTS products and satellite network slicing offer new services and access to new markets. The development of new radio interfaces, including the possibility for dynamic traffic steering based on Quality of Service (QoS) and Mobile Edge Computing (MEC) create an opportunity for satellite as a distribution mechanism and offsetting concerns about latency.

CGI is developing a range of solutions which enable network operators to quickly and efficiently design and optimise 5G networks with the use of satellites. By focusing on the benefits of satellite networks, we help open up the market for 5G by demonstrating that satellite networks can be brought into the system efficiently and quickly - to benefit both network operators and end users.

Noemí de Hevia Méndez is the Lead Telecoms Consultant at CGI UK. She has held technical, commercial and budget management roles in the wireless telecom industry for the past fifteen years, working in Spain, USA and the UK. She has in depth experience of Mobile Radio Access Networks having worked in various roles for Ericsson, Orange, Vodafone and DG Cities.