MSSA Insights

Previously, we discussed Roaming and Network Sharing. In this final article of the series, we turn to service realization and how NTN enables 5G services such as voice, messaging, and data.

Service realization brings 5G experiences to space. Messaging, voice, and data services all require adaptations of terrestrial models. SMS over NAS supports IoT and emergency messaging, while IP Multimedia Subsystem-based (IMS-based) solutions enable rich communication and regulated voice calls.

For quick wins, OTT apps can deliver voice services without heavy infrastructure changes. Data services range from NB-IoT optimizations like Distributed Open Non-Access Stratum (DoNAS) to advanced 5G Core-based solutions with network slicing for premium tiers. These innovations ensure that whether you’re sending an emergency text from the middle of the ocean or streaming video from a remote location, the experience remains reliable.

Terrestrial networks alone cannot meet the demands of a world that expects seamless, always-available communication across borders, geographies, and environments. Non-Terrestrial Networks extend this foundation by filling critical coverage gaps and enabling continuity where terrestrial infrastructure cannot reach.

The MSSA Reference Architecture provides a common framework for coordination, roaming, and resource management. It enables collaboration across traditionally siloed domains, ensuring that satellite and terrestrial networks operate as a unified system rather than parallel technologies.

This shift marks a transition from isolated coverage solutions to a truly integrated global connectivity fabric. Through smart orchestration, flexible architectures, and strong industry alignment, NTN will deliver reliable, high-quality service anywhere on Earth where everyone is connected to everything, everywhere through a globally interoperable communications ecosystem.

Future updates in our Reference Architecture will explore emerging topics and provide deeper insights into areas introduced in this first release. If you have questions or want to connect, visit:
https://www.mss-association.org/contact-us/.

Previously, we discussed Resource Management in NTN. Now, let’s examine how network selection, ID management, and roaming agreements enable global connectivity.

Network Selection and Network ID Management

Managing connectivity across multiple satellite orbits and inclinations is challenging. These multi-orbit constellations create Earth-fixed cells of varying diameters, which impact traditional tracking area (TA) and routing logic (RA). To keep users connected seamlessly, networks need dynamic beam size adjustments, multiple PLMN ID broadcasts for flexible Satellite Network Operator (SNO)/Mobile Network Operators (MNO) relationships, and ephemeris information sharing (SIB19) for accurate positioning. These capabilities ensure devices can attach to the right network and maintain service continuity even as satellites move.

Roaming adds another layer of complexity. Smooth transitions between terrestrial and satellite networks require IPX agreements for interconnection and business-rule-based priorities to manage traffic and access across borders. Frequency management is also critical. Satellites must adapt bands and channels to border conditions to comply with local licenses. By combining strategic policies with advanced technical features, NTN can deliver a truly global 5G experience without compromising reliability or compliance.

Roaming and Network Sharing

When subscribers move beyond their home network footprint, agreements between SNOs, Mobile Satellite Service (MSS) licensees, and MNOs become critical. These agreements define how connectivity is maintained, how subscriber accounts are managed, and how billing and service priorities are handled. Different models exist, including MSS-to-MSS roaming, MSS-to-Satellite Service Provider arrangements, and cross-border setups between MNOs and MSS licensees. In order to provide a seamless roaming experience, networks must support multiple PLMN IDs so devices can attach to the right operator, and IPX agreements are needed for secure interconnection between roaming partners.

Continuity in subscriber session transitions is also critical where users can switch from terrestrial to satellite connectivity without interruption. Combined with dynamic network selection and frequency management along the borders, roaming in NTN isn’t just about coverage; it’s about building a global ecosystem of agreements and technologies that keep people connected everywhere.

In parallel, network sharing becomes a strategic lever to optimize scarce spectrum and infrastructure. While gateway-level multiplexing offers a baseline option, greater value is realized through mutualized RAN approaches such as MOCN/MORAN and network slicing combined with RAN sharing. These models are preferred because they allow tighter integration with the beam arbitrator and Layer-2 scheduler, enabling more efficient resource allocation and consistent QoS across shared environments. Practical models for roaming, network sharing, and collaboration between operators are necessary for cost-effective deployment and rapid global scaling. These approaches reduce infrastructure duplication and facilitate broader service availability.

What’s Next:
We’ll explore MSS Reference Architecture: Service Realization and how NTN brings 5G services like voice, messaging, and data.

In our previous post, Enabling End-to-End Service Delivery, we explored MSSA’s role and introduced our Reference Architecture, including how we address each component within the service chain to enable end-to-end service delivery. Today, we’ll dive into Resource Management: how satellites balance power, bandwidth, and coverage to deliver seamless service.

Resource Management: Doing more with less.

Unlike terrestrial networks, satellites operate with tight power budgets, limited bandwidth, and constrained processing capacity. Making the most out of limited resources is crucial in NTN communication. Satellites can’t power all their beams simultaneously, and they also face limitations on beamforming, potential interference, and bandwidth. In reality, only 10-20% of beams can be active at full or reduced power at any given time.

As a result, strategies for beam hopping (shifting coverage to where it’s needed) and frequency/time reuse (dynamically allocating power, bandwidth, and beams based on demand while reducing inter-system interference) need to be in place. Other approaches, like beam forming and satellite tracking (mapping Earth-fixed cells to moving satellites), should also be considered to help coordinate beams and keep systems running smoothly without overhauling the entire New Radio (NR) architecture.

Mitigating these constraints can be accomplished by optimizing beam hopping with a mandatory beam arbitrator (multi-cell scheduler) to reduce overhead and optimize NR cell signaling (SSB/SIB/PRACH and paging/random access periodicities).

What’s Next:
Next, we’ll look at MSS Architecture: Roaming and Network Sharing in NTN ‒ how agreements and technologies keep people connected everywhere.

In our previous post, we introduced the paradigm shift driven by NTN [read here]. Today, we’ll focus on MSSA’s mission and our Reference Architecture, the blueprint for seamless global connectivity.

The Mobile Satellite Services Association (MSSA) and its members advance and promote the value of satellite communications in the mobile satellite bands for everyone and across all applications. This includes enabling seamless global mobile connectivity by integrating terrestrial and satellite networks (non-terrestrial, or NTN) in a way that facilitates innovation, choice, and competition.

The MSSA Reference Architecture contributes to the development of a unified and accessible global communications ecosystem, enabling robust mobile connectivity and a consistent user experience regardless of location. It establishes best practices that span the entire spectrum of service delivery, which includes satellite constellations, ground infrastructure, and mobile devices, along with detailing the service delivery. MSSA ensures that the growing demands for high-speed, reliable, and secure connectivity are met effectively by addressing each component within the service chain.

Mobile Satellite Services (MSS) are represented as an integrated value chain covering the four main segments listed below:

• Space Segment: Consists of a satellite constellation that delivers coverage, capacity, and reliability by relaying communications between user devices and the ground network.

• Ground Segment: Includes gateways, Network Operations Centers (NOC), Satellite Control Centers (SCC), and cloud-based platforms connecting satellites to terrestrial networks.

• User Segment: Encompasses a range of devices, from smartphones and wearables to IoT sensors. The architecture of these devices is designed with mass-market devices in mind that typically feature constrained power and limited antenna capabilities. This reinforces the need for system-level optimization to achieve robust real-world performance.

• Service Layer: Delivers connectivity beyond the reach of terrestrial networks and supports both consumer and enterprise use cases provided either via MNO partnerships or direct-to-consumer service offering for voice, messaging, SOS, location, and data. Mission critical and monitoring communications are provided by enterprise IoT across key industries.

The diagram below depicts the satellite services delivery components.

This end-to-end approach lays a foundation for the broad adoption of satellite-enabled connectivity solutions, which enhances interoperability among diverse networks and systems. Through the implementation of these practices, operators and stakeholders benefit from greater reliability and seamless integration, which are essential for expanding connectivity to any device, anytime, anywhere.

Powering 5G from Space: The 4 Pillars of 5G Satellite Networks

Delivering 5G through satellites isn’t just rocket science; it’s a balancing act. Non-Terrestrial Networks are transforming global connectivity. NTN extends mobile connectivity to places where fiber and towers can’t reach. So how do they keep your connection seamless while orbiting hundreds of kilometers above Earth?

The answer lies in delivering four critical network functions that create the backbone of NTN architecture. We’ll take a closer look at what each network function entails, highlighted in the MSS Reference Architecture.

What’s Next:
In our next article, we’ll dive into Resource Management in NTN: how satellites optimize limited resources.

Welcome to our new article series exploring the future of mobile connectivity through Non-Terrestrial Networks (NTN) based on the Association’s MSS Reference Architecture. This series dives into how satellite and terrestrial networks are coming together to deliver seamless global connectivity, why it matters, and what’s next.

Introduction

The telecommunications industry has experienced a significant paradigm shift driven by the emergence of NTN. NTN is reshaping the way mobile connectivity is perceived and implemented across the globe. Satellites were once viewed as niche infrastructure, reserved for specialized user equipment or terminals. Today, satellites have now become an integral part of mainstream connectivity solutions. Satellite solutions are currently recognized as a logical extension of existing terrestrial networks.

Demand for resilient, seamless global connectivity is accelerating the adoption of advanced NTN solutions, including Direct to Device (D2D) and IoT. These capabilities are essential for delivering broad, reliable coverage whenever it’s

needed and providing strong value across consumer, business, civilian, government, and defense end users.

Realizing the full potential of NTN requires more than just technological innovation but also achieving alignment among stakeholders to effectively unlock future opportunities in satellite-enabled communications.

What’s Next:
In our next post, we’ll explore the MSS Reference Architecture: Enabling End-to-End Service Delivery — the foundation for global interoperability.

Our Insights section is expanding with new content that dives deeper into real-world applications – from consumer, commercial, civil and government applications globally – on land, in the air, and at sea. This latest addition introduces the first use case in a series that will spotlight innovative solutions from MSSA member companies successfully integrating terrestrial and satellite networks. We start with Ericsson’s milestone achievement in space connectivity.

RESOURCES:

MSSA Technical Document: MSS Reference Architecture

Ericsson press release: Ericsson, Qualcomm, and Thales Alenia Space reach milestone in space-based connectivity

MSSA Filing: MSSA Presents at CITEL MSS_D2D_IoT Case Studies 2 June 2025

The mission to bridge the gap between terrestrial and satellite networks is powered by the visionary leadership of our Members. Our MSSA Committee Chairs and Vice Chairs – representing a powerhouse of satellite operators, mobile network operators (MNOs), and chipset vendors – serve as the architects of this new frontier. These leaders anchor the Association’s core pillars: the Technical, Regulatory, Strategy, and Marketing Committees.

By steering specialized workstreams like the MSS Reference Architecture Work Group, they don’t just manage meetings; they facilitate the vital  technical specifications and best practices that ensure the industry remains aligned on 3GPP standards and the strategic use of L- and S-band spectrum. This collective expertise creates a unified voice to facilitate innovation, choice, and competition.

This collaborative leadership is the primary catalyst for accelerating the development and global integration of open, interoperable Non-Terrestrial Network (NTN) solutions. Through these strategic initiatives, MSSA is actively  dismantling the barriers to seamless global roaming and sparking a viable marketplace for high-performance cellular-like services anywhere on Earth. Our Committee work does more than enhance regulatory frameworks: it ensures that advanced NTN services are scalable, sustainable, and ready for mass-market adoption – delivering the highest possible value to consumer, business, civilian, government, and defense end users.

Interested in contributing your expertise to this transformative effort? Join our mission to help shape the future of global connectivity, sign up for our Interest List, and follow us on LinkedIn.

Stay tuned for future Insights focused on each MSSA Committee!