Spacebridge Re-enters RF Business

by Elizabeth Tweedie

Montreal, Canada, March 4, 2025--According to Yole Group in the report “Market and Technology Report: RF GaN” the market for radio frequency gallium nitride (RF GaN) devices is expected to grow to US$2.2 billion by 2029, a Compounded Annual Growth Rate (CAGR) of 10% from 2023.  Though Satcom represents only 10% of the RF GaN market, the market for Satcom GaN devices is forecast to exceed that growth, with a CAGR of 13.7%, to reach US$220 million by 2029, up from US$102M in 2023.  This accelerated growth is attributed to both the increased use and competitiveness of GaN , as opposed to gallium arsenide (GaAs) in ground systems and the proliferation of LEO systems. 

David Gelerman, owner, President and CEO of SpaceBridge, is recognized as the innovative pioneer who introduced GaN technology into Satcom over 20 years ago. Although he exited the RF business, via an asset and intellectual property sale in 2018, he remained involved in the industry and launched SpaceBridge Inc. the same year.  SpaceBridge is a VSAT ground equipment vendor focused on deploying DVB-RCS2 TDMA solutions to satisfy broadband needs of enterprise, cellular backhaul and government/military customers.  

Nevertheless, encouraged by growth in Satcom GaN technology, David turned attention back to RF and initiated efforts to design 3rd generation GaN empowered amplifier products.  As a result of these efforts SpaceBridge is re-entering the RF business with a full suite of products addressing C, Ku and X-bands. The BUCs target all frequency ranges from low to Ultra High Power. Ranges, providing an alternative to Traveling Wave Tubes (TWTs). 

 This year’s new product release comes on the heels of 2024’s launch of the ESTELLA VSAT platform. Described as “a transformative satellite communications solution,” Estella is an “all-in-one” highly flexible solution designed to fit the needs of many different market segments.  Traditional hubs take up a minimum of one complete rack, Estella, with its small footprint, requires only two rack units, meaning far lower power consumption and cooling requirements.  The real innovation however, lies in the software.

Estella is an “all-in-one” highly flexible solution designed to fit the needs of many different market segments.  It combines 3D multi-frequency time division multiple access (MF-TDMA), with dynamic single channel per carrier (SCPC) and burst mode-frequency division multiple access (BM-FDMA).  Each of these technologies have advantages, but come with trade-offs.  

TDMA assigns specific fixed time slots to individual terminals so that the total bandwidth can be shared without interference, but since the parameters are usually fixed to accommodate the most-demanding user or terminal, it doesn’t provide the most efficient use of bandwidth and comes with high overheads.  3D TDMA on the other hand, permits variable timeslot sizes enabling each remote to utilize a modulation/coding/block (MCB) size based on its needs.  

SCPC in contrast, dedicates a channel to a user, which is ideal when an application needs consistently high bandwidth, for real-time video or sustained communications, for example, but wastes a lot of capacity when used for bursty applications.  WaveSwitch, an integral part of Estella, allows remotes to be switched between dedicated SCPC carriers and shared TDMA carriers preserving full bit count integrity on a per burst interval.  

BM-FDMA or Dynamic Rate Assignment (DRA) defines the return link channel/carrier per burst to accommodate constantly changing traffic patterns.  This means that the carrier definitions are created dynamically every burst interval.  This is particularly important for applications that demand high security, as the frequency allocations are constantly changing, which makes carrier detection and interception very difficult.

SpaceBridge is re-entering the RF business with a full suite of products addressing C-, Ku- and X-bands. The BUCs target all frequency ranges from low to Ultra High Power. Ranges, providing an alternative to Traveling Wave Tubes (TWTs).

Estella essentially, optimizes bandwidth utilization by allowing the delivery of services over common bandwidth pools.  TDMA and/or WaveSwitch (SCPC like carriers) carriers are created dynamically, in order to optimize satellite performance and service delivery. In essence, ESTELLA performs network wide link budgets every 26.5 milliseconds, ensuring the system responds rapidly to accommodate network demand changes and provide protection against link degradations

Every burst interval, Estella determines whether a remote would be best served by a TDMA or SCPC link, in order to optimize bandwidth usage and network performance.  This can provide up to a 15% higher throughput compared to dedicated TDMA carriers.

This complete flexibility coupled with the inherent security characteristics of Estella means that it is suitable for a wide range of markets.  For example, for cellular backhaul, a data-centric network, Estella gives mobile network operators (MNOs) the opportunity to right-size their networks according to their specific needs.  Bandwidth sharing, traffic optimization, efficient forward/return link, and quality of service (QoS) enforcement, are just some of the characteristics of Estella suited to this market.

For a Broadband ISPs the scalability of Estella, (it can reach thousands of remotes if necessary), is a huge plus, as its ability to support oversubscribed services.  Estella also supports transmission control protocol over IP (TCP/IP), an acceleration technique that minimizes latency, so important for operators of networks using geostationary (GEO) satellites.  Similarly for large scale Enterprise Networks (bank branches, gas stations etc.) the same advantages apply.

Internet of things (IoT) networks, frequently involve massive networks spread over large geographical distances, but tend to need low data rates, unless there is an exception, when one particular remote may need to switch to high data rate.  For example, if low pressure is detected on a pipeline, it may be necessary to send a remote with a cameral to that area to locate leaks.  Estella’s cost effective, low power requirements make it an ideal hub for these networks.

Military SATCOMS is one of the key target markets for Estella, as not only is this segment growing in importance for satellite communications, the inherent features built into this hub are ideally tailored to this very demanding market segment.  For example, Estella may be deployed in geographically redundant mode.  This means that in the event of any physical or cyber threat, a remote passive hub can be brought online or traffic transferred to another (geographically distanced) active hub, minimizing critical downtime.  In addition, the inherent security features incorporated into Estella, give military users confidence that their demanding requirements will be met.  These features include: robust communications security advanced electronic signature (COMSEC AES)256 encryption on both the forward and return link, protecting transmissions from interception, and also

DRA and frequency hopping spread spectrum (FHSS) which obfuscate the return channel to defeat jamming and interference.

It is hardly surprising then, that the first user for Estella is the Chilean Ministry of Defense, a user for which performance and service delivery is critical.   In partnership with Telcoven (a global Systems Integrator), SpaceBridge announced last year that it had signed a contract with the Chilean MOD to modernize the satellite technology used by the government of Chile.  Carlos Cabrera, CEO Telcoven, Chile commented: “As the turnkey integrator for the modernization of Chile’s satellite telecommunications system. Telcoven is proud to leverage SpaceBridge’s Estella VSAT hub system.  This collaboration underscores our commitment to providing topnotch solutions for the safety and security of the Chilean people.”

David Gelerman commented: “SpaceBridge solutions are second to none. We are extremely pleased how well the market has accepted Estella and our new RF product lines and are excited to be working with our strong partners to roll out new networks and products around the world.”

It's unusual to give a hub a girl’s name and some of you may be wondering if there is a story behind this.  There is indeed.  As many of you know Stella Gelerman is also part of the SpaceBridge team.  Her name is derived from the Latin word for “star;” a beacon of light and hope that illuminates the path forward.  The hub name was chosen by SpaceBridge staff (without the input of family members), both as a tribute to Stella, who is regarded as one of the foundational pillars of the company, and recognized as being one of the forces that have shaped SpaceBridge into what it is today; and also as a representation of the fact that this hub represents the way forward for SpaceBridge, opening new markets and ways to connect.

Some people have had stars or animals named after them.  I know of only one lady who has had a hub named after her! 
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Elisabeth Tweedie is Associate Editor of the Satellite Executive Briefing and has over 20 years experience at the cutting edge of new commmunications entertainment technologies. She is the founder and President of Definitive Direction (www.definitivedirection.com), a consultancy that focuses on researching and evaluating the long-term potential for new ventures, initiating their development, and identifying and developing appropriate alliances. She can be reached at:
etweedie@definitivedirection.com