Furuno Electric Co., Ltd. (Headquarters: Nishinomiya, Hyogo Prefecture; President and CEO: Yukio Furuno; hereinafter "the Company") plans to begin sales of its new dual-band GNSS frequency standard generator (GNSSDO※1) "GF-100 Series (models: GF-102 / GF-103 / GF-105S / GF-105G)" in November 2026.
Product Lineup
KEY FIGURES
Model
Form Factor
Holdover (24h)
Output
Features
GF-102
Short
±20μs
10MHz, 1PPS
Combines fundamental performance with cost-effectiveness
GF-103
Short
±5μs
10MHz, 1PPS
Popular model chosen for a wide range of applications
GF-105S
Short
±1.5μs
10MHz, 1PPS
Delivers top-tier performance in a compact enclosure
GF-105G
Grande
±1.5μs
10MHz, 1PPS
Ideal replacement for GF-8805
Release Date
November 2026 (planned)
Background
GNSS-based time synchronization is a foundational technology for critical infrastructure supporting society, including telecommunications, power, finance, and broadcasting. While these infrastructures rely on precise timing, recent years have seen growing real-world threats to GNSS signals from interference (jamming※2) and spoofed signals (spoofing※3). In such environments, robustness—ensuring service continuity even during disruptions—is essential. Traditional holdover functionality was primarily designed for GNSS signal loss due to events like lightning-induced antenna failure. However, in cases of jamming or spoofing, receivers may continue to lock onto abnormal signals, rendering conventional systems insufficient. The GF-100 Series actively detects such GNSS signal anomalies and autonomously switches to self-sustained operation (holdover) using its internal oscillator, thereby avoiding adverse effects from abnormal signals while maintaining stable time synchronization. The GF-100 Series adopts a multi-layered defense design (Defense in Depth) to protect against various threats, ranging from routine signal degradation to intentional interference. Furthermore, numerous devices require precise time synchronization, including commercial radio base stations, PTP grandmaster clocks, broadcast equipment, and power monitoring systems. GNSSDOs integrate a dual-band GNSS receiver and a high-precision oscillator into a single module, enabling equipment manufacturers to incorporate time synchronization capabilities—including countermeasures against GNSS vulnerabilities—without developing them in-house. The GF-100 Series contributes to improved development efficiency and faster time-to-market for such manufacturers.
Main Features
1 Active Holdover upon GNSS Signal Anomaly Detection
When signal anomalies such as jamming or spoofing are detected, the device automatically switches to holdover mode, maintaining stable time synchronization without being affected by abnormal signals. This function can be enabled or disabled based on operational requirements. The design extends beyond conventional responses to antenna failures, enabling proactive handling of intentional radio interference.
Illustration of Active Holdover Operation
2 L1 / L5 Dual-Band Reception with Independent L5 Search
In contrast to conventional L1 single-band reception, the GF-100 Series supports L1 / L5 dual-band reception. It features an independent L5 search function that does not rely on the L1 band, allowing continuous time synchronization via the L5 band even when L1 reception conditions deteriorate.
3 GNSS Signal Authentication (OSNMA / QZNMA)
Supports Galileo's signal authentication feature "OSNMA※4" and QZSS's "QZNMA※5." By verifying the authenticity of received GNSS signals, it reduces the risk of timing errors caused by spoofed signals.
4 Dynamic Satellite SelectionTM※6
Dynamically selects satellites with high signal quality in urban multipath※7 environments, maintaining high-precision time synchronization performance.
5 T-RAIM (Time Receiver Autonomous Integrity Monitoring)
Continuously evaluates the reliability of satellite signals used for time synchronization and automatically excludes abnormal signals.
6 Compact Design and Hardware Compatibility
Available in two form factors: Short (34×27×15.5mm) and Grande (100×52×14.1mm). Previously, the top-tier holdover performance of ±1.5μs/24h was only available in the Grande form factor (GF-8805). The GF-105S achieves equivalent performance in the Short form factor, reducing installation area by approximately 80%. All models maintain hardware compatibility with the current GF-88 Series, enabling easy replacement in existing equipment.
Recommended Antenna
Pairing with the multi-GNSS timing antenna "Model: AU-500" maximizes the performance of the GF-100 Series. The "Model: AU-500" features high noise resistance and IP67 environmental protection.
Reference: Participation in Jammer Test
Furuno has been participating continuously since 2024 in the international GNSS vulnerability verification event "Jammer Test," held in Andøya, Norway. This event evaluates the resilience of GNSS receivers under real jamming and spoofing conditions. In September 2026, Furuno plans to conduct field tests to verify the robustness of the GF-100 Series in real-world environments. The GF-100 Series incorporates insights gained from previous testing.
Image of Multi-GNSS Timing Antenna "Model: AU-500" During Jammer Test Evaluation
Going forward, Furuno will continue to support the stable operation of social infrastructure such as telecommunications, broadcasting, and power systems through GNSS and time synchronization technologies, contributing to the realization of a safe, secure, comfortable society and maritime environment that is friendly to people and the planet.
※1 GNSSDO: Short for GNSS Disciplined Oscillator. A device that uses GNSS signals to control a high-precision oscillator, outputting stable frequency and time signals.
※2 Jamming: The act of transmitting interfering radio waves to disrupt GNSS signal reception. Includes not only intentional interference but also radio waves from nearby communication equipment that may interfere with GNSS signals.
※3 Spoofing: The act of transmitting false GNSS signals to cause receivers to calculate incorrect position or time information.
※4 OSNMA: Short for Open Service Navigation Message Authentication. A signal authentication feature provided by Galileo.
※5 QZNMA: Short for Quasi-Zenith Navigation Message Authentication. A signal authentication feature provided by QZSS.
※6 Dynamic Satellite SelectionTM: Multipath-resistant technology based on an algorithm developed by NTT.
※7 Multipath: A phenomenon where satellite signals reflect off buildings or other structures, arriving at the receiver via multiple paths. This degrades time synchronization accuracy.
Related Links
GF-100 Series Product Page
https://www.furuno.com/jp/products/gnss-timing/gf-100/index.html
GNSS Receiver Website
https://www.furuno.com/jp/gnss/
Jammer Test Participation Report
https://www.furuno.com/jp/gnss/column/202501-01/
※The information contained in this release is current as of the date of announcement and is subject to change without prior notice.
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Furuno Electric Co., Ltd.
Since achieving the world's first practical fish finder in 1948, Furuno has continuously introduced numerous world-first and Japan-first products in the marine electronics field, leveraging its proprietary ultrasonic and electronic technologies. Today, the company has established a sales network in over 100 countries and solidified its position as a leading global manufacturer of marine electronics.
Furuno Electric Co., Ltd. R&D Building "SOUTH WING"
Headquarters: Nishinomiya, Hyogo Prefecture
Founded: 1951 (Showa 26)
Business: Manufacturing and sales of marine and industrial electronic equipment
Capital: 7,534 million yen
Employees (consolidated): 3,411
Sales (consolidated): 140,616 million yen
President: Yukio Furuno
Listed on: Tokyo Stock Exchange Prime Market
FACT BOX
- Source: PR TIMES
- Category: 製品発売
- Organizations: NTT / Galileo / QZSS