FASST is Futaba's inaugural 2.4GHz system, uniquely designed for RC systems. It incorporates industrial-class spread spectrum processing ICs and establishes a secure 2.4GHz link in crowded radio environments using a Hybrid Spread Spectrum system. This sets it apart from competitors who struggle to maintain stable RF links.

Second Generation Frequency Hopping Spread Spectrum

S-FHSS is a simplified version of the FHSS protocol developed by Futaba for use in entry-level and mid-range RC models. This allows for up to 8 channels, S-FHSS offers reliable radio communication with fast response times and good range. S-FHSS receivers are compatible with select Futaba transmitters equipped with S-FHSS technology.

Second Generation Frequency Hopping Spread Spectrum

S-FHSS is a simplified version of the FHSS protocol developed by Futaba for use in entry-level and mid-range RC models. This allows for up to 8 channels, S-FHSS offers reliable radio communication with fast response times and good range. S-FHSS receivers are compatible with select Futaba transmitters equipped with S-FHSS technology.

T is for "Third"

T-FHSS is next generation system of S-FHSS that employed the telemetry communication.

Practical performance such as effective radio range is comparable to FASSTest, and you can enjoy flights using telemetry sensors with peace of mind.

However, it does not have the 12-channel mode that FASSTest is equipped with, so it is a reasonably priced system for those who do not need that much functionality.

T is for "Third"

This mode is a car system with faster response than normal (T-FHSS) mode and controls of up to 4 channels. To minimise the latency this mode does not have telemetry. You can select ON/OFF of SR mode for each CH port of the receiver. Also, when SR mode is ON, please use a servo that supports SR mode. When SR mode is OFF, it is digital servo-only mode.

Futaba's F-4G mode is recognized as the fastest response setting in their car system.

The critical factor in enhancing response speed involves accelerating the cycle at which information about steering, throttle, and other radio control actions is sent to the receiver. To address this, Futaba's 2.4GHz system for cars has progressed from the FASST series C1 and C2 to variations of the FHSS series, culminating in the T-FHSS SR mode. However, Futaba aimed to further improve response times by reevaluating the signal processing method from the ground up, successfully developing a new system named "F-4G."

F-4G delivers approximately twice the response speed of the T-FHSS SR mode. This improvement sharpens the sensation of "on the rail" driving, where, in high-speed races, the travel distance while maneuvering is halved compared to the previous system, greatly enhancing the precision of following the desired path.

Moreover, the F-4G compatible receiver utilizes a diversity system with two antenna setups to significantly reduce the chance of reception interference. The selection algorithm for these antennas has been optimized specifically for automotive environments to ensure optimal signal reception under the dynamic conditions encountered while driving. This maximizes the performance of the F-4G system. The full potential of F-4G is also unleashed when used with servos that support "UR (Ultra Response) mode."

Futaba has effectively halved the time required for signal transmission, further refining the sense of precise control.

By shortening the transmission cycle and employing the diversity system, a faster and more reliable response is guaranteed. Unlike the previous fastest mode, T-FHSS SR, which did not support telemetry, F-4G includes this feature.

The receiver's 1-4 channel ports are individually configurable for analog, digital, SR mode, or UR mode settings. Additionally, it supports control of up to 10 channels, the maximum for a car controller.

The Model ID function serves as a safety feature that prevents the receiver from responding if model data with settings that do not match the aircraft is mistakenly selected.

Each transmitter, also referred to as a radio, is assigned a unique ID code at the manufacturing stage, and the receiver can memorize this ID code through a "link operation." As a result, the receiver accepts signals only from the linked transmitter, effectively preventing interference issues between RC models at the same flying field. This setup eliminates the need for traditional frequency management methods like "frequency pins," enhancing operational reliability. This technology is equipped in all Futaba 2.4GHz transmitters, ensuring that there are no glitches or signal overlaps when multiple RC models are operated in the same area.

Dual receiving antennas contribute to keeping the best-receiving capability under various situations like wiring shading, the reflection of radio waves, etc.