Alpha Sagittarius

Product name: Alpha Sagittarius

Team leader: Đani Vrsalović


The project is secure and reliable long-range and bandwidth wireless communication based on the standard WiFi protocol, and serves to solve the problem of establishing the infrastructure to offer services for the management of autonomous robotic systems.

The system was prototype-proven through 2020, with a successful demonstration of high-resolution video and real-time video transmission over a distance of up to five kilometers.

The project serves to build network infrastructure and connect all types of autonomous unmanned systems. With technological advances, the possibility of using autonomous robotic systems to perform tasks that have so far required humans is becoming more present.

The main task of the project is to enable broadband communication between the control station and the mobile element of the system over long distances within the visual circle (VLS - Visual Line of Sight) of the horizon. In the case where geography is not the limiting factor, with the antenna at a height of two meters above the horizon, the distance is 5 kilometers. If natural geographical elements are used, for example a hill one hundred meters high, the range is then over 35 kilometers. Bandwidth is defined by the need for a real-time high-definition (Full HD) video signal communication channel.


Security is reflected in the 256-bit encryption of the control station and the robot, which with today's available tools is impossible to compromise in real time. Encryption is software built into the standardized WiFi protocol.


The system consists of two main elements, the control part and the robotic part.

The control part consists of a control computer with a user interface adapted to the needs of the task, and a directional antenna with multiple broadband channels for high bandwidth connected to a high-gain WiFi radio device.

The mobile, robotic part consists of another part of a pair of radio devices, with a spherical antenna that transmits a signal to the control station.

Reliability is defined by the robustness of the communication system in the ability to maintain stable communication and in conditions of poor signal propagation, interference from external sources of electromagnetic radiation (other radio sources, antennas, etc.). The system autonomously defines the criteria to be used for the communication channel, based on implemented algorithms based on artificial intelligence and interference pattern recognition. An additional element of reliability is the integration of different redundant frequency channels. For example, the system in the basic configuration operates at a frequency of 5.8 GHz, but can also operate at 2.4 GHz, 1.3 GHz, or other installed.

The supporting elements of the system are a satellite navigation module that reads the position of the robot and serves to direct the beam of the control antenna, and a rotator mounted on the antenna system bracket. Optional elements of the system are software-defined radio (SDR) which can be used to set additional communication options, but also as a sensor for the detection of other emission sources in the radio spectrum.


The system enables almost real-time data transmission, where the only delay (latency) in communication is the physical delay of signal propagation from one terminal to another, and never exceeds 250 milliseconds, which is considered a real-time transmission system. This is an important fact because it allows remote control of autonomous systems in real time, thus achieving a factor of human control in any situation. Through software development with its own solutions, open source software has been upgraded to enable the simultaneous sending of video signals from control channels (telemetry) through a single communication channel.

The communication system does not require a license to operate. All radio channels and electromagnetic spectrum used are within the frequency range that do not require a special permit from the Croatian Network Regulatory Agency, the competent authority in charge of activities in the so-called. ISM range. The only exception is in the case when a very large range is required, for which it is necessary to seek permission to increase the output power of the transceiver. The system is completely based on the WiFi standard, which is thoroughly documented and is the basis of digital communication. All equipment used in the system is commercially available on the market and does not require additional certification.


A project can be both a product and a service. In the case of products, a complete system with accompanying equipment, hardware and software, and documentation is supplied.

In the case of the service, these are mostly clients who do not have the need to use the equipment permanently, or do not have trained staff who can manage the equipment. Then the equipment and / or operator is hired, on an hourly basis or on a work assignment basis.

Founded: 2018.

Company name: Alpha Sagittarius d.o.o.

Team members:

Mirko Borovac: Bachelor of mechanical engineering, development of mechanical component. Winner of the Rector's Award of the University of Split 2018 and 2019. Semi-finalist of the Ericsson Innovation Awards 2018. Knowledge of software for CAD / CAM design.

Matej Šalinović - Bachelor of Electrical Engineering, Development of Electrical Component. Lecturer / mentor of robotics in the IRIM Croatian Makers League. Winner of the Rector's Award of the University of Split 2018. Production of PCB logic circuits, control and automation of equipment. Marine equipment repairman. Quality control. Knowledge of software for system element simulations.

Josip Wolf - Bachelor of Electronics, Development of Embedded Electronics and Software. Experience in software development in Python, C, C ++, Lua, Java programming languages. Setting up network IT systems. Production of control units, programming of micro controllers. Real-time aircraft control.

Đani Vrsalović - company director, project planning, finance. Graduated in mechanical engineering, doctoral student in mechanical engineering at the University of Split. 15 years of experience in the process industry, commissioning of working machines and equipment.


Address: Vrboran 45, Split


Media: Splitski dron na tržište će 2021. Nova hrvatska bespilotna letjelica uskoro stiže na tržište