Grant: Open Research Institute – P4XT Phase 2

Date of Grant: Sept. 10, 2020
Grant Amount: $507,020

Open Research Institute (ORI) is a non-profit research and development organization which provides all of its work to the general public under the principles of Open Source and Open Access to Research.

ORI’s Multiplexing Transponder Program (P4XT) is a global constellation of GEO payloads, spaced 90 degrees apart, that will provide global amateur radio satellite service. ARDC has provided funds to support Phase 2 of this project, which will produce a number of complete transponders, including a large number of development articles. The complete transponder design leads directly to production of flight hardware in Phase 3. In addition, the project will create ground station modem designs, including a cost-optimized modem intended for volume production.

All hardware and software designs will be open source and available to the general public at no cost.

Project Goals

The goal of this project is to provide both designs and equipment for an advanced, accessible, and enjoyable amateur radio system that will operate with a 5GHz uplink and a 10GHz downlink. Modern and relevant digital communications techniques will be enthusiastically employed to create a powerful and useful communications system that all amateurs can enjoy. Many dozens of simultaneous users can take advantage of high-bandwidth digital multimedia communications. The system can be configured for thousands of simultaneous voice users. Legacy modes can be supported as well. Any uplink channel can be designated as a legacy analog mode, and the channel transported through the payload.

Reference Design

The reference design will be in GNU Radio. GNU Radio is the leading software platform for development of software defined radio. It is free and open source, enabling participation without cost to anyone interested in contributing to the project.

Many parts of the radio recipe have already been published in both GNU Radio and in WireShark, a free and open source toolchain for network and protocol analysis.

A reference design in GNU Radio allows amateurs to build stations ranging from completely hand-built to configuring commercial off-the-shelf gear. Also, we will have a manufactured radio that you can purchase. All of the ground stations are reusable and reconfigurable. They support any payload that uses the common air interface. These include payloads at GEO (Phase 4B, ORI PX4T), HEO (Phase 3E), and beyond (Lunar Orbiting Platform Gateway in coordination with ARISS).

Additionally, these radios will work as terrestrial microwave stations. Groundsats on mountaintops or towers establish a fun and flexible digital microwave experience.

The interface to the Ground Station is HTML5. This reduces software maintenance, reduces barriers to entry, and allows for remote operation.

For more information about the project, take a look at the project proposal. You can also learn more about ORI at