AGREEMENT BETWEEN DIGITAL LOCATIONS, INC. AND THE FLORIDA INTERNATIONAL UNIVERSITY BOARD OF TRUSTEES
Appendix A
STATEMENT OF WORK
Objectives and Background
Current terrestrial cellular networks are not capable of providing connectivity to users in remote locations such as in a desert or a forest, or in the middle of the ocean. In addition, hurricanes, tornadoes, and wildfires often leads to network failure. During such emergency or life- threatening situations, communicating safety instructions from rescue teams or requesting emergency services becomes impossible. Alternatively, direct satellite to phone connectivity is highly useful in disaster response and can provide connectivity all over the world.
Apple with Global Star, Lynk with AST Mobile, and T-Mobile with SpaceX have each teamed up to implement direct phone to satellite systems. Apple is using Global Stars geosynchronous equatorial orbit (GEO) satellites to enable SOS service. User’s text is received by one of the Globalstar’s satellite and sent back to a ground station which is then routed to emergency service. In ideal conditions with a direct view of the sky and the horizon, a message might take over 15 seconds to send, and over a minute to send from under trees with light or medium foliage. If the user is standing under heavy foliage or surrounded by other obstructions, a connection to a satellite might fail to establish.
T-Mobile has plans to use Starlink satellites, lunched by SpaceX, to enable direct phone to satellite communication. SpaceX has already launched many and plans to launch nearly 30,000 second generation Low-Earth Orbit (LEO) satellites that will make up its next-generation swarm in 2023. Starlink uses the X-band and is already providing internet service in many countries. But to the best of our knowledge, they have, so far, only tested the direct satellite to phone service in a laboratory environment.
Lynk launched their first satellite in 2019, as a proof of concept, and they recorded the first successful test of a cell phone link to space on February 24, 2020. So far, they have launched one satellite named as ‘’Blue Walker 3’’ on Sep 10, 2022, into the orbit. It is the largest commercial phased array ever deployed to LEO at 693 square feet in size and ~520km altitude. This satellite can provide a field-of-view of 700 miles.
Lynk’s plan is to launch mini satellites, weighing about 55 pounds (25 kilograms). They will orbit at about 310 miles (500 kilometers) around the Earth. The company can provide commercial services with just a few dozen satellites, but to provide 4G coverage, Lynk will need to launch thousands of its small vehicles. Lynk aims to launch 5 more satellites in the orbit by 2023 and 1000 satellites by 2025 to achieve a full Earth coverage. Ultimately, Lynk aims to increase the coverage density until it reaches its full constellation size of about 5,000 satellites. Lynk's satellite passes over each point on the Earth about twice per day.
The network will provide global GSM and LTE cellular services, operating in most cellular frequencies used worldwide in the 617-917 MHz band. AST talked a lot about its goal of connecting regular mobile phones via its satellite network, offering 30 Mbps and talking about indoor coverage. The expectation was criticized by Tim Farrar from TMFAssociates, saying it is little too high.
Our approach
Apart from the Starlink’s internet service (using X-band), the available direct satellite to mobile service is extremely slow, just enough to send emergency notification when the user is under the open sky or when there are minimal obstructions.
Phase 1 Tasks and Deliverables
During Phase 1, FIU team (PI Alwan, co-PI Madanayake) will carry out the following efforts. Task timelines may overlap as needed.
Task 1: In-depth study of commercially available direct phone to satellite technologies (2 months). The outcome of this study will help us identify the specific sub-6 GHz band and the mmWave band that will be adopted in this effort. Task 1 deliverable will be a report that will help establish a baseline for performance and system parameters from future systems based on public
domain sources. Additionally, inspired by NSF’s ICORPS program, without divulging technological solutions, we will reach out to potential customers of the proposed technologies to conduct interviews designed to test hypothesis on the problem solution fit so that our envisaged technologies are designed to attack real world problems and we can be reasonably sure there is a market for the technology.
Deliverables: The project will furnish a final report, covering findings from the customer outreach activities and literature survey, as well as preliminary mathematical and computer-based simulation modeling of new types of antenna arrays and radio architectures that may result in a significant expansion of the state-of-art in mmWave high-capacity wireless communication systems for future applications across distances of up to 1000 km.
