How “probabilistic look-aside” can help improve internet speeds for consumers
By Hillary Roman
The Interference Problem
The space in Earth’s orbit has become crowded with satellites. Some companies are operating many non-geostationary orbit (NGSO) satellites that together form a constellation, providing broadband and other communications services. As more NGSO constellations are launched, more systems compete for the same frequency bands, creating a growing risk of harmful interference that can reduce data rates.
When satellites from different constellations serve the same region from roughly the same angle, operators may need to respond. They can: 1) take no action, allowing data rate degradation to passively occur; 2) “look-aside,” where a constellation determines that one of its satellites is at risk of a conflict and proactively assigns transmission to another one of its satellites; or 3) use “band-splitting,” where the available bandwidth is divided equally between operators. The Federal Communications Commission (FCC) has adopted band-splitting as the default approach when operators cannot agree to an alternative. Each of these strategies has drawbacks. Constellations taking no action at all can experience unnecessary interference; always utilizing look-aside means operators will have to switch transmissions to a satellite in a suboptimal position; and band-splitting, while ostensibly fair, reduces the available radio spectrum resulting in reduced internet speeds for subscribers.
“Now that the number of satellites in orbit is increasing at an extraordinary rate, we need to invent new strategies that allow satellite constellations to operate in the same shared spectrum without excessively interfering with each other,” said Jon Peha, professor of engineering and public policy at Carnegie Mellon University.
Probabilistic Look-Aside
New research from Carnegie Mellon University offers a better solution. In the 2026 IEEE DySPAN Best Paper Award winning paper, “Limiting Mutual Interference Between NGSO Satellite Constellations via Probabilistic Look Aside,” Ganghui Lin, Jon Peha, Marvin Sirbu, and Alex Hills introduce a novel strategy they call “probabilistic look-aside.” Rather than always or never looking aside, satellite constellations can improve data-rate performance by using look-aside with a fixed probability when they detect a possible conflict based on satellite positions. In practical terms, the researchers propose a way for competing satellite operators to reduce harmful interference without needing detailed real-time coordination, relying instead on publicly available satellite position information.
Read the full story on the Carnegie Mellon Engineering and Public Policy website.
Originally published on June 30, 2026, by Hillary Roman on the Carnegie Mellon Engineering and Public Policy website.
