Predict, Don't React.
ephemeris as lead time for the cellular control plane
a Direct-to-Cell control plane built on the publicly knowable future · Hannah B. Pasandi, UC Berkeley Sky Computing Lab
in plain terms

A satellite base station's path is published maths: anyone can compute where it will be. Yet the control loop that manages your connection still senses and reacts as if the future were unknowable. Expose the ephemeris as a shared signal and three control loops gain seconds to tens of minutes of lead time.

the inversion

Sense-then-react was built for towers that cannot see the future

Direct-to-cell over LEO ships with the same sense-then-react control loop 3GPP built for terrestrial cells, timers widened to absorb satellite motion. But the constraint has inverted: the base station now moves on a deterministic trajectory, and its near future is publicly knowable from TLE ephemeris that Release 17 already broadcasts.

three loops

One public signal, three timescales of lead time

TLE ephemeris publicly knowable future Loop-R · radio / handoverseconds of lead time Loop-A · application / delay-tolerantminutes of lead time Loop-P · cross-jurisdiction pre-stagingtens of minutes of lead time 1.14x vs Release-18 CHO 18x 130x median, 425x at P90
Predict-then-Act. Expose ephemeris as a shared control-plane signal that a radio loop (handover), an application loop (delay-tolerant traffic), and a pre-staging loop (cross-jurisdiction context) all consume. Honest at the radio loop. The gain there is deliberately modest, 25 seconds of lead time versus 22 for Release-18 conditional handover (1.14x); the orders of magnitude live at the application and pre-staging loops, 18x and 130x median, 425x at the ninetieth percentile. Geometry-grounded. SGP4 predictions fall within 2 seconds of the LeoCC dataset, predicted cell-rotation rate within 6 percent of published dwell ranges, with roughly 50 ms of handover-time error.
status

Predict, Don't React is in submission. These are geometry-grounded upper bounds on available lead time, not claims of realized production gains.

the family

The homepage principle, as a control plane

This is the site's commitment made literal: decide on predicted future state and bound the prediction error, rather than react to the measured present. It anchors the Direct-to-Cell Satellite line and shares its prediction-first spine with teNET.

When the future is public, reacting to the present is a design choice, not a necessity.

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