Direct-to-Device LEO Satellite Communication: A System Architecture for Universal 5G NTN Connectivity with Focus on Nepal

Over 2.6 billion people still have no dependable internet access. The hardest cases to solve are not cities but the remote valleys, highland plateaus, and scattered rural communities where running fiber or building cell towers makes no economic sense. Nepal, with more than 40 percent of its land above 3,000 meters, sits right at the center of this problem. This paper describes a four-layer satellite communication architecture that lets an ordinary smartphone connect directly to a Low Earth Orbit satellite without any hardware change beyond swapping in a 5G Non-Terrestrial Network modem chip. The first layer is a reconfigurable metamaterial phased-array antenna built into the phone bezel: four circularly polarized elements with onebit phase shifters that steer an electronic beam across a sixtydegree elevation arc, reaching 3 to 6 dBi of gain without moving parts. The second layer is the NTN modem itself, duty-cycle gated so the satellite transmitter only wakes when the terrestrial signal drops below a usable level, keeping average power below five watts. The third layer is a predictive handover engine that reads the satellite orbit data and pre-negotiates the next connection before the current one starts to fade, cutting handover gaps to under fifty milliseconds. The fourth layer is the ground segment, where standard 5G core interfaces accept the satellite node as just another base station. A worked link budget shows 12.3 dB of margin at the worst elevation angle, supporting one to ten megabits per second with better than 99 percent availability and 20 to 50 milliseconds of end-to-end latency. The paper closes with a discussion of three remaining engineering challenges and what this architecture could mean specifically for Nepal’s digital future and emerging space sector.

• Status: presented at Space Con 2026. That status is the author's own claim — it has no public record and no entry in the claim ledger, so it cannot be checked from this page.
• The premise that more than 40 percent of Nepal's land sits above 3,000 metres carries no citation in the paper. It is stated here as the paper states it; it was not independently verified.

No experiment asserted. This is architecture, feasibility or position work, so there is no measurement to reproduce and no artifact owed.

@misc{poudel2026direct,
  title  = {Direct-to-Device LEO Satellite Communication: A System Architecture for Universal 5G NTN Connectivity with Focus on Nepal},
  author = {Sushant Poudel and Aashika Pandey},
  year   = {2026},
  note   = {Space Con 2026},
  url    = {https://sushantpoudel2028.com.np/papers/leo-d2d.pdf}
}

Claims about his own work that the ledger covers are re-checked weekly against their public source by sushant-me/reputation — 27 claims today, 19 checked live. Coverage is stated rather than implied: it does not yet extend to every manuscript listed here. The reproducibility note above is part of that record: where no artifact exists, the page says so instead of implying one.