> ## Documentation Index
> Fetch the complete documentation index at: https://docs.adsumnetworks.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Satellite IoT: NB-NTN on nRF9151

> Non-terrestrial NB-IoT: the same nRF9151 modem reaching a satellite where there is no cell. What ships today as knowledge, and the BLG20x gateway coming soon.

<Note>
  **Coming soon.** Satellite NB-NTN ships today as knowledge and a guided run for the nRF9151. The BLG20x gateway that carries it, with signed images and licensed source, is in early access. [Ask for it](mailto:support@adsumnetworks.com?subject=BLG20x%20early%20access).
</Note>

Non-terrestrial NB-IoT is the 3GPP standard that lets a narrowband modem attach to a satellite instead of a cell tower. Same protocol family as NB-IoT, same nRF9151 silicon, no dish and no separate satellite modem. It is for devices where there is no terrestrial coverage at all: pipelines, livestock, buoys, remote assets, anything that spends its life beyond the last cell.

## How it fits

<div className="adsum-fig">
  <div className="adsum-order">
    <div className="adsum-hop">
      <div className="adsum-hop-n">1</div>
      <div className="adsum-hop-b"><b>Wi-Fi, Ethernet or cellular</b><span className="adsum-hop-s is-live">where they exist</span><span>The everyday ways out. Cheapest first, in the order you set.</span></div>
    </div>

    <div className="adsum-hop">
      <div className="adsum-hop-n">2</div>
      <div className="adsum-hop-b"><b>Satellite NB-NTN</b><span className="adsum-hop-s">last resort</span><span>When nothing terrestrial is in reach. Small payloads, long intervals, metered by design.</span></div>
    </div>
  </div>

  <p className="adsum-cap">The same failover order the gateways already use, with satellite as the final way out.</p>
</div>

Satellite links are slow and costly per byte. The firmware treats them the way it treats a metered SIM: standby until needed, digests rather than streams, and a console that never hides what the link is costing.

## What ships today

* **Knowledge for the nRF9151**: attaching to a satellite network, the modem settings that differ from terrestrial NB-IoT, and how to read the trace when it will not attach. Needs a [free account](/account).
* **A guided run** on the nRF9151 DK, with the same board shell and modem trace as [cellular](/cellular).

<Warning>
  NB-NTN modem firmware runs only on an nRF9151 of the **LACA A1A** revision, not A0A, and not on the nRF9160 or nRF9161. Check the module label before you start. Satellite service also needs a subscription with a provider that runs NB-NTN in your region.
</Warning>

## What is coming

The **BLG20x** gateway: Bluetooth LE 6 in, Wi-Fi 6, cellular and satellite NB-NTN out, with embedded edge AI on the nRF54. Signed images to judge and deploy, licensed source to ship, and board knowledge so the agent already holds its pinouts. [Every way to have it](/gateway-firmware#coming-soon-blg20x).

<CardGroup cols={2}>
  <Card title="Cellular IoT on nRF91" icon="tower-cell" href="/cellular">
    LTE-M, NB-IoT and GNSS bring-up, the board shell and the modem trace.
  </Card>

  <Card title="Gateway firmware" icon="microchip" href="/gateway-firmware">
    Signed images, licensed source, and the BLG20x in early access.
  </Card>
</CardGroup>