Fanstel BLG20x, with Adsum Networks firmware
The indoor Bluetooth-to-satellite relay, for a site that stays put, on mains power.
About this relay
- Bluetooth in, Edge AI on board, satellite out. Your Bluetooth LE devices, pre-processed on the relay and sent over satellite NB-NTN, with Wi-Fi, LTE-M and NB-IoT tried first when in reach.
- Satellite needs a view of the sky. Indoors, place the relay at a window facing the satellite; where that is not enough, choose the LBG20x, which mounts outdoors.
- A fixed position, set once. There is no GNSS on board: the position the satellite link needs comes from your phone, or is typed in, when you commission it.
- Mains powered, indoors. USB-C power in a compact 90 × 65 × 28 mm enclosure, −40 to +80 °C operating.
- Never loses data. Records wait in 2 MB of flash until your platform acknowledges them; alarms are never overwritten.
- Commissioned over Bluetooth. From Adsum IoT Coder or a phone, every value read back: name the site, choose the uplinks and their order, pick the devices to carry.
- Kept secure. Signed boot and signed updates, over Bluetooth or the mobile network, with security fixes for five years.
What the licence includes
The production image
Signed images for both processors. No device limit, and no data limit of ours: your SIM plan sets it.
Security fixes for five years
Free for five years. New versions over the air for twelve months; then renew for another year at half the price, or not.
Certified on the real board
Every version passes our reliability and security tests on the board before it reaches you.
The evidence pack
Certificate, test report, SBOM in SPDX, advisory register and VEX: the technical file for the firmware.
Every device profile
All the profiles in the production firmware, and new ones as they ship.
Commissioning from a browser
Pair over Bluetooth, name the site, choose the uplinks and their order, pick the devices to carry.
Your devices, your rules, certified
Add your own Bluetooth IoT devices, and decide what the relay does with their data, in Adsum IoT Coder. It takes hours, and we certify your version on the real board.
Specifications
Hardware · Fanstel BLG20x
| Cellular and satellite | Nordic nRF9151: LTE-M, NB-IoT and NTN satellite; internal LTE antenna |
|---|---|
| Bluetooth | Fanstel BM20 module on the nRF54LM20B, Bluetooth 6.0: Cortex-M33, 2036 KB flash, 512 KB RAM |
| SIM and storage | Nano-SIM, eSIM footprint; 2 MB external flash |
| Position | No GNSS on board: set at commissioning, from a phone or typed in |
| Wi-Fi | Wi-Fi 6 (WM02C, nRF7002, 2.4 and 5 GHz) on the BLG20BC02C |
| Controls | Two buttons, indicator lights, a buzzer |
| Power, size, climate | USB-C, with an AC adapter; IP51; 90 × 65 × 28 mm, desk or wall mount; −40 to +80 °C operating |
| Certifications, sales | FCC, ISED and CE pending at Fanstel, who sells it |
Firmware · Adsum Networks
| Platform | nRF Connect SDK, Zephyr RTOS, MCUboot on both processors |
|---|---|
| Bluetooth LE | Passive and active scanning; three central sessions; LE Secure Connections only; 32 access rules and an expected-device list of 128 |
| Uplink | Wi-Fi (2.4 GHz, WPA2 or WPA3, where fitted), LTE-M, NB-IoT, satellite NB-NTN, cheapest first; confirmable CoAP, or MQTT with or without TLS off satellite; protobuf or CBOR; records held in 2 MB of flash until acknowledged |
| Updates | Over Bluetooth, both processors, in under six minutes; over LTE-M or NB-IoT, never satellite; signed; test boot, health gate, automatic roll-back; settings kept |
| Security | Signed boot; TrustZone isolation; bonded, authenticated commissioning; a new device pairs only after a 3-second button hold |
Hardware facts are Fanstel's: check the model you order. Satellite proof: a status and two alerts, sent over satellite from a window and acknowledged, on 13 September 2026.
Questions
Can I buy a licence for just one relay?
Yes, any number from one. The price per relay depends on how many you buy: 1 to 9, 10 to 99, 100 to 999, or 1,000 or more, the same quantity breaks Fanstel uses for the hardware.
Is this a subscription?
No. The licence is perpetual and includes five years of security fixes and a year of new versions. Keeping new versions after that is optional: half the licence price a year, invoiced each year if you want it. Without it the firmware keeps working on the version you have.
Do I need an Adsum account?
Yes, a free one: licences are granted to the account you name when you order, and the production image is downloaded from the Hardware page in Adsum IoT Coder.
How do I pre-order and pay?
Through the order form on this site: choose the relays, then give your company and the Adsum account the licences go to. Nothing is charged today. We email you an invoice from Stripe when the production firmware ships, in November; you pay it by card or bank transfer, or cancel before, and the licences are in your account once it is paid. Meanwhile, a sample relay from Fanstel comes with our free demo firmware.
Do I need a licence to try it?
No. The relay arrives from Fanstel with our free demo firmware: commission and test it in minutes. Ten devices, 10 MB a month over mobile and 10 KB a month over satellite, no time limit. License it when you go to production.
What happens after the first year?
The firmware keeps working, and its security fixes stay free for five years. New versions and support renew at half the licence price a year, never under £5 a relay, one year at a time; or you stay on the version you have.
Which SIM do I need?
Your own. For satellite, any SIM that uses Skylo's NB-NTN service works today, and we add other networks as we test them. Coverage is the network's: check its map for your country. The terrestrial edition needs a SIM with LTE-M or NB-IoT.
My device is not in the catalogue. Can you add it?
Yes: ask for it, and we reply within one business day. It is free with an order of 10 licences or more, two sample units and the maker's documentation, and it ships in the next production release; otherwise, we quote it. A device that only advertises its data usually takes hours; for one that needs more, we tell you how long. We usually need two sample units, the maker's documentation for their data and, if the data is encrypted, a test key for those samples, never your production keys. After testing we keep the samples to re-test future releases, or return them at your cost: your choice. Or write the profile yourself in Adsum IoT Coder.
Where do my records go?
To your platform: ThingsBoard, any MQTT broker or any CoAP endpoint. You choose it when you commission the relay.
Do you sell the hardware?
No. Fanstel makes and sells it ($80 a sample and $60.48 each at 1,000); we link to Fanstel's page. You buy the firmware licence from us.
Satellite edition or terrestrial edition?
The satellite edition sends over satellite NB-NTN when no cell is in reach, and over LTE-M and NB-IoT first. The terrestrial edition is the cheaper choice for fleets that never leave coverage. Neither includes airtime: that comes with your SIM.
What does certified mean?
Certified by Adsum means this version passed our reliability and security tests on the real board. It is not a conformity assessment under the Cyber Resilience Act or any other regulation.