LBG20x gateway firmware, datasheet (PDF)
Three pages to read away from the screen or send on: what it does, how it works, how it is tested, and the specifications.
Two processors, one relay, one position
The radio half listens, remembers, and sends over Wi-Fi where it can. The wide-area half takes the relay’s own GNSS fix, chooses the mobile uplink and delivers. One serial link joins them and carries records, commands and the radio half’s updates.
Both halves run Zephyr behind their own MCUboot, with TF-M on the cellular one, and the link between them is framed with a sequence number and a CRC-16, with a heartbeat every second. If the link drops, both keep working and the store keeps filling.
Its own position
A satellite link times itself from the relay’s position, so a relay that moves can lose the satellite. The LBG20x measures its own:Edge processing, and what each uplink carries
The radio half is an nRF54LM20B, the Edge AI processor of the pair, and it is where data is reduced before anything is sent: per-device state, rules with hysteresis and hold, alerts and digests. The relay sends the decision, not the data, which is what makes a satellite link of a few kilobytes a month usable.The bearer ladder
The relay falls to a lower rung after three failed attaches, with a stated reason, or when a budget is spent or a rung is removed, and returns to a cheaper one every six hours by default, set per relay. Satellite needs the satellite edition, Nordic’s NB-NTN modem firmware, an NB-NTN SIM and a position. The deployment classes, terrestrial, satellite and both, are the BLG20x’s.
What reaches your platform
The records are the BLG20x firmware’s: a 52 B digest per device per window, a 13 B alert, a 30 B status, and a 76 B daily health record, up to eight records in one confirmable send of about 1 kB. Sizes are in protobuf; CBOR is also supported, and MQTT with or without TLS off satellite. A satellite datagram is 128 B at most. One real datagram carried 46 B of transport and 40 B of payload, one status and one alert, with 42 B of headroom: sent over a geostationary NB-NTN service on 9 October 2026, on the relay’s own GNSS position, and acknowledged by the platform with 2.01. Registration on the satellite took 117 to 122 s.Devices, access and records
Commissioning, and the buttons
1
Open the window
Hold DFU1 for 3 to 8 seconds. A new device pairs only after this hold.
2
Connect
Pair over LE Secure Connections, from Adsum IoT Coder or a phone’s browser.
3
Position
The relay’s own GNSS fix, or a phone’s, or typed in, with its uncertainty.
4
Commission
Name and credential, Wi-Fi, the mobile network and the class, the platform, the expected devices.
5
Verify
Read the unit back and compare it field by field.
DFU1 reaches both processors, so a press both report within two seconds counts once.
The cue light
The LBG20x has no sounder. A light plays the BLG20x’s sounds as flashes, and every cue also shows on the front lights:
The relay lights it once at power-on, as a lamp test.
Updates, and recovery
Updates arrive over Bluetooth at the desk, both processors from Adsum IoT Coder or the commissioning page with every setting kept, and over LTE-M and NB-IoT in the field. Images are signed, with a test boot that confirms behind a health gate and rolls back by itself if it does not. An update never travels over satellite. A relay claimed with your computer’s key takes images from no one else. Measured on the unit, 11 October 2026: both processors over Bluetooth, 947 kB in 101 seconds and 450 kB in 132 seconds. Recovery is the BLG20x firmware’s: a hung processor is rebooted by its watchdog and the cause reported; a dropped link between the halves stops neither; an update that does not confirm is undone at the next boot; a configuration that fails three boots is rolled back and reported; acknowledged records are already in flash when power is lost.Tested to prove it
Industrial grade is a claim about tests, so these are the tests the firmware goes through on the real board, not in a simulator. A version you customise goes through them again.Reliability: does it keep working?
FunctionEvery feature, end to end, on every release, across Bluetooth devices, SIMs and networks; GNSS with and without sky.
FailoverEach uplink lost and recovered, LTE-M to NB-IoT to satellite and back; SIM, network and roaming refusals.
StressThe full device list, floods of Bluetooth traffic, bursts of alerts, a full store, weak and patchy signal.
DurabilitySoak runs for days; thousands of power cycles, cold boots and brown-outs; flash wear; memory watched for leaks.
Fault injectionPower cut mid-write and mid-update, a corrupted image, a bad configuration, a stalled processor. It must recover alone.
UpdatesEvery release applied over the air from the last one, interrupted, resumed, confirmed, and rolled back.
Security: can it be broken into?
Boot and updateOnly signed images start. Tampered, unsigned and downgraded images are refused.
HardeningDebug ports locked in production; no open shell, no default password, no secret left in the image; keys in secure storage.
BluetoothPairing, replay and man-in-the-middle attacks; unauthenticated writes refused; a flood cannot fill the store.
NetworkEncrypted transport checked; malformed, oversized, replayed and spoofed messages refused.
Fuzzing, pen testMalformed data thrown at every input for hours; static analysis; a penetration test of each major release.
Supply chainA software bill of materials (SBOM) from the real build, scanned against known vulnerabilities on every release.
CRA readiness
Security fixes are free for five years from each licence’s first download: the support period the EU Cyber Resilience Act asks of a manufacturer. Every production licence includes the evidence pack: the certificate, the test report, an SBOM in SPDX for each build, the advisory register and VEX, with the secure-by-design posture the CRA readiness check reports. The demo carries none of it. Licences are per relay at www.adsumnetworks.com.The hardware, from Fanstel
Hardware facts are Fanstel’s, from its product specification (draft 0.90, September 2026). The LBG20 comes in several models, so check the one you order.
What this version does not do
- Battery and charging are next: the nPM1300’s charger status and the battery level, on your platform.
- Tamper and orientation are next, from the motion sensor, which already wakes a fix when the relay moves.
- LoRa is next, once its M.2 card is available.
- No USB data on the mainboard V2. Its USB-C carries power only, so claiming and updating go over Bluetooth.
- The modem firmware is installed before deployment and cannot be updated in the field.
- The evidence pack comes with the production licence, not with the demo.
Figures were measured on the evaluation configuration, an LBG20BC02C with the mainboard LBG-MB-V2. Features marked next are in development.
The LBG20x
The relay, the firmware, and every way to have it.
The first run, step by step
Pair, claim, commission, and see readings on your platform.
Datasheet (PDF)
Three pages, for reading away from the screen.
Satellite IoT: NB-NTN
What a satellite link is good for, and what it costs.