I asked the same thing when we did our first site, so here’s what I learned.
It comes down to the concentrator chip (SX1302/SX1303 family in current gateways, SX1301/1308 in older ones). It isn’t one radio, it’s a baseband that demodulates 8 channels in parallel and on each channel every spreading factor at once. A sensor doesn’t have to „connect“ either: it transmits, every gateway in range hears it, done. No association like Wi-Fi. So listening to hundreds of sensors is mostly listening to short bursts that rarely overlap.
The cheap indoor ones use the same chip family. What you give up is the outdoor stuff: enclosure, a good antenna up high, cellular backhaul, GPS.
For Hermetry, check three things before buying:
- A model for your band. Hermetry’s network server follows the gateway’s frequency plan, so the gateway and your sensors just need to be on the same one.
- Basics Station support (LNS). The old UDP packet forwarder isn’t supported.
- It lets you set tc.uri, upload tc.trust and set the token (tc.key). Hermetry doesn’t use CUPS, you configure it once by hand.
On the channels: Hermetry sends the gateway its radio configuration when it connects (on EU868 the 8 channels plus a 250 kHz LoRa channel and an FSK channel), so you don’t set channels yourself.
Keisha, for a warehouse: indoor gateway in the middle, mounted high, and check RSSI/SNR of the furthest sensors in the frames log before you trust coverage. Racking full of metal eats a lot.