NB-IoT Technology

NB-IoT. Narrowband Internet of Things. Built on LTE leftovers. Not quite 5G, not quite anything. It’s LPWAN over licensed spectrum. Telecom-grade, enterprise-sounding, battery-saving – in theory. Meant for sending tiny data over long range with low power. In practice? Sometimes it works. Sometimes it sulks.

Vendor and URL

This beauty comes from:
Main vendor: 3GPP (same folks who made LTE, 5G, and your phone bill confusing)
Official docs: https://www.3gpp.org
If the link’s dead, don’t worry – there are 700 PDFs to replace it.

Technical Public Documentation

PDF hell, absolutely. You want specs? They’ve got thousands of pages. Full spec: TS 36.300 and friends (grab popcorn)
GitHub repo: https://github.com/ARMmbed/mbed-os (if you want embedded fun)
Also check LTE-M vs NB-IoT debates. Spoiler: nobody agrees on anything.

Overview

NB-IoT is cellular LPWAN. Uses part of the LTE network. Super low bandwidth, super high coverage. Meant for devices that chirp once a day and sleep the rest. It’s a carrier’s dream and a developer’s slow-motion nightmare. But it does the job. Usually.

Architecture

Standard LTE cell tower. UE (User Equipment) is your sensor, modem, or coffee machine. Everything goes through the mobile core network. You don’t build the infrastructure. You rent it. And pray the operator didn’t misconfigure your APN.

Device Roles

There’s no mesh, no routers, no star topology. Just the device (UE) and the tower. Device connects to eNodeB. Tower sends to MME. Cloud eats it. Everyone has a role, nobody talks to anyone else.

Channelization

Operates in licensed spectrum (usually 900 MHz or 800 MHz). Can run inside LTE (in-band), beside it (guard-band), or all alone (standalone, ex-GSM). Network decides. You don’t get a vote.

Frames

Based on LTE RRC, MAC, and NAS frames – which means it's complex and full of TLAs (Three Letter Acronyms). Payloads are small. Header overhead is huge. You pay for every bit. CRC? Yeah. Error correction? Of course. Sanity? Optional.

Networking

It’s cellular. No peer-to-peer. No custom routing. Devices connect using standard LTE attachment procedures. IPv6 and IPv4 supported, but most operators wrap everything in MQTT tunnels or CoAP socks anyway.

Security

SIM-based authentication. Same as your phone, but without voice or fun. Data can be encrypted via IPsec or app layer (TLS/DTLS). Operator controls a lot. You control not much. Security? There, but not always obvious.

Networking Process

Boot. Attach to network. Get IP. Connect to APN. Handshake. Maybe wait 30 seconds. Send a tiny payload. Go back to sleep. Repeat tomorrow. Or fail, retry, and wake up your firmware watchdog. Depends on the mood of the cell tower.

Use Cases

Great for meters, smart cities, vending machines, parking sensors, agriculture stuff. If it sends small data and sits still, NB-IoT wants to be its friend. Just don’t expect real-time updates or high throughput. This isn’t Wi-Fi. This is molasses over LTE.