HCIA-IoT flashcards

31 cards. Read the term and the definition here. The deck at the top of this page is optional.

IoT four-layer architecture

Perception/device layer with sensors and actuators, network layer for access and transport, platform layer for device management and analytics, and application layer for industry solutions. Each layer has distinct functions and interfaces.

LPWA

Low Power Wide Area technology family for long-range, low-bit-rate, battery-powered devices. Includes licensed cellular NB-IoT and LTE-M plus unlicensed LoRa, Sigfox, and similar proprietary systems.

NB-IoT bandwidth

NB-IoT occupies a 180 kHz bandwidth, matching one LTE resource block. It can be deployed in-band, in guard band, or standalone, and supports uplink single-tone or multi-tone transmission.

LoRa spreading factor

Chirp spread spectrum parameter from SF7 to SF12. Higher spreading factors increase range and robustness but lower data rate and lengthen time-on-air, so duty cycle limits bite harder.

LoRaWAN Class A

Default LoRaWAN class: each uplink is followed by two short receive windows. The device sleeps otherwise, giving the lowest power consumption but downlink only after an uplink.

CoAP

Constrained Application Protocol running over UDP with a compact 4-byte header. Uses GET, POST, PUT, DELETE methods and supports observe for server push to constrained nodes.

MQTT QoS levels

QoS 0 delivers at most once, fire and forget. QoS 1 delivers at least once with possible duplicates. QoS 2 delivers exactly once via a four-step handshake.

Zigbee

Low-power mesh networking standard built on IEEE 802.15.4 at 2.4 GHz. Supports coordinator, router, and end-device roles with typical range around 10 to 100 meters per hop.

6LoWPAN

Adaptation layer that carries IPv6 over IEEE 802.15.4 frames. It compresses IPv6 and UDP headers and fragments packets to fit the small 127-byte frame payload.

RPL routing protocol

IPv6 routing protocol for low-power and lossy networks. It builds a destination-oriented DAG rooted at a border router and supports upward and downward routes.

MQTT topic wildcards

The plus sign matches exactly one topic level; the hash sign matches all remaining levels. Subscribers use filters with wildcards; publishers must use concrete topic names.

IPv6 address size

IPv6 uses 128-bit addresses versus 32-bit IPv4 addresses. The larger space removes the need for NAT and supports addressing very large numbers of IoT endpoints.

IoT gateway functions

A gateway translates between protocols such as Modbus and MQTT, buffers data during outages, performs local edge processing, and authenticates downstream devices before cloud forwarding.

Cellular attach sequence

Device selects a network, performs random access, sets up an RRC connection, runs authentication and security, then establishes a PDN or PDU session to reach the IoT platform.

Device shadow

A cloud-side representation storing the last reported state and desired state of a device. Applications can read or set state even while the physical device is offline.

Product model

Platform definition of a device type: its services, properties, commands, and events. Individual devices are instances of a product model and carry unique identifiers and secrets.

OTA upgrade flow

Create a signed upgrade package, create an upgrade task, target devices, notify them, then each device downloads, verifies, installs, and reports the result back to the platform.

Rule engine

Platform feature combining a trigger such as device data or an event, optional conditions, and actions such as forwarding to a topic, database, or application without custom code.

Northbound and southbound APIs

Northbound APIs expose platform capabilities to applications for device CRUD, command delivery, and data queries. Southbound interfaces connect devices directly or through gateways into the platform.

Device lifecycle states

Typical platform states are registered, activated/online, offline, deactivated, and deregistered. Commands and OTA tasks generally reach only devices in the online state.

Device bootstrap authentication

Device presents its unique device ID plus a secret or X.509 certificate, the platform verifies it, and the device obtains a session token used for subsequent MQTT, CoAP, or HTTP access.

TLS and DTLS

TLS secures TCP-based IoT traffic such as MQTT and HTTPS. DTLS provides equivalent confidentiality and integrity for UDP-based traffic such as CoAP, tolerating datagram loss.

Hardware root of trust

A secure element or TPM that stores private keys and performs cryptographic operations inside tamper-resistant hardware, so keys cannot be extracted even if device software is compromised.

Secure boot

Boot process that verifies a cryptographic signature on firmware before execution, chaining trust from an immutable root. Blocks unauthorized or tampered firmware from running on the device.

Symmetric vs asymmetric crypto

Symmetric algorithms such as AES and HMAC use one shared key and are fast for bulk data. Asymmetric algorithms such as RSA and ECC use key pairs for exchange and signatures but are slower.

IoT credential risks

Common weaknesses include default or hardcoded passwords, shared credentials across devices, weak random number generation, and unencrypted local buses exposing secrets to physical attackers.

Smart metering connectivity

Electricity and water meters commonly use NB-IoT or power line communication. Requirements are deep indoor and basement coverage, multi-year battery life, and very high connection density per cell.

Industrial closed-loop control

Factory control loops need deterministic low latency and high reliability, met by TSN, industrial Ethernet, or 5G uRLLC. Best-effort LPWA links are unsuitable for actuation in these loops.

V2X technologies

Vehicle-to-everything communication uses IEEE 802.11p-based DSRC or cellular C-V2X. Both target low-latency direct messages for safety, such as cooperative awareness and hazard warnings.

Smart agriculture sensing

Soil moisture, temperature, and humidity sensors deployed over wide rural areas typically use LoRa or NB-IoT. Telemetry drives irrigation actuation, forming a closed control loop.

Solution technology selection

Choose connectivity by matching coverage, mobility, data rate, latency, power budget, and cost. Only then select a platform whose device management and APIs fit the application.