IEEE 802.15.4 Standard

IEEE 802.15.4 Standard

• Well-known standard for low data-rate Wireless Personal Area Networks (WPAN).
• Used for low-data-rate monitoring and control applications with extended-life, low-power consumption.
• Measures temperature or status of specific devices.
• Uses the first two layers (PHY, MAC), plus logical link control (LLC) and service specific convergence sub-layer (SSCS).
• Operates in the Industrial, Scientific, and Medical (ISM) band.
• Employs direct sequence spread spectrum (DSSS) modulation.
• Tolerant to noise and interference, improving link reliability.
• Low-speed versions use Binary Phase Shift Keying (BPSK).
• High data-rate versions use offset-quadrature phase-shift keying (O-QPSK).
• Uses carrier sense multiple access with collision avoidance (CSMA-CA) for channel access.
• Multiplexing allows interference-free access at different times.
• Power consumption is minimized via short packet transmissions and low duty cycle.
• Standard transmission range is 10m to 75m.
• Achieves up to 1000m transmission range outdoors.

IEEE 802.15.4 Device Types

• Full Function Device (FFD) can communicate with all device types and supports the full protocol.
• Reduced Function Device (RFD) can only communicate with an FFD, has lower power consumption, and requires minimal CPU/RAM.

IEEE 802.15.4 Frames

• A beacon is a reference signal that aids in synchronization and efficiently interacts within the network
• A beacon also informs devices in the network about the network's status.

IEEE 802.15.4 Topologies

• Star topology
• Peer to Peer topology

Zigbee

• Tuya provides a platform for building and managing smart devices, enabling manufacturers to create IoT devices compatible with ecosystems like Amazon Alexa and Google Assistant.
• Tuya's platform includes hardware, software, and a cloud-based system.
• Smart Life is the mobile app for managing Tuya-powered smart devices, with the ability to turn devices on or off remotely, set up automations and schedules, and control devices via voice commands.
• Tuya devices integrate with major smart home ecosystems, allowing users to control devices from a single app, create scenes, and monitor energy consumption.
• Amazon, Apple, Nokia, Panasonic, and Philips are all companies involved in smart technology.

Zigbee Features

• Enhancement of IEEE 802.15.4
• Uses layer 3 and above and works with the 802.15.4 layers 1 and 2.
• Uses layers 3 and 4 to define additional communication enhancements, which includes authentication, encryption, and data routing.

Zigbee Topologies

• Star, Cluster Tree, and Mesh are Zigbee Topologies

Zigbee Mesh

• Mesh enables any node to communicate with any other node within its range
• Messages can be relayed through intermediate nodes if nodes are out of range.
• The network can be deployed over large areas.
• Meshes increase network reliability.
• If a node fails, the message can still be relayed through another area.
• Zigbee mesh networks are self-configuring and self-healing.

Zigbee Device Types

• Coordinator (ZC) forms the root of the ZigBee network.
• Router (ZR) is capable of running applications and relaying information between nodes.
• End Device (ZED) has limited functionality and cannot relay data from other devices
• End Devices can also enhance battery life by being asleep a significant amount of time, and have lower requirements than ZR or ZC.

Zigbee Network Layer

• The AODV broadcasts a route request to its immediate neighbors to find the final destination
• Neighbors relay information, and the request spreads throughout the network
• Upon discovery of the destination, a low-cost path is calculated and informed to the requesting device via unicast messaging.

Applications of Zigbee

• Building automation
• Smart energy for home energy monitoring
• Health care for medical and fitness monitoring
• Home automation for control of smart homes
• Light Link for control of LED lighting
• Telecom services