Resources for ZigBee and IEEE 802.15.4
Published:
This page summarizes resources for ZigBee and IEEE 802.15.4. It is still under active update.
Overview
IEEE 802.15.4 defines the physical and MAC layers. ZigBee is based on IEEE 802.15.4 but also defines higher layer protocols.
IEEE 802.15.4 is also adopted by 6LoWPAN, WirelessHART, THREAD, etc.
IEEE 802.15.4
Physical Layer
Frequency Band
- 868 MHz, Europe, channel $k$ = 0, $f_c = 868.3$ MHz
- 915 MHz, America, Australia, channel $k=$ 1 - 10, $f_c = 906 + 2(k-1)$ MHz
- 2.4 GHz, Worldwide, channel $k$ = 11 - 26, $f_c = 2405 + 5*(k-11)$ MHz, OQPSK
OQPSK PHY
Figure from https://uk.mathworks.com/help/comm/ug/end-to-end-ieee-802-15-4-phy-simulation.html.
All OQPSK PHYs map every 4 PPDU bits to one symbol. The 2.4 GHz OQPSK PHY spreads each symbol to a 32-chip sequence, while the other OQPSK PHYs spread it to a 16-chip sequence. Then, the chip sequences are OQPSK modulated and passed to a half-sine pulse shaping filter (or a normal raised cosine filter, in the 780 MHz band).
Run the Matlab End-to-End IEEE 802.15.4 PHY Simulation to have a deep understanding on the modulation.
Please refer to Section 1.1.1.2 O-QPSK PHY of the Rohde & Schwarz Application Note for a detailed introduction.
MAC Layer
CSMA-CA
- Direct Transmission
- Indirect Transmission (Polling)
MAC Type
- Data Frame
- Beacon Frame
- Acknowledgement Frame
- MAC Command Frame
ZigBee
Network Architecture and Topology
- Star Topology
- Tree Topology
- Mesh Topology
Tutorial
Check the first chapter of IEEE 802.15.4 Stack User Guide for a brief introduction of IEEE 802.15.4.