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IEEE 802.15.4 Connectivity Technologies in IOT

Communication Protocols

The following communication protocols have immediate importance to consumer and industrial IoT :
Features of IEEE 802.15.4
  • Well-known standard for low data-rate WPAN.
  • Developed for low-data-rate monitoring and control applications and extended-life low-power-consumption uses.
  • This standard uses only the first two layers (PHY,MAC) plus the logical link control (LLC) and service specific convergence sub-layer (SSCS) additions to communicate with all upper layers
  • Operates in the ISM band.




  • Uses direct sequence spread spectrum (DSSS) modulation
  • Highly tolerant of noise and interference and offers link reliability improvement mechanisms.
  • Low-speed version 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 users or nodes interference-free access to the same channel at different times.
IEEE 802.15.4 Variants



IEEE 802.15.4 Types





Full Function Device (FFD)
  • Can talk to all types of devices
  • Supports full protocol
Reduced Function Device (RFD)
  • Can only talk to an FFD
  • Lower power consumption
  • Minimal CPU/RAM required
IEE 802.15.4 Frames



Beacon Enabled Networks
  • Periodic transmission of beacon messages
  • Data -frames sent via Slotted CSMA/CA with a super frame structure managed by PAN coordinator
  • Beacons used for synchronization & association of other nodes with the coordinator
  • Scope of operation spans the whole network.

Non-Beacon Enabled Networks
  • Data-frames sent via un-slotted CSMA/CA (Contention Based)
  • Beacons used only for link layer discovery
  • Requires both source and destination IDs.
  • As 802.15.4 is primarily, a mesh protocol, all protocol addressing must adhere to mesh configurations
  • De-centralized communication amongst nodes
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