Trending Technology Machine Learning, Artificial Intelligent, Block Chain, IoT, DevOps, Data Science

Recent Post

Codecademy Code Foundations

Search This Blog

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
Books :

No comments:

Post a Comment

Popular Articles