PowerPoint

IEEE 802.15.4-SupframeOutlineIEEE 802.15.4SuperframeCSMA/CAReference

Wireless sensor network

,Sensor WebSWIEEE 802.15.4IEEE 802.15WPAN(Low Rate-Wireless Personal Area Network, LR-WPAN)(IEEE, Institute of Electrical and Electronics Engineers) 2003 ZigBee

IEEE802.15.4(1)(2)(3)

IEEE 802.15.4IEEE 802.15.4 LR-WPAN 250kb/s40kb/s20kb/s16-bit (short address) 64-bit (extended addressguarantee time slotGTS CSMA/CA CRC-16 2450MHz 16 915MHz 10 868MHz 1 IEEE 802.15.4

peer-to-peer mesh networkIEEE 802.15.4IEEE 802.15.4(Full Function Device, FFD)(PAN coordinator)(Reduced Function Device, RFD)(PAN coordinator) (FFD)

IEEE 802.15.4

IEEE 802.15.4

IEEE 802.15.4IEEE 802.15.4Beacon FramecoordinotardeviceData FrameAcknowledgment FrameAcknowledgment Frame IEEE 802.15.4 MAC Command FrameMAC Command FrameIEEE 802.15.4IEEE 802.15.4Beacon FramecoordinotardeviceData FrameAcknowledgment FrameAcknowledgment Frame IEEE 802.15.4 MAC Command FrameMAC Command Frame

Superframe Superframe IEEE 802.15.4 Beaconnon-Beacon modeSuperframeSuperframe(Inactive portion) : (Active portion) : 16 [0~15](slot)16 (Contention access period)(Contention free period)()(guarantee time slots, GTS)

Superframe Superframe (Beacon)

CSMA/CA algorithmIEEE 802.15.4CSMA/CA Beacon(Superframe)slotted CSMA/CAslotted CSMA-CA Backoff Period (BP) = aUnitBackoffPeriod = 80 bits (0.32 ms)unslotted CSMA/CA

ReferenceIEEE 802 Working Group, IEEE 802 Working Group, Standard for Part 15.4:Wireless Medium Access Control (MAC)and Physical Layer (PHY) Specifications for Low Rate Wireless Personal Area Networks(LR-WPANs), ANSI/IEEE 802.15.4, April. 2012.