IEEE 802.15.14 (May 2003)

Low-Rate WPANLow-Power

DSSS

DSSS

DSSS

An IEEE 802.15.4 WPAN

Devices:FFD: Full-Functional Device.

3 modes =[PAN Coordinator, Coordinator, Device]49 primitives (14 PHY+ 35 MAC) (1/3 of Bluetooth)

RFD: Reduced-Functional Devicesimple devices; e.g. Light switch, infrared sensor38 primitives

Beacon payload (optional): for higher layers to include info on the beacon.

GTS fields and Pending address fields: max number of GTS assigned and max number of pending addresses (the coordinator has pending data to be delivered to those addresses) is 7.

BO: Beacon OrderSO: Superframe Order

BI = aBaseSuperFrameDuration*2^BO symbols

SD = aBaseSuperFrameDuration*2^SO

symbols

THUS, Every beacon specifies

the duration of the superframe, the duration of active frame, for whom the GTSs are, who has data pending on the coordinator, is the coordinator accepting new devices ?, etc. ....

for further info, see the standard specification from IEEE

Peer to Peer communication:

unslotted CSMA/CA, peers always receiving

or peers synchronized (outside standard scope)

ACK are sent right just after the Data and do not need CSMA/CA

Beacons are sent at the beginning of the superframe w/o using CSMA/CA

Data is sent using slotted/unslotted CSMA/CA

IEEE 802.15.4 Frames/packets

Max payload= 102 to 118 bytes (max PHR=127) (TinyOS data packets are usually 29 bytes)FCS (CRC) for frame to detect bit errorsFrame Control : 16 bits which indicate type, is ack required? , is security enabled? , source and destination address types ... is it intraPAN communication?

For further details see 7.2.1.1 in the standard

IEEE 802.15.4 Frames/packets

NETWORK LAYER

Topologies supported

Self configuring and self healing:association and orphaning

NETWORK LAYER

Securitycapabilities:

1.- No security2.- ACL3.- Frame Integrity3.- Symmetric Key Encryption4.- Sequential Freshness

MicaZ

subset of IEEE 802.15.4

no Beacon-Enabledno PAN starting/mantainingno GTS ...

Thus, DSSS, unslotted CSMA/CA ?

Future directions of TinyOS and Mica motes?

REFERENCES

Information, figures and slides were gathered from:

1.Jianliang Zheng and Myung J. Lee, “Will IEEE 802.15.4 Make Ubiquitous Networking a Reality?: A Discussion on a Potential Low Power, Low Bit Rate Standard”, IEEE Communications Magazine, Vol. 42 No. 6, June 2004.2.“802.15.4”, IEEE Std 802.15.4™-2003, IEEE Standards, October 2003.3.Jon Adams, The ZigBee Alliance, “Meet the ZigBee standard”, Sensors Magazine, vol. 20, no. 6, June 2003. http://www.sensorsmag.com/articles/0603/14/main.shtml4.William C. Craig, CDC-P810, Communications Design conference, April 2004.

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