IEEE (May 2003) Low-Rate WPAN Low-Power

DSSS

An IEEE 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 Device simple devices; e.g. Light switch, infrared sensor 38 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 Order SO: 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 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 errors Frame 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 in the standard

IEEE Frames/packets

NETWORK LAYER Topologies supported

Self configuring and self healing: association and orphaning NETWORK LAYER

Security capabilities: 1.- No security 2.- ACL 3.- Frame Integrity 3.- Symmetric Key Encryption 4.- Sequential Freshness

MicaZ subset of IEEE no Beacon-Enabled no PAN starting/mantaining no 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 Make Ubiquitous Networking a Reality?: A Discussion on a Potential Low Power, Low Bit Rate Standard”, IEEE Communications Magazine, Vol. 42 No. 6, June “ ”, IEEE Std ™-2003, IEEE Standards, October Jon Adams, The ZigBee Alliance, “Meet the ZigBee standard”, Sensors Magazine, vol. 20, no. 6, June William C. Craig, CDC-P810, Communications Design conference, April and may be subjected to copyright issues.