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Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [IEEE 802.15.4 Tutori

Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [IEEE 802.15.4 Tutorial] Date Submitted: [4 January, 2003] Source: [Jose Gutierrez] Company: [Eaton Corporation] Address: [4201 North 27th Street, Milwaukee WI. 53216]

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Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [IEEE 802.15.4 Tutori

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  1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [IEEE 802.15.4 Tutorial] Date Submitted: [4 January, 2003] Source: [Jose Gutierrez] Company: [Eaton Corporation] Address: [4201 North 27th Street, Milwaukee WI. 53216] Voice:[(414) 449-6525], FAX: [(414) 449-6131], E-Mail:[josegutierrez@eaton.com] Re: [IEEE 802.15.4 Overview; Doc. IEEE 802.15-01/358r0, TG4-Overview; Doc IEEE 802.15-01/509r0] Abstract: [This presentation provides a tutorial on the 802.15.4 draft standard.] Purpose: [] Notice: This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15. José A. Gutierrez

  2. IEEE 802.15.4Tutorial José A. Gutierrez

  3. 802.15.4 Applications Space • Home Networking • Automotive Networks • Industrial Networks • Interactive Toys • Remote Metering José A. Gutierrez

  4. 802.15.4 Applications Topology Cable replacement - Last meter connectivity Virtual Wire Wireless Hub Stick-On Sensor Mobility Ease of installation José A. Gutierrez

  5. Some needs in the sensor networks Thousands of sensors in a small space  Wireless but wireless implies Low Power! and low power implies Limited Range. Of course all of these is viable if a Low Cost transceiver is required José A. Gutierrez

  6. Solution: LR-WPAN Technology! By means of IEEE 802.15.4 José A. Gutierrez

  7. 802.15.4 General Characteristics • Data rates of 250 kb/s, 40 kb/s and 20 kb/s. • Star or Peer-to-Peer operation. • Support for low latency devices. • CSMA-CA channel access. • Dynamic device addressing. • Fully handshaked protocol for transfer reliability. • Low power consumption. • Frequency Bands of Operation • 16 channels in the 2.4GHz ISM band • 10 channels in the 915MHz ISM band • 1 channel in the European 868MHz band. José A. Gutierrez

  8. 802.15.4 Architecture Upper Layers Other LLC IEEE 802.2 LLC IEEE 802.15.4 MAC IEEE 802.15.4 IEEE 802.15.4 868/915 MHz 2400 MHz PHY PHY José A. Gutierrez

  9. IEEE 802.15.4 PHY Overview Operating Frequency Bands Channel 0 Channels 1-10 2 MHz 868MHz / 915MHz PHY 868.3 MHz 902 MHz 928 MHz 2.4 GHz PHY Channels 11-26 5 MHz 2.4 GHz 2.4835 GHz José A. Gutierrez

  10. IEEE 802.15.4 PHY Overview Packet Structure • PHY Packet Fields • Preamble (32 bits) – synchronization • Start of Packet Delimiter (8 bits) • PHY Header (8 bits) – PSDU length • PSDU (0 to 1016 bits) – Data field Start of Packet Delimiter PHY Header PHY Service Data Unit (PSDU) Preamble 6 Octets 0-127 Octets José A. Gutierrez

  11. IEEE 802.15.4 PHY Overview Modulation/Spreading • 2.4 GHz PHY • 250 kb/s (4 bits/symbol, 62.5 kBaud) • Data modulation is 16-ary orthogonal modulation • 16 symbols are ~orthogonal set of 32-chip PN codes • Chip modulation is MSK at 2.0 Mchips/s • 868MHz/915MHz PHY • Symbol Rate • 868 MHz Band: 20 kb/s (1 bit/symbol, 20 kBaud) • 915 MHz Band: 40 kb/s (1 bit/symbol, 40 kBaud) • Data modulation is BPSK with differential encoding • Spreading code is a 15-chip m-sequence • Chip modulation is BPSK at • 868 MHz Band: 300 kchips/s • 915 MHz Band: 600 kchips/s José A. Gutierrez

  12. IEEE 802.15.4 PHY Overview Common Parameters • Transmit Power • Capable of at least 1 mW • Transmit Center Frequency Tolerance •  40 ppm • Receiver Sensitivity (Packet Error Rate <1%) • -85 dBm @ 2.4 GHz band • -92 dBm @ 868/915 MHz band • RSSI Measurements • Packet strength indication • Clear channel assessment • Dynamic channel selection José A. Gutierrez

  13. IEEE 802.15.4 PHY Overview PHY Primitives • PHY Data Service • PD-DATA – exchange data packets between MAC and PHY • PHY Management Service • PLME-CCA – clear channel assessment • PLME-ED - energy detection • PLME-GET / -SET– retrieve/set PHY PIB parameters • PLME-TRX-ENABLE – enable/disable transceiver José A. Gutierrez

  14. IEEE 802.15.4 MAC Overview Design Drivers • Extremely low cost • Ease of implementation • Reliable data transfer • Short range operation • Very low power consumption Simple but flexible protocol José A. Gutierrez

  15. IEEE 802.15.4 MAC Overview Typical Network Topologies José A. Gutierrez

  16. IEEE 802.15.4 MAC Overview Device Classes • Full function device (FFD) • Any topology • Network coordinator capable • Talks to any other device • Reduced function device (RFD) • Limited to star topology • Cannot become a network coordinator • Talks only to a network coordinator • Very simple implementation José A. Gutierrez

  17. IEEE 802.15.4 MAC Overview Star Topology PAN Coordinator Master/slave Communications flow Full function device Reduced function device José A. Gutierrez

  18. IEEE 802.15.4 MAC Overview Peer-Peer Topology Cluster tree Point to point Full function device Communications flow José A. Gutierrez

  19. IEEE 802.15.4 MAC Overview Combined Topology Clustered stars - for example, cluster nodes exist between rooms of a hotel and each room has a star network for control. Communications flow Full function device Reduced function device José A. Gutierrez

  20. IEEE 802.15.4 MAC Overview Addressing • All devices have IEEE addresses • Short addresses can be allocated • Addressing modes: • Network + device identifier (star) • Source/destination identifier (peer-peer) José A. Gutierrez

  21. IEEE 802.15.4 MAC Overview General Frame Structure • 4 Types of MAC Frames: • Data Frame • Beacon Frame • Acknowledgment Frame • MAC Command Frame José A. Gutierrez

  22. IEEE 802.15.4 MAC Overview Optional Superframe Structure GTS 2 GTS 1 Contention Access Period Contention Free Period 15ms * 2n where 0  n  14 Transmitted by network coordinator. Contains network information, frame structure and notification of pending node messages. Network beacon Beacon extension period Space reserved for beacon growth due to pending node messages Contention period Access by any node using CSMA-CA Guaranteed Time Slot Reserved for nodes requiring guaranteed bandwidth [n = 0]. José A. Gutierrez

  23. IEEE 802.15.4 MAC Overview Traffic Types • Periodic data • Application defined rate (e.g. sensors) • Intermittent data • Application/external stimulus defined rate (e.g. light switch) • Repetitive low latency data • Allocation of time slots (e.g. mouse) José A. Gutierrez

  24. IEEE 802.15.4 MAC Overview MAC Data Service Recipient MAC Originator MAC MCPS-DATA.request Channel access Data frame Originator Recipient Acknowledgement (if requested) MCPS-DATA.indication MCPS-DATA.confirm José A. Gutierrez

  25. IEEE 802.15.4 PHY Overview MAC Primitives • MAC Data Service • MCPS-DATA – exchange data packets between MAC and PHY • MAC Management Service • MLME-ASSOCIATE/DISASSOCIATE – network association • MLME-SYNC / SYNC-LOSS - device synchronization • MLME-SCAN - scan radio channels • MLME-GET / -SET– retrieve/set MAC PIB parameters • MLME-START / BEACON-NOTIFY – beacon management • MLME-POLL - beaconless synchronization • MLME-GTS - GTS management • MLME-ORPHAN - orphan device management • MLME-RX-ENABLE - enabling/disabling of radio system José A. Gutierrez

  26. For more Information visit: www.IEEE802.org José A. Gutierrez Principal Engineer e-mail: JoseGutierrez@eaton.com RF/Communications Group Innovation Center - Eaton Corp. 4201 North 27th Street Milwaukee, WI. 53216 José A. Gutierrez

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