1. IEEE 802.15.4 Standard The IEEE 802.15.4 (Low Rate Wireless Personal Area Network) Standard Lance Hester Ken Cornett Florida Communication Research Lab Motorola Labs May 20, 2002

2. 20 May 20022 Florida Communication Research Lab IEEE What? IEEE 802 LAN/MAN Standards Committee 802.1 Higher Layer LAN Protocols Working Group 802.11 Wireless Local Area Network Working Group … 802.15 Wireless Personal Area Network Working Group … 802.17 Resilient Packet Ring Working Group …… TG1 WPAN/Bluetooth Task Group TG2 Coexistence Task Group TG3 WPAN High Rate Task Group TG4 WPAN Low Rate Task Group … … Formed in November, 2000

3. 20 May 20023 Florida Communication Research Lab IEEE 802.15.4-- What it is: An WPAN standard optimized for low (0.01- 115.2 kb/s) data throughput applications with simple QoS requirements Lower power, lower cost than other WPANs (e.g., Bluetooth) Capable of multiple network types (star, cluster tree, etc.) Using ZigBee Consortium for marketing and compliance (like WECA/Wi-Fi/802.11b) What it is not: A WLAN A Bluetooth™ replacement (e.g., no isochronous voice capability) Optimized for multimedia, TCP/IP, or other high data rate applications A system, network, or application set

4. 20 May 20024 Florida Communication Research Lab 802.15.4 Physical Layers 2.4 GHz: 250 kb/s raw data rate, 1 Mc/s chip rate Chips: O-QPSK with half-sine shaping (a.k.a. MSK) Data: 16-ary orthogonal modulation 16 channels; 5 MHz channel separation -85 dBm sensitivity @ 1% PER (20 byte packets) Variable length payload size dependent upon addressing 868 (915- U.S.) MHz: 20 (40) kb/s raw data rate, 300 (600) kc/s chip rate Chips: BPSK with raised-cosine shaping Data: differential BPSK 1 (10) channels; 2 MHz channel separation @ 915 MHz -92 dBm sensitivity @ 1 % PER (20 byte packets)

5. 20 May 20025 Florida Communication Research Lab 802.15.4 Physical Characteristics Transmission Range ~ 10 meters indoors; ~ 30 meters outdoors @ Tx-Power = - 3 dBm (0.5 mW) Maximum regulated transmit power levels Power Consumption < 100  A Expected duty cycle of 1% and low power operation (under 0 dBm [1mW]) Power Supply AA battery Lifetime approx. 1 year Frequency BandGeographical Region Max. conductive power/ Radiated field limit Regulatory Document 2.4 GHzJapan10 dBm (10 mW)ARIB STD-T66 Europe (except Spain and France) 20 dBm (100 mW) EIRP or 10 dBm (10 mW) /MHz peak power density ETS 300- 328 USA30 dBm (1000 mW)47 CFR 15.247 902-928 MHzUSA30 dBm (1000 mW)47 CFR 15.247 868 MHzEurope14 dBm (25 mW)ETS 300-220

6. 20 May 20026 Florida Communication Research Lab 802.15.4 Physical Characteristics Bi-directional communication supported Uni-directional communication not supported All messages are acknowledged DSSS modulation mitigates multipath interference “1000 ns” chip length >> 30 ns propagation delay

7. 20 May 20027 Florida Communication Research Lab Chip Set information Yes! There is IC development for the 802.15.4

8. 20 May 20028 Florida Communication Research Lab 802.15.4 Medium Access Control (MAC) Features Extremely flexible support: Star, cluster tree, other network topologies, with optional network beacon  Application flexibility Slotted Access CSMA-CA Superframe period switchable from 15 ms to > 4 minutes  Trade power consumption, message latency, and throughput Optional guaranteed time slots in superframe  Low-latency applications (e.g., mice, wireless gaming) Low duty cycle: Can be < 0.1%  Low power consumption  Good coexistence with other services

9. 20 May 20029 Florida Communication Research Lab 802.15.4 MAC Super Frame Structure Beacon Contention Access Period Contention Free Period GTS 1 GTS 2 Super Frame Duration Allocated slot Network Beacon Contention Period Reserved for nodes requiring guaranteed bandwidth Access by any node using CSMA-CA Transmitted by nodes. Contains network information, super frame structure, and notification of pending messages

10. 20 May 200210 Florida Communication Research Lab Node Types Supported Distribution node Controls the network topology at that node Master/coordinator or mediation device  Stores routing information Talks to other distribution and slave nodes Slave node Cannot control the network Very simple implementation  Does not store routing information Talks only to a distribution node

11. 20 May 200211 Florida Communication Research Lab Related technology Cost Network Scalability Area (meters 2 ) High Moderate Low 10 2 10 6 10 0 10 4 Bluetooth 802.11b - ‘Wi-Fi’ 802.3 - ‘Wired Ethernet’ M2M 802.15.4 Fixed & Wireless Fixed Low latency intensive Intended for high power apps To complex for low- rate low-power apps 198019902000 2010 0.1 10 1 100 Data Rate (Mbps) 1G 802.15.3 802.15.1 2G 2.5G 3G 4G 802.11b PSTN 802.11x 802.3 802.11a Transitions from Wired to Wireless Evolution Path with Sustaining Innovation “Bluetooth” 802.15.4 Variable w/ Duty Cycle

12. 20 May 200212 Florida Communication Research Lab How Does 802.15.4 Match Up? Surveyed Wireless Sensor Wants IEEE 802.15.4 Provisions Low data rates Data rates  115.2 kb/s Usage of unlicensed frequencyISM band operation Long battery life Low duty cycle operation  Low power consumption Low cost devicesStandard for ultra low cost and low complex devices Architecture which adapts to accommodate various node types Platform for various networking schemes and supports multiple node types (e.g. distribution and slave nodes) Market acceptanceMember of well known 802 family