1. Part I: An overview of Zigbee(802.15.4) & u-PHI(Si2) Part II: Approach of Artificial Nervous System Date:4/12 Advisor:Prof. CY Huang Speaker: Scott

2. Outline Part I –What is ZigBee? –ZigBee Target Markets –ZigBee in the wireless world –ZigBee Network Topologies –MAC layer of 802.15.4 –Performance study(CUNY) –What is u-PHY? –Comparison with competitive techs Part II –Approach of Artificial Nervous System –Hierarchy Control / Sense mechanism –Possible Application –To do works

3. What is ZigBee? A standard for mesh networking –Built on the IEEE 802.15.4 standard –Reliability through meshed connectivity Designed for low power applications –Very long battery life Low data rate –20-250Kb/sec (depending on band) Very Secure –AES-128 encryption available Self configuring –Allows ad hoc networks –Ease of installation and configuration

4. Security HVAC Lighting Control Access Control Lawn & Garden Irrigation Asset Mgt Process Control Environmental Energy Mgt Patient monitoring Fitness monitoring Security HVAC AMR Lighting Control Access Control TV VCR DVD/CD RF Remotes ZigBee Target Markets ZigBee Wireless Control that Simply Works RESIDENTIAL/ LIGHT COMMERCIAL CONTROL CONSUMER ELECTRONICS PC & PERIPHERALS INDUSTRIAL CONTROL PERSONAL HEALTH CARE BUILDING AUTOMATION Chart Copyright ZigBee Alliance 2004

5. ZigBee in the wireless world Chart Copyright ZigBee Alliance 2004

6. ZigBee Network Topologies A simple star topology Only need one coordinator Full function device (FFD). Other sense nodes can be simple end device. Reduce function device(RFC)

7. ZigBee Network Topologies FFD (Full Function Device) Can act as a ZigBee Router & coordinator Helps form the mesh and route data RFD (Reduced Function Device) Can’t act as a router Only an end node Sensors

8. ZigBee Network Topologies

9. MAC layer of 802.15.4 Generating network beacons if the device is a coordinator Synchronizing to the beacons: Supporting personal area network (PAN) association and disassociation Employing the carrier sense multiple access with collision avoidance (CSMA-CA) mechanism for channel access Handling and maintaining the guaranteed time slot (GTS) mechanism Providing a reliable link between two peer MAC entities

10. Data Transmission in 802.15.4 Direct data transmission: This applies to all data transfers, device ←→coordinator,P2P. CSMA-CA is needed in this mode. Indirect data transmission: This only applies to data transfer, coordinator → devices. In this mode, a data frame is kept in a transaction list by the coordinator, waiting for extraction by the corresponding device. A device can find out if it has a packet pending in the transaction list by checking the beacon frames received from its coordinator. CSMA-CA is needed in this mode. (Low Power functions can only be applied in this mode!) GTS data transmission: This only applies to data transfer, device ←→coordinator No CSMA-CA is needed in GTS data transmission.

11. Superframe Structure in 802.15.4 Length is adjustable No need CSMA-CANeed CSMA-CA Direct, indirect

12. NS2 simulator of 802.15.4(CUNY, Samsung) Scenario Define & Topology

13. Scenarios in CUNY simulation 80m # of nodes 100 Transmission range 9 m Speed 250k bps BER 10 -5 Poisson traffic : 0.1pps (packet per sec) 0.2, 1, 5, 10 pps Packet size: 90 bytes Simulation time: 1000s

14. Performance study of 802.15.4 RTS (req to send)+ CTS (clear to send) is designed for hidden node problem. Zigbee cancel this function

15. Performance study of 802.15.4 Collision decreases when BO increases. High Collision rate is due to the hidden node problem.

16. Performance study of 802.15.4 ? GTS can not control the hop delay? Zigbee is designed for low data transmission. GTS only occupy 12.5% each superframe in this case. Guess: 1pp traffic may break the Qos guarantee.

17. Remark of Zigbee Zigbee does design for low rate data, 1pp (90 bytes) traffic seems to be the upper bound of the traffic load. Indirect transmission sacrifices the latency to gain the low power properties. Sleep time calculation in not perform in this study. I think this can be an important index in low power design.

18. What is u-PHI? 建立微瓦級無線近身網路 (Wireless Body Area Network) 監控系統 微瓦級射頻 (RF) 電路與實體層 (Physical Layer) 演算法 微瓦級媒體層 (Media Access Control) 與網路層 (Networking) 協定 Central Processing Node Body Area Network (BAN) 3G/GPRS WiFi WiMAX Physician Medical Server Emergency Health Care Center Family Body Area Network Internet ECG Sensors Motion Sensors Pulse Sensors Wireless Sensor Nodes (WSN)

19. Target Wireless UWB High Speed High Bandwidth Standardization 手機應用 電信服務 醫療服 務 社會資 源浪費 減少 軟體服務 Better Life u-PHI Ultra Low-Power Wireless Customized System Personal Healthcare

20. Wireless tech trend Range Data Rate (Mbps) ZigBee 802.15.4 802.15.3 802.15.3a 802.15.3c WPAN WLAN WMAN WWAN WiFi 802.11 0.010.11101001000 IEEE 802.22 WiMax IEEE 802.16 IEEE 802.20 Bluetooth 802.15.1 Opposite Trends Power Consumption Target Specification

21. NCTUIMECImperial College Systemu-PHIIR-UWBBluetoothIR-UWBZig-Bee ModulationOFDM/CDMAPPMFHSSPPMBPSK/O-QPSK Center Frequency(Hz) 1.4G (WMTS) 3~4G2.4GNo RF868M/915M/2.4G Radio B. W.(Hz)5M528M1M1G300k/600k/2M Data Rate(bps)20k/80k/160k100k250k~1M20k/40k/250k Data CompressionYesNo Burst/Continuous Transmission Mode YesNo Sensor Nodes1~10 N/A ~254 NetworkSimple star N/A Star/ad-hoc P2P/ cplx cluster tree Range(m)3< 2N/A10~75 Radio Power(dBm)-10-7-100~ -24 Total Power(W)1m 150m50m Energy(J/bit)6.25n10n150n2500n/1250n/200n NoteTaiwanBelgiumUK Comparison with competitive techs

22. Remark of u-PHI U-PHI is similar to Zigbee but more focus on low power design. 1/50 power consumption than Zigbee! Less nodes and simple star topology might limit it further application!? Does it can keep the low power criteria even with so many complex techs on it? (OFDMA, beam forming…)

23. Approach of Artificial Nervous System Not only sense but also act! sensory nerve Motor nerve

24. Hierarchy Control mechanism sensory nerve Motor nerve Abstract command (ex. kick) Detail command (ex. Move knees, foots)

25. Hierarchy sense mechanism sensory nerve Motor nerve Abstract sense (ex. hurt) PHY sense (ex. collision) (Reflex action) Detail command (kick)

26. Possible Application Health care an artificial limb (for handicaps) Robot control Game controller (like wii) Human rescue (localization) …

27. To do works & Problems Combine the low power properties of u-PHI and cluster tree topology of Zigbee. Guarantee Qos in low data transmission protocol. (Real time sense & act) Fast auto reconfigure mechanism (Fast repair from problem nervous System)

28. To do list Familiar with the NS2 Zigbee platform Low power MAC design in a simple star network(u-PHI) Low power MAC design in a tree network Low power MAC design in a tree network and keep certain Qos requirement Low power MAC design in a tree network & keep certain Qos requirement & fast reconfiguration mechanism