Wireless Sensor Networks with Smart Phones CHEN Xinyu

Wireless Sensor Networks with Smart Phones CHEN Xinyu 2011 -11 -01 Dept. of Computer Science & Engineering, The Chinese University of Hong Kong

Outline Representational scenarios Wireless protocols Application development Conclusion Dept. of Computer Science & Engineering, The Chinese University of Hong Kong 2

Wireless Sensor Networks (WSNs) r A number of small devices, each with n n n A micro-controller A wireless interface One or more sensors/actuators Dept. of Computer Science & Engineering, The Chinese University of Hong Kong 3

Vision from Smart Phones r Sensors as a network of accessories that can be discovered by and communicated with smart. Hearing phones EEG Pulse Blood Pressure ECG Glucose Oxygen Body Area Networks EMG Motion Sensor Dept. of Computer Science & Engineering, The Chinese University of Hong Kong 4

Smart Phones with Sensors/Actuators Android@Home Automation • Light control • Power control • Window control • Door control • TV control • Home stereo system • … Dept. of Computer Science & Engineering, The Chinese University of Hong Kong 5

Outline Representational scenarios Wireless protocols Application development Conclusion Dept. of Computer Science & Engineering, The Chinese University of Hong Kong 6

Lo. WPAN Low-power Wireless Personal Area Network r Standards r n IEEE 802. 15. 1 Bluetooth Ú n IEEE 802. 15. 4 Ú r Eliminate wiring 250 kb/s Companies n Zig. Bee Ú n n Owned and controlled by a consortium of companies Z-Wave, En. Ocean, Mesh. Scape Synapse Wireless: SNAP Ú Synapse Network Appliance Protocol Dept. of Computer Science & Engineering, The Chinese University of Hong Kong 7

Io. T and IPv 6 r Internet of Things n r Having uniquely identifiable objects along with their virtual representations accessible and controllable using an Internet-like structure IPv 6 n n IPv 4: uses 32 -bit addresses IPv 6: uses 128 -bit addresses 340, 282, 366, 920, 938, 463, 374, 607, 431, 768, 211, 456 Ú No need for NAT anymore n Network Address Translation Ú Dept. of Computer Science & Engineering, The Chinese University of Hong Kong 8

IPv 6 over 802. 15. 4 r Fragmentation n IPv 6: Minimum MTU is 1, 280 bytes Ú n r 802. 15. 4: Maximum 127 bytes Head compression n n r Maximum Transmission Unit IPv 6: 40 bytes 802. 15. 4: effective link payload is 81 bytes Routing n n IPv 6: A link is a single broadcast domain 802. 15. 4: a mesh of short-range connections Dept. of Computer Science & Engineering, The Chinese University of Hong Kong 9

Mesh-Under vs. Route-Over APP TCP/UDP IPv 6 6 Lo. WPAN Adaptation Layer 802. 15. 4 MAC 802. 15. 4 PHY Dept. of Computer Science & Engineering, The Chinese University of Hong Kong 10

Mesh-Under vs. Route-Over APP TCP/UDP IPv 6 6 Lo. WPAN Adaptation Layer 802. 15. 4 MAC 802. 15. 4 PHY Dept. of Computer Science & Engineering, The Chinese University of Hong Kong 11

Mesh-Under vs. Route-Over APP TCP/UDP IPv 6 6 Lo. WPAN Adaptation Layer 802. 15. 4 MAC 802. 15. 4 PHY Dept. of Computer Science & Engineering, The Chinese University of Hong Kong 12

Mesh-Under vs. Route-Over APP TCP/UDP IPv 6 6 Lo. WPAN Adaptation Layer 802. 15. 4 MAC 802. 15. 4 PHY Dept. of Computer Science & Engineering, The Chinese University of Hong Kong 13

RPL: Routing Protocol for LLNs r Ro. LL working group n r Routing over Low-power and Lossy Network (LLN) Routing state propagation n Conventional Link-state: scoped flooding Ú Distance-vector: periodic routing beacons Ú n r Spatial diversity n r Trickle: adaptive exchange rate A router maintains multiple potential parents Expressive link metrics n ETX: Estimated Number of Transmissions Dept. of Computer Science & Engineering, The Chinese University of Hong Kong 14

Outline Representational scenarios Wireless protocols Application development Conclusion Dept. of Computer Science & Engineering, The Chinese University of Hong Kong 15

Application Development r Tiny. OS: Monolithic image n n Loaded into the wireless node’s microcontroller using a physical link (USB) Applications have to be recompiled for each different type of microcontroller Ú when changed Ú r nes. C n Network Embedded Systems C Dept. of Computer Science & Engineering, The Chinese University of Hong Kong 16

Application Development r Virtual machine n Java: Android Ú n Python: Android@Home? Ú r Dalvik VM Py. Mite Python n n An open source scripting language "Battery included" Ú n A standard distribution includes many modules Dynamically typed Ú Java: statically typed Dept. of Computer Science & Engineering, The Chinese University of Hong Kong 17

Killer-Apps The industry has not yet found a true "killer-app" for WSN r Provides r n Rich and easy API for application developers Ú n Hide the details of WSN Open application development Ú Indicated by the success of Android and i. Phone Dept. of Computer Science & Engineering, The Chinese University of Hong Kong 18

Conclusion r Scenarios: WSN with smart phones n n n r Networking n n r Body area networks Home automation … 6 Low. PAN: IPv 6 over 802. 15. 4 Routing? Applications n Python? Dept. of Computer Science & Engineering, The Chinese University of Hong Kong 19

Dept. of Computer Science & Engineering, The Chinese University of Hong Kong 20