Advancements in Ubiquitous Sensor Networks: Technology, Applications, and Challenges

1. USN introduction Hanback Corp.

2. Ubiquitous Sensor Network

3. Background • Ubiquitous Society • Provide information or service anytime, anywhere in a intangible manner • Base Technology for Ubiqitous Env.: USN • Tech. for Human’s behavior pattern or environment monitoring • More intelligent service is possible • Purpose of USN • Collecting, Processing & Transmitting Data by establishing network • One of the most highlighted Tech.[MIT’s Technology Review, Feb. 2003]

4. Wireless Sensor Network • Characteristics • Accuracy of Sensor Devices • Limited Power– battery system • Limited size and price • Limited bandwidth –무선 채널의 한계 • LimitedRF output • Trade-off among elements

5. Hardware Platform of (Smart) Sensor • Devices • CPU: 8bit/16bitsmall/low power micro controller • Wireless modem: • Short distance/low power wireless communication device • RFM TR1000, Chipcon CC1000, Bluetooth, IEEE 802.15.4 • Battery System • Wireless Sensor Network Platform • Berkeley Motes/Mica2/Mica2Dot, Intel Research iMote, Stargate, Hanback ZigbeX

6. Crossbow MICA-2 (Berkeley Mote) • Processor • Atmel 8-bit 프로세서 (CPU 8Mhz) • 128KB Flash program memory • 4KB SRAM • RF Interface • Chipcon CC1000 • Radio range: 약 10m • Data rate: 40 Kbits/sec • Frequency range: 300 ~ 1000 MHz • OS: TinyOS • Multi-Sensor Board <MICA 2> <Sensor Board>

7. Intel iMote • High performance and high throughput • Node for video and audio information • Computing • Strong ARM 32-bit RISC processor • 512KB Flash, 64 KB SRAM • Radio Transceiver • Bluetooth • Data rate: 500Kbps~1Mbps • Frequency : 2.4 GHz (ISM) • OS: TinyOS

8. Rockwell WINS • COU • StrongARM SA 1100, 32-bit processor, 1MB SRAM, 4MB flash • RF Interface • 900MHz spread spectrum radio, with dedicated microcontroller: 32KB RAM, 1MB bootable flash • Size • 3.5”x3.5”x3” package size

9. MIT µAMPS • ‘highly integrated, yet flexible sensor node based on two dedicated chips’ (off-the-shelf -> systems on chip) • StrongARM SA1110 32-bit, 206MHz, RISC processor • 3 acoustic sensors attached to each node, for estimation of direction of target (µAMPS I)

10. UCLA Medusa MK-2 • radio-acoustical localization • ATMega 128L 8-bit, 8MHz, 4KB flash, 4KB SRAM ( interface w/ sensors & radio) • ARM Thumb 32-bit, 40MHz, 1MB flash, 136KB RAM (more demanding processing) • TR1000 radio Monolithics (OOK, ASK modulation) • ultrasonic ranging system, light & temperature

11. Hanback Zigbex • Computing • Atmel 8-bit RISC microcontroller • 128KB Flash program memory • 4KB SRAM • Radio Transceiver • Chipcon CC2420 • Radio range: (130m) • Data rate: 240 Kbits/sec • Frequency range: 2.4 GHz (ISM) • TinyOS, Nano-Qplus(ETRI KoreaOS) • RFID reader+ RFID tag • Base sensor + Multi-modal Sensor Board

12. RFID • RFID (Radio Frequency Identification) : • Implemented in 1960s. • Low price tag. • A RFID system : • RFID Tag (or Transponder): micro chip for identification using serial number(passive or active) • Passive(w/o battery) • Active (w/ battery ) • RFID Reader: reading device

13. RFID System

14. ConvetionalID Systems • Bar Code

15. Comparison with ID Systems

16. Ubiquitous Sensor Networks • Ubiquitous Sensor Networks • RFID&wireless sensor network: • RFID tagging and environment monitoring • Flexible networking • Event based collection • Network maintainability • From node to sink, communication must be survived • Easy network configuration • Improved Ad-Hoc network

17. Ad Hoc Wireless Networks • Ad Hoc Networks • Enabling technology to establish network without BS or AP. • Characteristics • Easy installation • Low management cost • Limited transmission distance • Dynamic topology establishment • Security vulnerability

18. USN vs. Ad Hoc Networks • Similarity: • Dynamic topology • Self-organization • Energy limitation • Routing by nodes • Difference(USN): • Much limited resource (power, size, memory, etc) • Many number of nodes • Working on more severe environment

19. Research Topics

20. USNRelated Projects • Smart Dust and PicoRadio (UC at Berkeley) • WINS (UC at Los Angeles) • Wireless Integrated Network Sensor • COUGAR (at Cornell Univ.) • “The Network is the Database” • IrisNet (at Carnegie Mellon Univ.) • Internet-scale Resource-Intensive Sensor Network Service • RFID/USN ITRC (Korea)

21. USN Protocol Stack • Sensor network architecture • Research subject in Protocol stack • Energy efficient networking • Localization • Synchronization • Efficient Data aggregation

22. MAC Layer • Assumption • Energy efficiency • Maximization of Bandwidth • MAC protocols for USN • Cellular system’s MAC: • high QoS • Mac in Bluetooth and ad-hoc : • TDMA by Master node

23. Network Layer (Routing) • Requirements • energy-efficiency routing protocols • Scalability • Data aggregation

24. Transport Layer • Resource Limitation Plug-in Transport Layer • TCP Ack mechanism is too costly. • Transport Protocol is needed only for USN

25. Application Layer • Open research • Database • Middleware

26. The End !!!