20080304 rfid usn기초 v2.ppt [호환...

무선 센서 네트워크의 기술 동향무선 센서 네트워크의 기술 동향

2008. 03. 13

김재현 / 아주대학교

WWireless IInformation aNNd NNetwork EEngineering RResearch Lab.WWireless IInformation aNNd NNetwork EEngineering RResearch Lab. Ajou University, Korea

Contents

USN 개념 및 소개

RFID 기술 및 응용RFID 기술 및 응용

센서 네트워크 장점 및 응용

USN 플랫폼 구성 요소 및 역할USN 플랫폼 구성 요소 및 역할

USN 기술 및 요구사항

무선 센서 네트워크 표준무선 센서 네트워크 표준

결론

참고문헌참고문헌

김재현 / 아주대학교USN 개요 - I 2


USN (Ubiquitous Sensor Network) 이란 ?Infrastructure network for realizing ubiquitous computingInfrastructure network for realizing ubiquitous computing environment using sensor nodes with sensing, processing and wireless communication capabilities

모든 사물에 전자 태그 부착

사물 정보 및 환경정보까지 감지

네트워크에 연결하여 실시간 관리

U qUbiquitousSSensor

Network네트워크에 연결하여 실시간 관리 Network

물류/유통 : SCM,재고관리동물관리

USNUSN홈 네트워크

쇼핑센터 : 자동계산대동물관리

USNUSN

병원환자 관리

홈 네트워크교통 : 텔레매틱스

ITS시스템

교통요금


환경 : 공해감시

(자연)재해관리

병원환자 관리

RFID 기술 및 응용



RFID (Radio frequency Identification) 이란 ?RFID is a simple form of ubiquitous sensor networks that are used toRFID is a simple form of ubiquitous sensor networks that are used to identify physical objects

Remote identificationNon-line-of-sightAutomatic reading

Tag RF Channel Reader Local Server Network


* RF – Radio Frequency


RFID 주파수 및 응용 분야

ID cardName: Rei ItsukiNo : 00012345

POST CARD

No.: 00012345Div.: Mu VCCompany: Hitachi, Ltd.

Embedded μ-chip

Invitation forHitachi Exhibition 2002

GlobalPassport, ID card

13.56Mhz(ISO 18000-3)

433.92MHz(ISO 18000-7)

960MHz (ISO 18000-6)

2.45GMhz(ISO 18000-4)

125KHz,134KHz(ISO 18000-2)

860MHz



RFID 기술 별 가격 전망

$100

Acti S

$50

$10ive C

hip

Sem

i-Active$10

$1

30c

e Chip P

assiv30c

10c

ve Chip

Chipless

5c

1c 이상

s


자료출처 : ID TechEx


RFID 가격 별 적용 분야 및 특성

분야 이용목적 기능특성태그 가격대

위치측정

10만원 정도

1만원 정도

군사의료

군용품의료기기

위치측정진단기능보안

교통 (요금지불,도난방지 보험 등)

차량 주행증자동 요금지불

주행 중 요금지불인증 보안

1천~5천원

도난방지,보험 등) 자동 요금지불 인증,보안

출입통제유통 (컨테이너,파렛트)

출입통제컨테이너,파렛트,가축등의 추적

보안

100~1000원

50원

항공,세탁물가구,미술품

물품관리고속 읽기,쓰기위조 방지

제조(공장),목재 자산관리 위조 방지50원

10원 정도

( ),소매(고가품목) 제품,목재 등의 추적 추적

소매(저가품목)교통(티켓)

소매품 관리 및 추적교통기관의 티켓추적

저 가격,저 기능추적 기능


자료출처 : IDTechEx


RFID 기술 발전 전망

2006년2005년 2007년 ~2010년구 분

2004년

지능화네트워크화, 초소형화, 초저가화고속화, 소형화, 저가화

태그/칩

, ,, ,

저전력 CMOS 칩 NANO, MEMS 초소형 칩 폴리머 칩

표면 탄성파 재질 이용 회로코일-콘덴서 회로

프린팅 안테나 패키징 칩 내장형 안테나 패키지 안테나

리더단일 대역 빔성형 안테나/RF 기술 다중대역, 광대역 안테나/SDR 기술

프린팅 안테나/패키징 칩 내장형 안테나 패키지 안테나

코드 읽기 전용 태그 센서통합 다기능 태그 자율통신 태그

리더

네트워크

연동

리더/인터넷 연동 이동통신망/휴대인터넷 연동 4G/BCN 연동

고속 다중 인식: 100 Tag/초 200 Tag/초 300 Tag/초

텔레매틱스, 홈네트워크 연동

서비스•업무 자동화•장거리 다중 물품 인식•고가 물품 관리

• 물품 정보 인식/ 추적

• 환경감지 정보 이용/관리/추적• 사물 위치 측정/추적

• 생활용품 인식/ 관리

• 사물간 자율 통신

텔레매틱스, 홈네트워크 연동



Multi-tag anti-collision algorithm in RFID

Arbitration Air Interface(R->T / T->R)

EPC Data rate(R->T / T->R)

Security

ISO 18000 6 Framed Pulse interval ASK / not 33 kbps /ISO 18000-6TYPE A

Framed Slotted

Pulse interval ASK / FM0

notdefined

33 kbps /40 kbps

None

ISO 18000-6 Probabilistic Manchester-ASK / not 8/40 kbps /None

TYPE B Binary tree FM0 defined 40 kbpsNone

AutoID Class 0

Bit-by-bit Binary Tree

Pulse Width Mod./FSK

64/96b40/80 kbps /40/80 kbps

24-bit killClass 0 y p

AutoID Class 1

Binary treeusing 8 bin slots

Pulse Width Mod. / Pulse Interval AM 64/96b

70.18 kbps/140.35 kbps

8-bit kill

EPCglobal Gen 2

ProbabilisticSlotted

Pulse interval ASK /Miller, FM0

96/496b40 kbps /640 kbps

32-bit kill,Access


센서 네트워크 장점 및 응용센서 네트워크 장점 및 응용



Sensor Network ApplicationsBuilding AutomationBuilding AutomationPersonal Health CareIndustrial Control

PERSONAL HEALTH CARE

Telecom ServicesHome Control

INDUSTRIALCONTROL

Consumer ElectronicsPC & Peripherals

TELECOM SERVICESCONTROL SERVICES

PC & BUILDING AUTOMATION CONSUMER HOME


PERIPHERALSAUTOMATION ELECTRONICSCONTROL


Sensor Network ApplicationsBuilding AutomationBuilding Automation

Security, HVAC, AMR, lighting control, and access controlPersonal Health Care

Patient monitoring and fitness monitoringPatient monitoring and fitness monitoringIndustrial Control

Asset management, Process control, and energy managementTelecom Services

m-commerce, info services, and object interactionHome Control

Security, HVAC, lighting control, access control, and irrigationConsumer Electronics

TV VCR DVD/CD and remoteTV, VCR, DVD/CD, and remotePC & Peripherals

Mouse, keyboard, and joystick



Characteristics of USNLarge number of sensor nodes

Maybe 10 to 100,000 nodes (scalability)Node position may not be predeterminedLow cost

Low energy consumptionTo relocate & recharge large number of nodes is impossibleLife time of sensor network depends on battery life time

Network self-organizationLarge number of nodes in hostile locations

Manual configuration unfeasibleN d f il & d j i h kNodes may fail & new nodes join the networkAd-hoc sensor network protocols

Collaborative/Distributed processingL ll i l i f d d dLocally carry out simple computation -> forwards and aggregate data

Query ability (Sensor Database)Single node or group of nodesB d ll d f i &


Base nodes collect data from given area & create summary messages


USN and Ad-hoc Network Comparison

Items for comparison Sensor Network Ad-hoc Network

Number of nodes 100 ~ 1000 10 ~ 100

Deployment Densely Relatively sparsely

Failure Prone to failure Not prone to failurep

Communication Broadcast Point-to-point

Topology change Very frequent Almost steadyTopology change Very frequent Almost steady

Power Limited Rechargeable

Resource Limited Relatively highResource Limited Relatively high

ID Local ID Global ID(IP address)


* Source – APNOMS 2005 Tutorial, Okinawa, Japan

플랫폼 구성 요소 및 역할USN 플랫폼 구성 요소 및 역할


USN 플랫폼 구성 요소 및 역할

USN Protocol StackCoordinating to minimize duty cycle and communicationCoordinating to minimize duty cycle and communication

Adaptive topology, routing, and adaptive MACIn-network processing

Data centric routing and programming models

Logical Function of layersLogical Function of layers

Application User Queries, External Database

Transport Application Processing, Aggregation, Query Processing

Network Adaptive topology, Geo-Routing

Data link MAC, Time, Location, Adaptive

Ph i l C i ti S i A t ti


Physical Communication, Sensing, Actuation


USN Protocol StackPhysical LayerPhysical Layer

NeedsSimple, but robust modulation, transmission, and receiving technique

Transmission mediaRadio

ISM (Industrial, Scientific, Medical) 915MHz band widely suggestedInfraredOptical media

Open research issuesModulation scheme

Need simple and low-power modulation schemeHardware design

Tiny, low-power, low-costPower-efficient hardware management strategy



USN Protocol StackData Link LayerData Link Layer

Responsible for multiplexing of data streams, Medium Access control (MAC) and Error ControlMedium Access Control (MAC)Medium Access Control (MAC)

Creation of the network infrastructureFairly and efficiently communication resources sharing between sensor nodes

MAC for Sensor NetworkSMACS (Self-Organizing Medium Access Control for Sensor Networks)EAR (Eaves-drop-And-Register) AlgorithmCSMA-Based MAC schemeHybrid TDMA/FDMA-Based MAC scheme

Power Saving Modes of OperationError Control

FEC (Forward Error Correction)ARQ (Automatic Repeat Request)



USN Protocol StackNetwork LayerNetwork Layer

NeedsData Routing

iRequirementPower efficiency, Data-centric, Data aggregation

S h D i tiScheme DescriptionFlooding Broadcasts data to all neighbor nodes

Gossiping Sends data to one randomly selected neighbor

LEACH Forms a cluster to minimize energy loss

SPIN Sends data to sensor nodes only if they are “interested”, has 3 types of messages (ADV, REQ, DATA)

Directed diffusion Sets up gradients for date to flow from source to sink during interest disseminitionDirected diffusion Sets up gradients for date to flow from source to sink during interest disseminition

Power Efficiency Routing

Pick a route based on : Max. Power Available(PA), min Energy (ME), , Min Hop(MH), or Max Min PA

Smecn Create a sub-graph of the sensor network that contains the minimum energy path


Smecn Create a sub graph of the sensor network that contains the minimum energy path

SAR Creates multiple trees where the root of each tree is one hop neighbor from the sink


USN Protocol StackTransport LayerTransport Layer

NeedsMaintain the flow of data if the sensor networks applications requires it

ResearchCommunication between user and sink node

TCP or UDP via the internet or satelliteCommunication between sink node and sensor node

UDP type protocol, because sensor node has limited memory

NamingNot based on global addressingAttribute-based naming



USN Protocol StackApplication LayerApplication Layer

NeedsDepending on the sensing tasks, different types of application software built and usedand used

Application layer protocolsSMP (Sensor Management Protocol)

S d i i i i h k i SMPSystem administrators interact with sensor networks using SMPTADAP (Task Assignment and Data Advertisement Protocol)SQDDP (Sensor Query and Data Dissemination Protocol)


기술 및 요구 사항USN 기술 및 요구 사항

- Location Technology in USN

- Time Synchronization in USNy

- USN Management

- USN Management Requirement

- USN Management Goal

- USN Management Architecture

- USN Management Functional Area


Location Technology in USN

Discovery of absolute or relative locationGeographical routing (location attribute based naming andGeographical routing (location attribute based naming and addressing)Tracking of moving objectsContext (location) aware applicationsContext (location) aware applications

Challenges in USNEnergy constraintgyHarsh environment with multi-pathsMinimal infrastructure (Few beacons, No backend computation)

M t h i f l ti iMany techniques for location sensingTOA (Time Of Arrival)TDOA (Time Difference Of Arrival)TDOA (Time Difference Of Arrival)AOA (Angle Of Arrival)SSR (Signal Strength Ranging)GPS t


GPS, etc.

Time Synchronization in USN

Critical at many layers of sensor networkCommunication localization distributed DSP etcCommunication, localization, distributed DSP, etc.Conventional approaches

GPSIndoors?, cost, size, energy

NTP (Network Time Protocol)Delay and jitters due to MAC and store-and-forward relayingy j y gDiscovery of timer servers (nodes synchronize with one of a pre-specified list of time servers)

Reference-broadcast synchronization (RBS)Reference-broadcast synchronization (RBS)Very high precision sync. with slow radios

Beacons are transmitted, using physical-layer broadcast, to a set of receiversTime synchronization is based on the difference between reception times, do not sync sender with receivers


USN Management

Why isn’t SNMP (Simple Network Management Protocol) adaptable to USN?Protocol) adaptable to USN?

Sensor-specific failures are not handledDifficult to find the failed nodesPhysical connections are not utilizedCommonly, there is not a management agentSpecifying nodes is difficultSpecifying nodes is difficultNetwork is self-configured, so that management server doesn’t have all information of sensor nodes

Ch llChallengesPresent many and drastically different challenges. For example:

Deployment of nodes, Discarding of nodesp y , gRequire augmentation to (or new approaches over) traditional network and service management techniquesNeed to take into account specific characteristics of WSNs (e g energy


Need to take into account specific characteristics of WSNs (e.g., energy waste)

USN Management Requirements

Fault toleranceHandle loss of nodes - Lack of Power, Physical damage, Environmental interferenceinterference

ScalabilityHandle high density of nodes - The number of sensor nodes is an extreme value of millions

P d ti tProduction costsMake them low cost - Cost of a single node is very important to justify the overall cost of the network

Operating environmentp gSurvive and maintain communication - The bottom of an ocean, biologically contaminated field, battlefield

Transmission mediaWireless Radio infrared optical mediaWireless - Radio, infrared, optical media

Hardware constraintsNodes are tiny - Very small size, very light node, limited memory, limited battery

Power consumptionPower consumptionLimited Tx, computation, lifetime - Replenishment of power is impossible

Changing TopologyNodes - Nodes moving, new nodes, loss nodes


USN Management Goal

Promote resources productivityMaintain the quality of the services providedMaintain the quality of the services providedApplication-dependent and the management solution design is affected

USN USNM tAffectApplications Management

DesignAffect

Developing management solutions for USNNot trivialBecome worse due to the physical restrictions of sensor nodesBecome worse due to the physical restrictions of sensor nodes

Energy, bandwidth, ……Significantly different with the management of traditional networks


networks

USN Management Architecture


USN Management Functional Areas

Functions

Fault

- Faults in USNs are not an exception and tend to occur frequently, thus fault management is a critical function

- This is one of the reasons that make USN management different from traditional network managementS lf di ti th t k it it lf d fi d f lt il bl d- Self-diagnostic : the network monitors itself and find faulty or unavailable nodes

- Self-healing : the network prevents disruptions or that acts to recover itself or the node after the self-diagnostic

- Self-organization : is the property which the sensor nodes must have to organize themselves to Configuration form the network

- Self-configuration : nodes setup and network boot up must occur automatically

Accounting-It includes functions related to the use of resources and corresponding reportsIt establishes metrics quotas and limits that can be used by functions of other functional areasAccounting -It establishes metrics, quotas and limits that can be used by functions of other functional areas

-It must provide self-sustaining functionalities

Performance- There is a trade-off to be considered : the higher the number of managed parameters, the

higher the energy consumption and the lower the network lifetimePerformance - On the other hand, if enough parameter values are not obtained, it may not be possible to manage the network appropriately

Security- Security functionalities for USNs are intrinsically difficult to be provided because of their ad-

hoc organization, intermittent connectivity, wireless communication and resource limitations


Security- A USN is subject to different safety threats : internal, external, accidental, and malicious

선 센서 네 워 준무선 센서 네트워크 표준

- IEEE 802.15.4

- ZigBee overview


무선무선 센서센서 네트워크네트워크 표준표준

IEEE 802 Wireless Space

WWAN IEEE 802.22

WMANWiMax

IEEE 802.20

Ran

ge

WLAN WiFi

WiMaxIEEE 802.16

ZigBee802.15.4

15 4c802.15.3802 15 3WPAN

WLAN WiFi802.11

Bluetooth15.4c 802.15.3cWPAN

0.01 0.1 1 10 100 1000

802.15.1


Data Rate (Mbps)


IEEE 802.15.4 overviewLow Cost Power and Rate (20 40 250Kbps)Low Cost, Power, and Rate (20, 40, 250Kbps) Short Range (less than 10m)Dynamic device addressingSupport for low latency devices Reliable by fully handshake protocolCSMA-CA channel access. Low power consumptionApply toApply to

u-Smart Home Network : Energy save, Consumer Electronics, Toy, SecurityH l h h k d i i SHealth care check and monitoring System

TopologyStar or peer-to-peer topology


p p p gy


IEEE 15.4 PHY

2MHz 5MHzChannel 1-10 Channel 11-26Channel 0

868MHz 902MHz 928MHz 2 4GHz 2 4835GHz

Frequency 868MHz 915MHz 2.4GHz

D t R t 20kb 40kb 250kb

868MHz 902MHz 928MHz 2.4GHz 2.4835GHz

Data Rate 20kbps 40kbps 250kbps

Modulation BPSK BPSK O-QPSK

# of Channel 1 10 (2MHz) 16 (5MHz)

Packet period 53.2ms 26.6ms 4.25ms

Receiver sensitivity < -92dBm < -92dBm < -85dBm

Range 10 20m(1mW) 10 20m(1mW) 10 20m(1mW)


Range 10~20m(1mW) 10~20m(1mW) 10~20m(1mW)


MAC overviewFeatures of the MAC sub-layerFeatures of the MAC sub layer

Beacon managementChannel accessGuaranteed time slot managementGuaranteed time slot managementFrame validationAcknowledged frame deliveryAssociation and disassociationAssociation and disassociationSecurity mechanisms

FFD (Full Function Device)A device capable of operating as a coordinator or device, implementing the complete protocol set.

RFD (Reduced Function Device)A device operating with a minimal implementation of the IEEE 802.15.4 protocol.Can not be a coordinator device



802.15.4 MAC/PHY Frame Format

Frame Sequence Address Payload FCS

2octet 1 4-20 n ≤ 102 2

MAC

MHR MSDU MAF

control number info Payload FCS

3.75~50.625~2.5

1octet

MAC

SHR PHR Physical Service Data Unit (PSDU)

Preamble SFD FL MAC Protocol Data Unit (MPDU)

PHY

Physical Protocol Data Unit (PSDU)

- FCS : Frame Check Sequence - MHR : MAC Header - MSDU : MAC Service Data Unit

PPDU size : 13.5 + ( 4 to 20) + n (≤ 135.5 Octet)


- MAF : MAC Footer - FL : Frame Length - SFD : Start Frame Delimiter - SHR : Synchronization Header - PHR : Physical Header - PPDU : Physical Protocol Data Unit


IEEE 802.15.4 Operational Modes

IEEE 802.15.4 MAC

Beacon Enabled Non Beacon Enabled

Superframe Unslotted CSMA/CA

Contention Access Period (Without GTS)

Contention Access/ Contention Free Periods

(With GTS)

Slotted CSMA/CA Slotted CSMA/CA

/ Slot Allocations



IEEE 802.15.4 Superframe Structure

김재현 / 아주대학교USN 개요 - I 39 39


IEEE 802.15.4 Superframe StructureThe superframe structure without GTSsThe superframe structure without GTSs

Frame Beacon

Inactive PeriodContention Access Period

The superframe structure with GTSsThe superframe structure with GTSsFrame Beacon

Inactive PeriodContention

Access Period

Contention Free Period


CSMA/CA protocol

Use different Inter Frame Space (IFS) to differentiate traffictraffic

SIFS (Short Inter Frame Space) : High PriorityPIFS (PCF Inter Frame Space) : Medium PriorityDIFS (DCF Inter Frame Space) : Low Priority

DIFS Contention WindowPIFSDIFS

Sense channel during DIFS

Slot time

Busy Medium Backoff-Window Next FrameSIFS

Defer Access Backoff slot reduced when channel is idle


CSMA/CA protocol

Exponential Back-off AlgorithmCW : Contention Window ( 0 to CW min ~ CW max ) :CW : Contention Window ( 0 to CW_min ~ CW_max ) :

Backoff delay = int(CW * Random()) * Slot TimeSlot time : Receiver turn on time + propagation delay + media busy detection timedetection time

CW_min : 11.a = 15, 11.b = 7, 11.b HR = 31, CW_max = 1023 CW is doubled when transmission is failed

CW_max=255 255300

Example

127150

200

250

CW_min=7

3163

0

50

100

1 2 3 4 5 6


1 2 3 4 5 6

CSMA/CA protocol

CSMA/CA with ACKDefer access based on Carrier SenseDefer access based on Carrier Sense

CCA from PHY and Virtual Carrier Sense stateDirect access when medium is sensed free longer than DIFS, otherwise d f d b k ffdefer and backoffReceiver of directed frames to return an ACK immediately when CRC correct

When no ACK received, then retransmit the frame after a random backoff (up to a maximum limit)


CSMA/CA protocol

Hidden Node ProblemWhile STA-A sends data to STA-BWhile STA-A sends data to STA-B

STA-C may try to communicate with STA-BResulting in the collision in STA-B

STA-A don’t know whether there is STA-C or notUse RTS-CTS dialogue to resolve Hidden Node Problem

STA-BSTA-A STA-C

Collision


CSMA/CA protocol

CSMA/CA with RTS-CTS


CSMA/CA protocol

Exposed Node ProblemBy RTS-CTS dialogueBy RTS-CTS dialogue

B C EDAF

RTS RTS

DATA DATA

CTS CTS

DATA DATA

ACKACK


Reserved area

ZigBee OverviewZigBee Overview


Basic Network Characteristics

65,536 network (client) nodes27 channels over 2 bands27 channels over 2 bands250Kbps data rateO ti i d f ti i iti l li ti dOptimized for timing-critical applications and power management

Full Mesh Networking SupportFull Mesh Networking Support

Network coordinatorFull Function nodeReduced Function node

Communications flowVirtual links


Basic Radio Characteristics

ZigBee technology relies upon IEEE 802.15.4, which has excellent performance in

l SNR i t


low SNR environments

ZigBee Mesh Networking


ZigBee Stack Architecture (1/2)

Application/ProfilesZigBee or OEM

(User Defined)

ZigBee Characteristics- Addressing

Assign the address to node dependApplication Framework

Assign the address to node depend on network configuration

- Location

Network/Security Layers

MAC Layer

ZigBee

Alliance

Platform

Have a location information depend on a network topology in sensor network

PHY LayerIEEE - Synchronization

Common Sync Technology is used

(NTP RBS TPSN FTSP)(NTP, RBS, TPSN, FTSP)


ZigBee Stack Architecture (2/2)

Initiate and join network

Applicationj

Manage networkDetermine device relationshipsSend and receive messagesSend and receive messages

Application ZDOApplication ZDO

App Support (APS)SSPSecurity functions

Device managementDevice discovery

Medium Access (MAC)

NWKSSP

Network organizationRoute discovery

Device bindingMessaging

Service discovery

Physical Radio (PHY)

( )Message relaying

Messaging


ZigBee Device Types

ZigBee Coordinator (ZC)One required for each ZB network.Initiates network formationInitiates network formation.

ZigBee Router (ZR)ZigBee Router (ZR)Participates in multihop routing of messages.

ZigBee End Device (ZED)Does not allow association or routing.gEnables very low cost solutions


ZigBee Network Topologies

ZigBee CoordinatorZigBee RouterZigBee End Device


ZigBee End Device

<Mesh>

결론


RFID 기술 및 응용RFID 기술 및 응용


USN 플랫폼 구성 요소 및 역할USN 플랫폼 구성 요소 및 역할

USN 기술 및 요구사항

무선 센서 네트워크 표준무선 센서 네트워크 표준


참고문헌

유승화, “RFID/USN 시장 및 기술 동향”, 2004.S. Birari and S. Iyer, “PULSE : A MAC Protocol for RFID Networks”, USN2005, Dec. 2005.J. R. Cha and J. H. Kim, "Performance evaluation of EPCglobal Gen 2 protocol in wireless channel," in Proc. OPNETWORK 2006, Washington D.C, USA, Aug. 28 -Sep. 01, 2006.차재룡, 김재현, "RFID 시스템에서의 태그 수를 추정하는 ALOHA 방식 Anti-차재룡, 김재현, RFID 시스템에서의 태그 수를 추정하는 ALOHA 방식 Anticollision 알고리즘," 한국통신학회논문지, 제 30권, 9A, pp.814-821, 2005년 9월.ISO/IEC 18000-6:2003(E), Part 6: Parameters for air interface communications at 860-960 MHz, Nov. 26, 2003.Auto-ID Center, Draft Protocol Specification for a Class 0 Radio FrequencyAuto ID Center, Draft Protocol Specification for a Class 0 Radio Frequency Identification tag., 2003.Jong T. Park, "Management of Ubiquitous Sensor Network," APNOMS Tutorial, Okinawa, Japan, 2005.B Heile "Wireless Sensors and Control Networks: Enabling New Opportunities withB. Heile, Wireless Sensors and Control Networks: Enabling New Opportunities with ZigBee," ZigBee Alliance, 2006.ZigBee Alliance, ZigBee-2007 Specification: ZigBee Document 053474r16, 2007.오승환, “WiMedia UWB환경하에서 동기화 및 QoS 제공 메커니즘 연구”, 2007.


20080304 rfid usn기초 v2.ppt [호환...

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