here is winner's home. - 20080220 usn 강좌 김재현.ppt [호환...

USN 기본US 기본[Fundamentals of RFID/USN]

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워 운용

제 I 장. USN 개념 및 소개

제 II 장. 센서 네트워크 장점 및 운용

제 III 장. USN 플랫폼 구성요소 및 역할

제 IV 장. USN 요소기술

제 V 장 WPAN basics제 V 장. WPAN basics

제 VI 장. 결론

제 VII 장. 참고문헌

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제 1장. USN 개념 및 소개제 1장. USN 개념 및 소개

- USN 개념 및 구조- USN 정보- USN 정보 자원USN 정보 자원

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유비쿼터스 기본 구도유비쿼터 기본 구

기본기본 조건조건 기본기본 방향방향기본기본 개념개념

• Connected

• Fresh

• 언제 어디서나 누구라도

컴퓨터와 네트워크를

간단/편리/안전하게 활용

• Broadband/Seamless

• Traceability• Fresh

• Invisible

간단/편리/안전하게 활용

할 수 있는 환경• 초소형 컴퓨터(칩/센서/

태그 등)가 모든 사물과

공간에 파고들어 서로

• Traceability

• Positioning

• Real

• Calm & Silent

공간에 파고들어, 서로

통신할 수 있는 차세대

정보사회

• Sensing/Monitoring

• Context Awareness

<출처 : USN개요 및 Air Interface 기술_송형규>

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USN 기본 개념기본 개념

USN (Ubiquitous Sensor Network) 개념

어느 곳에나 부착된 태그와 센서노드로부터 사물 및 환경 정보를 감지• 어느 곳에나 부착된 태그와 센서노드로부터 사물 및 환경 정보를 감지․

저장․가공․통합하고 상황인식 정보 및 지식 콘텐츠 생성을 통하여 언제,

어디서, 누구나 원하는 맞춤형 서비스를 자유로이 이용할 수 있는 첨단

지능형사회의 기반 인프라

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USN 발전 단계발전 단계

USN은 초기에 전자태크를 이용 개체를 식별하는 단계에서, 센싱 기능을 부가하여 환경 정보를 동시에 취득하는 단계를 거쳐 태그 상호능을 부가하여 환경 정보를 동시에 취득하는 단계를 거쳐 태그 상호간 통신을 통하여 ad-hoc 네트워크를 형성하여 다른 저급태그를제어하는 단계로 발전

전자태그 제어

전자태그간 통신

(Ad-hoc network)

(Control)

환경정보센싱

이력 관리 (Sensing)

(Read/Write)

환경정보센싱

ID 인식(Read)

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(인식기능 위주) (지능형 자율 센서망)(센싱 기능 융합)


USN 구조구

USN (Ubiquitous Sensor Network) 구조

USN 응용서비스 계층

물류 유통 환경 방재 교통 홈네트워크

USN 미들웨어

APIAPIAPI

USN 미들웨어 계층

BcN

USN 미들웨어

BcN 백본 및엑세스 네트워크 계층BcN

USN 게이트웨이USN 게이트웨이

USN 게이트웨이

USN 정보자원 계층센서 네트워크RFID 센서 네트워크

USN 통합서버

센서 네트워크

싱크노드

센서노드

RFID

RFID 리더

Passive TagActive TagSensor Tag

센서 네트워크

싱크노드

센서노드

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센서노드Sensor Tag 센서노드

유비쿼터스 환경유비쿼터 환경

Anything-to-anything network by wire, wireless network and ubiquitous computingand ubiquitous computing

Every service offering anytime, anywhere, by anydevice, etc

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유비쿼터스 플랫폼유비쿼터 플랫폼

Integrated service platform by open architecture

Profile management based on customer ’s presenceProfile management based on customer s presence and location in order to provide intelligent and active services

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유비쿼터스 플랫폼유비쿼터 플랫폼

Intelligence and context based platform manipulates raw data from ubiquitous space connected bydata from ubiquitous space connected by communication networks

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유비쿼터스 유무선 통신유비쿼터 유무선 통신

In ubiquitous network, seamless handover is essential for silent communicationsilent communication

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유비쿼터스 터미널유비쿼터 터미널

Convergence terminal with perceptual and ubiquitous interface accelerates ubiquitous computinginterface accelerates ubiquitous computing

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유비쿼터스 컴퓨팅유비쿼터 컴퓨팅

Core technologies for ubiquitous computing network

• Pico-cell communication : Ad-hoc UWB Bluetooth Wireless• Pico-cell communication : Ad-hoc, UWB, Bluetooth, Wireless 1394, etc.

• Ubiquitous terminal : portable terminal, fixed terminal with function of digital appliancefunction of digital appliance

• Advanced sensor : ubiquitous sensing, touch screen, etc. with perceptual interface

MEMS(Mi El t M h i l S t ) d i t• MEMS(Micro ElectoMechanical System) and micro-computer chip

• Others : CPU/OS, 1 chip RF, 3D display, wearable terminal,

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유비쿼터스 컴퓨팅유비쿼터 컴퓨팅


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USN 정보정

USN 정보

유비쿼터스 환경을 구성하는 정보 수집 매체(RFID, 센서노드 등)에대한 정보(설치위치, 데이터 종류)뿐만이 아니라 정보 수집 매체에대한 정 (설치위치, 데이터 종류)뿐만이 아니라 정 수집 매체에의해 감지되고 저장․가공․통합된 사물 및 환경 정보

USN 정보의 종류

센싱 관련 : 센서로부터 취득되는 정보 (온도, 습도, 진동 등)

센서 관련 : 센서 자체에 관한 정보 (센서ID, 설치위치 등)

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센싱 데이터 / 센싱 정보센싱 데이터 / 센싱 정

센싱 데이터(Data-Code)

센서로부터 취득되는 데이터 (온도, 습도, 진동 등)

센싱 정보(Information-Code)

센서로부터 취득되는 데이터를 처리(평균)하여 보다 신뢰성 있는의미를 가질 수 있는 정보

센싱 정보(Information-Code)

정

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센서 정보센서 정

센서 정보

센서노드 자체에 관한 정보 (센서ID, 설치위치 등)

USN Code (S-Code, L-Code) : USN 표준화 포럼에서 정립 중

USN 정보자원 식별 체계

USN 정보자원에서 발생하는 데이터를 유용하게 사용하기위해 USN 정보자원에게 부여하여 USN 정보자원을 유일하게 식별할 수 있는 체계게 식 수 있 체계

식별 체계 예)

RFID EPC-RFID : EPC

-Mobile RFID : mCode, micro-mCode

-센서노드 : USN Code (USN 표준화 포럼, 한국전산원)

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센서노드 USN Code (USN 표준화 포럼, 한국전산원)

USN 메타 데이터메타 데이터

USN 메타 데이터

USN 정보자원을 관리하기 위한 각종 데이터

USN 정적 메타 데이터

센서 제조사, 제조일 등의 변화하지 않는 데이터

USN 동적 메타 데이터

센싱 데이터 및 정보를 서술하는 데이터 (센싱 데이터 측정 시간 등)

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USN 프로파일파일

USN 프로파일

센서노드와 관련된 각종 정보를 정리한 일람표센서노드와 관련된 각종 정보를 정리한 일람표

센서노드의 관리, 서비스 제공에 필요한 기본 정보를 정리한 USN 기본 프로파일과 부가적 정보를 정리한 USN 확장 프로파일로 구성됨됨

USN 기본 프로파일

센서노드의 관리, 서비스 제공에 필요한 기본 정보를 정리한 일람표

USN 기본 프로파일

USN 확장 프로파일

한 일람표

센서노드의 관리, 서비스 제공에 필요한 부가적 정보를 정리한 일람표

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USN 정보자원정 자원

유비쿼터스 환경에서 인간 친화적인 맞춤형 서비스를 제공하기 위

USN 정보자원

유비쿼터스 환경에서 인간 친화적인 맞춤형 서비스를 제공하기 위해 사물 및 환경 정보를 수집하고, 가공하는 모든 단계에서 사용되는 물리적 또는 논리적 요소

USN 정보자원의 종류

물리적 요소

• RFID 태그/ RFID 리더

• 센서/ 센서노드• 센서/ 센서노드

• 싱크노드

• USN 게이트웨이

• USN 통합서버

논리적 요소

-센서 네트워크

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-센서 네트워크

RFID 태그 // RFID 리더태 // 리더

RFID 태그

사물의 유일 식별 코드나 정보를 저장, 리더의 요청에 의해 또는 상황에 따라 외부에 자신의 정보를 리더로 전송하는 장치

전지가 없는 수동형 태그부터 박막의 전지 및 트랜시버를 갖춘 SAL (Smart Active Label) 태그까지 다양한 종류의 태그 존재

RFID 리더

사물에 부착된 태그의 정보를 인식한 후, 수집된 정보를 RFID 미들웨어에 제공하는 장치

RFID 리더

웨어에 제공하는 장치

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RFID 태그 // RFID 리더태 // 리더



USN게이트웨이

RFID태그① Reader launch

electromagnetic

USN 미들웨어

APIAPIAPI

USN 미들웨어 계층Delivery information Electromagnetic

waves

electromagnetic waves

and supply power② Reader detect

the TAGin electromagnetic

waves

BcNBcN 백본 및엑세스 네트워크 계층

USN 통합서버

RFID리더

Decoder

Transceiver

Antenna

waves

③ TAG send the information and

reader receive that


USN 게이트웨이

USN 정보자원 계층센서 네트워크

싱크노드

RFID

리더

센서 네트워크

통합서버

싱크노드싱크노드

센서노드

RFID 리더


싱크노드

센서노드

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센서센서

센서

물리 또는 환경계의 현상을 정량적으로 측정하는

반도체 기술을 바탕으로 하는 MEMS 기술이 기존의 기계식 센서를일괄생산 공정이 가능한 초소형 초경량 전자식 반도체 센서로 대체일괄생산 공정이 가능한 초소형, 초경량 전자식 반도체 센서로 대체

USN의 다양한 응용 영역에 따라 조도, 열, 습도, 가속도/지진강도, 음향, 지자기, 위치 등과 같은 다양한 센서를 통합하여 사용 가능

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센서센서



USN

게이트웨이

USN 미들웨어

APIAPIAPI


센싱데이터


USN 통합서버

싱크노드 센서노드


USN 게이트웨이


싱크노드

RFID

리더

센서 네트워크

통합서버

싱크노드싱크노드

센서노드

RFID 리더


싱크노드

센서노드

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센서노드센서

센서노드

환경, 물리계에서 센싱된 정보 또는 센서에 관련된 특정 이벤트를유무선 통신 기술 기반으로 하여 전달하거나 컴퓨팅을 수행하는 센서, 프로세서, 통신소자, 전지 등으로 구성되는 시스템으로 데이터처리, 통신경로 설정 등을 수행

단일센서노드 : 온도 조도 위치 등을 센싱할 수 있는 센서노드단일센서노드 : 온도, 조도, 위치 등을 센싱할 수 있는 센서노드

복합센서노드 : 온도, 조도 등의 센서가 복합된 형태의 센서노드

private : 일부 단체에서 특정한 용도를 위해 설치하여 사용하는 센서노드로서 일반인들이 접근할 수 없는 형태

센서노드 타입

하는 센서노드로서 일반인들이 접근할 수 없는 형태

public : 정부 또는 공공기관 등이 설치하여 일반인들이 모두 접근할 수 있는 형태의 센서노드

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센서노드의 일반적 구조센서 의 일반적 구

센서or

Battery

MCU센서or

Actuator

Memory RF 모뎀 I/F

MCU 다양한 MCU 사용 (8bit ~ 32bit)

메모리 부가적으로 추가 RAM 또는 Flash (EEPROM)

RF 모뎀 소출력 무선 모뎀 ( 대체로 IEEE802.15.4 compatible)

센서 ( ) 온도 습도 도 초음파 센서 등 다양

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센서 (or Actuator) 온도, 습도, 조도, 초음파 센서 등 다양

센서노드의 분류센서 의 분류

성능에 의한 분류

• 고성능 센서 노드 (32bit MCU)• 고성능 센서 노드 (32bit MCU)

• 일반적 센서 노드 (8bit or 16bit MCU)

기능에 의한 분류

• 센서 노드

• 라우터

• BS 또는 Sink 노드BS 또는 Sink 노드

크기에 의한 분류

• 원보드 타입 (MCU,MEMORY, RF MODEM, SENSOR)

• 초소형노드

• MCU + MEMORY + RF MODEM + SENSOR = Single Chip

플랫폼에 의한 분류 (MCU)플랫폼에 의한 분류 (MCU)

• MCS-51Based

• AVR Based

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• MSP430 Based

센서노드 설계시 고려사항센서 설계시 려사항

어떤 Application 에서 사용될 것인가?

• 네트워크 사이즈 센서 노드의 기능 구분 전원 문제• 네트워크 사이즈, 센서 노드의 기능 구분, 전원 문제

어떤 MCU를 사용할 것인가?

• 51계열, AVR계열, MSP430계열, ARM계열

• Application에서의 Processing

어떤 RF 모뎀을 사용할 것인가?

• CC2420 CC2430 Radio Pulse Nordic 등등• CC2420, CC2430, Radio Pulse, Nordic 등등

어떤 I/O (센서 또는 엑추에이터)를 연결할 것인가?

• 센서의 종류 및 연결방식

• 센서의 소비전류

개발 기간?

• Long-term vs Short-term Project• Long-term vs. Short-term Project

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센서노드 설계[MCU]센서 설계[ ]

MCU 선정 기준

• 성능 소비전류 Peripheral 가격 개발자의 과거 사용 경험• 성능, 소비전류, Peripheral, 가격, 개발자의 과거 사용 경험

항 목 MCS-51 AVR MSP430

Performance 2.5 ~ 3MIPS 8MIPS at 8MHz Up to 16MIPS

Supply Clock Up to 32MHz 8MHz 32kHz

Internal Flash 64K 128K 120KInternal Flash 64K 128K 120K

Internal RAM 1K 4K Up to 10k

Timers 4 (Max) 4 (8bit/16bit) 10 (Max)

ADCs 8 8 8

PWM O O O

UART 2 2 2

Operating Voltage 2.7V 2.7V 2.2 ~ 3V

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소비전류 8.5mA(A)/75uA(PD) 5.5mA(A)/ 25uA(PD) 430uA(A)/ 0.1uA(PD)

센서 노드 설계[RF]센서 설계[ ]

RF 모듈 선정 기준

사용주파수 Receiver Sensitivity Tx Power Power사용주파수, Receiver Sensitivity, Tx Power, Power Consumption

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싱크노드싱

싱크노드

센서노드에서 감지된 센싱 데이터를 취합하거나, 이벤트성 데이터를센서 네트워크 외부로 연계하고 관련 센서 네트워크를 관리하는 시스템스템

대체로 하드웨어/소프트웨어적으로 센서노드보다 역량이 큰 시스템

33

싱크노드싱

통합형 분리형



통합형 분리형


외부망

외부망

APIAPIAPI


USN 게이트웨이(+싱크노드)

유무선(인터넷) 연결

싱크노드

BcN

USN 미들웨어

BcN 백본 및엑세스 네트워크 계층


센서네트워크센서네트워크

BcN


USN 게이트웨이

USN 정보자원 계층

엑세스 네트워크 계층

USN 통합서버


싱크노드

RFID

RFID 리더

Passive TagActive Tag

센서 네트워크

싱크노드

34

센서노드

Active TagSensor Tag 센서노드

USN 게이트웨이게이 웨이

USN 게이트웨이

IP 기반으로 액세스할 수 있는 다양한 네트워크(LAN, WLAN, CDMA, WiBro, Satellite 등)를 통하여 USN 서비스를 제공할 수 있도록 IP 기반 네트워크와 센서 네트워크를 연계하는 시스템기반 네트워크와 센서 네트워크를 연계하는 시스템

싱크노드와 기존의 서비스 네트워크 사이에 위치하며 필요에 따라싱크노드와 기존의 서비스 네트워크 사이에 위치하며 필요에 따라싱크노드가 게이트웨이 내에 구현되기도 함

35

USN 게이트웨이게이 웨이



USN 미들웨어

APIAPIAPI

USN 미들웨어 계층USN 통합 서버


USN 통합서버 디렉토리USN 메타데이터센싱데이터

. . .


USN 게이트웨이


싱크노드

RFID

리더

센서 네트워크

통합서버

싱크노드

디렉토리서버

USN 메타데이터서버

센싱데이터서버

싱크노드

센서노드

RFID 리더


싱크노드

센서노드

36

USN 통합 서버통합 서버

USN 통합 서버

USN 관련 정보를 저장 또는 관리하기 위한 통합 서버

센싱 데이터를 저장하기 위한 데이터 베이스 존재

센싱 데이터 서버

USN 메타 데이터 서버

센싱 데이터를 저장하기 위한 데이터 베이스 존재

USN 메타 데이터를 저장하기 위한 데이터 베이스 존재

디렉토리 서비스를 제공하기 위한 데이터 베이스 존재

디렉토리 서버

37

디렉토리 서비스를 제공하기 위한 데이터 베이스 존재

센서 네트워킹센서 네 워킹

센서 네트워킹

센서 네트워크를 형성하는 다수의 센서노드들과 싱크노드, USN 게이트웨이로 형성되는 자기조직적 네트워크

센서노드들과 싱크노드 간의 네트워크 형성과 싱크노드와 USN 게이트웨이 간의 네트워크 형성으로 크게 구분됨이 웨이 간의 네 워 형성 게 구분됨

38

워 운용






제 VI 장. 결론


39

제 2장. 센서 네트워크 장점 및 운용제 2장. 센서 네트워크 장점 및 운용

40

센서 네트워크 장점 및 운용센서 네 워 장점 및 운용

Sensor Network Applications

• Building Automation• Building Automation

• Personal Health Care

• Industrial ControlPERSONAL HEALTH CARE

• Telecom Services

• Home Control

• Consumer Electronics

INDUSTRIALCONTROL

Consumer Electronics

• PC & Peripherals

TELECOM SERVICESCONTROL SERVICES

PC & BUILDING AUTOMATION CONSUMER HOME

41

PERIPHERALSAUTOMATION ELECTRONICSCONTROL


Sensor Network Applications• Building AutomationBuilding Automation

- Security, HVAC, AMR, lighting control, and access control

• Personal Health Care

- Patient monitoring and fitness monitoringPatient monitoring and fitness monitoring

• Industrial Control

- Asset management, Process control, and energy managementmanagement

• Telecom Services

- m-commerce, info services, and object interaction

• Home Control• Home Control

- Security, HVAC, lighting control, access control, and irrigation

• Consumer Electronics• Consumer Electronics

- TV, VCR, DVD/CD, and remote

• PC & Peripherals

M k b d d j ti k

42

- Mouse, keyboard, and joystick


Characteristics of USN• Large number of sensor nodes

M b 10 t 100 000 d ( l bilit )- Maybe 10 to 100,000 nodes (scalability)- Node position may not be predetermined- Low cost

• Low energy consumptionLow energy consumption- To relocate & recharge large number of nodes is impossible- Life time of sensor network depends on battery life time

• Network self-organizationL b f d i h til l ti- Large number of nodes in hostile locations

Manual configuration unfeasible

- Nodes may fail & new nodes join the network- Ad-hoc sensor network protocols

• Collaborative/Distributed processing- Locally carry out simple computation -> forwards and

aggregate data• Query ability (Sensor Database)Query ability (Sensor Database)

- Single node or group of nodes- Base nodes collect data from given area & create summary

messages

43


USN and Ad-hoc Network Comparison

Items for comparison Sensor Network Ad-hoc Network

f 100 1000 10 100Number of nodes 100 ~ 1000 10 ~ 100

Deployment Densely Relatively sparsely

Failure Prone to failure Not prone to failure

Communication Broadcast Point-to-point

Topology change Very frequent Almost steady

Power Limited Rechargeable

Resource Limited Relatively high

ID Local ID Global ID(IP address)

44


USN Protocol Stack

• Coordinating to minimize duty cycle and communication• Coordinating to minimize duty cycle and communication

- Adaptive topology, routing, and adaptive MAC

• In-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

45

Physical Communication, Sensing, Actuation


USN Protocol Stack

• Physical Layer• Physical Layer

- NeedsSimple, but robust modulation, transmission, and receiving technique

Transmission media- Transmission mediaRadio

• ISM (Industrial, Scientific, Medical) 915MHz band widely suggested

InfraredInfrared

Optical media

- Open research issuesModulation scheme

• Need simple and low-power modulation scheme

Hardware design

• Tiny, low-power, low-cost

• Power-efficient hardware management strategy• Power-efficient hardware management strategy

46


USN Protocol Stack• Data Link LayerData Link Layer

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

- Medium Access Control (MAC)Medium Access Control (MAC)Creation of the network infrastructure

Fairly and efficiently communication resources sharing between sensor nodes

MAC for Sensor Network- MAC for Sensor NetworkSMACS (Self-Organizing Medium Access Control for Sensor Networks)

EAR (Eaves-drop-And-Register) Algorithm

CSMA-Based MAC scheme

Hybrid TDMA/FDMA-Based MAC scheme

- Power Saving Modes of Operation

- Error ControlFEC (Forward Error Correction)

ARQ (Automatic Repeat Request)

47


USN Protocol Stack

• Network Layer• Network Layer

- NeedsData Routing

RequirementRequirement

• Power efficiency, Data-centric, Data aggregation

Scheme DescriptionScheme Description

Flooding 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

48

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


USN Protocol Stack

• Transport Layer• Transport Layer

- NeedsMaintain the flow of data if the sensor networks applications requires itit

- ResearchCommunication between user and sink node

• TCP or UDP via the internet or satellite

Communication between sink node and sensor node

• UDP type protocol, because sensor node has limited memory

- NamingNot based on global addressing

Attribute-based naming

49


USN Protocol Stack

• Application Layer• Application Layer

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

- Application layer protocolsSMP (Sensor Management Protocol)

• System administrators interact with sensor networks using SMP

TADAP (Task Assignment and Data Advertisement Protocol)

SQDDP (Sensor Query and Data Dissemination Protocol)

50

워 운용






제 VI 장. 결론


51

제 3장. USN 플랫폼 구성요소 및 역할제 3장. USN 플랫폼 구성요소 및 역할

- IEEE 802.15.4- Zigbee

52

USN 플랫폼 구성요소 및 역할플랫폼 구성 및 역할

IEEE 802 Wireless Space

WWAN IEEE 802.22

e

WMANWiMax

IEEE 802.20

Range

WLAN WiFi

WiMaxIEEE 802.16

ZigBee802.15.415 4c

802.15.3802 15 3WPAN

WLAN WiFi802.11

Bluetooth15.4c 802.15.3cWPAN

0.01 0.1 1 10 100 1000

802.15.1

53

Data Rate (Mbps)

0.01 0.1 1 10 100 1000


IEEE 802.15.4 overview

• Low Cost Power and Rate (20 40 250Kbps)• Low Cost, Power, and Rate (20, 40, 250Kbps)

• Short Range (less than 10m)

• Dynamic device addressing

• Support for low latency devices

• Reliable by fully handshake protocol

• CSMA-CA channel access.CSMA CA channel access.

• Low power consumption

• Apply to

S t H N t k : E g s C s- u-Smart Home Network : Energy save, Consumer Electronics, Toy, Security

- Health care check and monitoring System

• Topology

- Star or peer-to-peer topology

54


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)

55

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


MAC overview• Features of the MAC sub-layerFeatures of the MAC sub layer

- Beacon management

- Channel access

- Guaranteed time slot managementGuaranteed time slot management

- Frame validation

- Acknowledged frame delivery

Association and disassociation- Association and disassociation

- Security mechanisms

• FFD (Full Function Device)

A d i bl f ti di t- A device capable of operating as a coordinator or device, implementing the complete protocol set.

• RFD (Reduced Function Device)

A d i ti ith i i l i l t ti f th- A device operating with a minimal implementation of the IEEE 802.15.4 protocol.

- Can not be a coordinator device

56


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)

57

- 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

58


IEEE 802.15.4 Superframe Structure

59


IEEE 802.15.4 Superframe Structure

• The superframe structure without GTSs• The superframe structure without GTSs

Inactive PeriodContention Access Period

Frame Beacon

Inactive PeriodContention Access Period

Contention Free Period

60

제 3장. USN 플랫폼 구성요소 및 역할제 3장. USN 플랫폼 구성요소 및 역할

- IEEE 802.15.4- Zigbee overview

61

Basic Network Characteristics

65,536 network nodes

27 channels over 2 bands27 channels over 2 bands

250Kbps data rate

Optimized for timing-critical applications and power p g pp pmanagement

• Full Mesh Networking Support

Network coordinatorFull Function nodeReduced Function node

Communications flowVirtual links

62

Basic Radio Characteristics

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

63

performance in low SNR environments

ZigBee Mesh Networkingg g

64


65


66


67


68

ZigBee Stack Architecture (1/2)g ( / )

Application/Profiles ZigBee or OEM

(User Defined)

ZigBee Characteristics

- Addressing

Application Framework

Addressing

Assign the address to node depend on network configuration

Network/Security Layers

MAC Layer

ZigBee

Alliance

Platform

- Location

Have a location information depend on a network topology i k

MAC Layer

PHY LayerIEEE

in sensor network

- Synchronization

Common Sync Technology is dused

(NTP, RBS, TPSN, FTSP)

69

ZigBee Stack Architecture (2/2)g ( / )

Initiate and join network

Application

jManage networkDetermine device relationshipsSend and receive messagesSend and receive messages

Application ZDOApplication ZDO

App Support (APS)

SSPSecurity functions

Device managementDevice discovery

Medium Access (MAC)

NWK

SSP

Network organizationRoute discovery

Device bindingMessaging

Service discovery

Physical Radio (PHY)

( )Message relaying

Messaging

70

ZigBee Device Typesg yp

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)gDoes not allow association or routing.

Enables very low cost solutions

71

ZigBee Network Topologiesg p g

ZigBee CoordinatorZigBee RouterZigBee End Device

72

ZigBee End Device

<Mesh>

워 운용






제 VI 장. 결론


73

제 4장. USN 요소 기술제 4장. USN 요소 기술

- Location Technology- Time Synchronization- USN ManagementUSN Management- Specific Management Functions

74

Location Technology in USNgy

Discovery of absolute or relative location• Geographical routing (location attribute based naming andGeographical routing (location attribute based naming and

addressing)

• Tracking of moving objects

• Context (location) aware applicationsContext (location) aware applications

Challenges in USN• Energy constraint

• Harsh environment with multi-paths• Harsh environment with multi-paths

• Minimal infrastructure (Few beacons, No backend computation)

Many techniques for location sensingMany techniques for location sensing• TOA (Time Of Arrival)

• TDOA (Time Difference Of Arrival)

AOA (A l Of A i l)• AOA (Angle Of Arrival)

• SSR (Signal Strength Ranging)

• GPS, etc.

75



76

Time Synchronization in USNy

Critical at many layers of sensor network

• Communication localization distributed DSP etc• Communication, localization, distributed DSP, etc.

• Conventional approaches

- GPSIndoors?, cost, size, energy

- NTP (Network Time Protocol)Delay and jitters due to MAC and store-and-forward relaying

Di f ti ( d h i ith fDiscovery of timer servers (nodes synchronize with one of a pre-specified list of time servers)

Reference-broadcast synchronization (RBS)

V hi h i i ith l di• Very high precision sync. with slow radios

- Beacons are transmitted, using physical-layer broadcast, to a set of receivers

- Time synchronization is based on the difference between reception times, do not sync sender with receivers

77



78

USN Managementg

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

• Sensor-specific failures are not handled

• Difficult to find the failed nodes

• Physical connections are not utilized

• Commonly, there is not a management agent

• Specifying nodes is difficultp y g

• Network is self-configured, so that management server doesn’t have all information of sensor nodes

ChallengesChallenges

• Present many and drastically different challenges. For example:

D l t f d Di di f d- Deployment of nodes, Discarding of nodes

• Require augmentation to (or new approaches over) traditional network and service management techniques

79

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

USN Management Requirementsg q

Fault tolerance• Handle loss of nodes - Lack of Power, Physical damage,

Environmental interferenceEnvironmental interference

Scalability• Handle high density of nodes - The number of sensor nodes is an

extreme value of millions

Production costs• Make them low cost - Cost of a single node is very important to

justify the overall cost of the network

Operating environmentOperating environment• Survive and maintain communication - The bottom of an ocean,

biologically contaminated field, battlefield

Transmission media• Wireless - Radio, infrared, optical media

Hardware constraints• Nodes are tiny - Very small size, very light node, limited memory,

limited batterylimited battery

Power consumption• Limited Tx, computation, lifetime - Replenishment of power is

impossible

Ch i T l

80

Changing Topology• Nodes - Nodes moving, new nodes, loss nodes

USN Management Goalg

Promote resources productivity

Maintain the quality of the services providedMaintain the quality of the services provided

Application-dependent and the management solution design is affected

USNApplications

USNManagementDesign

Affect

Developing management solutions for USN• Not trivial

Design

• Not trivial

• Become worse due to the physical restrictions of sensor nodes

- Energy bandwidth ……Energy, bandwidth,

• Significantly different with the management of traditional networks

81

USN Management ArchitectureArchitecture

82

USN Management Functional Areasg

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 management

- 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

g p p y gform the network

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

A ti-It includes functions related to the use of resources and corresponding reports

Accounting -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

83

Security hoc organization, intermittent connectivity, wireless communication and resource limitations- A USN is subject to different safety threats : internal, external, accidental, and malicious



84

Power Managementg

Manage how a sensor node uses its power

ExampleExample

• Sensor node may turn off its receiver after receiving a message from one of its neighbors

- Avoid getting duplicated messages

• When the power level of the sensor node is low

- Broadcast to its neighbor when it is low in powerg p

- Cannot participate in routing messages

- Reserve the remaining power for sensing

Re i e e tsRequirements

• Using battery

• Limited Power

• Expand the life time of sensor node

• Reduce the overhead

85

Power Management in Layersg y

Physical layer• Low Power Modulation Scheme• Transceiver, Sensor, Process : Small, Low Power, Low Cost

Data link layer• Energy efficiency MAC protocol

- Adaptive duty cycling – S-MAC, ASCENT, SPAN- Wake up on-demand – STEM, Wake-on-Wireless

• Reduce the collision, signaling, frame overhead(• Power saving mode (ex. On/Off mode)

Network Layer• Energy-efficiency routing• Energy-efficiency data aggregation algorithms• Location based routing

Transport Layer• Use UDP message protocol between Sink and Sensor node• Limited memory and processing power

Application Layer

86

• Energy-efficiency Applications

Topology Managementp gy g

Goal

• To coordinate the sleep transitions of all nodes while• To coordinate the sleep transitions of all nodes, while ensuring adequate network connectivity, such that data can be forwarded efficiently to the data sink.

RequirementsRequirements

• Heterogeneous node

• Data discovery & data dissemination

• Limited memory & power constraint

• Application requirements

• Node mobility• Node mobility

Ad-hoc Self-organization

• LCA (Linked Cluster Algorithm)

• LAA (Link Activation Algorithm)

• DEA (Distributed Evolution Algorithm)

87

Topology Managementp gy g

Some Techniques

• SMACS (Self-Organizing Medium Access Control for Sensor• SMACS (Self-Organizing Medium Access Control for Sensor networks)

• EAR (Eavesdrop And Register)

SAR (S ti l A i t R ti )• SAR (Sequential Assignment Routing)

• SWE (Single Winner Election)

• MWE (Multi Winner Election)

88

Security Managementy g

Requirements• Peanut CPU (slow computation rate)Peanut CPU (slow computation rate)

• Battery power: trade-off between security and battery life

• Limited memory

• High latency: conserve power turn on periodically• High latency: conserve power, turn on periodically

Security Management in USN• Applications need security (privacy)

Ab f it bl tt k h fi &• Absence of security enables attacks such as spoofing & replay attacks, resulting in DoS or system compromise

• Intrusion prevention : First line of defense

I t i d t ti : S d li f d f• Intrusion detection : Second line of defense

Main Security Threats in USN• Radio links are insecure

• Sensor nodes are not temper resistant

Attacker types• Mote-class

89

• Outside / inside


Attacks

• Physical attack• Physical attack

• Denial-of-service

• Battery exhaustion

• Clock synchronization

• Location discovery

• Attacks on routingAttacks on routing

- Spoofed, altered, or replayed routing information

- Selective forwarding

Si kh l tt k- Sinkhole attack

- Sybil attack

- Wormholes

- HELLO flood attacks

- Acknowledgment spoofing

90


Countermeasures

• Link layer encryption – selective forwarding• Link layer encryption selective forwarding

• Using a counter – Replay attacks

• Limiting the number of neighbors per node – Insider attacks

• Bi-directionality of the link – HELLO flood

• Geographically routing – Wormhole attacks

91

Context Managementg

Gathering the “User Context”

RequirementRequirement• User intent prediction

• Application deployment support

• Runtime context service

Activity

• Runtime context service

• Real-time service

• Inter-user coordination and collaboration

C t t

EnvironmentSelf

Context• Any information that can be used to characterize the

situation of an entity

C id d l t t th i t ti f tit• Considered relevant to the interaction of an entity

• Considered relevant to the interaction between a user and an application, including themselves

CContext Model• The ACTIVITY – behavior, task

• The ENVIRONMENT – physical status, social surroundings

92

• The SELF – status of device itself

Context Managementg

Key Components• Context discovery and acquisitionContext discovery and acquisition

• User interface

• Context management and modeling

• Context composition and gathering• Context composition and gathering

Group Context Management• Enable syntactic and semantic interoperability between

context- aware applicationscontext- aware applications

• Enable seamless integration of various kinds of contexts and make it easy to be inferred

User ContextUser Context• User intent prediction

• Application development support

R ti t t i• Runtime context service

• Inter-user coordination and collaboration

93

워 운용






제 VI 장. 결론


94

제 5장. WPAN Basics 제 5장. WPAN Basics

- IEEE 802.15 overview- IEEE 802.15.1- IEEE 802 15 2IEEE 802.15.2- IEEE 802.15.3

95

IEEE 802.15 Overview

802.15.1 802.15.3 WiMedia 802.15.4

ObjectivesObjectives Bluetooth High Rate UWB Low Rate/Zigbee

Frequency Frequency bandband 2.4~2.4835Ghz 2.4GHz 3.1GHz~10.6GHz 868/915MHz

2.4GHz

MACMAC FH/TDD79 Ch, 1600hop/sec

CSMA/CA,S-Aloha,

TDMA

CSMA/CATDMA

TopologyTopology Piconet, Piconet,Child piconet Peer2Peer Star,TopologyTopology ,

Scatternet Child piconet, Neighbor piconet

Peer2Peer ,Peer2peer

Data RateData Rate < 3Mbps(sync.)< 723Kbps(Async.) < 55Mbps 53.3Mbps

~480Mbps 20k~250kbps

ModulationModulation GFSKQPSK, DQPSK, 16/32/64-QAM (11,22,33,44,55

Mbps)QPSK, DCM BPSK(868/915MHz)

O-QPSK(2.4GHz)

1m(1mW)RangeRange 1m(1mW)100m(100mW) 5~10m 10~20m

Major VenderMajor VenderNokia,Sony,

EricssonXtreme spectrum,

TimedomainHP, Intel, Microsoft,

Samsung Philips, Motorola

96



97

Examples of 802.15.1 Applicationp pp

Make calls from a wireless headset connected remotely

to a cell phoneto a cell phone.

Eliminate cables linking computers to printers, keyboards,

and the mouse.

Hook up MP3 players wirelessly to other machines to

download music.

Set up home networks so that a couch potato can

remotely monitor air conditioning, the oven, and

childrens’ Internet surfing.childrens Internet surfing.

Call home from a remote location to turn appliances on

and off, set the alarm, and monitor activity.

98

IEEE 802.15.1 Overview

Concept• Short Range, Low Power, Low CostShort Range, Low Power, Low Cost

Class Maximum Permitted Power Range

Class 1 100 mW (20 dBm) ~ 100 m

Cl 2 2 5 W (4 dB ) 10

Can be used for

Class 2 2.5 mW (4 dBm) ~ 10 m

Class 3 1 mW (0 dBm) ~ 1 m

Ca be used o• Data (max 753 kbps) / Voice(3.64kbps) Access

• Appliance Cable replacement

• Personal Ad-Hoc Connectivity• Personal Ad-Hoc Connectivity

Standard (Bluetooth SIG and IEEE802.15.1)• 1999 : Version 1.0b

2001 V i 1 1 (1Mb )• 2001 : Version 1.1 (1Mbps)

• 2004 : Version 2.0 (3Mbps)

• 2007 : Version 2.1 (3Mbps)

99

Topology • Piconet, Scatternet

Channel Allocation

TDD/Single slot

Multi-slot allocation

100

Service Profile and Protocol Stack

Appropriate protocol stack for service profilesExample :Example :

UDP TCP

OBEXvCard/vCal

WAPWAE

AT TCS

Dial Up Networking

FAX Profile

Headset profile

PPP

IPUDP TCP AT-

CommandsTCS BIN SDP

LMPL2CAP

RFCOMM

Audio Stream

Radio

BaseBand SCOACL

LMP

- LMP : Link Manager Protocol - HCI :Host Control Interface - SDP : Service Discovery Protocol L2CAP : Logical Link Control and Adaptation Protocol TCS : Telephony Control protocol Spec

101

- L2CAP : Logical Link Control and Adaptation Protocol - TCS : Telephony Control protocol Spec. - SCO Synchronous Connection Oriented Link - ACL: Asynchronous Connectionless Link - OBEX OBject EXchange protocol - WAE : WAP Application Environment

Explanation of Protocol Stack(1)p ( )

IEEE 802.15.1 consist of core protocols, cable replacement and telephony control protocols, and adopted protocols.C t lCore protocols

• Radio

- Specify details of the air interface, including frequency, the user of frequency hopping, modulation scheme, and transmit power

• Baseband

- Concerned with connection establishment within a piconet, addressing, packet format, timing, and power control

• LMP

- Responsible for link setup between Bluetooth devices and ongoing link management. This includes security aspects such as authentication and encryption, plus the control and negotiation of baseband packet sizes.

• L2CAP

- Adapt upper-layer protocols to the baseband layer. L2CAP provides both connectionless and connection-oriented services.

• SDP

- Device information, services, and the characteristics of the services can be queried to enable the establishment of a connection between two or more Bluetooth devices.

102

Explanation of Protocol Stack(2)p ( )

Cable Replacement Protocol• RFCOMMRFCOMM

- Present a virtual serial port that is designed to make replacement of cable technologies as transparent as possible.

Telephony Control Protocol• TCS BIN

- A bit-oriented protocol that defines the call controlA bit oriented protocol that defines the call control signaling for the establishment of speech and data calls between Bluetooth devices.

Adopted Protocolsdop ed o oco s• Defined in specifications issued by other standards-making

organizations and incorporated

- PPP, TCP/UDP/IP, / /

- OBEXA session-level protocol

Provides functionality similar to that of HTTP, but in a simpler fashion

103

- WAE/WAPApplication environment and protocol

Topologyp gy

S tt t

Piconet

• Standby state Scatter net• Standby state

• Master

• Park state

• Slave

- Active state

- Sniff stateSniff state

- Hold state

Scatternet

Stand by

Parked

Master

Slave

104



105

IEEE 802.15.2 Overview

Objective

• Develop coexistence model for 802 11 and Bluetooth• Develop coexistence model for 802.11 and Bluetooth

Coexistence Mechanism

• Collaborative Coexistence Mechanisms

- AWMA (Alternative Wireless Medium Access)

- PTA (Packet Traffic Arbitration)

Non Collaborative Coexistence MechanismsNon Collaborative Coexistence Mechanisms

- Adaptive Frequency Hopping

- Adaptive Packet Selection and Scheduling

- Transmission Power Control/Rate Scaling

106

Collaborative Coexistence Mechanisms

CollaborativeCoexistence802 11 Device 802 15 1 DeviceCoexistenceMechanism

802.11 Device 802.15.1 Device

AWMAMedium FreeGeneration

Medium Free

802.11MAC

802.15.1Link ManagerStatus Status

Generation

PTAControlTx Confirm Tx Confirm

Tx RequestTx Request

802.11 PLCP 802.15.1

(status) (status)

+ PHY Baseband

107

* More detailed inform : http://ieee802.org/15/pub/TG2-Draft.html



108

IEEE 802.15.3 (High Rate) Overviewg

Objective

• Low complexity Low cost Low power Short Range QoS• Low complexity, Low cost, Low power, Short Range, QoS Capable, Peer to peer communication, High data rate (> 20Mbps)

PHYPHY

• 2.4GHz 5 Channels

MAC Functionality

• Fast Connection Time

• Ad hoc Network

• QoS support• QoS support

• Security

• Dynamic Membership

• Efficient data transfer

Topology

• Piconet Child piconet Neighbor piconet

109

• Piconet, Child piconet, Neighbor piconet

• Piconet Coordinator (PNC), Device (DEV)

Examples of 802.15.3 Applicationp pp

Connecting digital still cameras to printers or kiosks

Laptop to projector connectionLaptop to projector connection

Connecting a personal digital assistant (PDA) to a camera or PDA to a printer

Speakers in a 5:1 surround-sound system connecting to the receiver

Video distribution from a set-top box or cable modemVideo distribution from a set-top box or cable modem

Sending music from a CD or MP3 players to headphones or speakers

Video camera display on television

Remote view finders for video or digital still cameras

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IEEE 802.15.3 PHY

2.4 GHz PHY now as PHY part of 802.15.3

• Channel Allocation• Channel Allocation

CHNL_ID Center frequency High-density 802.11b coexistence

1 2 412 GH X X1 2.412 GHz X X2 2.428 GHz X3 2.437 GHz X4 2 445 GH X4 2.445 GHz X5 2.462 GHz X X

Modulation Data RateQPSK 11 MbpsQ p

DQPSK (Basic) 22 Mbps16-QAM 33 Mbps32-QAM 44 Mbps

111

Q p64-QAM 55 Mbps

Qualities of the 802.15.3 MACQ

Coordinator (PNC) – Device (DEV) topology

• PNC assigns time for connections• PNC assigns time for connections

• Commands go to and come from the PNC.

Communication is peer-to-peer

Quality of Service

• TDMA architecture with guaranteed time slots (GTSs)

Security and AuthenticationSecurity and Authentication

112

MAC Frame Format

Easy Connection and Disconnection

• Authentication• Authentication

• Addressing

• Security-Key setting

• Bootstrap

Any DEV can be PNC

Power save modePower save mode

MAC frame is in Superframe

N SS

MAC Header

Non SecureSecure

MAC frame bodyMAC frame body

1

Stream index

3

Fragmentation control

1 1 2

SrcID

DestID

PNID

2

Frame control

0 ~ 4 Ln

FCS Frame payload

0 ~ 4

FCS

8

Integrity Code

Ln

Security Payload

2

SFC

2

SECID

113

- SrcID : Source ID – DestID : Destination ID – PNID: Piconet ID - SFC : Secure Frame Count - SEC ID : Security ID

Superframe Structurep

Super frame #m-1 Super frame #m Super frame #m+1

Beacon #m CAP Asynchronous Isochronous Asynchronous Isochronous

CFP (Contention Free Period)

Beacon #

Contention Access GTS GTS GTS GTS

CFP (Contention Free Period)#m Access

Period MTS1 MTS2 GTS1

GTS2 … GTS

n-1GTSn

1 000 65 535μs1,000 ~ 65,535μs

CSMA/CAData/Control

S-ALOHAData/Control

TDMAData

114

- MTS : Management Time Slots - GTS : Guaranteed Time Slots

Access methods

Beacon

• TDMA only sent by the PNC• TDMA, only sent by the PNC

CAP

• CSMA/CA, types of data and commands can be restricted by PNC

• PNC can replace the CAP with management time slots (MTSs) using slotted-aloha access.

CFP

• TDMA, assigned by the PNC

• GTSs are unidirectional• GTSs are unidirectional

115

Types of GTSyp

GTS may have different persistence

• Dynamic GTS: position in superframe may change from• Dynamic GTS: position in superframe may change from superframe to superframe

• Pseudo-static GTS: PNC may change position, but needs to communicate and confirm with both DEVscommunicate and confirm with both DEVs

MTS

• Used for PNC/DEV communication

• May be used to substitute for CAP

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Topologyp gy

Independent piconet: PNC and DEV

Dependent piconetDependent piconet

• Child piconet : # DEV > 255, extended area, Communication with PNC or DEV in parent piconet

• Neighbor piconet : when no available channel in parent piconet, communication with PNC or DEV in neighbor piconet

Reserved time Bea CAP GTS GTS GTS

CFPReserved time

BeaconContention Access Period GTS 1 GTS 2 … GTS n

CFPBeacon

Reserved time conCAP GTS

1GTS2 …

GTSn

Reserved time

DEV1 C-

C

DEV2

CDEV 1

CP

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C-PNC

C-DEV2

P-PNC

PNC selection/handover/

Alternate coordinators (ACs) broadcast capabilities

Based on criteria “best” AC is chosen and becomes theBased on criteria, best AC is chosen and becomes the PNC

PNC begins to issue beacon

PNC hands over task if more “capable” AC joins the piconet

• Exception only if security policy is verified• Exception only if security policy is verified

118

Joining/transferring datag/ g

DEV joins with association command

PNC allows based on resourcesPNC allows based on resources

DEV authenticates (if required)

DEV can either

• Send data in CAP (if allowed)

• Request GTS for specific connection

GTSs ma be eitherGTSs may be either

• Stream data: connection has QoS requirements

• Non-stream: connection has no QoS requirements

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Wimedia Alliance (UWB)( )

‘06년 1월 IEEE 802.15.3a 활동 중단

• MBOA와 DS-CDMA 대립 때문• MBOA와 DS-CDMA 대립 때문

• Wimedia Alliance와 UWB forum으로 양분, 독자 표준 추진 중

Wimedia Alliance develop, maintain, enhance and reference technical specifications including:

• PHY and MAC

• Convergence architecture to provide coexistence andConvergence architecture to provide coexistence and fairness including support for multiple applications (e.g., Wireless USB, Wireless 1394 FireWire, bluetooth, IP, etc.)

• A protocol adaptation layer for the Internet ProtocolA protocol adaptation layer for the Internet Protocol

• IP-based application profiles

120

Multi-band OFDM Alliance (MBOA)

Multi-band OFDM PHY

• The overall 7 5GHz frequency bandwidth of UWB is divided• The overall 7.5GHz frequency bandwidth of UWB is divided into 14 bands, with each having a bandwidth of 528MHz.

• In each 528MHz band, 100 out of 128 sub-carriers are used for data transmissionfor data transmission

< Band group allocation of MBOA PHY on the UWB >

121

Band group allocation of MBOA PHY on the UWB

WiMedia MAC

UWB MAC Superframe Structure

256 medium access slots (MASs)256 medium access slots (MASs)

Beacon Period (BP)

Data Transfer Period (DTP)( )

Prioritized Contention Access (PCA) and Distributed Reservation Protocol (DRP)

122

Prioritized Contention Access (PCA)( )

TXOP Limit

TXOP foreshortenCW DataBurst & Burst ACK (B-ACK)

MIFS SIFSAIFS Slot Time

Tx

Rx

DRP beagin

Priority AC CW_min CW_max TXOP- AIFSN PHY Parameter Value

PCA QoS Parameters Supported in MBOA MAC Interframe Spaces(IFS) defined for MBOA

DRP beagin

limit

1 AC_BK 15 1023 1 frame 7

2 AC_BK 15 1023 1 frame 7

0 AC BE 15 1023 1 frame 4

pMIFSTime 6 * TSUM = 1.875 us

pSIFSTime 32 * TYSM = 10 us

pCCADetectTime 15 * TSYM = 5.625 us

Sl tTi 8_

3 AC_BE 15 1023 1 frame 4

4 AC_VI 7 511 1024 us 2

5 AC_VI 7 511 1024 us 2

pSlotTime 8 us

123

6 AC_VO 3 255 256 us 1

7 AC_VO 3 255 256 us 1

Distributed Reservation Protocol (DRP)

The contention free DRP channel access

Coordinated by information carried by the beaconsCoordinated by information carried by the beacons

Soft DRPHard DRPBPST

MAS AIFSB Sl MAS

SIFS MIFS SIFSBackoff

slot

AIFSBeacon Slot

124

Merge of multiple BPsg p

Overlapping BPs

• When the BPST of a device falls within an alien BP• When the BPST of a device falls within an alien BP

- After receiving Alien Beacon

- Change own BPST to the BPST of Alien BP

- Select own the beacon slot used in Alien BP

125

Merge of multiple BPsg p

Non-overlapping BPs

• When a device detects an alien BP that not overlap in time• When a device detects an alien BP that not overlap in time with its own BP

- Detect Alien BP

DRP ti ith ti t f li BP- DRP reservation with reservation type of alien BP

- Receive alien beacon, then calculate own new BPST

126

워 운용






제 VI 장. 결론


127

결론

USN 개념 및 소개

센서 네트워크 장점 및 운용센서 네트워크 장점 및 운용

USN 플랫폼 구성요소 및 역할

• IEEE 802.15.4 and ZigBee

USN 요소기술

• Location Technology

Time Synchronization• Time Synchronization

• USN Management

WPAN basics

• IEEE 802.15.1, IEEE 802.15.2, IEEE 802.15.3

128

참고문헌

유승화, “RFID/USN 시장 및 기술 동향”, 2004.S. Birari and S. Iyer, “PULSE : A MAC Protocol for RFID Networks”, USN2005 Dec 2005USN2005, 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 Anti차재룡, 김재현, RFID 시스템에서의 태그 수를 추정하는 ALOHA 방식 Anti-collision 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 2003communications at 860-960 MHz, Nov. 26, 2003.Auto-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 2005Tutorial, Okinawa, Japan, 2005.B. Heile, "Wireless Sensors and Control Networks: Enabling New Opportunities with ZigBee," ZigBee Alliance, 2006.ZigBee Alliance, ZigBee-2007 Specification: ZigBee Document 053474r16 2007053474r16, 2007.오승환, “WiMedia UWB환경하에서 동기화 및 QoS 제공 메커니즘 연구”, 2007.

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