20071114 USN 개요 I (RFID USN기초).ppt [호환...

USN 개요 - I[F d l f RFID/USN][Fundamentals of RFID/USN]

2007. 11. 14

김재현 / 아주대학교

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

Contents

USN 개념 및 소개USN 기본 개념USN 기본 개념

RFID 기술 및 응용

센서 네트워크 장점 및 응용센서 네트워크 장점 및 응용

USN 플랫폼 구성 요소 및 역할USN Protocol StackTechnologies for USNStandards for USN

결론

참고문헌

김재현 / 아주대학교USN 개요 - I 2

USN 개념 및 소개


USN 개념 및 소개

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 (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



RFID 시스템에서의 간섭 및 해결방안Tag-to-Tag interferenceTag-to-Tag interference

Occur when multiple tags respond to the same reader simultaneouslyCan be avoided only by having each tag respond at different times

d h l i i lli i l i h l hi i fNeed to the multi-tag anti-collision algorithm to resolve this interference



RFID 시스템에서의 간섭 및 해결방안Reader-to-Tag interferenceReader-to-Tag interference

Occurs when a tag is in the interrogation zone of multiple readers and more than one reader transmits simultaneously.

C b id d l b h i i hb i d diffCan be avoided only by having neighboring readers operate at different times or different frequencies.Need to the multi-reader anti-collision algorithm to resolve this interference.

R1 Read Range

T1T2

T3

R1

T3R2 Read Range

Reader


Tag


RFID 시스템에서의 간섭 및 해결방안Reader-to-Reader interferenceReader-to-Reader interference

Occurs when the signal from neighboring readers interfereCan be avoided only by having neighboring readers operate at different times or different frequencytimes or different frequency.Need to the multi-reader anti-collision algorithm to resolve this interference.

R2 Interference Range

R1 Read Range

R1 R2

R2 Read Rangeg

T2

T1ReaderTag



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



RFID 태그 인식 기술TYPE ATYPE A

STATE

2nd REQSlot4Slot3Slot2Slot11st REQREADER

IDLE1011 COLL 0101

TAG1(1011)

STATE IDLE1011 COLL 0101

1011

TAG3(0011)

TAG2(1010)

0011

1010

0011

1010

TAG4(0101)

( )

Frame size = 4

00

0101

00

Frame size = ?


Frame size 4 Frame size ?

Need to vary the Frame size for the number of tags


RFID 태그 인식 기술TYPE BTYPE B

T1 T2

T3

T4

0

1

0

T1 T2 T4

0 01 1 1 1

1 2 3 4 5 6 7 98 10 11 12Iterations

1 2 3 4 5 6 7 98 10 11 12Coll Succ IdleColl Coll Coll Coll IdleSucc Succ Succ



RFID 태그 인식 기술Class 0Class 0

REPLY

TAG

X(0)

READER

REPLY

TAG READERTAGREADERTAGREADERREADER

X(0)REPLYCMDREPLYX(0)CMD

TAG1(001)

STATE

0

X

0 1

X 001 X

TAG3(100)

TAG2(011) 0 1 0

1 1TAG3(100) 1 1




Reader TAG

COMMAND PingIDPingIDS llIDCOMMAND

REQ.Bin 0(000)

Bin 1(001)

Bin2(010)

Bin 3(011)

Bin 4(100)

Bin 5(101)

Bin 6(110)

Bin 7(111)

POINTERLENGTHVALUE

STATUS

PingID0000 00000000 0100

1010IDLE IDLE SUCC IDLE IDLE SUCC IDLE IDLE

PingID0000 00000000 01111010010

IDLE SUCC COLL IDLE IDLE IDLE IDLE IDLE

ScrollID0000 00000000 01111010001

TAG 1

TAG 2(1010001110101010)

(1010010101001010)

00111010

01010100 10100101

(1010001110101010)

(1010010101001010)

(1010001110101010)

(1010010101001010)

TAG 1 sends ITM ( Full ID )(1010001110101010)

(1010010101001010)

(1010001110101010)

(1010010101001010)TAG 3

(1010010101001010)

(1010010010011010)0100100101001101

(1010010101001010)

(1010010010011010)

(1010010101001010)

(1010010010011010)

(1010010101001010)

(1010010010011010)

(1010010101001010)

(1010010010011010)




………………0 1 1 0 0 1 1 1Tag_1 1 0 0 0 00

………………0 1 1 1 0 1 0 1Tag_2 1 1 0 0 0

………………0 1 1 1 0 1 1 1Tag_3 0 1 0 0 0

0

0

0 0 0[LEN] 1

Bin000

Bin111

Bin110

Bin101

Bin100

Bin011

Bin010

Bin001

0 00Pi ID [LEN] 1 [VALUE] 0 010 0 0[LEN] = 1 0 0

00 0 0[LEN] = 4 0 0

0

1 1

PingID [LEN]=1,[VALUE]=0

PingID [LEN]=4,[VALUE]=0011

01

ScrollID [LEN]=7,[VALUE]=0011001

00 0 0[LEN] = 4 0 0 1 1PingID [LEN]=7,[VALUE]=0011101



Sc o [ ] 0,[ U ] 00 0 0



RFID 태그 인식 기술Class 1 Gen 2Class 1 Gen 2

R dReader

Command QueryRepSelectQuery Tag1 Tag2ACKQueryRep

Session S.C.

T t I F

0n.a.

000 A A

S0

A

2

B

10

n a

n.a.S0

n a

S0

Target I.F.

Q Sn.a.n.a.

000 A A

S0 S0

A

2

Bn.a.n.a.

n.a.

n.a.

n.a.

Act Send RN16WaitSend RN16.Send EPC (ID)

where S C : Slot Counter I F : Inventoried Flag S : Session Act : Action


where, S.C. : Slot Counter, I.F. : Inventoried Flag, S : Session, Act. : Action

센서 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)


Location Technology in USN


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


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


SUSN Management

- USN Management

- USN Management Requirement

- USN Management Goal

- USN Management Architecture

USN M t F ti l A- USN Management Functional Area


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

S ifi i f SSpecific Management Functions of USN

- Power Management

- Topology Management

- Security Management

- Context-Awareness Management


Power Management

Manage how a sensor node uses its powerExampleExample

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

Avoid getting duplicated messagesWhen the power level of the sensor node is low

B d t t it i hb h it i l iBroadcast to its neighbor when it is low in powerCannot participate in routing messagesReserve the remaining power for sensing

RequirementsUsing batteryLimited PowerExpand the life time of sensor nodeReduce the overhead


Reduce the overhead

Power Management in Layers

Physical layerLow Power Modulation SchemeTransceiver, Sensor, Process : Small, Low Power, Low Cost

Data link layerEnergy efficiency MAC protocolgy y p

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

Reduce the collision, signaling, frame overheadPower saving mode (ex. On/Off mode)

Network LayerEnergy-efficiency routinggy y gEnergy-efficiency data aggregation algorithmsLocation based routing

Transport LayerTransport LayerUse UDP message protocol between Sink and Sensor nodeLimited memory and processing power

Application Layer


Application LayerEnergy-efficiency Applications

Topology Management

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

RequirementsHeterogeneous nodeD t di & d t di i tiData discovery & data disseminationLimited memory & power constraintApplication requirementsApplication requirementsNode mobility

Ad-hoc Self-organizationgLCA (Linked Cluster Algorithm)LAA (Link Activation Algorithm)


DEA (Distributed Evolution Algorithm)

Topology Management (Con’t)

Some TechniquesSMACS (Self-Organizing Medium Access Control for SensorSMACS (Self-Organizing Medium Access Control for Sensor networks)EAR (Eavesdrop And Register)SAR (Sequential Assignment Routing)SWE (Single Winner Election)MWE (M lti Wi El ti )MWE (Multi Winner Election)


Security Management

RequirementsPeanut CPU (slow computation rate)( p )Battery power: trade-off between security and battery lifeLimited memoryHigh latency: conserve power turn on periodicallyHigh latency: conserve power, turn on periodically

Security Management in USNApplications need security (privacy)Absence of security enables attacks such as spoofing & replay attacks, resulting in DoS or system compromiseIntrusion prevention : First line of defenseIntrusion detection : Second line of defense

Main Security Threats in USNRadio links are insecureRadio links are insecureSensor nodes are not temper resistant

Attacker types


Mote-classOutside / inside

Security Management (Con’t)

AttacksPhysical attackPhysical attackDenial-of-serviceBattery exhaustionClock synchronizationLocation discoveryAttacks on routing

Spoofed, altered, or replayed routing informationSelective forwardinggSinkhole attackSybil attackW h lWormholesHELLO flood attacksAcknowledgment spoofing


Security Management (Con’t)

CountermeasuresLink layer encryption selective forwardingLink layer encryption – selective forwardingUsing a counter – Replay attacksLimiting the number of neighbors per node – Insider attacksBi-directionality of the link – HELLO floodGeographically routing – Wormhole attacks


Context Management

Gathering the “User Context”RequirementRequirement

User intent predictionApplication deployment supportR ti t t i

Activity

Runtime context serviceReal-time serviceInter-user coordination and collaboration

Environment Self

ContextAny information that can be used to characterize the situation of an entityConsidered relevant to the interaction of an entityConsidered relevant to the interaction of an entityConsidered relevant to the interaction between a user and an application, including themselves

Context ModelContext ModelThe ACTIVITY – behavior, taskThe ENVIRONMENT – physical status, social surroundings


The SELF – status of device itself

Context Management (Con’t)

Key ComponentsContext discovery and acquisitionContext discovery and acquisitionUser interfaceContext management and modelingC i i d h iContext composition and gathering

Group Context ManagementEnable syntactic and semantic interoperability between context-Enable syntactic and semantic interoperability between contextaware applicationsEnable seamless integration of various kinds of contexts and make it easy to be inferredeasy to be inferred

User ContextUser intent predictionApplication development supportRuntime context serviceInter user coordination and collaboration


Inter-user coordination and collaboration

Standards for USN- IEEE 802.15.4

- ZigBee


Standards for USN

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)

Standards for USN

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

Standards for USN

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)

Standards for USN

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


Standards for USN

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

Standards for USN

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


Standards for USN

IEEE 802.15.4 Superframe Structure

김재현 / 아주대학교USN 개요 - I 60 60

Standards for USN

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>

Security in ZigBeey g


Security in ZigBee

ZigBee Protocol Stack Overview


Security in ZigBee

Application LayerAPS (Application Support) sublayerAPS (Application Support) sublayer

APSDE(APS Data Entity)Generation of the application level PDU (APDU)

i di d iBinding and FragmentationGroup address filteringReliable transport / Duplicate rejection

APSME(APS Management Entity)Binding managementAIB management / Group managementSecurity

ZDO (ZigBee Device Object)InitializingInitializingAssembling configuration information

Manufacturer defined application objects.


Security in ZigBee

Network (NWK) LayerNLDE (Network Layer Data Entity)NLDE (Network Layer Data Entity)

Generation of the Network level PDU (NPDU)Topology-specific routing

NLME (Network Layer Management Entity)Configuring a new deviceStarting a networkStarting a networkJoining, rejoining and leaving a networkAddressingNeighbor discoveryRoute discoveryReception controlpRoutingSecurity


ZigBee Protocol Stack OverviewZigBee Protocol Stack Overview

MAC Layer & PHY Layer : IEEE 802.15.4-2003 (LR-WPAN)Over-the-air data rates of 250 Kbps 40 Kbps and 20 KbpsOver-the-air data rates of 250 Kbps, 40 Kbps, and 20 Kbps

Star or peer-to-peer operation

Allocated 16-bit short or 64-bit extended addresses

Optional allocation of guaranteed time slots (GTSs): TDMA

Carrier sense multiple access with collision avoidance (CSMA-CA) channel access

Fully acknowledged protocol for transfer reliability (use retransmission)

Low power consumption

Energy detection (ED)

Link quality indication (LQI)16 channels in the 2450 MHz band, 10 channels in the 915 MHz band, and 1 channel in the 868 MHz band


Frame StructureFrame Structure


Frame StructureFrame Structure

APS layerExtended header

for fragmentation

NWK layerRadius

the range(maximum number of hops) of a radius-limited transmission.Sequence number

prevent routing same packetsSource route subframe

for source routing, store the route information from source to destination

MAC la erMAC layerPAN ID

allows communication between devices within a network and enables i i b d i h k


transmissions between devices another networks

Design objectives for ZigBee SecurityDesign objectives for ZigBee Security

ZigBee devices areb d ti i t llbased on tiny microcontrollershave low memory (code and data)deployed in home/industrial scenarios p yeasy to use

So we needencryption primitive must be simple to implement and executeencryption primitive must be simple to implement and executelow overhead for key storage / maintenanceflexible enough to support home/industrialeasy to use


Design objectives for ZigBee SecurityDesign objectives for ZigBee Security

Secure the InfrastructureNetwork access controlNetwork access controlIntegrity of packet routingPrevent unauthorized use of packet transport

Application data securityMessage integrity

protects message from being modified in transitAuthentication

provides assurance on the originator of messageFreshness

prevents replay attacksp eve s ep y c sPrivacy

prevents an eavesdropper from listening messages


History of ZigBee Security

Version r14Entity authentication is addedEntity authentication is addedIncorporating errata and clarifications

Version r15, r16Residential/Commercial mode is changed to Standard/Hi-security modeCommand tunneling is addedgPermission control table is addedIncorporating errata and clarifications

V i 17Version r17Entity authentication is used for frame counter synchronizationMore test vectors for securityMore test vectors for securityIncorporating errata and clarifications


ZigBee SecurityZigBee Security

- AES : Advanced Encryption Standard, one of block cipher function- CCM : CTR-CBC-MAC mode of operation


- CCM* : CTR-CBC-MAC mode of operation with some modification- CTR : CounTeR mode of operation- CBC-MAC : Cipher-Block Chaining-Message Authentication Code mode of operation

ZigBee Device Types on SecurityZigBee Device Types on Security

Trust center(TC)ZigBee CoordinatorZigBee CoordinatorTrust Manager

Authenticate devices that request to join network

Network ManagerMaintains and distributes network keys

Configuration ManagerE bl d d i bEnables end-to-end security between devices by assisting in setup of link keys

RouterRouting security informationLiaison for devices which not have network key

End device


Key TypesKey Types

Link keyMaster key Derived using SKKE yBasis of security between two devices (insider protection)Derived using SKKE between two d i

yBasis for long-term security

devices

Network KeyNetwork Keyshared key : basis of network-wide securityprotects infrastructure and application data from outsider attacks

Keys can be factory-installed or setup over the air or using out-of-band mechanismseavesdropping should be prevented when this is setup

Link and Network keys can be updated periodically


y p p y

* SKKE : Symmetric-Key Key-Establishment

SymmetricSymmetric--Key Key Establishment Key Key Establishment (SKKE) Protocol(SKKE) Protocol


QEU, QEV : 16-byte random sequence


Initiator U Responder V

Secret Key GenerationZ = HashMasterKey(U | V | QEU | QEV)

Secret Key GenerationZ = HashMasterKey(U | V | QEU | QEV)

Key Derivation Functionmackey = Hash(Z | 0x01)linkkey = Hash(Z | 0x02)

Key Derivation Functionmackey = Hash(Z | 0x01)linkkey = Hash(Z | 0x02)

Keyed Hash FunctionMacTag2 = Hashmackey(0x03 | U | V | QEU | QEV)

Keyed Hash FunctionMacTag2' = Hashmackey(0x03 | U | V | QEU | QEV)

(3) Send SKKE-3 frame(with MacTag2)

Compare MacTag2 and MacTag2'(If different, stop SKKE)


* | : Concatenation

V believe that U is correct device


U believe that V is correct device


Standard ModeStandard Mode

Residential mode in ZigBee 2006Provide reduced security in ZigBee

No SKKENo SKKENo device authentication during joining procedureUse only one key type : Network key

Key typeKey typeNetwork key

Provides network layer frame security & integrity (protect external attack)

AdvantageMinimize storageLow capability device can act as trust centerTrust center can be easily replaced with anotherTrust center can be easily replaced with another deviceEasy to maintain

DisadvantageDisadvantageCannot protect internal attacksNo authentication during joining procedure


HiHi--security Modesecurity Mode

Commercial mode in ZigBee 2006Provide full security in ZigBee

Do SKKE

C : KN , KM,AC, KL,AC KM,BC, KM,BC

Do SKKEDevice authentication during joining procedureUse all key types

D : KN , KM,AD, KL,AD

Key typeMaster keyLink key

Provides APS layer frame security & integrity B : K K KProvides APS layer frame security & integrity (protect internal attack)

Network keyProvides network layer frame security & integrity (protect external attack) A : KN , KM,AB, KL,AB

B : KN , KM,AB, KL,AB KM,BC, KL,BC

(protect external attack)

AdvantageProvide all security functions in ZigBee

ZigBee CoordinatorZigBee Router

KM,AC, KL,AC KM,AD, KM,AD

DisadvantageIncrease storage overheadLow capability device cannot act as trust center

ZigBee End Device

KN Network Key

K M t k b t A d B


Low capability device cannot act as trust center

KL,AB Link key between A and B

KM,AB Master key between A and B

ZigBee Security ServiceZigBee Security Service

128-bit Symmetric Key CryptographyBlock Cipher Mode : 128-bit AES(Advanced EncryptionBlock Cipher Mode : 128 bit AES(Advanced Encryption Standard)Low overheadStrongStrongNIST(National Institute of Standards and Technology) approved security

Frame SecurityEncryption & Message Authentication : AES-CCM*Device level and/or network levelIntegrity is option : 0, 32, 64 or 128 bit MIC(Message IntegrationIntegrity is option : 0, 32, 64 or 128 bit MIC(Message Integration Code)

Message protection vs. Message overhead


ZigBee Security ServiceZigBee Security Service

Key ManagementHash

AES MMO(AES M t M O )AES-MMO(AES-Matyas-Meyer-Oseas)Cryptographic Hash

HMAC(keyed-Hash Message Authentication Code) with AES-MMOKey Establishment Protocoly

SKKE protocolNetwork key & Link key Update

AuthenticationSKKE ProtocolEntity Authentication

Similar to SKKE protocolUse network key instead of master keyNot establish link key

Device ManagementDevice UpdateDevice Leaving


g

Example of Frame Security Example of Frame Security (APS layer, Outgoing)(APS layer, Outgoing)

UnsecuredPayload

Frame Counter(4)

Source Address(8)

Security Control(1)

<Nonce N>

Security Level(3bits)

Key Identifier(2bits)

Extended Nonce(1bit)

Reserved(2bits)

000

Link Key

Authentication data

00 CCM* Encryption &

Authentication

Nonce

Security Control(1)

Frame Counter(4)

Key Sequence Number(1)

APS Header Auxiliary frame Header Secured APS payload & MIC


* Colored block represent same value

Example of Frame Security Example of Frame Security (Network layer, Outgoing)(Network layer, Outgoing)

UnsecuredPayload

Frame Counter(4)

Source Address(8)

Security Control(1)

<Nonce N>

Security Level(3bits)

Key Identifier(2bits)

Extended Nonce(1bit)

Reserved(2bits)

011

Network Key

Authentication data

00 CCM* Encryption &

Authentication

Nonce

Security Control(1)

Frame Counter(4)

Source Address(8)

Key Sequence Number(1)

NWK Header Auxiliary frame Header Secured NWK payload & MIC


* Colored block represent same value

Procedures Procedures --Device Authentication & UpdateDevice Authentication & Update

Hi-Security Mode

Receive NWK address

device updatep(a device joined!)

Transport master key(if master key not preconfigured)

Do device authentication and establish link key

Transport network key

Authenticate between router and joiner device


Procedures Procedures --Device Authentication & UpdateDevice Authentication & Update

Standard Mode


Procedures Procedures --Network key updateNetwork key update

TrustCenter Device1 Device2

T t K C d(NWK K N)

Replace alternate or active network key with network key

N

Transport-Key Command(NWK Key, N)

Switch-Key Command(N)

Make network key N the activeMake network key N the active network key or Ignore

Transport-Key Command(NWK Key, N)

Replace alternate or active network key with network key

N

Switch-Key Command(N)

Make network key N the active network key or Ignore


Procedures Procedures --EndEnd--toto--end key establishmentend key establishment


Procedures Procedures --Network leaveNetwork leave

RouterTrustCenter Device

Remove Device Command

Leave CommandLeave Command

RouterTrustCenter Leaving Device

Leave Command

Update-Device Command


ApplicationApplication--specificspecific

Out of band methods for key setup

Wired line(RS-232), NFC, RFID, USB, etc.

Cost/Security tradeoff for number of link keys needed

With 128KB flash / 8KB RAM / debug mode : about 6-10 link keys

Policy for expiration and update of keysy p p y

Hours or days

P li f ti d iPolicy for accepting new devices

ID/Password, MAC address filtering, etc.


Disadvantage/Disadvantage/Weakness in ZigBee SecurityWeakness in ZigBee Security

No MAC layer security

Due to program code size or message length limitationDue to program code size or message length limitation

Possible attacksWorm-hole attack Acknowledgement spoofing Attack which targetsWorm-hole attack, Acknowledgement spoofing, Attack which targets channel reservation, etc.

Trust center based security

Authentication, End-to-end key establishment contain communication between device and trust center

If device is far from TC, then it has too much overhead


Security Stack ImplementationSecurity Stack Implementation

Hardware environmentChipset : Chipcon CC2430

802.15.4 support

128KB flash memory128KB flash memory

8KB RAM

Support AES block cipher modes

Board : Aiji ZDB Ver 2.0

Software environmentIAR Embedded Workbench for MCS-51 Evaluation(C code)

Chipcon 802.15.4 packet sniffer

Implement security stack on UbiFOS(ZigBee stack of Aiji system)


Test EnvironmentTest Environment

Using Chipcon 802.15.4 Sniffer for CC2430


Test Test -- Device authentication(1Device authentication(1--hop)hop)

Direction : Device ←→ TC

Association Request →

Beacon Request →

Beacon ←q

Association Response ←

Transport-Key(Master key) ←


SKKE-1 ←

Test Test -- Device authentication(1Device authentication(1--hop)hop)

SKKE-2 →

SKKE-3 ←

SKKE-4 →

Transport-key(Network key) ←


End-Device Announcement

(broadcast)

Problem in Problem in Device Authentication Authentication ProcedureProcedure

Device authentication in Hi-security modeTC must do & complete SKKE protocol with joiner device

For multi-hop environmentpRouting some messages from TC(joiner device) to joiner device(TC)

Attacker can target this featureAttacker can target this featureRepeat authentication procedure

ibl if k d ’ h kpossible even if attacker doesn’t have master key


Problem in Problem in Device Authentication Authentication ProcedureProcedure

Too much Overhead


Possible SolutionPossible Solution

Reduce the message exchange between TC and device, and router

and device.

Reduce unnecessary network traffic from attacker

Reduce authentication time


Performance : Preliminary Results

Actual completion time during device authentication (for 2-hop)ZigBee 2007 r16 : about 300msgProposed : about 220ms => 26.7% Improvement

Performance Expectation(@ 250kbps, no processing delay)

Completion Time(@250kbps)

0.25

0 15

0.2

)

R16Proposed

0.1

0.15

Tim

e(s)

0

0.05


0 2 4 6 8 10Number of hops between Coordinator and Joiner

결론

USN 개념 및 소개USN 기본 개념USN 기본 개념



USN 플랫폼 구성 요소 및 역할USN Protocol StackTechnologies for USNStandards for USN


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.


Back-up Slidesp


Wireless Personal Area Network (WPAN) basics(WPAN) basics


IEEE 802.15 OverviewIEEE 802.15 Overview

802.15.1 802.15.3 WiMedia 802.15.4ObjectivesObjectives Bluetooth High Rate UWB Low Rate/Zigbee

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

2 4GHzbandband 2.4GHz

MACMACFH/TDD79 Ch,

1600hop/sec

CSMA/CA,S-Aloha,

TDMA

CSMA/CATDMA

TopologyTopology Piconet,Scatternet

Piconet,Child piconet,

Neighbor piconet

Peer2Peer Star,Peer2peer

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

~480Mbps 20k~250kbps

QPSK, DQPSK, 16/32/64 QAM BPSK(868/915M

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

Mbps)QPSK, DCM

(Hz)

O-QPSK(2.4GHz)

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


100m(100mW)

Major Major VenderVender

Nokia,Sony,

Ericsson

Xtremespectrum,

Timedomain

HP, Intel, Microsoft, Samsung

Philips, Motorola

IEEE 802.15.1 OverviewIEEE 802.15.1 Overview

ConceptShort Range, Low Power, Low Cost

Class Maximum Permitted Power Range

Class 1 100 mW (20 dBm) ~ 100 m

Class 2 2 5 mW (4 dBm) 10 m

Can be used for

Class 2 2.5 mW (4 dBm) ~ 10 m

Class 3 1 mW (0 dBm) ~ 1 m

Data (max 753 kbps) / Voice(3.64kbps) Access Appliance Cable replacementPersonal Ad-Hoc Connectivityy

Standard (Bluetooth SIG and IEEE802.15.1)1999 : Version 1.0b2001 : Version 1 1 (1Mbps)2001 : Version 1.1 (1Mbps)2004 : Version 2.0 (3Mbps)2007 : Version 2.1 (3Mbps)

T l


Topology Piconet, Scatternet

Examples of 802.15.1 ApplicationExamples of 802.15.1 Application

Make calls from a wireless headset connected remotely to a cell phonea cell phone.Eliminate cables linking computers to printers, keyboards and the mousekeyboards, and the mouse.Hook up MP3 players wirelessly to other machines to do nload m sicdownload music.Set up home networks so that a couch potato can

t l it i diti i th dremotely monitor air conditioning, the oven, and childrens’ Internet surfing.C ll h f t l ti t t liCall home from a remote location to turn appliances on and off, set the alarm, and monitor activity.


Channel AllocationChannel Allocation

TDD/Single slot

M lti l t ll tiMulti-slot allocation


Service Profile and Protocol StackService 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


- 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)Explanation of Protocol Stack(1)

IEEE 802.15.1 consist of core protocols, cable replacement and telephony control protocols, and adopted protocols.Core protocols

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

BasebandC d ith ti t bli h t ithi i t dd iConcerned with connection establishment within a piconet, addressing, packet format, timing, and power control

LMPResponsible for link setup between Bluetooth devices and ongoing linkResponsible 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.

L2CAPAd t l t l t th b b d l L2CAP idAdapt upper-layer protocols to the baseband layer. L2CAP provides both connectionless and connection-oriented services.

SDPDevice information, services, and the characteristics of the services can


, ,be queried to enable the establishment of a connection between two or more Bluetooth devices.

Explanation of Protocol Stack(2)Explanation of Protocol Stack(2)

Cable Replacement ProtocolRFCOMMRFCOMM

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

Telephony Control ProtocolTelephony Control ProtocolTCS BIN

A bit-oriented protocol that defines the call control signaling for the t bli h t f h d d t ll b t Bl t th d iestablishment of speech and data calls between Bluetooth devices.

Adopted ProtocolsDefined in specifications issued by other standards-makingDefined in specifications issued by other standards making organizations and incorporated

PPP, TCP/UDP/IPOBEXOBEX

A session-level protocolProvides functionality similar to that of HTTP, but in a simpler fashion

WAE/WAP


Application environment and protocol

Topology

S tt t

PiconetStandby state Scatter netStandby stateMasterPark stateSlave

Active stateS iff t tSniff stateHold state

ScatternetScatternet

Stand by

Parked

Master

Slave


IEEE 802.15.2 OverviewIEEE 802.15.2 Overview

ObjectiveDevelop coexistence model for 802 11 and BluetoothDevelop coexistence model for 802.11 and Bluetooth

Coexistence MechanismCollaborative Coexistence MechanismsCollaborative Coexistence Mechanisms

AWMA (Alternative Wireless Medium Access)PTA (Packet Traffic Arbitration)

Non Collaborative Coexistence MechanismsAdaptive Frequency Hopping Adaptive Packet Selection and SchedulingAdaptive Packet Selection and SchedulingTransmission Power Control/Rate Scaling


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


IEEE 802.15.3 IEEE 802.15.3 (High Rate)(High Rate) OverviewOverview

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

PHY 2.4GHz 5 Channels

MAC FunctionalityF t C ti TiFast Connection Time Ad hoc Network QoS supportSecurity Dynamic MembershipEfficient data transferEfficient data transfer

Topology Piconet, Child piconet, Neighbor piconet


, p , g pPiconet Coordinator (PNC), Device (DEV)

Examples of 802.15.3 ApplicationExamples of 802.15.3 Application

Connecting digital still cameras to printers or kiosksLaptop to projector connectionLaptop to projector connectionConnecting a personal digital assistant (PDA) to a camera or PDA to a printercamera or PDA to a printerSpeakers in a 5:1 surround-sound system connecting to the receiverthe receiverVideo distribution from a set-top box or cable modemSending music from a CD or MP3 players to headphonesSending music from a CD or MP3 players to headphones or speakersVideo camera display on televisionp yRemote view finders for video or digital still cameras


802.15.3 PHY802.15.3 PHY

2.4 GHz PHY now as PHY part of 802.15.3Channel AllocationChannel 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 X

Modulation with Trellis Coded Modulation (TCM)

4 2.445 GHz X5 2.462 GHz X X

Modulation with Trellis Coded Modulation (TCM)

Modulation Data RateQPSK 11 MbpsQ p

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


Q p64-QAM 55 Mbps

Qualities of the 802.15.3 MAC

Coordinator (PNC) – Device (DEV) topologyPNC assigns time for connectionsPNC assigns time for connectionsCommands go to and come from the PNC.

Communication is peer-to-peerCommunication is peer to peerQuality of Service

TDMA architecture with guaranteed time slots (GTSs)g ( )

Security and Authentication


MAC Frame FormatMAC Frame Format

Easy Connection and Disconnection AuthenticationAuthenticationAddressingSecurity-Key settingBootstrap

Any DEV can be PNCPower save mode MAC frame is in Superframe

MAC Header

Non SecureSecure

MAC frame bodyMAC frame body

1

Stream index

3

Fragmentation control

1 1 2

SrcID

DestID

PNID

2

Frame

control

MAC Header

0 ~ 4 Ln

FCS Frame payload

MAC frame body

0 ~ 4

FCS

8

Integrity Code

Ln

Security Payload

2

SFC

2

SECID

MAC frame body


1 3 1 1 2 2 0 4 Ln0 4 8 Ln 2 2

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

Superframe StructureSuperframe Structure

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-1GTS

n

1 000 65 535μs1,000 ~ 65,535μs

CSMA/CAData/Control

S-ALOHAData/Control

TDMAData


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

Access methodsAccess methods

BeaconTDMA only sent by the PNCTDMA, only sent by the PNC

CAPCSMA/CA, types of data and commands can be restricted byCSMA/CA, types of data and commands can be restricted by PNCPNC can replace the CAP with management time slots (MTSs)

i l tt d l husing slotted-aloha access.

CFPTDMA assigned by the PNCTDMA, assigned by the PNCGTSs are unidirectional


Types of GTSTypes of GTS

GTS may have different persistenceDynamic GTS: position in superframe may change fromDynamic GTS: position in superframe may change from superframe to superframePseudo-static GTS: PNC may change position, but needs to communicate and confirm with both DEVs

MTSU d f PNC/DEV i tiUsed for PNC/DEV communicationMay be used to substitute for CAP


Topology

Independent piconet: PNC and DEVDependent piconetDependent piconet

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

1GTS

2 …GTS

nReserved time

DEV1 C-

C

DEV2

CDEV

1

CP


C-PNC

C-DEV2

P-PNC

PNC selection/handoverPNC selection/handover

Alternate coordinators (ACs) broadcast capabilitiesBased on criteria “best” AC is chosen and becomes theBased on criteria, “best” AC is chosen and becomes the PNCPNC begins to issue beaconPNC begins to issue beaconPNC hands over task if more “capable” AC joins the piconetpiconet

Exception only if security policy is verified


Joining/transferring dataJoining/transferring data

DEV joins with association commandPNC allows based on resourcesPNC allows based on resourcesDEV authenticates (if required)DEV ithDEV can either

Send data in CAP (if allowed)Request GTS for specific connectionRequest GTS for specific connection

GTSs may be either Stream data: connection has QoS requirementsQ qNon-stream: connection has no QoS requirements


Wimedia Alliance (UWB)Wimedia Alliance (UWB)

‘06년 1월 IEEE 802.15.3a 활동 중단MBOA와 DS CDMA 대립 때문MBOA와 DS-CDMA 대립 때문

Wimedia Alliance와 UWB forum으로 양분, 독자 표준 추진 중

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

PHY and MACConvergence architecture to provide coexistence and fairness including support for multiple applications (e.g., Wireless USB, Wireless 1394 FireWire, bluetooth, IP, etc.)Wireless 1394 FireWire, bluetooth, IP, etc.)A protocol adaptation layer for the Internet ProtocolIP-based application profiles


MultiMulti--band OFDM Alliance (MBOA)band OFDM Alliance (MBOA)

Multi-band OFDM PHYThe overall 7 5GHz frequency bandwidth of UWB is divided intoThe 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 transmission

< Band group allocation of MBOA PHY on the UWB >


Band group allocation of MBOA PHY on the UWB

WiMedia MACWiMedia MAC

UWB MAC Superframe Structure256 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)


Prioritized Contention Access (PCA)

TXOP Limit

TXOP foreshorten

Tx

CW DataBurst & Burst ACK (B-ACK)

MIFS SIFSAIFS Slot Time

Tx

Rx

DRP beagin

Priority AC CW_min CW_max TXOP-limit

AIFSN PHY Parameter Value

pMIFSTime 6 * TSUM = 1 875 us

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

1 AC_BK 15 1023 1 frame 7

2 AC_BK 15 1023 1 frame 7

0 AC_BE 15 1023 1 frame 4

3 AC BE 15 1023 1 f 4

pMIFSTime 6 TSUM 1.875 us

pSIFSTime 32 * TYSM = 10 us

pCCADetectTime 15 * TSYM = 5.625 us

pSlotTime 8 us3 AC_BE 15 1023 1 frame 4

4 AC_VI 7 511 1024 us 2

5 AC_VI 7 511 1024 us 2

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 accessCoordinated 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


Merge of multiple BPs

Overlapping BPsWhen the BPST of a device falls within an alien BPWhen the BPST of a device falls within an alien BP

After receiving Alien BeaconChange own BPST to the BPST of Alien BPSelect own the beacon slot used in Alien BP


Merge of multiple BPs

Non-overlapping BPsWhen a device detects an alien BP that not overlap in time withWhen a device detects an alien BP that not overlap in time with its own BP

Detect Alien BP DRP reservation with reservation type of alien BPReceive alien beacon, then calculate own new BPST


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