Beacon + BLEleejunwoo@gmail.com

Trends

* Apple에서 iBeacon 발표이후에관심집중- iOS nativ로지원함으로많은가능성제시- Apple Store, MLB 등사례제시- Estimote등에서 iBeacon 지원비콘공급

* 2014년상반기부터국내에서도많은관심- SKT에서자사의비콘과 LBS 서비스사업화- 스타트업을중심으로비콘을활용하는다양한시도- O2O 트렌드와함께많은가능성제시

* 그러나, 체감할수있는서비스는보이지않음- SKP의 Syrup 서비스정도가가시화- 스타트업의많은시도또한결과가보이지않음

그많던싱아는누가다먹었을까 ?

Game Change 스마트폰(mobility)과위치와결합

• SKP Syrup 서비스• Apple’s retail store: 250+ US

• Airport Premium Service• Starwood hotel

• Nivea’s StickNFind App

GeoFence + Push Notification !

Without user intervention

Facebook ‘Place Tips’

Enrich POI based on social relation

Trends 점점더일상의자연스러움으로진화

How to ? 비콘을활용하는전형적인프로세스

Beacon은 식별 정보를 Broadcasting(Advertisement)으로 전달

(정보를 수신하였는지 여부는 확인할 수 없음)

비콘의 정보와사용자 정보를

조합사용자화된유의미한정보 전달

(Push]

About iBeacon

* ‘비콘(beacon)’ 자체는식별정보를주기적으로발산하는의미- 애플의 iBeacon 발표이전에도통신분야에서사용되는개념

* ‘iBeacon’ – Apple WWDC 2013- iOS7의새로운기능으로발표- Bluetooth 4.0 표준에포함되어있는 BLE(Bluetooth Low Energy) 활용- Bluetooth 4.0 = Bluetooth Classic + Bluetooth Smart(BLE)

BLE를이용한애플의자체규격

Bluetooth 4.0

* Bluetooth Classic- Wireless devices, streaming rich content like video and audio- 충분한데이터를전달할수있는통신방식

* Bluetooth Smart- Sensor devices, sending small bits of data- BLE를이용하여저전력으로짧은데이터를전달하는규격

* Bluetooth Smart Ready- Devices that connect with both

저전력을소모하는규격을포함하는특징

Bluetooth 4.0 고속전송과저전력소모로구분

Bluetooth 4.0 고속전송과저전력으로구분

* More info: http://developer.bluetooth.org

About BLE

* 저전력 > 데이터레이트- 전력소모량을줄여배터리로도장시간동작이가능- 소형화, 유연성과편리함을제공- 경쟁기술: ANT(ANT+), Zigbee, NFC

* 소비전력계산- avg. ~ 100 µAh per day → up to 4 year from a coin cell battery- BLE Power consumption = 49µA(20 bytes payload) x 3V = 0.147mW- Coin Cell Battery(CR2032, 225mAh) = 225mAh / 49µA = 191 days

배터리로동작이가능한저전력규격

Estimote, CR2450(3V, 620mAh)

About BLE 구조의단순화로비용또한감소

* 저비용의디바이스개발이가능

Component Quantity Cost ($)

Battery 1 0.325

Antenna 1 0 (Printed Antenna)

EEPROM 1 0.89

Decoupling Cap 6 0.002

Signal Cap 5 0.002

Resistor 4 0.0001

Crystal 2 0.243

Bluetooth Low Energy IC 1 Approx $1

Total $2.72

About BLE

* Radio Frequency- Bluetooth use unlicensed 2.4GHz ISM(Industrial Scientific Medical) band- Bluetooth has built-in AFH(Adaptive Frequency Hopping) feature- Bluetooth Classic uses 79 one MHz channel- BLE uses only 40 two MHz wide channel(3 advertising channel)

* Bluetooth Smart: 1 Packet type – 2 PDU types- Advertising Channel : iBeacon, BLE devices- Data Channel : BLE devices

* BLE advertising: one-way broadcasting- packet can be up to 47 bytes in length(80 ~ 376 bits)- 1 byte preamble- 4 bytes access address(0x8E89BED6) – fixed- 2~39 PDU- 3 bytes CRC

Bluetooth Classic과구분되는규격

Packet Structure BLE packet structure

iBeacon

* iBeacon message: 30 bytes- iBeacon prefix(9 bytes): 0x0201061AFF4C000215- proximity UUID(16 bytes)- Major (2 bytes)- Minor (2 bytes)- TX power (1 byte)

* RSSI(Received Signal Strength Indicator)- TX power is the strength of the signal measured at 1 meter from the device

* Typical Distance Calculation(Calibration required)

double getDistance(int rssi, int txPower) {/** RSSI = TxPower - 10 * n * lg(d)* n = 2 (in free space)* d = 10 ^ ((TxPower - RSSI) / (10 * n))*/return Math.pow(10d, ((double) txPower - rssi) / (10 * 2));

}

iBeacon은 BLE 패킷의한종류로규격화

BLE Packet

d6 be 89 8e 40 24 05 a2 17 6e 3d 71 02 01 1a 1a ff 4c 00 02 15 e2 c5 6d b5 df fb 48 d2 b0 60 d0 f5 a7 10 96 e0 00 00 00 00 c5 52 ab 8d 38 a5

d6 be 89 8e # Access address for advertising data (this is always the same fixed value)40 # Advertising Channel PDU Header byte 0. Contains: (type = 0), (tx add = 1), (rx add = 0)

24 # Advertising Channel PDU Header byte 1. Contains: (length = total bytes of the advertising payload + 6 bytes for the BLE mac address.)

05 a2 17 6e 3d 71 # Bluetooth Mac address02 01 1a 1a ff 4c 00 02 15 e2 c5 6d b5 df fb 48 d2 b0 60 d0 f5 a7 10 96 e0 00 00 00 00 c5 # Bluetooth advertisement

52 ab 8d 38 a5 # checksum

02 # Number of bytes that follow in first AD structure01 # Flags AD type1A # Flags value 0x1A = 000011010

bit 0 (OFF) LE Limited Discoverable Modebit 1 (ON) LE General Discoverable Modebit 2 (OFF) BR/EDR Not Supportedbit 3 (ON) Simultaneous LE and BR/EDR to Same Device Capable (controller)bit 4 (ON) Simultaneous LE and BR/EDR to Same Device Capable (Host)

1A # Number of bytes that follow in second (and last) AD structureFF # Manufacturer specific data AD type4C 00 # Company identifier code (0x004C == Apple)02 # Byte 0 of iBeacon advertisement indicator15 # Byte 1 of iBeacon advertisement indicatore2 c5 6d b5 df fb 48 d2 b0 60 d0 f5 a7 10 96 e0 # iBeacon proximity uuid00 00 # major00 00 # minor

c5 # The 2's complement of the calibrated Tx Power

iBeacon 패킷구성

BLE Packet iBeacon 패킷구성

Preamble

1

Advertiser

4

PDU

2 - 39

CRC

3

MAC address

6

Header

2

Data

1 - 31

iBeacon Prefix

9

Proximity UUID

16

Major

2

8E89BED6

0201061AFF4C000215

Minor

2

size, type.. e.g. 112233445566

e.g. 4152554e-f99b-86d0-947070693a78 e.g. 4159 e.g. 27341

BLE Advertisement Frame

BLE Advertisement Payload

iBeacon Data

Measured Tx Pwr

2

e.g. -59

iBeacon information

RSSI Measured by receiver

MAC From BLE header

Proximity UUID (can be) company reference

Major, Minor Integer values identifying

the tag and/or zone

Measured Tx Pwr Calibrated power at 1m from

the iBeacon (dBm)

Protocol Stacks

• LL(Link Layer): 무선링크를설정하고콘트롤하는레이어• HCI(Hardware Controller Interface): 콘트롤러와호스트간의통신레이어• L2CAP(Logical Link Control to Adaptation layer Protocol)): 상위레벨로데이터서비스를제공하고콘트롤러로보낼패킷을쪼개거나조합하는레이어

• SM(Security Manager): AES-128bit 암호화• ATT(Attribute Profile): 서비스제어레이어• GATT(Generic Attribute Profile): ATT를이용하여프로파일과서비스를주고받을것인지를제어

• GAP(Generic Access Profile): 장치간연결제어(Advertising and Connections)

Bluetooth Smart(BLE) 프로토콜구조

Radio Frequency Bluetooth Smart 주파수규격

* BLE uses 2.4GHz ISM (unlicensed) band- 2MHz wide channel – 40 channel - Advertising channel: 3 channel(37, 38, 39)

ISM band ISM band를사용하는다양한무선규격

* Unlicensed Radio Frequency- Wi-Fi(802.11b/g/n/ax)- Bluetooth- ZigBee(802.15.4)- ANT(ANT+)- Wireless Etherernet- Wireless USB

Avoid Interference 채널간섭을줄일수있는설정

* 2.4GHz Wi-Fi 채널을 1, 6, 11로설정- 채널간간섭의확률을줄일수있음- Wi-Fi: CSMA(Carrier Sense Multiple Access) / CA(Collision Avoidance)

Interference 무선주파수에영향을미칠수있는요인

* Interference Types

- Physical objects: 800Mhz, 1800MHz, 2100Mhz,,,

- Radio interference: Many wireless technologies use an RF range of 2.4GHzDevices can cause noise and weaken the signal

- Electrical interference: Computer, Oven, Motorized devices

- Environmental factors: Lighting, weather, even human

iBeacon 결론적으로 advertising 패킷을 broadcasting

* iBeacon은단방향의메시지만송신

Proximity 근접도를측정할수있는정보포함

* 단방향의식별정보만을전송하지만,- RSSI를이용하여근접정도의계산이가능

* iOS Region Monitoring- If listening device crosses monitored region boundary- In case of entry, iOS will send notification within ~ 1 second- In case of exit, iOS wait about 20 seconds before exit notification is reported

(In order to avoid fake notifications)

* iOS monitoring mode and range mode- When the phone is not active,

iOS goes into a low-power modeRegion enter/exit events are detected

- When the phone and app are active, iOS goes into range modeDetect the signal strength and estimate the distance more precisely

Accuracy 거리측정에오차감안필요

* External factors which influence the Bluetooth radio frequency- absorption, interference, multipath fading, multipath propagation, diffraction - RSSI might fluctuate heavily

* Experimental Results- Distance of 20cm: deviation is 5~6cm- Distance of 1m: deviation is 15cm- Distance greater than 10m: deviation is 2~3m

-100

-95

-90

-85

-80

-75

-70

-65

-60

-55

-50

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

iBeacon RSSI (dBm) vs distance (m), line of sight

GS4 with iBeacon 100 GS4 with iBeacon 101 Nexus 7 with iBeacon 100 Nexus 7 with iBeacon 101

iBeacon Tx power 0dBm

‘measured power’ -61dBm @ 1 m

Accuracy 수신기에따른측정신호차이

* Wireless signal fluctuation을고려- device별신호수신에따른경향성존재- moving avg / 칼만필터 / CDF 등오차의보정필요

-90

-85

-80

-75

-70

-65

-60

-55

-50

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

iBeacon RSSI (dBm) vs distance (m), line of sight (RSSI averaged over 5 readings)

GS4 with iBeacon 100 GS4 with iBeacon 101 Nexus 7 with iBeacon 100 Nexus 7 with iBeacon 101 grand average

Indoor positioning

* If receiver detects three different beacon’s advertising packet,Relative position can be deduced- Beacon’s physical location should be supplied (via inquiry online service)- At least, Three different beacon’s RSSIs should be detected

* But,- Bluetooth radio wave may be fluctuated- Each beacon’s transmitting time can not be synchronized

LBS ≠ Positioning

실내에서의측위가능

UUID hierachy

* UUID: nationwide retail store identifier* Major: identifier of store location* Minor: identifier of department

* For security reason, UUID generation by uuidgen is recommended- create a new universally unique identifier (128-bit)- new UUID can reasonable be considered unique among all UUIDs- unique on the local system- unique on other system in the past and in the future

Identifier of iBeacon

RSSI Fingerprinting

* Bluetooth, Wi-Fi, Magnetic 등을측정하여공간에대한라디오맵구성- 크라우드소싱으로정보를수집하여구축비용절감- 구축된라디오맵을바탕으로실내외위치, 네비게이션정보를제공- Skyhook Wireless- CISCO LBS- KAILOS (https://kailos.io)

RSSI를이용한실내측위방법

BLE GATT Profile 저전력을이용하는다양한 BLE 서비스

* Bluetooth Smart GATT- BLE 장치간에서비스에대한데이터송수신방법을정의- BLE를활용하는다양한서비스는프로파일로정의(Bluetooth SIG)- https://developer.Bluetooth.org/TechnologyOverview/Pages/Profiles.aspx

BLE GATT Profile Profile 종류

Profile Description

Alert Notification (ANP) 경보 통지 프로파일

Blood Pressure (BLP) 혈압을 측정 프로파일

Cycling Power (CPP) 자전거의 크랭크에 전달되는 파워 정보 프로파일

Cycling Speed and Cadence (CSCP) 자전거의 속도와 케이던스 정보 프로파일

Find Me (FMP) 연결된 디바이스를 찾는 프로파일

Glucose (GLP) 혈당을 측정하는 프로파일

Health Thermometer (HTP) 체온을 측정하는 프로파일

Heart Rate (HRP) 심장 박동수를 측정하는 프로파일

HID OVER GATT (HOGP) GATT 프로파일 상의 휴먼 인터페이스 디바이스

Location and Navigation (LNP) 위치정보와 네비게이션 정보 프로파일

Phone Alert Status (PASP) 전화 경포 통지 정보 프로파일

Proximity (PXP) 근접 정보 프로파일

Running Speed and Cadence (RSCP) 러닝 스피드와 회전수의 측정 프로파일

Time (TIP) 시간 동기화를 위한 정보를 전달

Weight Scale Profile (WSP) 체중 측정 프로파일

IoT over BLE IoT환경에서주요하게활용될것으로기대

(from CSR presentation)

• A new radio, new protocol stack, new profile architecture and a new qualification regime

• It’s designed to run from coin cells and support an Apps Store model• It is a radio standard for a new decade, enabling the Internet of Things• Feature

• Mostly new PHY; some parts derived from the Basic Rate (BR) radio• New advertising mechanism, for easy of discovery & connection• Asynchronous connection-less MAC: used for low latency, fast

transactions (e.g. 3ms from start to finish)• New Generic Attribute Profile to simplify devices and the software that

uses them• Asynchronous Client / Server architecture

• Designed to be LOWEST cost and EASY to implement

Bluetooth 4.2 인터넷접속지원

* Bluetooth 4.2 Standard (2014-12-04)- 2.5x faster (huge packet)- privacy improvement- access the internet

* Update to 4.2- Privacy features may be available via firmware update- increased speed and packet size feature will require a hardware update

* ISIP(Internet Protocol Support Profile): Adopted (2014-12-16)- Support of exchanging IPv6 packets between devices over

the Bluetooth Low Energy transport- IPv6 / 6LoWPAN

Bluetooth 4.2 Internet Protocol Stack

* ISIP Router: used for devices that can route IPv6 packets- Access Point(such as home router, mobile phone)

* ISIP Node: devices that can only originate or consume IPv6 application packets- IPSS(Internet Protocol Support Service): discovery over GATT

Wireless Technology Compare with other technologies

BLE Compare with other technologies

BLE ANT ANT+ RF4CE ZigBee Wi-Fi Nike+ IrDA NFC

Remote Control √ x x √ x √ x √ x

Security √ x x x √ √ x x √

Health and Fitness √ √ √ x x x √ x x

Smart Meters √ x x x √ √ x x x

Cell Phones √ x √ x x √ x √ √

Automotive √ x x x x √ x x √

Heart Rate √ x √ x x x x x x

Blood Glucose √ x √ x x x x x x

Positioning √ x x x √ √ x x x

Tracking √ x x x √ x x x √

Payment x x x x x x x x √

Gaming √ x x x x x x √ x

Key Fobs √ x x √ x x x √ √

3D TV √ x x x x x x √ x

Smart Applications √ x x x √ x x x x

Intelligent Transport Systems √ √ √ x √ x x x x

PCs √ x x x x √ x √ √

TVs √ x x √ x √ x √ x

Animal Tagging √ x x x √ x x x √

Assisted Living √ √ √ x x x x x √

Table: Low-power wireless technology target markets (Digikey)

Pros and Cons

* Pros- 저전력기반으로유연성과환경구성에적합(배선구성불필요)- mobility 제공으로다양한분야에서활용가능- (iBeacon) 신호를전달하는용량(capacity)에제약이없음(단방향)

* Cons- (iBeacon) 주기적신호를발생(advertising)시키는단방향통신구조

: 밀집지역에정보를전달하기에적합한유형: 그러나, 비콘을활용하는서비스는용량에제약을받을수있음

- 1초간격(1Hz)의신호를인식하기위해서는 1초를기다려야함: 신호발생주기단축시, 배터리동작시간은단축

- 정확한위치식별을위해서는필요한조건이만족되어야함: triangulation 측량을위해서는 3개의비콘신호수신필요: 각비콘의물리적위치를알아야함: 오차를줄이기위해서는복잡한구성필요

BLE와 iBeacon의장점

Security Issue

* 비콘(region)의식별정보인 proximityUUID / Major / Minor 취약점- proximityUUID / Major / Minor를임의의값으로설정가능- region 기반의서비스의오류를야기시킬수있음→ 신뢰도가요구되는서비스에서비콘정보만의존하는것은위험

* iOS는비콘의안전성확보를위한최소한의조치- 와일드카드로비콘을감지하는것은불가능(proximityUUID 설정필요)- (android는 OS에서비콘을지원하지않으므로임의의비콘스캔가능)- world-wide beacon map: www.wikibeacon.org by Radius Network- “Apple Slowly Locking Down iBeacon ?”- proximityUUID를직접설정하는어플리케이션의등록거부

→ 신뢰도가요구되는서비스에서비콘정보만의존하는것은위험

Apple rejects manual input of UUIDs

Battery Drain issue

* 블루투스활용에따라배터리소모가증가하지만,- 스마트폰활용에치명(?)적일만큼배터리소모가증가하지는않으며,- 최신단말의경우에블루투스의배터리소모효율이나아지고있음- 블루투스활용(이어폰, 웨어러블등)도가향상됨에따라보편화전망

* 비콘이배터리소모에미치는영향- 감지범위내비콘의개수가배터리소모에미치는영향이큼- 비콘감지주기가배터리소모에미치는영향이큼(iOS : 1 sec)- 비콘의신호발생간격이짧으면배터리소모량이증가함

→비콘의배치와주기설정이사용자에게미치는영향고려필요

블루투스활용으로배터리소모는증가

Battery Drain issue iOS is worse than Android (experimental)

→ Android가 iOS에비해배터리소모영향이적음→ iOS는감지공간내비콘의개수에덜영향받음→ Android는커스터마이징에유리한반면, iOS는최적화된결과를제공→ 실질적인응용에서의배터리소모는 1% 수준으로예측(1일)

Scan Interval

* Android는블루투스제어를통해설정이가능- https://github.com/AltBeacon/android-beacon-library

* In iOS, 설정은알수없으나, 배터리소모를감안하여동작- Region Monitoring : foreground / background (1 second)

: unknown / inside / outside- Ranging : only works in foreground

: immediate(0.5m) / near(2m) / far(30m) / unknown- only 20 region can be registered

스캔의지속시간과스캔의간격

Management Issue

* 비콘관리의어려움- 비콘의정상적인동작여부를원격에서파악하기어려움- 비콘의설정변경또한용이하지않음- 음영지역, 신호발생주기, 전원공급상태는모두서비스의품질에영향- 배터리교체에대한관리부담(Estimote Beacon Sticker)

* 효과적인비콘관리방법 ?- 핸드핼드스캐너(Application)를이용한관리방법- 서비스와결합된크라우드소싱관리방법

→서비스의구성에서는설정과관리의어려움고려필요→ Bluetooth 4.2에서는 Internet connectivity 제공으로관리에이점

(IPv6 deployment 이슈)

Beacon is not connected to the Network

Conclusion iBeacon is useful because ,,, but,

Simple and Convenient Use of Radio Frequency

Bluetooth 4.0 Standard

Capacity Free

As an Interface

Disconnected

Security Issues

Localized Target

→어플리케이션의활용성이물리적공간과결합하여광범위하게확대

Case Study

* Antwerp museum- Estimote비콘을이용하여박물관내서비스- Push Notification / In-door Positioning

* Why ?- 공간을해치지않으면서정보제공필요

: 속성상부수적인정보제공의필요성- 박물관내관람객의이동행태

: 비콘을인식하는데까지소요되는시간: 통상적인보행속도등적합

- 박물관내형상이빈번하게변경되지않음: 공간의형상변경등이빈번하지않음: 실내측위등에이점

박물관활용사례

Case Study

* 공항내프리미엄서비스예시- Virgin Atlantic – London Heathrow- Use of Estimote’s beacon- 보안검색대이동시항공권팝업- 환전시환전수수료할인쿠폰발행- Airport map information- Thermometer / accelerometer- Luggage tracking(accelerometer) – future- Temperature change

* Why ?- 다수의이용객이밀집되는공간에효과적- 사용자에대한편의제공과더불어관리효과- 공항공간의특성상환경영향이미미함

Airport Premium Service

Case Study

* 호텔등에서 check-in으로활용- Starwood / Marriott / James / Hilton- Location-based suggestion- Check-in / Check-out

Door Key – personalized check-in

Case Study

* Automatic + iBeacon- OBD(On-Board Diagonostic)에비콘기능을추가- 차량을이동하는비콘으로,,,- 주차시간 / 주차비계산 /출입개폐기작동- 톨게이트, 주차장, 세차장, 주유소등에서사용- Bluetooth 3.0 + 4.0- OBD-II(K1962 standard)

* Why ?- 비콘신호를송신함으로써의서비스모델- 고정형태가아닌이동형으로의서비스모델- 보안이슈에대해서는고려필요

Door Key – personalized check-in

Case Study

* 위치와결합한 Gamification- http://beaconcrawl.com- Pub 연계를통한 Gamification- 스마트폰을이용한메뉴주문- 1차, 2차, 3차목적지미션을통해쿠폰발행

* Why ?- 오프라인서비스와의결합- 비콘을활용한다양한게임시나리오적용

비콘활용 Gamification

Scenario

→목적으로사용하기보다는수단으로활용해야,

* 시나리오에서는비콘의특성과영향이반드시고려되어야,- 비콘신호발생주기와측정간격을고려한사용

: 개발시점의환경보다는실환경에서의사용자행위를고려: 1초이상지연될수있는상황에적합한가 ?

- 박물관과같은환경에서의적합성: 특정한환경에서의사용자양상분석필요: notification – active / passive

- 신뢰도가요구되는서비스모델에서의적용위험성: 쿠폰과마일리지의차이점: 물리환경에서비콘의관리와통제의어려움

고려할점