Bluetooth & Bluetooth Low Energy internals

BluetoothIr. Davy Jacops Nov 2015

Technicolor Intro Bluetooth Market Tech Side Future Q&A

Bluetooth: Agenda

Intro Bluetooth Market Tech Side Future Q&A

Bluetooth: Agenda

Q&A Short range wireless communications technology Personal Area Networking “PAN” Applications

Cable replacement Voice & Data access points Ad-hoc networking

Key features Robustness Low power Low cost

Bluetooth Intro

Bluetooth Intro: History 1998:

BT SIG formed:: Ericsson, Toshiba, Intel, Nokia, IBM

Name “Bluetooth” officially adopted 1999:

Core spec 1.0 released First BT unplug fest BT technology “Best of show

technology award” at COMDEX 2000:

First BT enabled mobile phone First BT “single chip”

2001: First BT enabled printer First hands free car kit BT SIG is formed as non profit, non

stock corporation 2002:

>500 BT qualifed products First BT keyboard & mouse combo

2003: Adoption of core spec 1.2

2004: Adoption of core spec 2.0 + EDR

2005: shipment of 5M BT chipsets per week

2006: First BT enabled watch, > 1B BT

devices shipped SIG announces integration of BT and

WiMedia UWB 2007: First BT enabled TV shipped 2008: > 2B BT devices shipped in 10

years 2009: BT Core spec 3.0 HS 2010:

BT4.0 core spec adopted (BLE) PTS 4.1 launched incl BLE test suites

2011: “BT Smart” & “BT Smart” ready brands 29 new BT 4.0 profiles

2012: new profiles running & cycling data monitoring

2013: BT 4.1: IoT Native BT support in Android

2014 BT 4.2: IP connectivity Core spec 2.772 pages

Bluetooth Intro: FlavorsFlavor Subset name(s) Core

spec version

Max Data rate

Voice

Spec

Bluetooth “Classic”

Basic Rate (BR) 1.x 721.2 kbps V 1999Enhance Data Rate (EDR)

2.x + EDR

2.1 Mbps V 2004

Bluetooth “High Speed”

High Speed (HS)Alternate Mac PHY (AMP)

3.x + HS 54 Mbps (802.11 AMP)

V 2009

Bluetooth“Low Energy”

Ultra Low Power (ULP)Bluetooth Low Energy (BLE)BT SmartBT Smart Ready(Wibree)

4.x 1 Mbps X 2010

Bluetooth Intro: “Bluetooth”?

The idea for the Bluetooth name came from Jim Kardach of Intel, who was reading a historical novel about Vikings and King Harald Blåtand at the time.

The name is the link to the distant past. “Bluetooth” is derived from the nickname of King Harald Blåtand a Dane who (somewhat violently) brought together people in what are now Denmark, Norway, and Sweden into a single kingdom.

King Harald reigned from 958 to 986 and got his nickname from his penchant for eating blueberries.

Intro Bluetooth Market Tech Side Future Q&A

Bluetooth: Agenda

Personal AreaBluetooth

Local AreaWi-Fi 802.11

Wide AreaMobile 3G-4G

LTE

Short range communications suchas mobile / PC accessories

CABLE REPLACEMENT

The center of the connectedhome / enterprise

For applications that demandubiquitous coverage and high reliability

Bluetooth MarketPositioning

10.000+ new BT enabled products listed in 2014 24% up from 2013

3B devices shipped in 2014 90% penetration in all mobile phones Huge growth

Smart home Consumer electronics

Bluetooth MarketBasic Figures

Source: Bluetooth SIG 2014 annual report

Bluetooth MarketShipments

Bluetooth enabled device shipments worldwide (billion units)

Bluetooth MarketGrowth

Bluetooth Smart growth 2013-2014Source: ABI Research

Bluetooth MarketSIG member Companies

Bluetooth SIG members Monthly increaseSource: Bluetooth SIG

Bluetooth MarketWorldwide Press Coverage

Source: Bluetooth SIG

Intro Bluetooth Market Tech Side Future Q&A

Bluetooth: Agenda

Intro Bluetooth Market Tech Side

Basic Rate (BR) & Extended Data Rate (EDR)

Bluetooth Low Energy Future Q&A

Bluetooth: Agenda

Universal Wireless Standard Small & Cheap Low Power Wireless (<0.1W active power)

2.4GHz ISM band Spread Spectrum Frequency Hopping

Avoid interference in ISM 1600 hops/s (625µs time slots) Pseudo random sequence based on master BD address

TDD for send / receive Modulation

BR: GFSK-Gaussian Frequency Shift Keying EDR: PSK-Phase Shift Keying BLE: GSFK

1 – 100mW Range: up to 100m Voice & Data Secure BD address: 48 bit IEEE registered

Bluetooth: Tech Side

BT SIG documents Core Specification

How the tech works Bluetooth protocols

Profiles How the tech is used How different parts of the spec shall be used to

fulfill a desired function

Bluetooth: Tech Side

Bluetooth Core SpecificationBR/EDR Piconet

Piconet: • Set of devices connected in ad hoc fashion• 1 Master, 1..7 Slaves• Master determining hopping pattern• Slaves have to synchronize• Each piconet has a unique hopping

sequence• Participation in piconet = synchronization

to hopping sequence• >200 can be parkedM=Master

S=SlaveP=Parked (deepest sleep)SB=Standby

Source: Free University Berlin

Bluetooth Core SpecificationBR/EDR Forming a Piconet

• Master gives slaves its clock and BD addr.

• Hopping pattern:• Determined by master BD (48bit)• Hopping phase determined by

clock• Addressing

• AMA 3 bit• PMA 8 bit

M=MasterS=SlaveP=Parked (deepest sleep)SB=Standby

Source: Free University Berlin

Bluetooth Core SpecificationBR/EDR Multi-Slave timing

Source: Bluetooth Specification version 4.2

Bluetooth Core SpecificationBR/EDR Scatternet

• Linking of multiple co-located piconets through sharing of common master or slave devices

• Communication between piconets• Devices jumping back and forth

between piconetsM=MasterS=SlaveP=Parked (deepest sleep)SB=Standby

Source: Free University Berlin

Bluetooth Core SpecificationBR/EDR Freq Selection

Source: Free University Berlin

Bluetooth Core SpecificationBR/EDR ACL Packet Types

Source: Bluetooth Specification version 4.2

Bluetooth Core SpecificationBR/EDR Link Control Packet Types

Source: Bluetooth Specification version 4.2

Bluetooth Core SpecificationBR/EDR SCO Packet Types

Source: Bluetooth Specification version 4.2

Bluetooth Core SpecificationBR/EDR Protocol Stack

Source: Free University Berlin

• OBEX: Object Exchange• TCS BIN: Telephony Control

Binary• BNEP: Bluetooth Network

Encapsulation protocol• SDP: Service Discovery Protocol• RFCOMM: Radio freq comm.

Bluetooth Core SpecificationBR/EDR Robustness

Source: Free University Berlin

Bluetooth Core SpecificationBR/EDR Adaptive Freq Hopping

Source: Design-Reuse.com AFH

TimeWiFiBT

Bluetooth Core SpecificationBR/EDR Adaptive Freq Hopping

Source: Design-Reuse.com AFH

TimeWiFiBT

Profiles represent default solutions for a certain usage model Vertical slice through the protocol stack Basis for interoperability

Examples Serial Port Profile Headset Profile Dial-up Networking Profile Synchronization Profile …

Bluetooth Core SpecificationBR/EDR Profiles

Source: Bluetooth Specification version 4.2

Bluetooth Core SpecificationBR/EDR Profiles Example: Headset

Source: Bluetooth Developer Portal & Bluetooth Headset Profile Specification V12

Bluetooth Core SpecificationBR/EDR Profiles Example: Headset

Source: Bluetooth Developer Portal & Bluetooth Headset Profile Specification V12

Example headset scenario: Incoming audio connection In-band ring tone

Bluetooth Core SpecificationBR/EDR Profiles List

Source: Bluetooth Developer Portal

Intro Bluetooth Market Tech Side

Basic Rate (BR) & Extended Data Rate (EDR)

Bluetooth Low Energy (BLE) Future Q&A

Bluetooth: Agenda

BLE targets even more: Ultra-low peak, average and idle mode power

consumption (1/2 to 1/100 of BR) Lower memory requirements Ability to run for year(s) on coin cell batteries Lower cost Enhanced Range

Drawbacks No voice Lower data rates

Bluetooth Core SpecificationBluetooth Low Energy - Intro

Source: BLE Developers Handbook – Robin Heydon

BLE – how to reach the cost advantage Low cost ... needs high volume ... needs very successful products ... largest volume consumer electronics is cell phone / smart phone ... reason of success of BT classic …BLE will build on attach rate of BT classic > 1B devices in a couple of years Roll out already ongoing

Opens new markets Phone accessories Other devices such as Home Automation, TV, PC, BT classic upgrades

Bluetooth Core SpecificationBluetooth Low Energy - Intro

Source: BLE Developers Handbook – Robin Heydon

Bluetooth Core SpecificationBluetooth Low Energy - Intro

Source: BLE Developers Handbook – Robin Heydon

Bluetooth Core SpecificationBluetooth Low Energy - Intro

Source: BLE Developers Handbook – Robin Heydon

Low Energy: how low is “low”? “Few years on button-cell battery” ~ 230 mAh at 3 V Power a human being for 20s

BLE Asymmetric Design Central “Bluetooth Smart Ready” –

Peripheral “Bluetooth Smart” Advertiser – Scanner Slave – Master Server – Client (Attribute protocol)

Advertisers / Slaves / Servers Low memory / processing power / ultra low power

consumption / Low cost

Bluetooth Core SpecificationBluetooth Low Energy - Intro

Source: BLE Developers Handbook – Robin Heydon

BLE – PHY Internals GFSK Clock period = 1 s𝛍 40 Channels -20dBm < Tx power < 10dBm Rx sensitivity: -70dBm or better Distance: 2.5m … 40m ... 250m

Bluetooth Core SpecificationBluetooth Low Energy - PHY

Source: BLE Developers Handbook – Robin Heydon

BLE – Link Layer Standby: Inactive Advertising: Transmit

Advertising packets Broadcast packets

Scanning: Receive advertising packets

Initiating: Initiate a connection

Connected: Sub-states: Master or Slave

Bluetooth Core SpecificationBluetooth Low Energy - LC

Source: BLE Developers Handbook – Robin Heydon

Bluetooth Core SpecificationBLE – BT Classic Interop

Source: BLE Developers Handbook – Robin Heydon

BLE – Adaptive Frequency Hopping 37 channels Next Frequency:

hop = 5…16

Bluetooth Core SpecificationBluetooth Low Energy - AFH

Source: BLE Developers Handbook – Robin Heydon

Hop = 13

BLE – AFHAdaptiveFrequencyHopping

Bluetooth Core SpecificationBluetooth Low Energy - AFH

Source: BLE Developers Handbook – Robin HeydonAFH enabled AFH disabled

BLE – Connection Setup Connection request packet includes (among others):

Access Address to be used in the connection CRC initialization value Transmit window size Transmit window offset Connection interval Slave latency Supervision timeout Adaptive frequency-hopping channel map Frequency-hop algorithm increment Sleep clock accuracy

Bluetooth Core SpecificationBluetooth Low Energy

Source: BLE Developers Handbook – Robin Heydon

Connectionless model No cable replacement anymore Transient connections

Quickly create connection Do something & Disconnect

E.g. State notification every 5 minutes Only requires radio activity < 1s per day Radio OFF 99.999% of the time

Single connect / data / disconnect in about 3ms

Bluetooth Core SpecificationBluetooth Low Energy

Source: BLE Developers Handbook – Robin Heydon

Bluetooth Core SpecificationBluetooth Low Energy: Architecture

Source: BLE Developers Handbook – Robin Heydon

Characteristics (UUID) & Services

Discovery, connection, bonding, privacy

Types of profiles and how they are used

Rules for accessing data (att=labeled bits of data)

Mux, Flow control

HCI

Advertising, Scanning, conn mgt, CRC

GFSK / 1 bit = 1 us

Bluetooth Core SpecificationImplementation: Chipset Solutions

Source: BLE Developers Handbook – Robin Heydon

Single Chip

2 Chip 2 Chip

3 Chip

Bluetooth Core SpecificationBLE: Attribute Protocol

Source: BLE Developers Handbook – Robin Heydon

Bluetooth Core SpecificationBLE: Attribute Protocol

Source: BLE Developers Handbook – Robin Heydon

Bluetooth Core SpecificationBLE: Attribute Protocol

Source: BLE Developers Handbook – Robin Heydon

Bluetooth Core SpecificationBLE Profiles List

Source: Bluetooth Developer Portal

Intro Bluetooth Market Tech Side Future Q&A

Bluetooth: Agenda

“The best way to predict the future is to invent it.”Alan Kay

BluetoothFuture

Source: Bluetooth Developer Portal

BluetoothFuture

Source: Broadcom CES Blog Jan 2015

Bluetooth Future:Bluetooth “Smart”

“More Than 30 Billion Devices Will Wirelessly Connect to the Internet of Everything in 2020”ABI Research

Bluetooth Future:Bluetooth 4.x BLE and beyond

Source: Bluetooth SIG Brands

Bluetooth Future:Bluetooth “Smart Ready”

Source: Bluetooth SIG: Bluetooth Smart Ready devices

….

39 devices• Apple iPad, iPhone, MacBook, Mac mini• Google OnHub• …

Bluetooth Future:Bluetooth “Smart”

Source: Bluetooth SIG: Bluetooth Smart devices

….

172 devices

Bluetooth “Mesh” networking Extend range Control up to 64k BLE devices 100m .. Several

km Device grouping

Proposed by CSR (now Qualcomm) Expected release: 2016

Bluetooth Future:Bluetooth “Mesh”

Source: Bluetooth SIG: Bluetooth Smart devices

Intro Bluetooth Market Tech Side Future Q&A

Bluetooth: Agenda

BT core specification: TODO SIG Annual report 2014: https://www.bluetooth.org/en-us/Documents/Annual_Report_2014.

pdf SIG history: http://www.bluetooth.com/Pages/History-of-Bluetooth.aspx ABI research: https

://www.abiresearch.com/press/more-than-30-billion-devices-will-wirelessly-conne/ ABI research: https://www.abiresearch.com/market-research/service/internet-of-everything

/ Bluetooth Security: https://

courses.cs.washington.edu/courses/cse466/01au/Projects/BluetoothSecurity.ppt Bluetooth Low Energy: The Developer’s Handbook – Robin Heydon

http://www.amazon.com/Bluetooth-Low-Energy-Developers-Handbook/dp/013288836X Android BLE development API

http://developer.android.com/guide/topics/connectivity/bluetooth-le.html iOS BLE development API

https://developer.apple.com/library/ios/documentation/NetworkingInternetWeb/Conceptual/CoreBluetooth_concepts

References