Evolution of Bluetooth from v4.0 to v5.0 Brian Petted & Mahendra Tailor November 15, 2017
1 Laird Confidential Meet Your Presenters:
Mahendra Tailor Brian Petted Technology Leader Technology Leader [email protected] [email protected]
2 Laird Confidential The Evolution of BLE from v4.0 to v5.0
• Agenda / Topic Enumeration • BLE Feature Additions • BLE Top Level Changes • BLE Signaling (v4.0) (v5.0) - High Rate (2.0 Mbps) - Long Range (500 kbps, 125 kbps) - BLE Signal Spectra (v4.0)(v5.0): Compliance Considerations • Q&A Forum
3 Laird Confidential Comparison of BLE, Classic Bluetooth & Wi-Fi at the Time of v4.0 .
Classic Bluetooth about 2mbps
Wi-Fi > 100mbps
Throughput BLE < 50kbps
Power Consumption 4 Laird Confidential BLE Specification Timeline
4 x Range, 6 years 2 x Speed 5 8 x Advert Payload Dec 2016
Secure Connections Packet Length Extension 4.2 Dec 2014 Any Role Topology 4.1 Dec 2013 First introduction 4.0 Jun 2010 5 Laird Confidential Comparison of BLE, Classic Bluetooth at v5
Classic Bluetooth
BLE v5
Around 1mbps Throughput BLE
Power Consumption 6 Laird Confidential BLE Throughput Evolution in iOS v11
Write With Response 2.5 kbps
Write Without Response 5.2 kbps
Packed CE Length 37 kbps
Larger MTU 48 kbps
EDL (Extended Data Length) 135 kbps
L2CAP + EDL 197 kbps
L2CAP + EDL + 15ms Int 394 kbps
Source: Apple WWDC 2017
7 Laird Confidential One Reason for Throughput Improvement Came in v4.2
39 bytes LE Data Packet Extension! Duty Cycle as low as 6%
255 bytes
Duty Cycle increased to as high as 70%
8 Laird Confidential v4.2 : Security Enhancements
• LE Secure Connections (LESC) Secure Connections based on a long term key derived from a pairing based on a Diffie-Hellman exchange.
9 Laird Confidential Recap of where we are with v5
10 Laird Confidential High Speed
Physical Layer • 2 Msps modulation • 3 dB reduced sensitivity • 29% range reduction
Throughput increased to 1.4 Mbps
Source: Nordic Semiconductor
11 Laird Confidential Long-Range
Physical Layer • Standard 1 Msps modulation
Link Layer Header • From 8 to 18 bytes
2 Coding Schemes: S=2: 4.5 dB increased sensitivity • 68% range increase
S=8: 12 dB increased sensitivity • 400% range increase
Source: Nordic Semiconductor
12 Laird Confidential LE CODED: Coding Scheme
Forward Error Correction • 2 bits for every input bit
Pattern Mapper • S=2:1 symbol per input bit • S=8: 4 symbols per input bit
S=2 - 2 symbols per bit • 500 kbps
S=8 -8 symbols per bit • 125 kbps
Source: Nordic Semiconductor
13 Laird Confidential LE CODED : Increased range but reduced throughput
Source: Nordic Semiconductor
Increased Power Consumption
14 Laird Confidential Advertising Extensions in v5
Source: Nordic Semiconductor
15 Laird Confidential Advertising on Data Channels
Longer packets and coding • Congested advertising channels These are sent in primary channels
Reduces contention and duty cycle
This is sent in data channels
Source: Nordic Semiconductor
16 Laird Confidential Advert Extensions : Chained Data
17 Laird Confidential Advert Extensions : Synchronous Data
18 Laird Confidential Physical Layer Considerations
19 Laird Confidential The Evolution of BLE v4.0 to v5.0
Bluetooth Low Energy Hybrid Digital Transmission System / Frequency Hopping:
• 40 channels versus 79 channels on 2 MHz channel spacing versus 1 MHz
• Primarily a single-carrier system Hybrid Digital Transmission System (DTS) / FH
• Many protocol transactions occur on a single channel
• Frequency hopping only required for longer data sequences and rarely utilizes all channels in a hop sequence
• Frequency hopping sequence generation complexity lowered
20 Laird Confidential The Evolution of Bluetooth v4.0 to v5.0
• Bluetooth Low Energy Hybrid Digital Transmission System / Frequency Hopping:
21 Laird Confidential The Evolution of BLE v4.0 to v5.0
• BLE Specification declaration of changes from v4.0 to v5.0:
- Slot Availability Mask (SAM) - 2 Msym/s PHY for LE ✓ - LE Long Range✓ - High Duty Cycle Non-Connectable Advertising - LE Advertising Extensions - LE Channel Selection Algorithm #2
• PHY Baseline Discussion: BLE (v4.0) versus BT Classic • PHY Discussion: BLE v5.0 evolution from BLE v4.0 • PHY Discussion: BLE v5.0 PHY Details - R=1/2 k=4 Convolutional Encoder - Pattern Mapper • PHY Discussion: Spectrum and Compliance Considerations
22 Laird Confidential PHY Baseline Discussion BLE (v4.0) versus BT Classic
• PHY Baseline Discussion: BLE (v4.0) versus BT Classic (Non-Enhanced Data Rate [EDR])
• Bluetooth Classic: - Modulation Type GFSK (Gaussian Filtered Frequency Shift Keying) - Baseband Filter: Gaussian Pulse Shaping BT Product: BT=0.5 - Data Rate: 1 Mbps - Modulation Index: 0.28 – 0.35 (Sub MSK condition of 0.5) - Channelization of Carrier Frequencies: 2402 + k*1 [MHz] k=0,1,…,78 - Frequency Hopping Selection over 79 channels down to 20 channels (Adaptive Frequency Hopping)
• Bluetooth Low Energy (BLE – v4.0 v5.0)
- Modulation Type GFSK (Gaussian Filtered Frequency Shift Keying) - Baseband Filter: Gaussian Pulse Shaping BT Product: BT=0.5 - Data Rate: 1 Mbps - Modulation Index: 0.45 – 0.55 (MSK condition of 0.5 +/- 10% , Stable Modulation Index 0.5 +/- 0.1%) - Channelization of Carrier Frequencies: 2402 + k*2 [MHz] k=0,1,…,39 - Frequency Hopping Selection over 40 channels – Selection not considered here
23 Laird Confidential PHY Discussion: BLE v4.0 to BLE v5.0
Additions:
• Additional Uncoded Data Rate: 2 Mbps
• Additional Coded Data Rate: 500 kbps
- Convolutional Encoder Rate-1/2, Constraint Length k=4 - 2 coded bits per source bit - Coding Gain, Reduced Receiver Bandwidth
• Additional Coded Data Rate: 125 kbps
- Convolutional Encoder Rate-1/2, Constraint Length k=4 - Manchester Pattern Mapper (4:1 Rate buffer, 4 signal elements per coded bit) - Coding Gain, Further Reduced Receiver Bandwidth
24 Laird Confidential Coded Data Transmission: 500 kbps and 125 kbps
2 3 g0(x)= 1 + x+ x + x
+ + + PATTERN MAPPER z-1 z-1 z-1 P=1, S=2: [0 1][0 1] P=4, S=8: S=2: [0 1][0 0 1 1 , 1 1 0 0]
+ + + c=[c c c c …] 00 01, 10 11 s=[s00 s01, s10 s11 …] R = 500 kbps 2 3 dc Rs= 500 kbps g1(x)= 1+ x + x Convolutional Encoder R=½, k=4 Rse= 500 kse/s Rs= 125 ksps
000 000 000 000
001 001 001 001
010 010 010 010 PATTERN DE-MAPPER 011 011 011 011 P=1, S=2: [0 1][0 1] 100 100 100 100 P=4, S=8: S=2: [0 0 1 1 , 1 1 0 0][0 1] 101 101 101 101
110 110 110 110
111 111 111 111
Viterbi Decoder R=½, c=[c00 c01, c10 c11 …] s=[s00 s01, s10 s11 …] k=4 State Trellis Rdc= 500 kbps Rs= 500 kbps
Rse= 500 kse/s Rs= 125 ksps 25 Laird Confidential Coded Data Transmission: 500 kbps and 125 kbps • R=1/2 k=4 Convolutional Encoder, Viterbi decoder, Hard Decision –MatlabSimulation
• Coding Gain : Gc 12.99 dB 8.489 dB 4.5 dB
0 Bit Error Ratio - Uncoded and Coded data 10 coded uncoded
-1 10
-2 10
X: 12.99 -3 Y: 0.0008176 10 X: 8.489 Y: 0.00107
-4
Bit Error Ratio 10
-5 10
-6 10
-7 10 -15 -10 -5 0 5 10 15 20 S/N (dB) 26 Laird Confidential Coded Data Transmission: 500 kbps and 125 kbps • R=1/2 k=4 Convolutional Encoder, Viterbi decoder, Hard Decision –MatlabSimulation
• Coding Gain : Gc 12.99 dB 8.489 dB 4.5 dB
B500kbps 0.5 • Bandwidth Reduction Ratio, pattern mapping (Split Phase Manchester): 10 log10 10 log10 2 3.01 dB B125kbps 0.250 • 4 signal elements per bit, Tse = Tb • Expected Sensitivity Improvements: Coding Gain + Bandwidth Reduction, Manchester Coding Gain[1]
Coded / Rate Buffered Data Waveform 1
0.8 0.6
d(t) 0.4
0.2
0 0 1 2 3 4 5 6 7 8 5 dB t (nTb) Pattern Mapped (Manchester) Waveform 1 7 dB 0.8
0.6
s(t) 0.4
0.2 [1] Bluetooth Core Specification, Bluetooth Special Interest Group, December 6, 2016.
0 0 1 2 3 4 5 6 7 8 t (4nTb)
27 Laird Confidential Additional Data RatesAdditional Signal SpectraCertification Impacts
BLE Signal Spectral Density dBm/1 kHz 30 20 • 500 kbps 1 Mbps • 1 Mbps 2 Mbps 10
0 • Bandwidth Change • Bandwidth Change -10 • PSD Change • Band edge Change -20
-30 BLE Signal Spectral Density dBm/1 kHz BLE Signal Spectral Density dBm/1 kHz S(f) [dBm/1 kHz] 30 30 -40 20 20 -50 10 10 -60 0 0 -70 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 -10 -10 frequency [Hz] 6 x 10 -20 -20 BLE Signal Spectral Density dBm/3 kHz
30 -30 -30
S(f) [dBm/1 kHz] S(f) [dBm/1 kHz]
20 -40 -40
-50 -50 10 -60 -60 0 -70 -70 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 -10 frequency [Hz] 6 frequency [Hz] 6 x 10 x 10 -20
S(f) [dBm/3 kHz] -30
-40 • 125 kbps 1 Mbps -50 • Bandwidth Change -60 • PSD Change -70 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 frequency [Hz] 6 x 10 28 Laird Confidential PHY Discussion: BLE Evolution from v4.0 to v5.0
• Increased RX Sensitivity longer range • Lower coded data rates: Lower Throughput • Higher uncoded data rates: Higher Throughput • Spectrum has discrete components in 500 kbps and 125 kbps cases FCC PSD, BW re-test • Higher uncoded rates: FCC PSD re-test
2 Msym/s PHY for LE ✓ LE Long Range✓
High Duty Cycle Non-Connectable Advertising LE Advertising Extensions LE Channel Selection Algorithm #2 Diffie-Hellman Key Exchange
29 Laird Confidential Q&A / Wrap-Up
30 Laird Confidential Bluetooth 5 Offerings from Laird
SaBLE-x-R2 2.4 GHz Bluetooth 5 Low Energy (BLE) Module • Built upon the latest generation BLE Silicon (TI CC2640RF2 Wireless MCU) • Features dedicated ARM Cortex-M3 processor for host applications, M0 processor for BLE core, and Sensor Processor Engine • On-board trace Antenna or U.FL connector options available, certified with multiple antenna options • Drop-In Replacement for SaBLE-x for seamless BT5 upgrade path
BL652 Bluetooth 5 Low Energy (BLE) + NFC Module • Features new Nordic nRF52 with ARM Cortex M4F (512K Flash / 64K RAM) for hostless operation • On-board Chip Antenna or IPEX MHF4 connector options available, certified with multiple antenna options • Features innovative, event driven programming language to significantly simplify BLE module integration • Ultra-small 10 x 14mm
31 Laird Confidential Laird Confidential APPENDIX A: Bluetooth Basic Rate to BLE Evolution
33 Laird Confidential The Evolution of Bluetooth Basic Rate and EDR to BLE
• Bluetooth (Basic Rate / Enhanced Data Rate) Bluetooth Low Energy
• Orthogonal Frequency Hopping supports many half-duplex links • Communication Link support full duplex digital audio (hands-free) • Wireless Speakers (Advanced Audio Profile) • Battery System usually rechargeable
34 Laird Confidential The Evolution of Bluetooth Basic Rate and EDR to BLE
• Bluetooth (Basic Rate / Enhanced Data Rate) Bluetooth Low Energy [1]
• Modulation Type GFSK (Gaussian Filtered Frequency Shift Keying) • Baseband Filter: Gaussian Pulse Shaping BT Product: BT=0.5 • Data Rate: 1 Mbps • Modulation Index: 0.28 – 0.35 (Sub MSK condition of 0.5) • EDR2: 2 Mpbs π/4 DQPSK, EDR3 8 DPSK • Channelization of Carrier Frequencies: 2402 + k*1 [MHz] k=0,1,…,78 • Frequency Hopping Selection over 79 channels down to 20 channels (Adaptive Frequency Hopping)
[1] Bluetooth Core Specification, Bluetooth Special Interest Group, December 6, 2016.
35 Laird Confidential The Evolution of Bluetooth Basic Rate and EDR to BLE
Source: Near Communications
36 Laird Confidential The Evolution of Bluetooth Basic Rate and EDR to BLE
• Frequency Hopping Spectrogram for Two Frequency Hopping Links
Frequency Hopping Spectrogram
100
90
80
70
60
50 time index 40
30
20
10
10 20 30 40 50 60 70 frequency index
37 Laird Confidential The Evolution of Bluetooth Basic Rate and EDR to BLE
• Frequency Hopping Spectrogram for Adaptive Frequency Hopping relative to a single carrier wide-band signal
Frequency Hopping Spectrogram
100
90
80
70
60
50 time index 40
30
20
10
10 20 30 40 50 60 70 frequency index
38 Laird Confidential The Evolution of Bluetooth Basic Rate and EDR to BLE
• Bluetooth (Basic Rate / Enhanced Data Rate) Master/Slave Frequency Hopping [1]
[1] Bluetooth Core Specification, Bluetooth Special Interest Group, December 6, 2016.
39 Laird Confidential APPENDIX B: Bluetooth BLE v4.0 to v5.0 Additional Slides
40 Laird Confidential The Evolution of Bluetooth from v4.0 to v5.0
• Data Channel Selection [1], hop increment 5-16, “Used Channels”=Currently Assigned Channel Set: • unmappedChannel=(lastUnmapped Channel + hopIncrement)mod 37
[1] Bluetooth Core Specification, Bluetooth Special Interest Group, December 6, 2016.
41 Laird Confidential The Evolution of Bluetooth from v4.0 to v5.0
• Data Channel Selection [1], 37 used channels, hop increments 5-11:
BLE 4.0 frequency index 40 BLE 4.0 frequency index 40
35 35
30 30
25 25
20 20
frequency index frequency frequency index frequency
15 15
10 10
5 5
0 0 0 10 20 30 40 50 60 70 80 0 10 20 30 40 50 60 70 80 hop index hop index
[1] Bluetooth Core Specification, Bluetooth Special Interest Group, December 6, 2016.
42 Laird Confidential Coded Data Transmission: 500 kbps and 125 kbps • R=1/2 k=4 Convolutional Encoder, Viterbi decoder
1 1 • Coding Gain Bound: gc rd free 6 3 Gc 10log10 rd free 10log10 6 10log10 3 4.77 dB 2 2
• Pattern Mapper: Rate Buffered (4:1) NRZ to 4 signal element Split Phase Manchester Encoding
2 3 g0(x)= 1 + x+ x + x FM Modulator Df=a*kf + + + h=0.5=Df/(Rb/2) PATTERN MAPPER GAUSSIAN PULSE SHAPING FILTER t LINK LAYER 24-bit CRC GENERATION DATA WHITENING -1 -1 -1 P=1, S=2: [0 1][0 1] BT=0.5 jt DATA 24 10 9 6 4 3 7 4 z z z t k x d y e gCRC(x)= x + x + x + x + x + x + x + 1 g (x)= x + x +1 P=4, S=8: S=2: [0 1][0 0 1 1 , 1 1 0 0] N=2 f SOURCE w OSF=4,8 0 d=[d d d …] + + + o 1 2 c=[c c c c …] TX R = 1 Mbps 00 01, 10 11 s=[s00 s01, s10 s11 …] d R = 500 kbps 2 3 dc Rs= 500 kbps g1(x)= 1+ x + x Convolutional Encoder R=½, k=4 Rse= 500 kse/s Rs= 125 ksps
000 000 000 000 Hard Decision Baseband LPF FM Demodulator
001 001 001 001
010 010 010 010 PATTERN DE-MAPPER GAUSSIAN PULSE MATCHED FILTER LINK LAYER 24-bit CRC CHECKING DATA DE- 011 011 011 011 P=1, S=2: [0 1][0 1] BT=0.5 d j t 100 xˆ e DATA SINK 24 10 9 6 4 3 WHITENING 100 100 100 gCRC(x)= x + x + x + x + x + x + x + 1 7 4 P=4, S=8: S=2: [0 0 1 1 , 1 1 0 0][0 1] N=2 dt g (x)= x + x +1 101 101 101 101 w OSF=4,8 110 110 110 110
d=[do d1 d2…] 111 111 111 111 R = 1 Mbps d Viterbi Decoder R=½, c=[c00 c01, c10 c11 …] s=[s00 s01, s10 s11 …] RX k=4 State Trellis Rdc= 500 kbps Rs= 500 kbps
Rse= 500 kse/s Rs= 125 ksps
43 Laird Confidential Transmitter Spectrum
• +10 dBm 2 Mbps Uncoded Data Spectrum: • Matlab (FFT), Litepoint VSA • Power Spectral Density (dBm/1 kHz), dBm/10 kHz)
BLE Signal Spectral Density dBm/1 kHz 30
20
10
0
-10
-20
-30 S(f) [dBm/1 kHz] -40
-50
-60
-70 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 frequency [Hz] 6 x 10
44 Laird Confidential Transmitter Spectrum • +10 dBm 1 Mbps Uncoded Data Spectrum: • Matlab BLE (FFT), Matlab BTC (FFT) ,Litepoint BLE VSA • Power Spectral Density (dBm/1 kHz), (dBm/1 kHz), dBm/10 kHz)
BLE Signal Spectral Density dBm/1 kHz 30 BLE and BTC Signal Spectral Density dBm/1 kHz 30 BLE 20 20 BTC
10 10
0 0
-10 -10
-20 -20
-30 -30
S(f) [dBm/1 kHz] S(f) [dBm/1 kHz] -40 -40
-50 -50
-60 -60
-70 -70 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 frequency [Hz] 6 frequency [Hz] 6 x 10 x 10
45 Laird Confidential Transmitter Spectrum • +10 dBm, 500 kbps Coded Data Spectrum: Convolutional Code, Matlab (FFT) • Litepoint VSA • Power Spectral Density (dBm/3 kHz), dBm/10 kHz)
BLE Signal Spectral Density dBm/1 kHz 30
20
10
0
-10
-20
-30 S(f) [dBm/1 kHz] -40
-50
-60
-70 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 frequency [Hz] 6 x 10
46 Laird Confidential Transmitter Spectrum • +10 dBm ,125 kbps Coded Data Spectrum: Convolutional Code, Pattern Mapper (Manchester) • Matlab (FFT), Agilent Spectrum Analyzer, Litepoint VSA • Power Spectral Density (dBm/3 kHz), (dBm/3 kHz), dBm/10 kHz)
BLE Signal Spectral Density dBm/3 kHz 30
20
10
0
-10
-20
S(f) [dBm/3 kHz] -30
-40
-50
-60
-70 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 frequency [Hz] 6 x 10
47 Laird Confidential PHY Discussion: Evolution of BLE from v4.0 to v5.0
• Bluetooth Low Energy (BLE – v4.2 v5.0) • Preamble: 8 bits of 1 0 1 0 1 0 1 0 or 0 1 0 1 0 1 0 1 0 1 depending on leading bit in access address or synch. • 2M sends 16 bit 1-0-1-0 patterns • Coded LE sends 80 bits 0 0 1 1 1 1 0 0 • Link Layer Packet for Coded LE: (CI=Coding Indicator, TERM=Termination Sequence (all zeros to initialize Convolutional Encoder).
48 Laird Confidential