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