ARUBA 2014 : 802.11ac Wi-Fi fundamentals v2
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ARUBA 2014 : 802.11ac Wi-Fi fundamentals v2
- 1. ATMOSPHERE 2014 AIRHEADS@ 802.11ac Wi-Fi Fundamentals Eric Johnson June 2014
- 2. CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved 2 #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Agenda 11ac Standards Physical Layer Overview 11ac Data Rates Radio Realities Receivers Antennas 11ac Beamforming 11ac Products
- 3. 3 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@802.11ac Technology Overview Think of 11ac as an extension of 11n • 11n specification introduced/leveraged: • 2.4 and 5 GHz supported • Wider channels (40 MHz) • Better modulation (64- QAM) • Additional streams (up to 4 streams) • Beam forming (explicit and implicit) • Backwards compatibility with 11a/b/g 11ac introduces • 5 GHz supported • Even wider channels (80 MHz and 160 MHz) • Be?er modulaAon (256-‐QAM) • AddiAonal streams (up to 8) • Beam forming (explicit) • Backwards compaAbility with 11a/b/g/n • Refer to h?p://www. 802-‐11.ac.net for in-‐depth informaAon
- 4. 4 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Wider Channels • 80 MHz channel widths supported in first generation – 80 MHz is 4.5x faster than 20 MHz – 80 MHz is contiguous – Per packet dynamic channel width decisions • Future releases will allow for 160 MHz channel widths – 160 MHz can be either contiguous or in two non- contiguous 80 MHz slices
- 5. 5 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Channel Allocations
- 6. 6 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ 802.11ac Channels (ETSI) Channel Freq (MHz) UNII I and UNII II 2x 80 MHz 4x 40 MHz 8x 20 MHz Channel Freq (MHz) UNII II extended 2x 80 MHz 5x 40 MHz 11x 20 MHz 36 4844 5240 56 6460 Band Edge 5180 5200 5220 5240 5260 5280 5300 5320 5350 Band Edge 5150 100 112108 116104 120 128124 5500 5520 5540 5560 5580 5600 5620 5640 Band Edge 5470 136 140 Band Edge 5680 5700 5725 132 5660
- 7. 7 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ 802.11ac Channels (FCC) Channel Freq (MHz) UNII I and UNII II 2x 80 MHz 4x 40 MHz 8x 20 MHz Band Edge Channel Freq (MHz) 5850 US UNII III 1x 80 MHz 2x 40 MHz 5x 20 MHz Channel Freq (MHz) UNII II extended 3x 80 MHz 6x 40 MHz 12x 20 MHz 36 4844 5240 56 6460 Band Edge 5180 5200 5220 5240 5260 5280 5300 5320 5350 Band Edge 5150 149 161157153 5745 5765 5785 5805 Band Edge 5725 165 5825 100 112108 116104 120 128124 5500 5520 5540 5560 5580 5600 5620 5640 Band Edge 5470 136 140 Band Edge 5680 5700 5725 132 5660 144 5720 Weather Radar
- 8. 8 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@Dynamic Bandwidth Management • Bandwidth management is an important aspect of the 11ac Wi-Fi standard. 802.11ac has several bandwidth combinations allowed from 20 MHz to 160 MHz wide channels. With this increase in available channel bandwidth comes greater flexibility, BUT comes the challenge of optimizing the use of wider bandwidth in an efficient manner. • Each 802.11ac network includes a 20 MHz primary channel. This primary channel is accessed using carrier sensing to make sure the channel is free from interference from other networks. Another use for the primary channel is co-existence and backwards compatibility with older Wi-Fi standards.
- 9. 9 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@Improved CCA for Secondary Bands • In 802.11ac the interference detection threshold has also improved. Wi-Fi AP’s use interference detection to reduce overlap and collisions with other AP’s operating on secondary channels. • The standard defines a sensitivity threshold for the signal strength on the secondary channel that an AP must measure in order to determine if that secondary channel is busy. • 802.11n uses -62 dBm as the sensitivity threshold for interfering 802.11n signals • 802.11ac improved this to -72 dBm, which means that 802.11ac networks have improved sensitivity towards collision avoidance and overlap detection. • Dynamic bandwidth management and increased sensitivity of the clear channel assessment (CCA) threshold are the features that improve the performance of 802.11ac 9
- 10. 10 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@Dynamic Bandwidth Management: Channel Usage with Two APs
- 11. 11 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Wave 2
- 12. 12 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Wave 2 of 11ac • What will wave 2 802.11ac deliver? • MU-MIMO • Use AP MIMO resources more effectively • Transmit data to multiple devices simultaneously: for example 4SS AP streaming data to four 1SS clients simultaneously • 4x4:4SS • Benefit of additional stream mostly for MU-MIMO • Not anticipating any 4x4:4SS client devices • Adds 33% to max datarate • VHT160 • Doubles max datarate • Practical problem: only 2 VHT160 channels available in entire 5GHz band • Max 5GHz radio throughput triples again! • 450 (11n 3x3 HT40), 1,300 (11ac 3x3 VHT80), 3,467 (11ac 4x4 VHT160) • When will it be available? • Radio chipsets available late 2014 • Products in 2015
- 13. 13 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Reasons not to wait for Wave 2 • Unlikely to see any 4x4:4SS client devices • Use of VHT160 not practical for typical enterprise deployment • MU-MIMO is a nice-to-have optimization. • How well it will work and what the real benefits are is still not entirely clear • Requires new client devices (Wave 1 clients also not FW upgradeable) • Wave 1 is here now (technology, products, market momentum), offering huge advantages over 11n. Wave 2 is the expected next step in the evolution of the technology. • In general: the next wave in technology is always around the corner, something better is always coming Once Wave 2 is available, we’ll for sure be talking about Wave 3. • No different from when 11n 2x2 products were introduced and it was clear that 3x3 products would be available within 18 months.
- 14. 14 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ 11ad and what it means • 60GHz band, three channels in most countries (each 2.16GHz wide), each providing up to 6.8Gbps PHY datarate • No MIMO • Challenges: Non-Line of Sight (NLOS) connections, range, penetrating obstacles (and people) • Targeted to clean up a cluttered desk or TV cabinet • Likely not appropriate for traditional AP use. But can be interesting for related applications like wireless docking, high-capacity WLAN hotspots, AP backhaul/aggregation, etc. • It is being investigated (but no product plans as of yet) • Standard is available, certification program in place • Wi-Fi Alliance WiGig Alliance
- 15. 15 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Understanding 11ac Data Rates
- 16. 16 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Terminology • Symbol: basic element containing 1 to 8 bits of information • Tone/Sub-Carriers: OFDM is made up of many tones. Each symbol is mapped to a tone. • Cyclic Extension: technique used in OFDM to protect against multipath interference – You need cyclic extension but it is dead air and consumes transmit time • Guard Band: Space between channels. In these regions tones have a constant value of zero amplitude • Pilot Tones: Used to train the receiver and estimate the channel • Radio Channel: For Wi-Fi 20, 40, 80, or 160 MHz of spectrum • Propagation Channel: everything that happens between the transmitter and receiver • FEC: Forward Error Correction. Redundant information that is sent to assist the receiver in decoding the bits.
- 17. 17 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Sub-carriers 52 subcarriers (48 usable) for a 20 MHz non-HT mode (legacy 802.11a/g) channel fc +10MHz-10MHz 26 carriers 26 carriers 56 subcarriers (52 usable) for a 20 MHz HT mode (802.11n) channel fc 28 carriers 28 carriers 114 subcarriers (108 usable) for a 40 MHz HT mode (802.11n) channel fc +10MHz-20MHz 57 carriers 57 carriers +20MHz-10MHz 242 subcarriers (234 usable) for a 80 MHz VHT mode (802.11ac) channel An 80+80MHz or 16MHz channel is exactly two 80MHz channels, for 484 subcarriers (468 usable) 121 carriers 121 carriers fc +10MHz-20MHz +20MHz-10MHz-40MHz -30MHz +30MHz +40MHz OFDM subcarriers used in 802.11a, 802.11n and 802.11ac +10MHz-10MHz Guard Tones
- 18. 18 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ QAM constellations Amplitude +1 Amplitude -1 Quadrature-1 Quadrature+1 Amplitude +1 Amplitude -1Quadrature-1 Quadrature+1 Amplitude +1 Amplitude -1 Quadrature-1 Quadrature+1 16-QAM constellation 64-QAM constellation 256-QAM constellation Constellation diagrams for 16-, 64-, 256-QAM
- 19. 19 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@How do I get to the data rate for a given MCS? • Basic Symbol Rate – 312.5 KHz – 3.2 µs • Cyclic Extension – t/4 0.8 µs – t/8 0.4 µs • Bits Per Tone – BPSK 1 – QPSK 2 – 16 QAM 4 – 64 QAM 6 – 256 QAM 8 19
- 20. 20 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Raw Data Rates • #Tones * Bits per Tone * Symbol Rate – 16 QAM, 20 MHz – 52 * 4 * 0.3125 = 65 Mbps 20
- 21. 21 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Correct for Cyclic Extension 21
- 22. 22 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Apply FEC Coding 22
- 23. 23 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Transmitters
- 24. 24 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Transmitter Line Up 24 DAC Symbol Generation Up Convert PA
- 25. 25 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Transmitter Terms • Conducted Power – This is the power that leaves the connectors • EIRP: Effective Isotropic Radiated Power – This is the conducted power (dBm) + antenna gain (dBi) in the direction of interest – cable losses (dB) • Peak EIRP – This is what is regulated – It is the conducted power + peak gain – cable losses • dBm: log power ratio to milliwatt • dBi: antenna gain relative to isotropic • dBr: relative power eg:used with describing transmit mask 25
- 26. 26 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Transmitter Non-Idealities • DAC Quantization: this is due to the limited number of bits in a practical Digital to Analog Converter – This noise source is not affected when the power is reduced • PA Non Linearity: OFDM has a high Peak to Average Ratio. The peaks in the OFDM signal cause distortions which manifest as noise like shoulders – Known as spectral regrowth – For every one 1 dB drop in tx power the regrowth drops by 3 dB • 2 dB net • The in channel noise is referred to as EVM – Error Vector Magnitude • The out of channel noise interferes with other Wi-Fi channels and determines how close we can space antennas 26
- 27. 27 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@802.11n Signal Frequency Domain 27 0 5 10 15 20 25 30 35 40 60− 50− 40− 30− 20− 10− 0 Frequency (MHz) Amplitude(dB) Digital Domain After DAC PA Non Linearity 0 5 10 15 20 25 30 35 40 60− 50− 40− 30− 20− 10− 0 a
- 28. 28 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ 802.11 Symbol Stream 28 0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 15− 11.25− 7.5− 3.75− 0 3.75 7.5 11.25 15 Time (symbols) LinearAmplitude
- 29. 29 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ EVM • As the depth of modulation increase the number of bits per symbol increases • The in-band noise introduces uncertainty wrt to the actual symbol position • Higher order modulations decrease the space between code points • To make higher order modulations work the tx power needs to be reduced • The EVM noise will add with interference and background noise 29 16 QAM
- 30. 30 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ BPSK 1/2 -‐5 -‐5 QPSK 1/2 -‐10 -‐10 QPSK 3/4 -‐13 -‐13 16QAM 1/2 -‐16 -‐16 16QAM 3/4 -‐19 -‐19 64QAM 2/3 -‐22 -‐22 64QAM 3/4 -‐25 -‐25 64QAM 5/6 -‐28 -‐27 256QAM 3/4 N/A -‐30 256QAM 5/6 N/A -‐32 802.11n EVM (dB) 802.11ac EVM (dB) Modulation Coding Rate EVM Specfication and 22x tx table 30
- 31. 31 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Receivers
- 32. 32 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Receiver Line Up 32 ADC Symbol Decode Down Convert LNA
- 33. 33 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Receiver Impairments • Analog Compression – Modern LNAs have very effective input power tolerance • Digital Compression – This is where a high power signal hits the Automatic Gain Control (AGC) Circuit. Gain drops and receiver sensitivity degrades – The radio can be totally blocked if the power hits the Analog to Digital Converter (ADC) and consumes all the bits • Intermodulation – Again, the effective linearity of modern LNAs reduces the impact of this 33
- 34. 34 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ DAS Interference: Example • Without filtering any signal that hits the receiver above -45 dBm will cause a reduction of sensitivity • The degradation continues until about -15 dBm at which point the signal is totally blocked • With a 100 mW (20 dBm) DAS system at 2100 MHz – Tx 20 dBm – Effective rx antenna gain 3 dBi – 1st meter at 2100 MHz -39 dB • Power at 1m -19 dBm – No impact distance 40 meters 34
- 35. 35 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Advanced Cellular Coexistence • Proliferation of DAS and new LTE bands at 2.6 GHz are creating issue for Wi-Fi solution • All new APs introduced by Aruba in the last 12 months and going forward have implemented significant filtering into the 2.4 GHz radio portion to combat this • Design solution – Use high-linear LNA followed with a high-rejection filter to achieve rejection target and little sensitivity degradation; – Design target: Minimal Sensitivity degradation with -10dBm interference from 3G/4G networks (theoretical analysis).
- 36. 36 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Practical Coverage
- 37. 37 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Coverage Example 1. Sample coverage for 3x3 11n AP (or 3x3 11ac AP with 11n clients) in HT40 mode • Coverage area sustains MCS5 and up 360 405 450
- 38. 38 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Coverage Example 2. Upgrade to 3x3 11ac AP with 11ac clients, still using 40Mhz channels (VHT40) • Radius for 600Mbps (MCS9) area is 1/4 of that for 450Mbps (MCS7) 360 405 450 540 600
- 39. 39 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Coverage Example 3. Equivalent range for clients using 80MHz channels (VHT80) – Rates roughly double, relative range for each of the MCS rates does not change, but 80MHz range is ~70% of equivalent (same MCS) 40MHz range 780 878 975 1170 1300 585
- 40. 40 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Relative Range 802.11ac Rates Datarate 40MHz 80MHz MCS0 45 97.5 MCS1 90 195 MCS2 135 292.5 MCS3 180 390 MCS4 270 585 MCS5 360 780 MCS6 405 877.5 MCS7 450 975 MCS8 540 1,170 MCS9 600 1,300 Signal level and rela@ve range -‐dB r MCS0 87 63 MCS1 85 50 MCS2 83 40 MCS3 79 25 MCS4 76 18 MCS5 71 10 MCS6 66 5.6 MCS7 63 4.0 MCS8 58 2.2 MCS9 51 1.0
- 41. 41 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Antennas
- 42. 42 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@Reading Antenna Pattern Plots - Omni 42 Azimuth Elevation Omnidirectional Antenna (Linear View) -3 dB Sidelobes
- 43. 43 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@Reading Antenna Pattern Plots - Sector 43 Azimuth Elevation Sector Antenna (Logarithmic View) -3 dB -3 dB SidelobesBacklobe Front Back Side
- 44. 44 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ 44 ANT-2x2-5010 Heat Maps
- 45. 45 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@Ant-2x2-5010 Antenna Patterns 45 • Model 0 15 30 45 60 75 90 105 120 135 150 165 180 195 210 225 240 255 270 285 300 315 330 345 a a 5 dB per division • Measured
- 46. 46 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Ant-2x2-5010 Simple projection 46 0 15 30 45 60 75 90 105 120 135 150 165 180 195 210 225 240 255 270 285 300 315 330 345 a a 5 dB per division Assuming 20m install height 0m 20m 50m 100 m 200 m
- 47. 47 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Analysis • The heatmaps are shown across 100m by 100m and 1000m by 1000m areas • These are flat earth models and the antenna is straight up above the plane • 2 ray propagation effects are not included 47
- 48. 48 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ C/I Contours CI dBm C/I Contours CI dBm Heat Map: Antenna at 5 m height 48 100 m 1000 m
- 49. 49 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ C/I Contours CI dBm C/I Contours CI dBm Heat Map: Antenna at 10 m height 49 100 m 1000 m
- 50. 50 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ C/I Contours CI dBm Heat Map: Antenna at 20 m height 50 100 m 1000 m C/I Contours CI dBm
- 51. 51 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ C/I Contours CI dBm C/I Contours CI dBm Heat Map: Antenna at 40 m height 51 100 m 1000 m
- 52. 52 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@Antenna Basic Physics • When the charges oscillate the waves go up and down with the charges and radiate away • With a single element the energy leaves uniformly. • Also known as omni-directionally 52
- 53. 53 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@Building Arrays: 2 Elements • By introducing additional antenna elements we can control the way that the energy radiates • 2 elements excited in phase 53 λ/2 0 30 60 90 120 150 180 210 240 270 300 330 Linear Plot 0 15 30 45 60 75 90 105 120 135 150 165 180 195 210 225 240 255 270 285 300 315 330 345 dB Plot
- 54. 54 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ 0 15 30 45 60 75 90 105 120 135 150 165 180 195 210 225 240 255 270 285 300 315 330 345 Building Arrays: 4 Elements • By introducing additional antenna elements we can control the way that the energy radiates • 4 elements excited in phase – Equal amplitude 54 Linear Plot dB Plot 0 30 60 90 120 150 180 210 240 270 300 330
- 55. 55 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ 0 15 30 45 60 75 90 105 120 135 150 165 180 195 210 225 240 255 270 285 300 315 330 345 0 30 60 90 120 150 180 210 240 270 300 330 Building Arrays: 4 Elements • By shaping the amplitude we can control sidelobes • 4 elements excited in phase – Amplitude 1, 3, 3, 1 55 Linear Plot dB Plot
- 56. 56 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ 0 15 30 45 60 75 90 105 120 135 150 165 180 195 210 225 240 255 270 285 300 315 330 345 0 30 60 90 120 150 180 210 240 270 300 330 Building Arrays: 4 Elements Phase • By altering phase we can alter the direction that the energy travels • 4 elements excited with phase slope – Even amplitude 56 Linear Plot dB Plot
- 57. 57 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ 802.11ac Beamforming
- 58. 58 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Beamforming: Notes • AP 22x series has 11ac beamforming support in 2.4 and 5 GHz bands • Works with clients that support 11ac beamforming function – This is at a minimum all 11ac client devices using Broadcom chipsets – Support will have to come to all devices to compete with Broadcom offering • 11ac beamforming is standards based – first standard that is doing this the “right” way – 11ac beamforming represents the consensus view of the 1000’s of contributors to the standards process • 11ac beamforming is implemented in baseband. – It works with all antenna subsystems – The total number of beamforming combinations is effectively infinite • 11ac actively tracks users so has a recent channel estimate between the AP and client that is updated frequently 58
- 59. 59 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@Channel state information, implicit and explicit beamforming estimation 59 Explicit feedback for beamforming (802.11n and 802.11ac) 1 (Beamformer) Here’s a sounding frame 2 (Beamformee) Here’s how I heard the sounding frame 3 Now I will pre-code to match how you heard me sounding frames Beamformed frames feedback from sounding Explicit feedback for beamforming Beamformer Beamformee Actual CSI
- 60. 60 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ 5− 4− 3− 2− 1− 0 1 2 3 4 5 1 10 4− × 1 10 3− × 0.01 Antenna 1 Antenna 2 Antenna 3 Wavelengths EFieldAmplitude Client Antennas h11 h21 h31
- 62. 62 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Line of Sight • 3 stream AP • Smartphone – 1 Antenna/1 Stream Client AP 0 10 20 30 40 50 60 70 8090100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350
- 63. 63 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Simple Reflection • Let’s introduce two reflection surfaces and look at the impact of one bounce on each side Client AP 0 10 20 30 40 50 60 70 8090100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 Virtual Antenna Pattern
- 64. 64 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Multi Stream Client • The reflections allow beamforming to send different streams with different antenna pattern through the system Client AP 0 10 20 30 40 50 60 70 8090100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 0 10 20 30 40 50 60 70 8090100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 0 10 20 30 40 50 60 70 8090100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 Stream1 Stream2Stream3
- 65. 65 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Beamforming • Stream 3 now appears on all three antenna – Here is how each transmitted component shows up at the client 65 5− 4− 3− 2− 1− 0 1 2 3 4 5 1 10 3− × 0.01 0.1 1 10 Antenna 1 Wavelengths EFieldAmplitude Now add them!
- 66. 66 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Similarly Stream 1 and 2 66 Stream 1 Stream 2
- 67. 67 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ 0 10 20 30 40 50 60 70 8090100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 0 10 20 30 40 50 60 70 8090100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 0 10 20 30 40 50 60 70 8090100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 11ac Beamforming across an 80 MHz channel • The standards based algorithm actually works out patterns for each sub carrier • Below is the pattern for stream 1 at 5460, 5500, 5540 MHz
- 68. 68 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Aruba 11ac Solutions
- 69. 69 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ AP-224/225 802.11ac 3x3 AP • Enterprise class 3x3 802.11ac • Aggregate TCP platform throughput performance >1Gbps • Two platform models: – AP-224: external antennas (3x, dual band) – AP-225: integrated antennas – “Advanced Cellular Coexistence” support • Dual radio: – 802.11n 3x3:3 HT40 2.4GHz(450Mbps), support for “TurboQAM” – 802.11ac 3x3:3 HT80 5GHz (1.3Gbps) – 11ac beamforming supported in both bands • Wired interfaces – Network: 2x 10/100/1000Base-T Ethernet, with MACSec support – USB 2.0 host interface, console port, DC power • Will require 802.3at PoE (or DC power) for full functional operation – Functional, but capabilities reduced when powered from 802.3af POE • Enterprise temperature range, plenum rated, TPM
- 70. 70 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@Indoor 802.11ac Needs an Outdoor Complement • Fully ruggedized for extreme environments • Gigabit performance • Simplified installation • Inconspicuous design • Designed for indoor-use • Gigabit performance
- 71. 71 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@AP-270 Series – Detailed Overview Antenna Gain: 5 dBi 2G: 3x3:3 11ac (2.4 GHz) 5G: 3x3:3 11ac (5.15 to 5.875 GHz) 11ac Beamforming Conducted Tx Power 2G: 23 dBm per branch (28 aggregate) MAX EIRP = 36 dBm 5G: 23 dBm per branch (28 aggregate) MAX EIRP = 36 dBm Power Interface: AC and 802.3at (PoE+) Power Consumption: 25 W Gigabit Ethernet WAN + LAN Port Advanced Cellular Coexistence Designed to Both IP66 and IP67 -40 to +65°C No Heater. Start and operate.
- 72. 72 @arubanetworks What 11ac can Deliver
- 73. 73 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@Performance: 3 Stream 11ac outdoors! 850 Mbps TCP!
- 74. 74 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf ATMOSPHERE 2014 AIRHEADS@ Performance: Samsung GS4
- 75. 75 CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved #AirheadsConf DOWNLOAD: Airheads Mobile JOIN: community.arubanetworks.com FOLLOW: @arubanetworks DISCUSS: #AirheadsConf ATMOSPHERE 2014 AIRHEADS@
- 76. 76 Thank You #AirheadsConf CONFIDENTIAL © Copyright 2014. Aruba Networks, Inc. All rights reserved