octoBox stackable anechoic wireless testbed


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octoBox is a stackable small anechoic testbed used for testing wireless throughput, including throughput of high order MIMO systems such as 802.11ac and LTE, range, data rate adaptation, roaming, mesh, DSRC , etc. Video at https://www.youtube.com/watch?v=QIaL7SFZpx4&feature=youtu.be

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octoBox stackable anechoic wireless testbed

  1. 1. info@octoscope.com June 2014
  2. 2. www.octoscope.com Why octoBox Controlled Environment? 2
  3. 3. www.octoscope.com Watch video at this link: https://www.youtube.com/watch?v=QIaL7SFZpx4 OB-38-TT Turntable octoBox 3
  4. 4. www.octoscope.com DUT Fingerprint – octoBox TT (Turntable) Plot Mbps 4
  5. 5. www.octoscope.com octoBox Stackable - Summary • Modern design optimized for wireless test applications • Stable and repeatable over- the-air coupling for testing devices with internal antennas • 700 MHz to 6 GHz • Easy interconnections among multiple boxes and multiple stacks 5
  6. 6. www.octoscope.com octoBox Configurations OB-26 quadStack OB-26 anechoic chamber MPE (Multipath emulator) OB-38 MPE Stack 6
  7. 7. www.octoscope.com octoBox Wireless Testbeds • octoBox testbeds ship assembled and ready to us in a crate • The crate door also acts as a ramp, making it easy to wheel the system out and get started 7
  8. 8. www.octoscope.com octoBox quadStack and triStack Dimensions octoBox-38 triStackoctoBox-26 quadStack 38.35” 24” 31.2” 42” 30.5” 26.35” 18” 25.2” 34”28.5” 6’6” 8
  9. 9. www.octoscope.com octoBox External and Internal Dimensions octoBox-38 (OB-38)octoBox-26 (OB-26) 38.35” 24” 31.2”26.35” 18” 25.2” 9
  10. 10. www.octoscope.com Optional RF Modules Two modules can be stacked (shown mounted on OB-38) 4 programmable RF attenuators individually controllable and powered via a single USB or Ethernet/PoE connection 10
  11. 11. www.octoscope.com Attenuator and Waveform Generator Modules Modules easily mount on the side of octoBox for construction of flexible testbeds. Unsurpassed isolation USB and Ethernet/POE ports are filtered to avoid data cables from acting as antennas and bringing interference into the testbed. 11
  12. 12. www.octoscope.com quadAtten/waveGen Module Dimensions 9.5” (24 cm) 1.5” (3.8 cm) 3.9” (9.9 cm) 12
  13. 13. www.octoscope.com Isolation and Filtering • Creating controlled RF conditions with good isolation is challenging, particularly for large-scale RF test setups, such as mesh configurations. Short wavelength high frequency signals couple via many paths, including copper cabling, poor/aging gasketing, ground loops, etc. Sources of interference may be difficult to locate in a multi-box setup. • Isolation considerations Isolation should be measured and specified with a fully cabled test setup. All copper cabling, including Ethernet and power cabling, will act as antennas contributing to RF coupling among enclosures and thus limiting attenuation range setting. Upfront investment into high grade enclosures with good data and power feed- through filtering and absorptive foam can save 1-2 months of chasing uncontrolled paths of interference in the test setup. octoBox modular feed-through high speed data filters Fits up to 4 filters 13
  14. 14. www.octoscope.com Single Box Shipping Package Rubber feet assembly AC Power entry Fan Filter inputs 14
  15. 15. www.octoscope.com octoBox-26 Internal View GPS antenna Wi-Fi antenna Cellular antenna Filtered Ethernet Filtered USB DUT shelf 13.35” Plastic rails and shelf 15
  16. 16. www.octoscope.com Filtered Data Ports Filters include: Gig Ethernet / POE USB HDMI DC power AC power and vents are also filtered Removable sections of gradient absorber provide easy access to connectors 16
  17. 17. www.octoscope.com OB-38-TT Internal View – Turntable Model 17
  18. 18. www.octoscope.com 8 Individually Controlled RF Ports 2 quadAtten modules individually control power of the 8 RF signals entering the octoBox 4x4 MIMO signal Interference quadAtten (2 stacked modules) 18
  19. 19. www.octoscope.com octoBox Anechoic Conditions; Plastic Rails RF-transparent plastic rails Hide cabling behind absorber for neat set-up 19
  20. 20. www.octoscope.com OB-26-TT Internal View - Smartphone Antennas Multiband cellular Wi-FiMultiband GPS Anechoic turntable construction – Only plastic parts penetrate absorber lining Filtered Ethernet and USB 20
  21. 21. www.octoscope.com Inside View – Smartphone DUT 21
  22. 22. www.octoscope.com Multipath Emulator • Wi-Fi manufacturers and evaluators test throughput performance in open air ‘real-life’ environment (e.g. a typical house or office) or using channel emulators. • octoScope has developed an octoBox based testbed that creates multipath closely approaching the IEEE 802.11n/ac Models B or C, emulating home and small office environment. • octoBox MPE (multipath emulator) creates multipath inside octoBox small anechoic chamber by generating reflections with stubs of coaxial cable. A quad multipath emulator fixture supports up to 4-stream MIMO. • octoBox-MPE has been simulated, prototyped, measured and compared to the IEEE models. • Data throughput tests have been performed by www.smallnetbuilder.com on a 2x2 and a 3x3 802.11ac MIMO configuration demonstrating MIMO gains inside octoBox with equivalent or higher throughput to that measured in a representative home environment. • See SmallNetBuilder.com test results at this link: http://www.smallnetbuilder.com/wireless/wireless-howto/32082-how-we-test- wireless-products-revison-7 octoBox-MPE module (stacked in the middle) emulates IEEE 802.11n/ac Models B or C corresponding to home and small office environment. Patents pending 22
  23. 23. www.octoscope.com octoBox-MPE MIMO OTA Testbed Diagram OTA = over the air DUT AP Test Antennas Traffic TX/RX Remote Desktop Multipath Emulator Master client quadAtten octoBox 23
  24. 24. www.octoscope.com 24
  25. 25. www.octoscope.com Internal View of Antenna Mounting MIMO antenna spacing controls correlation 25
  26. 26. www.octoscope.com Background MPE Frequency Response 2.4 GHz band 5 GHz band MPE (Multipath emulator) 26
  27. 27. www.octoscope.com octoBox-MPE vs. IEEE Model B (House Model) Model B 0ns 10 ns 20ns 30ns 40ns 50ns 60ns 70ns 80ns Cluster 1 0 -5.4 -10.8 -16.2 -21.7 Cluster 2 -3.2 -6.3 -9.4 -12.5 -15.6 -18.7 -21.8 Time domain response obtained from measured frequency domain 27
  28. 28. www.octoscope.com Automated MIMO Throughput vs. Range Test 0 50 100 150 200 250 300 350 400 0 10 20 30 40 50 60 Throughput(Mbps) Attenuation Setting (dB) TCP Throughput Measured using octoBox MPE testbed using automated throughput script - early 802.11ac device http://www.octoscope.com/English/Products/octoBox_MPE/octoBox_MPE.html Multiple points can be measured Repeatable controlled environment Measurement process is automated Script controls IxChariot and programmable attenuators, outputs Excel plot OB-38 MPE Stack MPE MPE = multi path emulator 28
  29. 29. www.octoscope.com octoBox-TT (Turntable) Plot 0 20 40 60 80 100 120 140 160 180 200 -180 -165 -150 -135 -120 -105 -90 -75 -60 -45 -30 -15 0 15 30 45 60 75 90 105 120 135 150 165 Throughput vs. rotation angle 0dB (Mbps) 5dB (Mbps) 10dB (Mbps) 15dB (Mbps) 20dB (Mbps) 25dB (Mbps) 30dB (Mbps) 40dB (Mbps) 45dB (Mbps) 50dB (Mbps) 55dB (Mbps) 60dB (Mbps) Mbps 29
  30. 30. www.octoscope.com Antenna Mounting System What’s important for near-field metrics is OTA coupling stability. octoBox antenna mounting system octoBox offers unparalleled flexibility in mounting test antennas for OTA coupling stability. And it also enables simultaneous measurements of multiple radios in the DUT. 30
  31. 31. www.octoscope.com octoBox Antenna Arrangement for Smartphones Dual-band Wi-Fi/Bluetooth Antenna More antennas can be added for MIMO testing GPS antenna 1573.42; 1575.42; 1577.42 MHz 2G/3G/LTE antenna octoBox plastic rail and DUT shelf system iPhone DUT 704-787 MHz 824-960 MHz 1575.42 MHz 1710-1990 MHz 2110-2170 MHz 2496-2700 MHz This configuration supports the iPhone and most other smartphones and pads on the market 31
  32. 32. www.octoscope.com Isolation and Absorption • Superior isolation and absorption support over the air coupling and ensure robust operating margin for conducted coupling of RF signal • Isolation Allows accurate path loss setting Prevents errors caused by ambient noise and crosstalk • Absorption >20 dB achieved using gradient absorptive foam Eliminates standing waves that cause nulls in the signal Improves overall isolation of the enclosure Standing waves create fluctuations in the signal Dual gasketing and right angle door seals 2.25” gradient absorptive foam covers inside surfaces Gradient absorber matches impedance of metal to air 32
  33. 33. www.octoscope.com Controlled Environment Test Ethernet Programmable attenuator RF isolation box USB Feed- through filters Distance and motion emulated using a programmable attenuator to model path loss (flat fading) or a channel emulator to model multipath and Doppler fading Signal coupled via cabling (conducted) or over the air (OTA) Master and DUT are isolated from each other to achieve wide dynamic range of the measurement by eliminating crosstalk octoBox-26 small anechoic chamber 33
  34. 34. www.octoscope.com Controlled Environment Measurement Example Noise, interference and Master to DUT coupling must be well below intended signal level at DUT for metrics such as rate/MCS adaptation or roaming performance Wi-Fi DUT’s data rate adaptation behavior vs. RSSI all the way down to the RSSI level of -95 dBm. Measured DUT RSSI is less than -95 dBm. This means Master to DUT coupling of less than -100 dBm. 802.11b (DSSS-CCK) – 1, 2, 5.5, 11 Mbps; 2.4 GHz 802.11a (OFDM) – 6, 9, 12, 18, 24, 36, 48, 54 Mbps; 5 GHz 802.11g – both 11b and 11a rates; 2.4 GHz 802.11n – up to 600 Mbps; 2.4 and 5 GHz Data rate adaptation vs. RSSI MCS = modulation coding scheme DUT = device under test 34
  35. 35. www.octoscope.com Basic Radio Performance Tests • RX sensitivity • TX spectrum, EVM • Range • Adaptive Modulation • Roaming behavior • Performance in the presence of noise and interference Noise/interference generator DUT = device under test EVM = error vector magnitude RF combiner Variable RF attenuator Master DUT Isolation box 35
  36. 36. www.octoscope.com Roaming Test 36
  37. 37. www.octoscope.com octoBox Roaming Test Configuration USB Controller or Ethernet switch Client/bridge under test Traffic source/sink 1:4 RF combiner octoBox-26 Stackable Traffic source/sink AP2 AP1 octoBox-26 Stackable RF attenuators Feed-through Ethernet filters RF port ATTEN1 Ethernet Spare combiner ports for connecting a sniffer ATTEN2 37
  38. 38. www.octoscope.com octoBox Roaming Test Script Programmable attenuator ramp Ping request- response delay Connection outage due to roaming 38
  39. 39. www.octoscope.com Roaming Results - Details from Sniffer 3.16 sec 9.04 sec 6.63 sec 0 5 10 15 20 25 30 35 40 45 50 0 2 4 6 8 10 12 14 dBabovenoise Seconds RSSI 61:30 RSSI 5a:f0 ping requests ping replies deassociate deauthenticate authenticate assoc req-resp Last ping response: 3.16 sec Association: 6.63 sec First ping response: 9.04 sec Wireshark Sniffer AirPcap Nx USB dongles 39
  40. 40. www.octoscope.com Wireless Mesh Test 40
  41. 41. www.octoscope.com Wireless Mesh Testing Wireless Mesh Metrics • Self-healing, self-forming • Throughput, QoS vs. hops • Throughput, QoS vs. range • Routing efficiency • Dealing with interference Multi-radio mesh nodes can communicate on different channels with multiple neighbors simultaneously. In a single-channel mesh throughput is cut in half at each hop. 41
  42. 42. www.octoscope.com Wireless Mesh Test Configuration Maximize attenuators to force auto-re- routing of traffic flow to test self-healing Fixed attenuators to set traffic flow via one branch or another to test self configuration 1 Nodes are in octoBox isolation chambers octoBox quadStack isolation enclosures with built-in RF combiners and attenuators RF splitters used to direct signal to multiple neighboring devices 42
  43. 43. www.octoscope.com Wireless Mesh Testing - Example RF CombinerRF Switch RF Attenuator Antenna octoBox upper chamber #1 octoBox lower chamber #3 94:39:e5:01:3d:62 94:39:e5:01:68:ed bc:77:37:ab:33:5d PC in open air #2 bc:77:37:ab:33:5d 94:39:e5:01:3d:62 94:39:e5:01:68:ed octoBox Console USBcablegoingthroughdatafilter tocontrolPingblasterrunningon#3 Ping request - response traffic #2 #3 #1 #1 #2 #3 43
  44. 44. www.octoscope.com Delay Through Mesh ~ 2 msec delay One hop Seconds Ping round trip delay (ms) ~ 12 msec delay with bursts of long delays (>1 seconds) Zero hops bc:77:37:ab:33:5d 94:39:e5:01:3d:62 94:39:e5:01:68:ed bc:77:37:ab:33:5d 94:39:e5:01:3d:62 94:39:e5:01:68:ed BATMAN = better approach to mobile ad hoc networking 44
  45. 45. www.octoscope.com Connected Car DSRC Test DSRC = direct short range communications 45
  46. 46. www.octoscope.com Connected Car Testbed – Large Intersection Emulate groups of connected vehicles traveling over a busy highway interchange 46
  47. 47. www.octoscope.com Example Large-scale DSRC Testbed DSRC testbed emulates motion of groups of cars with respect to other groups 8-port wireless channel emulator Motion Multipath Noise Up to 24 radio modules in each chamber 192 radios in the testbed octoBox quadStack 47
  48. 48. www.octoscope.com Example: 3” x 5” x 1” DSRC DUT DUTs Layers of absorptive foam (not shown) separating DUTs horizontally and vertically providing 10 dB of isolation per layer Ethernet hub Test antennas DSRC = direct short range communications 48
  49. 49. www.octoscope.com Channel Emulator to Emulate Road Signalamplitudeatcar2 Time Car 1 Car 2 Wireless channel emulator Car 1 radio Car 2 radio Multipath fading Shadow fading Doppler fading Slow shadow fade due to truck passing through signal path between 2 cars g octoBox RF anechoic chambers 49
  50. 50. www.octoscope.com Specifications Feature Specification AC power entry module IEC-320 C14 inlet connector 120/240VAC 50/60Hz with 6A 5x20mm fuse Cooling 80mm square axial fan Filters over inlet and outlet for isolation Filtered high speed data connections gigEthernet (with PoE), USB, HDMI, DB9, DB25 or DC power ports RF ports 8 RF barrel connector ports Isolation >80 dB, fully cabled setup, up to 6 GHz Absorption >20 dB from 1.3 to 40 GHz; >15 dB down to 700 MHz 50
  51. 51. www.octoscope.com Dimensions and Weight American Metric Outside: 18”H x 26.35”W x 25.2”D (-26 model) 24” H x 38.35”W x 31.2”D (-38 model) Inside: 13.35”H x 19.35”W x 13.35”D (-26 model) 19.35”H x 31.5”W x 21. 5”D (-38 model) Weight: 95 LBS (-26 model) 172 LBS (-38 model) Outside: 45.7cm H x 67cm W x 64cm D (-26) 61cm H x 97 cm W x 79cm D (-38) Inside: 34cm H x 49cm W x 34cm D (-26) 49cm H x 80cm W x 54.6cm D (-38) Weight: 43 kg (-26 model) 78 kg (-38 model) 7 cm antenna length Queenstar QWH-VPRR00 51
  52. 52. www.octoscope.com octoBox Testbed Summary Over the air coupling Realistic environment - Multipath - Path loss - Interference Robust stackable design Wheels for easy moving Filtered vents for cooling Filtered data ports - Gig Ethernet/PoE - USB - HDMI - AC and DC power RF attenuators and interference sources controlled and powered via filtered Ethernet or USB for easy and neat testbed construction Multipath emulator 52
  53. 53. www.octoscope.com Thank you! • View octoBox information • http://www.octoscope.com/English/Products/octoBox_MPE/octoBox_MPE.html • View our publications, including articles, white papers, test reports and online tutorials • http://www.octoscope.com/English/Resources/Articles.html • Contact sales@octoscope.com +1.978.222.3114 53