WiFi 6 - FHI
Transcript of WiFi 6 - FHI
WiFi 6Wifi6 is coming, but what will change?
Sjoerd Hakstege – van Eekhout
Phoenix Contact B.V.
Wifi Alliance StandardsNew naming for the different Wifi versions
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Wifi Name IEEE Standard Data-Rate
Wifi 6 802.11ax (Wave1&2) 4800+ Mbps
Wifi 5 802.11ac (Wave1&2) 1300+ Mbps
Wifi 4 802.11n 450 Mbps
Wifi 3 802.11g 54 Mbps
Wifi 2 802.11a 11 Mbps
Wifi 1 802.11b 54 Mbps
AdvantagesWiFi 6 / IEEE 802.11ax
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More devices
Higher efficiency
Higher security
Higher Range
Longer battery life
Higher data throughputBetter QoS
Higher Relaibility
Lower Latency
Higher density
• Orthogonal frequency-division multiple access (OFDMA) uplink and downlink (UL/DL)
• Longer orthogonal frequency-domain multiplexing (OFDM) symbol
• Multi-user multiple-input multiple-output (Mu-MiMo) 8×8 and UL/DL
• Spatial reuse, also referred to as BSS Coloring
• Target Wake Time (TWT) — power saving
• 1024 quadrature amplitude modulation (1024-QAM)
• New PHY headers
• Enhanced outdoor robustness
• 5 GHz and 2.4 GHz support
802.11ax focuses on nine main enhancements
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Wireless ApplicationsNext Wireless LAN Generation
Smart devicesMoving Systems
Mobile robots
IIoT-devicesVideo Surveillance
ShuttleM2M
AGV
Tablets
WLAN AX / WiFi6: 3 main advantages for industrial applications
Faster, optimized capacity, IoT ready
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ODFMA MU-MIMO BSS Coloring
Long OFDM Symbol
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20 MHz / 64 = 312,5 kHzSymbol duration 3.2 usec
20 MHz / 256 = 78,125 kHzSymbol duration 12.8 usec
64 Subcarrier 256 Subcarrier
4xn/ac ax
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Long OFDM Symbol
WLAN AX / WiFi6: 3 main advantages for industrial applications
Faster, optimized capacity, IoT ready
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ODFMA MU-MIMO BSS Coloring
WLAN AX / WiFi 6 advantages
Faster, optimized capacity, IoT ready
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OFDMA
Application example
OFDMA
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OFDM - Orthogonal Frequency Division Multiplexing (802.11n/ac)
OFDMA
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time
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64 Sub
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OFDMA - Orthogonal Frequency Division Multiple Access (802.11ax)
OFDMA
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time
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Station 1
Station 2
Station 3
Station 4
Station 5
Station 6
Station 7
Station 8
Station 9
Station 1
Station 2
Station 3
Station 4
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Station 9
Station 1
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Station 3
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OFDMA (Multiple Access)
OFDMA
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RUResource Units
time
Station 1
Station 2
Station 3
Station 4
Station 5
Station 6
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2 MHz
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2 MHz
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2 MHz
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256 Sub
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OFDM vs OFDMA
OFDMA
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time
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OFDM vs ODFMA
OFDMA
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OFDMP
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DL Data Station 1
SIFS
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UL ACK Station 1
Contention
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DL Data Station 2
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UL ACK Station 2
SIFS Contention
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DL Data Station 3
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UL ACK Station 3
SIFS
OFDMA
Pre
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SIFS SIFS
DL Data Station 1
DL Data Station 2
DL Data Station 3 Pre
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MU-ACKRequest
Pre
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UL ACK Station 2
UL ACK Station 3
OFDM vs ODFMA; Network Efficiency
OFDMA
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Source: HP/aruba
WLAN AX / WiFi 6 advantages
Faster, optimized capacity, IoT ready
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✓Network efficiencyLow latency
ODFMA MU-MIMO BSS Coloring
MIMO
MU-MIMO
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Downstream: wave 1Upstream: wave 2
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MIMO(Single-MIMO)
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MU – MIMO(Multiuser MIMO)
Spatial-Streams
▪ Reduce latency and jitter
▪ Operate more efficiently
▪ Best for low bandwidth applications
▪ Best with small packets
ODFMA and MU-MIMO are complementary
MU-MIMO
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ODFMA
MU-MIMO
▪ Increase capacity
▪ Higher data rates per user
▪ Best for high bandwidth applications
▪ Best with large packets
WLAN AX / WiFi 6 advantages
Faster, optimized capacity, IoT ready
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✓Network efficiencyLow latency
Network efficiencyLow latency✓
ODFMA MU-MIMO BSS Coloring
WLAN AX / WiFi 6 advatages
Faster, optimized capacity, IoT ready
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BSS Coloring
Overlapping WLAN Cells
BSS Coloring
BSS Coloring and Spatial reuse
BSS Coloring
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Relaible Communication radius
Interferenceradius
AP1 AP2
Channel 36 Channel 36
Relaible Communication radius
Interferenceradius
STA-A
STA-B
WLAN B WLAN A
BSS Coloring and Spatial reuse
BSS Coloring
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AP1 AP2
Channel 36 Channel 36
STA-A
STA-B
< -62 dBm?
Signal detect
> -82 dBm
(CCA Threshold)
Read colour
demodulate trafic
same colour
CSMA/CA
no
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yes
yes
yes
no
> -62 dBm
yes
transmitting
no
(CCA Threshold)
Non- Coloring vs BSS Coloring
BSS Coloring
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BSS A
BSS B
BSS A
BSS B
Without coloring
With coloring
One packet at a time
Simultaneously with transmission in other BSS‘s
▪ Increase capacity
▪ Adaptive Clear Channel Assessment (ACCA) can adjust signal level threshold
▪ Decrease channel contention problem
▪ Signals with same BSS color use a low RSSI threshold for deferral, therefor reducing collision in same BSS.
▪ Signals with OBSS use a higher RSSI threshold for deferral, therefor allowing more simultaneous connection
▪ It provides some degree of airtime fairness
“BSS colouring” or “Spatial Reuse” Benefits
BSS Coloring
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WLAN AX / WiFi 6 advantages
Faster, optimized capacity, IoT ready
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✓Enhanced WLAN coexistenceMore network capacity✓
Network efficiencyLow latency
Network efficiencyLow latency✓
ODFMA MU-MIMO BSS Coloring
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https://content.aerohive.com/802.11ax_dummies_book
Aruba white paper: https://www.arubanetworks.com/assets/wp/WP_802.11AX.pdf
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