Standardiza)on of emergent Wireless LAN technology and
evalua)on
Hiroshi Mano (University of Yamanashi)
May 2014 1 Hiroshi Mano (University of Yamanashi)
Groups Type Group Description Chair WG WG11 The IEEE 802.11 Working Group Adrian Stephens SC PUB Publicity Stephen McCann SC WNG Wireless Next Generation Clint Chaplin SC ARC Architecture Mark Hamilton SC JTC1 ISO/IEC/JTC1/SC6 shadow committee Andrew Myles SC REG Regulatory Richard Kennedy TG MC Maintenance (Revision C) Dorothy Stanley TG AH Operation in 900 MHz bands Dave Halasz TG AI Fast Initial Link Setup Hiroshi Mano TG AJ China Millimeter Wave (CMMW) Xiaoming Peng TG AK General Link Setup Donald Eastlake 3rd TG AQ Pre-association Discovery Stephen McCann TG AX High Efficiency Wireless LAN (HEW) Osama Aboul-Magd
14.6.19
Slide 3
IEEE 802.11 Standards Pipeline
PHY
Sponsor Ballot
MAC
Study groups
Published Standard
WG Letter Ballot
802.11 -2012
802.11aa Video Transport
802.11ac VHT 5GHz
TG without Approved draft
Discussion Topics
Published Amendment
802.11af TVWS
802.11ai FILS
802.11 ah
WNG
802.11ae QoS Mgt Frames
802.11ad VHT 60 GHz
PAD 802.11AQ
802.11aj
802.11-2015
GLK 802.11AK
802.11ax
14.6.19
IEEE 802.11 Revisions
802.11k RRM
802.11r Fast Roam
a 54 Mbps 5GHz
b 11 Mbps 2.4GHz
d Intl roaming
802.11V Network
Management
802.11s Mesh
802.11u WIEN
802.11Y Contention
Based Protocol
802.11n High
Throughput (>100 Mbps)
802.11W Management
Frame Security
802.11z TDLS
802.11p WAVE
802.11 -1999
PHY
MAC
802.11 -2012
802.11 -‐2007
802.11aa Video Transport
802.11ae QoS Mgt Frames
802.11ah <1GHz
802.11ac VHT
6Gbps @ 5GHz
802.11ai FILS
802.11ad VHT
6Gbps @ 60GHz
802.11af TV Whitespace
802.11 -‐2003
g 54 Mbps 2.4GHz
e QoS
i Security
h DFS & TPC
j JP bands
f Inter AP
802.11ak GlobalLink
802.11aj 40 & 60 GHz
802.11aq Service Discovery
14.6.19
Wi-‐Lan is following same way of the Internet.
• Freedom improve the revolu)on . – Best effort, Stupid network – Autonomous deployment
• No King, No president… • Technology accelerated new services. – Consump)on of Band width was rapidly increased.
• The satura)on of technology open the eye of slept incumbent again.
• More control, central government, ……? • Is the future internet given by King or Peoples? • Is the future Wireless connec)on give by…?
May 2014 Hiroshi Mano (University of Yamanashi) 5
What is IEEE802.11ai FILS (Fast Ini)al Link Setup)
• New amendment to IEEE802.11 • Purpose – Reduce the number of packet exchanges during ini)al link setup.
– Reduce the AP and Network discovery )me for passive scan. – Reduce the AP and Network discovery )me for ac)ve scan.
• Benefit – Improve the efficiency of spectrum usage by reducing the unnecessary air )me occupa)on.
– Improve the ba_ery life )me by reducing the power consump)on of scanning.
– Improves user experience of Wi-‐Fi in hot spots. – Improves user experience with Wi-‐Fi IOT devices .(non click / automa)c connec)on)
Target performance of IEEE802.11ai FILS (Fast Ini)al Link Setup)
• Required performance of IEEE802.11ai • IEEE802.11ai aims at providing mechanisms enabling a fast ini)al link
set-‐up in less than 100ms. – Note: that IEEE802.11ai mechanisms will enable this performance but will
not guarantee the 100ms link set-‐up )me under all circumstances. • IEEE802.11ai amendment shall support a minimum user load.
Solu)ons shall demonstrate that they support at least 100 non-‐AP STAs entering an ESS within 1 second, and successfully conduc)ng a link set-‐up. – Note—IEEE802.11ai entertains submissions on the theore)cal limits of the
number of packet exchanges achievable in 1 second as a func)on of packet size and data rate.
• IEEE802.11ai amendment shall support robustness in the presence of high background load. Solu)ons shall demonstrate that they can provide a link set-‐up for media loads of at least 50%.
Hot spot environment issue • Environments
• Busy areas: The famous ”Tokyo Metro Sta)on” measurements • Increased amount of spectrum & number of networks & number
of devices • Signaling overhead • Unnecessary informa)on exchange
• QoS viola)on • Offloading, WLAN use is increasing • It is equally important to shorten the link setup )me as it is
to shorten the data transmission )me • Shorter scanning reduces power consump)on of the device
Hot spot environment issue 1 • Most of air )me is occupied by control frame • Especially undesired probe response frames is overflowing.
• KDDI’s report • Understanding
current situa)on of public Wi-‐Fi usage.
• h_ps://mentor.ieee.org/802.11/dcn/13/11-‐13-‐0523-‐02-‐0hew-‐understanding-‐current-‐situa)on-‐of-‐public-‐wifi-‐usage.pptx
Breakdown of Management frames
Frame type profile at metro station
Problem of high dense area • Low quality of Wi-‐Fi link due to the FCS errors by interference each other.
• Most of user turned off the Wi-‐Fi of their smart phone.
• Caused by – Power consump)on. – low quality of network access. – Huge undesired pop up of link detec)on.
• 11ai will solve by – Reduce the unnecessary management frame. – Reduce the unnecessary Probe Response by criteria list. – Improve more air )me by small number of ini)al link setup.
Feature of IEEE802.11ai (Scan)
• More control to scanning procedures: – Termina)ng the ongoing scan – More repor)ng op)ons of the scanning result – Immediate repor)ng – Repor)ng aner a channel is scanned – Legacy, repor)ng aner scanning is completed
• Announcing one or more neighbor BSS or channel informa)on in Beacon, Probe Response and Fast Discovery (FD) frame – Avoids scanning of channels with no AP – BSSID enables more precise ac)ve scanning – Addi)onal parameters may be included to provide more
informa)on of the neighbor BSSs
Feature of IEEE802.11ai (Higher layer setup)
• Reduce the number of packet exchanges during ini)al link setup. • All of necessary informa)on are exchanged in 2 to 3 round trip of packet exchanges.
– Note: IEEE802.11ai achieves to have an established IP-‐Link aner the set-‐up (ready to use for higher layer protocols / applica)ons) This is a major difference from what we have today (IP-‐setup follows anerwards) and saves lots of )me.
Trial report of feasibility study with FILS ! 20 FILS and 20 WPA2 are entering the
service area con)nuously. ! Measured the distance of STA and AP
where STA establish link successfully and received h_p contents.
! Measured the )me from Associa)on/FILS request to IP address assignment propriety applica)on.
! h_p://www.youtube.com/watch?v=xOKaVOPWXTU
• 90% (18/20) FILS STA established link before arriving at in the front of AP.
• 85% (17/20) WPA2 established link since they passed in the front of AP.
• Average link established )me between FILS request to IP address assignment is 0.742Sec.
• Average link established )me between Associa)on request to IP address assignment is 21.599Sec
FILS
Service Area
歩
移
動
WPA2
非接続
非接続
Established Link Point
Feasibility study of automobile applica)on • Fast ini)al link setup enables opportunis)c
vehicle to vehicle communica)on. • Toyota InfoTechnology Center measured the
number of user text message exchanges during specific )me period.
• Assump)on – Air coverage: 50m – Vehicle speed: 40km/h(11m/Sec) – Available communica)on )me : 5Sec
• WPA2: More than 4Sec communica)on )me is required to exchange messages.
• FILS: it is available to exchange messages under short communica)on )me. – Y: Number of exchanged messages – X: Communica)on )me
• This measurement did only consider the higher layer set-‐up features while using legacy scanning.
• We expect FURTHER performance increase if the sta)ons implemented the new scanning features.
Why do we need system evalua)on?
• The system , it is complicate. – Wireless Link – Transport behavior – Higher layer setup – Higher layer mobility – etc,.
• The system performance not only depends on wireless link quality.
• Every single building block inside system affects the total quality.
• Therefore we have to evaluate the system performance by End-‐to-‐End.
May 2014 15 Hiroshi Mano (University of Yamanashi)
Which kind of combina)on of the interferences should be evaluated?
• In case of shared spectrum band, there are complex interference over space, )me and frequency domain. – Infinite combina)on of interference occurs in shared spectrum band.
• Of course the interference in the same system should be evaluated. – Wireless LAN Vs Wireless LAN
• Moore over the interference between different system should be evaluated too. – Wireless LAN Vs DSRC, ZigBee,Bluetooth,LTE-‐u etc,.
f
P
Interference between different systems over frequency domain.
t
P
Frame interference over )me domain
Interference between different systems over space domain
May 2014 16 Hiroshi Mano (University of Yamanashi)
Today's system evalua)on method and limita)on.
• Computer simula)on – It is popular by economy, scalability and repeatability. – It provide evalua)on of wireless link with limited Interference condi)on.
– The real )me simula)on is limited by computer power.
• Field test – It is the only way to evaluate the end-‐to-‐end performance with real )me.
– The repeatability of field test is not sufficient and not so economical.
May 2014 17 Hiroshi Mano (University of Yamanashi)
Limit of computer simula)on
• Define the specifica)on of every single desired signals and undesired signals.
• Calculate the Eb/No (SINR) Vs BER between the system. ( Crea)ng BER (SINR) Table)
• Calculate the link budget of every single path including mul) paths
• Look up the BER (SINR) Table by the calculated Eb/No (SINR).
• Evaluate packet (frame) error rate.
• The combina)on of interference should be specified first.
• It does not scale for huge combina)on of complex interference.
~
Mod Demod
AWGN or Interference
Eb/No
BER
Tx Rx
Link Budget
Interference
Mul)-‐path
Packet Level Simulator
May 2014 18 Hiroshi Mano (University of Yamanashi)
Requirement of system evalua)on
• Complexity – Do not depend on par)cular radio specifica)on. – Provide reconfigurable radio sources of frequency, modula)on,
power, antenna, sensi)vity and etc,. – Provide evalua)on of the end-‐to-‐end performance with related
external system elements such as servers and controllers.
• Immediacy (Real )me) – Evalua)on should be performed in the real )me
• Repeatability – Test scenario should be reusable
• Scalability – Suppor)ng high dense environment of radio alloca)on.
May 2014 19 Hiroshi Mano (University of Yamanashi)
Overview of proposed wireless emula)on system
• Universal test bed for wireless system evalua)on
LAN LAN
Management Network
LAN LAN Service Network
2.4 GHz Outdoor Urban
IEEE802.11 AP
IEEE802.11 STA on High-‐speed vehicle
TV WS Outdoor Urban
IEEE802.11ah /AP
IEEE802.11ah STA
Broadcast Sta)on
2.4 GHz Indoor
IEEE802.11s STA’s
2.4 GHz 900 MHz Outdoor Urban
IEEE802.11 AP
IEEE802.11+LTE +IEEE802.18
LTE BS
TVWS DB Mobile IP etc,. Management Network
Mobile IP etc,.
High-‐speed Handover test (11ai,11u,…) TV White Space test Mesh Network test(11s). CogniNve Wireless test
Heterogeneous Network capability
IEEE802.11s STA’s
Programmable Wireless propaga/on+ Reconfigurable Wireless nodes
Virtual network testbed
Virtual W
ireless system
May 2014 20 Hiroshi Mano (University of Yamanashi)
System Image • Reconfigurable SDR
– FPGA base universal SDR Board + PC
• Scenario Generator – Sonware +PC
• Propaga)on emulator – FPGA Board +PC
P-‐WEM
P-‐SDR
P-‐SDR
P-‐SDR
P-‐SDR
Scenario Generator
P-‐SDR
P-‐SDR
P-‐SDR
P-‐SDR
May 2014 21 Hiroshi Mano (University of Yamanashi)
Reconfigurable SDR implementa)on • Evalua)on with several applica)ons and OS • Reconfigure the all of Radio func)ons
– LLC , modula)on, demodula)on • Reconfigure the characteris)c of frontend
• Channel offset, I/Q offset, Non Linear AMP, Roll off filters, etc,.
Guest OS
VM
Guest OS
VM
Guest OS
VM
LLC-High driver
Host OS (Linux)
LLC-Low (embedded MPU or hard ware)
Base Band Processor
Frontend
PCI-‐E I/F
FPGA
PC
Complex I/Q signal
Sin
I
Q
~ Cos
~ ~
NCO
Noise Noise
LUT
LUT
Gain
Filter
Filter
Heterodyne PA BPF
Gain
Gain
nonlinearity
May 2014 22 Hiroshi Mano (University of Yamanashi)
Scenario Generator • Sonware calculate the link loss, delay and phase shin of all of propaga)on path by every single scenario )me from given parameter such as – Path loss model – Antenna model – Loca)on (x,y,z) – Transmit power – Doppler frequency
May 2014 23 Hiroshi Mano (University of Yamanashi)
Propaga)on emulator • FPGA based propaga)on emulator add the fluctua)on of
delay, loss and phase on real )me (less than 1uSec). • And then add the all signals (100Mhz BW for each port)
to the des)na)on port.
d0
L0 ! t0
d1
L1 ! t1
d2
L2 ! t2
dm
Lm ! tm
N1 Tx N1Rx
N2Tx N2Rx
N3Tx N3Rx
NnTx NnRx
2n-‐n Propaga)on paths
May 2014 24 Hiroshi Mano (University of Yamanashi)
Emulate the interference effect between different system
• Measure the through put by iPerf.
• Interference of – OFDM vs OFDM
– OFDM vs CW
802.11AP 802.11STA
Interference
iPerf
Desire : OFDM 6Mbps, f=2442MHz
Un-‐desire: OFDM or CW, f=variable
Plot Desire/Un-‐desire power ra)o @10% outage of through put.
Compare proposed Emulator and RF circuit
-40
-20
0
20
40
2400 2420 2440 2460 2480
D/U
(dB
)
Undesired signal frequency (MHz)
D/U ratio @ 10% outage of through put (Desired signal frequency = 2442 MHz)
"CW (Emulator)"
"ODFM (Emulator)"
May 2014 25 Hiroshi Mano (University of Yamanashi)
Emulate the interference effect between different channel of
IEEE802.11 OFDM
802.11STA1 802.11STA2
iPerf
Link1: OFDM 6Mbps 7ch fix
Measure the through put of each Link by the parameter of the A_enua)on between each link.
802.11STA3 802.11STA4 Link2: OFDM 6Mbps ch variable
Valuable A_enua)on ATT
May 2014 26 Hiroshi Mano (University of Yamanashi)
Result
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Link a_enua)on [dB]
Through pu
t [Mbp
s]
Link a_enua)on [dB]
Through pu
t [Mbp
s]
Link a_enua)on [dB]
Through pu
t [Mbp
s]
RF connec)on Computer Simula)on
Emula)on
May 2014 27 Hiroshi Mano (University of Yamanashi)
Applica)on level emula)on
May 2014 28 Hiroshi Mano (University of Yamanashi)
Conclusion
• IEEE802.11ai – IEE802.11ai improve the user experience in high dense environment.
– IEEE802.11ai standard will be published in 2015 • Wireless & Wired Testbed for system evalua)on – Evaluate the system performance by End-‐to-‐End is required.
– Real )me wireless emula)on is available today. – Common evalua)on method is important for the new technology evalua)on.
– Sharing wireless emula)on system improve the evalua)on of new proposed ideas with fairness.
May 2014 29 Hiroshi Mano (University of Yamanashi)