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Month Year. [place presentation subject title text here]. Date: YYYY-MM-DD. Authors:. 1 Slide 1. John Doe, Some Company. Agenda. Introduction of IEEE802.11ai FILS (Fast Initial Link Setup) Overview of IEEE802.11ai Prospected use case Feature of IEEE802.11ai standard

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Place presentation subject title text here

Hiroshi Mano (ATRD)

Month Year

[place presentation subject title text here]

Date: YYYY-MM-DD

Authors:

1Slide 1

John Doe, Some Company


Agenda

Hiroshi Mano (ATRD)

Agenda

  • Introduction of IEEE802.11ai FILS (Fast Initial Link Setup)

  • Overview of IEEE802.11ai

  • Prospected use case

  • Feature of IEEE802.11ai standard

  • Trial report of feasibility study with FILS

  • Current status of IEEE802.11ai

  • Note

    • Overview on IEEE802.11ai principles and mechanisms to enable for Fast Initial Link Set-Up as of Nov 2013.

    • Disclaimer: This document has not been approved by IEEE802.11ai as an official overview document. It has been proposed by the authors based on submissions approved for going into the IEEE802.11ai Draft as well as on documents currently under creating.


Introduction of ieee802 11ai fils fast initial link setup 1 3

Hiroshi Mano (ATRD)

Introduction of IEEE802.11ai FILS (Fast Initial Link Setup) 1/3

  • Scope of IEEE802.11ai Standard:

    • This amendment defines modifications to the IEEE 802.11 Medium Access Control Layer (MAC) to enable a fast initial link set-up of IEEE 802.11 stations (STAs)

  • Purpose of IEEE802.11ai Standard:

    • This amendment defines mechanisms that provide IEEE 802.11 networks with fast initial link set-up methods which do not degrade the security currently offered by Robust Security Network Association (RSNA) already defined in IEEE 802.11.

  • Definition of “Initial Link Setup“

    • The initial link setup includes all operations required for IP data exchange:

      • Discovery of the network and the BSS

      • Authentication and association signaling

      • IP address configuration


Introduction of ieee802 11ai fils fast initial link setup 2 3

Hiroshi Mano (ATRD)

Introduction of IEEE802.11ai FILS (Fast Initial Link Setup) 2/3

  • Need for the IEEE802.11ai

    • The number of mobile devices incorporating IEEE 802.11 is steadily growing. Applications that are continuously running on those devices benefit from the high data rates of the IEEE 802.11 interface.  

    • The project’s primary need comes from an environment where mobile users are constantly entering and leaving the coverage area of an existing extended service set (ESS). Every time the mobile device enters an ESS, the mobile device has to do an initial link set-up to establish wireless local area network (LAN) connectivity. This requires efficient mechanisms that

      • (a) scale with a high number of users simultaneously entering an ESS

      • (b) minimize the time spent within the initial link set-up phase

      • (c) securely provide initial authentication.

    • The current IEEE 802.11 specification does not meet these requirements in some usage scenarios. An optimization of the link set-up is desirable. Optimizations may include improvements to

      • access point / network discovery,

      • secure authentication,

      • mechanisms to support concurrency in the exchange of higher layer protocol messages during the authentication phase (for example assignment of IP addresses).


Motivation

Hiroshi Mano (ATRD)

However

We are still in nomadic services.

Motivation

  • Limitation of market growth in the existing Wi-Fi

  • Wi-Fi evolved greatly for the past ten years and got big success in a market

    • Data rate :

      • 11/2Mbps →11b/11Mbps→11g/54Mbps →11n/300Mbps→11AC/Gbps

    • Securities :

      • WEP->WPA->WPA2

    • Service device

      • Desktop PC →Note Book →PDA → Portable game, Digital Camera →Smart phone.


Nomadic vs mobile

Hiroshi Mano (ATRD)

Mobile

STA do not need stop while in use.

Nomadic Vs Mobile

  • Nomadic

  • STA must be stationary while in use.

Reference :RECOMMENDATION ITU-R F.1399-1“Vocabulary of terms for wireless access”MWA & NWA


Today s market back ground

Hiroshi Mano (ATRD)

Today’s market back ground

  • Growth of portable device

    • Number of portable device which incorporate Wi-Fi is more than PC’s

    • Low power consumption device realized the use of the always-on connection type service.

  • New application’s request (Twitter, Face book…)

    • Push Notification Service

    • Quick update

      • Only cell phone provide these service

  • High bandwidth

    • Very SMALL CELL of each AP

  • True mobile usage

    • Users frequently pass through (isolated) hot spots while on the move

  • The dwell time of a user within a cell is short

  • Isolated hot spots cause frequent initial association / authentication


Prospect of use case 1

Hiroshi Mano (ATRD)

Prospect of use case 1

  • Quick update contents and push service.

    • New messages and location data are updated while just passing an AP‘s coverage.

    • So you do not have to stop many times like serious landing operation.

    • Service provider can distribute the handbill without stopping the foot of the customer.

      • Location

      • Pop E-mail

      • Twitter

New location and presence

Updated new twitters and messages

Get new handbills

Messages

Handbill

Location

No need stop! Just pass through!

Hiroshi Mano, Root, Inc.


Prospect of use case 2

Digital Signage+ Info Stand

Distribute information

RF Tag application

Automatic Electrical Cash Register

Security Gate

Hiroshi Mano (ATRD)

Prospect of use case 2

ID Exchange

No need stop! Just pass through!

Hiroshi Mano, Root, Inc.

Hiroshi Mano, Root, Inc.


Prospect of use case 3

Hiroshi Mano (ATRD)

Prospect of use case 3

  • Automatic metering

    • Power electric

    • Water meter

    • Gas meter

    • etc..

  • Drive through

  • Digital Signage

  • V2V,V2X


Hot spot environment issue 1 2

Hiroshi Mano (ATRD)

Hot spot environment issue 1/2

  • Environments

    • Busy areas: The famous ”Tokyo Metro Station” measurements

    • Increased amount of spectrum & number of networks & number of devices

  • Signaling overhead

  • Unnecessary information exchange

    • QoS violation

  • Offloading, WLAN use is increasing

  • It is equally important to shorten the link setup time as it is to shorten the data transmission time

  • Shorter scanning reduces power consumption of the device


Hot spot environment issue 2 2

Hiroshi Mano (ATRD)

Hot spot environment issue 2/2

  • Most of air time is occupied by control frame

  • Especially undesired probe response frames is overflowing.

  • KDDI’s report

  • Understanding current situation of public Wi-Fi usage.

  • 13/11-13-0523-02

  • hew-understanding-current-situation-of-public-wifi-usage.pptx

Frame type profile at metro station

Breakdown of Management frames


Feature of ieee802 11ai scan

Hiroshi Mano (ATRD)

Feature of IEEE802.11ai (Scan)

  • More control to scanning procedures:

    • Terminating the ongoing scan

    • More reporting options of the scanning result

    • Immediate reporting

    • Reporting after a channel is scanned

    • Legacy, reporting after scanning is completed

  • Announcing one or more neighbor BSS or channel information in Beacon, Probe Response and FILS Discovery frame (FD)

    • Avoids scanning of channels with no AP

    • BSSID enables more precise active scanning

    • Additional parameters may be included to provide more information of the neighbor BSSs


Active scanning expedited scanning procedure

AP1

Hiroshi Mano (ATRD)

AP1

AP2

AP2

AP3

AP3

Probe Request

STA 1

STA 2

STA 2

Delay probe request transmission

Abort probe request transmission

Probe Response

STA 1

Active scanning, expedited scanning procedure

  • If device has received a probe request, it should avoid transmitting the same probe request as transmitted


Active scanning probe response collision avoidance

Hiroshi Mano (ATRD)

AP1

AP1

AP2

AP2

AP3

AP3

Probe Request

STA 1

STA 2

STA 2

STA2 misses the probe request transmission

Receive probe responses

Probe Response

STA 1

Active scanning, Probe Response collision avoidance

  • The APs avoids sending unnecessary copies of probe responses

  • Single copy of probe response or beacon frame is enough

AP1

AP2

AP3

Probe Request

STA 1

STA 2


Active scanning comprehensive response

Hiroshi Mano (ATRD)

Chn 1

Chn 6

Chn 1

Chn 6

Probe Response + Neighbor List

Probe Request

Contains information of itself (AP 2), as well as AP 1 and AP 3 or channel 6

Request for information of other BSSs

STA 1

STA 1

AP1

AP1

AP2

AP2

AP3

AP3

Active scanning, comprehensive response

  • One probe response may contain information of multiple APs

  • The total amount of responses is reduced


Active scanning new response criteria

AP1

AP1

Hiroshi Mano (ATRD)

AP2

AP2

AP3

AP3

Probe Request

Probe response is transmitted if all the criteria are met

Criteria for AP delay performance & RSSI

STA 1

Probe Response

STA 1

Active scanning, new response criteria

  • Probe Request contains criteria to transmit Probe Response. Response is transmitted only if the criteria is met

  • Criteria include:

    • Transmission power

    • AP transmission Delay

    • Vendor specific information

    • Data delivery rate to Internet

    • AP capabilities


Active scanning probe response reception time element

Hiroshi Mano (ATRD)

Active scanning, Probe Response Reception Time element

  • The transmitters of the Probe Request may indicate how long the transmitter will be available to receive Probe Responses

  • Probe Response Reception Time is set to MAX_Probe_Response_Time


Passive scanning key enhancements

Hiroshi Mano (ATRD)

Passive Scanning, key enhancements

  • FILS Discovery (FD) frame: a new public action frame

    • small-size: 30-byte MAC framing + 10 to about 25 bytes FD frame body, i.e., 40 to 55 bytes for typical uses;

    • One Mandatory information item: SSID;

    • Optional information items: AP’s Next TBTT, AP-CCC, Access Network Options, Capability, Security, Neighbor AP information.

    • transmitted between beacon frame transmissions, for a fast AP/Network discovery;

    • Transmitted as non-HT duplicate PPDU, when using a larger channel than 20MHz;

Beacon

Example #1

FD frame

Primary channel of the transmitter

Preamble

Payload/FD Frame

T1

time

Preamble

Payload/FD Frame

Example #2

Preamble

Payload/FD Frame

T2

time

Preamble

Payload/FD Frame

Example #3

T3

time


Reducing sizes of the responses

Hiroshi Mano (ATRD)

Reducing sizes of the responses

  • AP Configuration Change Count (CCC) keeps count of changes of the parameters in Probe Response and Beacon

    • One octet in length

    • Changes of BSS Load, Average Access Delay and other rapidly changing parameters are not considered in CCC


Network discovery key enhancements

Hiroshi Mano (ATRD)

Network Discovery, key enhancements

  • GAS query enhancement by using an AP white-list

    • A new IE with one or multiple 6-byte BSSIDs in GAS request to indicate the AP(s) that the requesting STA wants to query.

  • GAS traffic reduction by using GAS Configuration Sequence Number

    • A new IE with an 1-byte unsigned integer:

      • indicating the version number of AP’s GAS configuration information set;

      • monotonically incrementing whenever there is any change in the AP’s GAS configuration information set;

      • Used in Beacon and/or Probe Response.


Feature of ieee802 11ai higher layer setup

Hiroshi Mano (ATRD)

Feature of IEEE802.11ai (Higher layer setup)

  • Reduce the number of packet exchanges during initial link setup.

  • All of necessary information are exchanged in 2 to 3 round trip of packet exchanges.

    • Note: IEEE802.11ai achieves to have an established IP-Link after the set-up (ready to use for higher layer protocols / applications) This is a major difference from what we have today (IP-setup follows afterwards) and saves lots of time.


Feature of ieee802 11ai higher layer setup1

Hiroshi Mano (ATRD)

Feature of IEEE802.11ai (Higherlayer setup)


Trial report of feasibility study with fils

Hiroshi Mano (ATRD)

Trial report of feasibility study with FILS

  • The effect of reducing packet exchange was evaluated by field test in Japan.

    • The details are reported in IEEE802.11 as,

      • https://mentor.ieee.org/802.11/dcn/13/11-13-0323-02-00ai-tgai-experimental-test-report-of-fils.pptx

  • FILS STAs completed the association process in significantly less time than WPA STAs.

    •  More time within the coverage area of an AP to use for (user) data exchange

  • The large number of frame exchanges for WPA2 STAs (as compared to FILS STAs) made them vulnerable for fading when entering the AP‘s coverage

    • If retransmission of a lost frame did not succeed after three attempts, the association process had to restart from the beginning

  • This field trial did only consider the higher layer set-up features while using legacy scanning.

  • We expect FURTHER performance increase if the stations implemented the new scanning features.


Trial report of feasibility study with fils 2 2

Hiroshi Mano (ATRD)

Trial report of feasibility study with FILS 2/2

  • 20 FILS and 20 WPA2 are entering the service area continuously.

  • Measured the distance of STA and AP where STA establish link successfully and received http contents.

  • Measured the time from Association/FILS request to IP address assignment propriety application.

    • http://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 time between FILS request to IP address assignment is 0.742Sec.

  • Average link established time between Association request to IP address assignment is 21.599Sec

Established Link Point

FILS

非接続

歩きながら移動

非接続

Service Area

WPA2


Feasibility study of automobile application

Hiroshi Mano (ATRD)

Feasibility study of automobile application

  • Fast initial link setup enables opportunistic vehicle to vehicle communication.

  • Toyota InfoTechnology Center measured the number of user text message exchanges during specific time period.

  • Assumption

    • Air coverage: 50m

    • Vehicle speed: 40km/h(11m/Sec)

    • Available communication time : 5Sec

  • WPA2: More than 4Sec communication time is required to exchange messages.

  • FILS: it is available to exchange messages under short communication time.

    • Y: Number of exchanged messages

    • X: Communication time

  • This measurement did only consider the higher layer set-up features while using legacy scanning.

  • We expect FURTHER performance increase if the stations implemented the new scanning features.


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