Wifi-RTTについて / Wifi-RTT

Google I/O 2018 わいわい報告会

Transcript

1. Google I/Oߦ͖ͬͯ·ͨ͠(Wi-Fi RTTʹ͍ͭͯ) @sasamihoo 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 1
2. profile 4 sasami(@sasamihoo ) 4 intern(Android Engineer) 4 IoTܥͷݚڀࣨ(M2) 4 Androidྺ1.5೥͘Β͍ 4 ࠓճGoogle I/OॳࢀઓͰ͢ 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 2
3. Google I/Oߦ͖ͬͯ·͠ ͨ!! 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 3
4. 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 4
5. 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 5
6. Target session How to get one-meter location-accuracy from Android devices 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 6
7. Overview of the session 4 1-meter level accuracy of indoor location positioning 4 API available in Android P Wi-Fi RTTΛར༻͢Δ͜ͱͰ1m͝ͱͰ ͷࣨ಺ͷAndroidͷσόΠεͷҐஔΛ ଌఆͰ͖ΔΑ͏ʹͳͬͨ 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 7
8. Current approach for detecting indoor positioning 4 gyro 4 Wifi-RSSI 4 Cell NLP 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 8
9. Current critical problem for getting fine location 4 Wifi-RSSI are affected by human activity(2.4Ghz) 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 9
10. What is Wifi RTT? 4 IEEE 802.11mc protocol 4 Using Time-of-Flight technology 4 get distance from total time of packet’s round trip ڑ཭ = (total time * speed- of-light(c)) / 2 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 10
11. How it works? 4 get total time from timestamp from the access point 2 * distance = ((t4-t1) - (t3-t2))*c t4-t1 = ΞΫηεϙΠϯτଆͷ࣌ؒͷ ࠩ෼ t3-t2 = σόΠεଆͷ࣌ؒͷࠩ෼ 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 11
12. how to get the device’s position? 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 12
13. Calculate Positioning 4 multilateration 4 more ranges, more constraints and get more accurate position 4 at least more 4 ranges 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 13
14. multilateration estimation case of no exact solution to that equation(no intersect) - squares solution 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 14
15. Demo 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 15
16. How to add RTT in our application? 4 IEEE 802.11mc protocol’s support of both Wi-Fi device and a mobile phone 4 location permission(ACCESS_FINE_LOCATION) 4 Wi-Fi scan available 4 no need to connect to the Wi-fi(using beacon packet) 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 16
17. Check the device support RTT? val packageManager: PackageManager = context.getPackageManager() rttSupported: Boolean = packageManager.hasSystemFeature(PackageManager.FEATURE_WIFI_RTT) 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 17
18. Check the access point support RTT? public fun filterRttApp(){ val scanResult: List<ScanResult> = wifiManager.getScanResults() for (scanResult: ScanResult in scanResults) { if (scanResult.is80211mcResponder()){ } } } 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 18
19. Start Ranging val request: RangingRequest = RangingRequest.Builder() .addAccessPoints(scanResults) .build() rttManager.startRanging(request, executor, RangingResultCallback(){ fun onRangingFailure(code: Int){ /* handle error*/ } fun onRangingResult(results: List<RangingResult>){ for (result: RangingResult in results){ doSomethingWithResults( result.getStatus(), result.getMacAddress(), result.getDistanceMs() ) } } }) 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 19
20. RTT Ranging Results type function name int getDistanceMm() int getDistanceStdDevMm() MacAddress getMacAddress() long getRangingTimestampMillis() int getRssi() int getNumAttemptedMeasurements() int getNumSuccessfulMeasurements() available in Android Preview P(https://developer.android.com/reference/android/net/wifi/ rtt/RangingResult) 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 20
21. Integration to Fused Location Provider(In the future) 4 enable to use Wifi-RTT collaborate with other solutions(GPS, gyro, Wifi-RSSI) 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 21
22. What devices and access points can use Wifi-RTT? needs support of IEEE 802.11mc protocol 4 Pixel phones 4 Google Wifi will support soon 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 22
23. Recap 4 Using Wifi RTT, 1-meter location accuracy is available 4 both access points and devices need to support of IEEE 802.11mc protocol 4 Available in Android P preview 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 23
24. Thanks! 2018.5.27 Google I/O 2018 Θ͍Θ͍ใࠂձ 24