Beacons Impact study Thomas Deillon & Thin Nguyen July 23 rd 2014

Overview Introduction Problematic Analysis methodology Experimentation Recommendation / Conclusion Back-Up Slides GVA Airport Use Case

Introduction

INTRODUCTION 4 General information A Bluetooth Low Energy (BLE) beacon is a device that continuously advertises a signal (between 100ms and 10s). This signal can be detected by BLE-capable devices to sense location, show location-based content and trigger pre-defined actions. A beacon is uniquely identified by its ID and the major and minor values, often representing a retailer (major) and a specific store area (minor).

INTRODUCTION 5 WIFI Frequency used WiFi is a signal that emits on 2.4Ghz (as Bluetooth) and works on 14 different channels : Best practices recommend to use only channels 1, 6 and 11 as they are the non- overlapping channels (i.e. not generating interferences).

INTRODUCTION 6 BEACONS Frequency used Beacons use 3 Bluetooth frequencies, named channels 37, 38 and 39, as shown below : For most beacon manufacturers, the frequency of emission is chosen dynamically. The beacons are probing their environment and perform “hopping” until they find a free frequency.

INTRODUCTION 7 Beacon manufacturers Different manufacturers for different usage. Be particularly aware of the battery life and the operational process. As an example, how to manage stock when a beacon cannot be switched off and its battery life is only 200 days ?

PROBLEMATIC

OVERVIEW Beacons can trigger an app on your smartphone to send notifications or promotional coupons as you entered a specific zone, such as a shop, cafe or airport lounge. It can also direct you to areas of interest and provide additional information on specific items, making museums and art galleries another potential user of the technology. It would be interesting to use them in Airports but how will they coexist or impact existing services (e.g. Wi-Fi) ?

ANALYSIS METHODOLOGY

11 Theory BASED Beacons’ frequencies are in between non-overlapping Wi-Fi channels 1,6 and 11 and consequently won’t impact WiFi AP on channels 1,6,7,8,9,10,11,12. Moreover, beacons where made in a way to minimize the interference. The output power of WiFi is much higher than Bluetooth and even using Wi-Fi channels 2,3,4,5,13,14 will only have a minor impact.

To investigate the impact of beacons on WiFi, we measured the maximum bandwidth throughput via FTP and the use of an Access-Point. The same experiment was then repeated with beacons on the path. The first PC is a FTP server and hosts a 200 MB file. The second PC is a FTP client and downloads the 200 MB file via the Access-Point. ANALYSIS METHODOLOGY 12 EXPERIMENTATION approach - Bandwidth 1 FTP server FTP client WiFi Ch. 1

ANALYSIS METHODOLOGY 13 WiFi analyzer is an application available in the Google Play store that can transform an Android device into a WiFi reader. Channel Wi-Fi viewer Wi-Fi Broadcasting Power and Channel EXPERIMENTATION approach – WIFI Channel 2

ANALYSIS METHODOLOGY 14 Bluetooth Smart Scanner is an application available on the iTunes store that can transform a device into Beacon reader. Discover BeaconsSee Beacon's Channel and Strength EXPERIMENTATION approach – Beacon Reader 3

ANALYSIS METHODOLOGY 15 The Spectrum Analyzer enables the viewing of 2.4Ghz channels’ usage & interferences EXPERIMENTATION approach – Spectrum 4 Blue: < 10% utilization Green: 20% utilization Yellow: 40% utilization Red: > 50% utilization Graph amplitude over time for all frequencies in the selected band, much like a seismometer graphs earthquakes.

EXPERIMENTATION

200 MB file transfer under ideal conditions (no other WiFi AP nearby or similar interferences – checked with the spectrum analyzer) EXPERIMENTATION 17 REFERENCES TEST 1 FTP server FTP client WiFi Ch. 6 Download timeDownload speed Average of 3 tests133.6 seconds11.92 Mbits / s This numbers are used as reference tests for the following experimentation

200 MB file transfer on Ch. 6 EXPERIMENTATION 18 INTERFERENCES TESTS 2 Youtube video (10% BW) on Ch. 4 Download time Download speed Average133.5 seconds11.92 Mbits / s The first AP is set on Channel 4 (2.427Ghz) to simulate 10 beacons on Channel (38) 2.426Ghz, which should interfere with the transfer rate on the second AP set on Channel 6 (2.437 Ghz) Beacons use, amongst others, the 2.426Ghz frequency (channel 38) which theoretically doesn’t impact WiFi when set on Channel 1, 6 or 11. The following test is to prove this point: The download time and speed shows that it doesn’t impact the WiFi (Ch. 6) performance and confirms the theory approach where Beacons + Wifi on Channels 1,6,7,8,9,10,11,12 don’t impact each other

EXPERIMENTATION 19 WORSE CASE SCENARIO MB file transfer with 13 beacons at 4db/20ms FTP server FTP client WiFi Ch. 4 Download timeDownload speedDecreasing Average of 3 tests138 seconds11.6 Mbits / s< 5 % In this worse case scenario (Beacons on 2.426Ghz and WiFi on 2.425Ghz), the bandwidth impact is minor (5% decrease). We can conclude that even in a situation where WiFi is on Channels 2,3,4,5,13,14, the Beacons’ impact on WiFi performance is negligible (<5%)

EXPERIMENTATION 20 BEACON INTERFERENCE 4 Using 13 Beacons (Estimotes, EM, Stick&Find), we measure the beacon / beacon interferences via the spectrum analyzer and the BLE reader application: Interferences on the 3 beacon frequencies Each beacons try, by “hopping”, to find a frequency which is free Beacons are nearly always “hopping” but the more beacons there are, the more hopping occurs

RECOMMENDATION / CONCLUSION

Recommendation / Conclusion 22 Before deploying Beacons : As you can see throughout the study, the beacons have a tiny impact on the WiFi airport network. In most situations and in order to pinpoint the concern of the airport IT, two measurements should be proposed to demonstrate this non-interference of the beacons:  The WiFi Android Analyzer app can show the WiFi channels spectrum used  A screenshot of the situation (using the spectrum analyzer) and an FTP test can be done as a reference After deploying the Beacons : Check the hopping interval of the beacons to determine if too many are used (which could degrade the user experience) and if the power is too important Be careful of the positioning of the beacons. Ideally, one beacon should see only two other beacons A screenshot of the situation (using the spectrum analyzer) and an FTP test can be done as a check

BACKUP SLIDES

GVA AIRPORT USE CASE

GVA Airport analysis 25 OVERVIEW MONTREUX JAZZCHECKIN 50CHALET SUISSESECURITY In GVA Airport, only WiFi frequencies 1,6,1 are used and consequently, the beacons won’t impact the existing service.

GVA Airport Analysis 26 Before deploying the Beacons: We went to GVA Airport to do a spectrum analysis for all the zones where the beacons will be implemented As an example, the following slides show the spectrum for all of the expected locations of the beacons for the Check-In zone

Check-In/Enregistrement E05 E06 E07 E08 E09 TIC - G. Brentini27

GVA Airport Analysis 28 E05 : E06 :

GVA Airport Analysis 29 E07 : E08 :

GVA Airport Analysis 30 E09 :

200 MB file transfer on land side - Main Arrival (FTP Client and Server are connected via an Pro WiFi Access -Point ) Beacons Impact Study at GVA Airport (1) 31 FTP serverFTP clientWiFi Ch. 1 Download timeDownload speed Average No Beacon500 seconds0.4 MB / s Average with 15 Beacons 500 seconds0.4 MB / s We can see that there is no impact with or without the beacons deployed

Beacons Impact Study at GVA Airport Spectrum Graphs with No Beacon 32

Beacons Impact Study at GVA Airport Spectrum Graphs with 15 Beacons deployed 33