SPWNED - iBeacon Technology

Research paper June 13, 2014

2014

PROJECT: INTERNET OF THINGS DENNIS ANDERSON, ERIC HORSTMANSHOF, NICK SCHELLEVIS, PETER XHOFLEER, SHIRLEY VERWEIJEN, WILLIAM RIJKSEN

HAN UNIVERSITY OF APPLIED SCIENCES | Ruitenberglaan 26, Arnhem

June 13, 2014 Informatics

General information Project period February 4th 2014 – June 27th 2014 Name student Dennis Anderson E-mail [email protected] Student number 495200

Name student Eric Horstmanshof E-mail [email protected] Student number 511497

Name student William Rijksen E-mail [email protected] Student number 482025

Name student Nick Schellevis E-mail [email protected] Student number 462693

Name student Shirley Verweijen E-mail [email protected] Student number 454877

Name student Peter Xhofleer E-mail [email protected] Student number 465180

Client Theo Theunissen E-mail [email protected] School HAN University of Applied Sciences Location Ruitenberglaan 26, 6826 CC Arnhem

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Versioning Version Date Name Change(s) 0.1 17-02-2014 Nick, Dennis Initial release

0.2 21-02-2014 Process feedback Theo Theunissen

0.3 31-03-2014 Nick Updated with research plan

0.4 07-04-2014 Nick Added chapters and changed layout

0.5 09-04-2014 Shirley Added sub question 7.

0.6 14-04-2014 Nick Added sub question 6.

0.7 16-04-2014 Nick Alternative order in document.

0.8 23-04-2014 Nick & Shirley Process feedback Theo Theunissen. Added terminology list.

0.9 07-05-2014 Nick Added sub question 10. Processed last of Theo’s feedback.

0.10 07-05-2014 Shirley Added sub question 9.

0.11 07-05-2014 Shirley Added introduction.

0.12 12-05-2014 Nick Chapter 5.6 added.

0.13 12-05-2014 Nick Chapter 5.3 updated to newest version.

0.14 12-05-2014 Nick Chapter 5.4 added.

0.15 14-05-2014 Shirley & Nick Processing feedback Theo. Processing internal feedback.

0.16 19-05-2014 Shirley & Nick Added chapter “Requirements for indoor positioning”. Changed chapter order. Added numbers to images and tables.

0.17 21-05-2014 Shirley Use of term beacon made consistent throughout document.

0.18 26-05-2014 Shirley Chapter “Why iBeacon technology” added.

0.19 02-06-2014 Nick Processing internal feedback. Added new version test results.

0.20 04-06-2014 Nick Processed feedback Theo.

0.21 10-06-2014 Nick Checked document again. Translated document to English.

1.0 11-06-2014 Nick Finalized document.

1.1 13-06-2014 Eric & Nick Some translation errors fixed.

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Table of contents General information ................................................................................................................ 2

Versioning .................................................................................................................................. 3

1 Introduction ................................................................................................................... 6

1.1 Over SPWNED (spawned) ........................................................................................ 6

2 Problem .......................................................................................................................... 7

3 Objective ....................................................................................................................... 7

4 Hypothesis ...................................................................................................................... 7

5 Questions ........................................................................................................................ 8

5.1 What techniques are currently available for indoor positioning? ...................... 8

5.1.1 Light Field Communication (LFC) .................................................................... 8

5.1.2 Infrared (IR) ......................................................................................................... 9

5.1.3 Radiofrequencies (RF) 865 MHz (UHF) – 10.6 GHz (SHF) ................................ 9

5.1.4 Dead-Reckoning .............................................................................................. 14

5.2 What are the differences and similarities between the positioning techniques? ................................................................................................................................... 15

5.2.1 Similarities .......................................................................................................... 15

5.2.2 Differences ........................................................................................................ 15

5.2.3 Summary ........................................................................................................... 16

5.3 What are the advantages and disadvantages of the positioning techniques? ................................................................................................................................... 18

5.3.1 Positive points ................................................................................................... 18

5.3.2 Negative points ................................................................................................ 18

5.4 Why iBeacon technology? .................................................................................... 21

5.5 What is iBeacon technology? ............................................................................... 22

5.6 How does iBeacon technology work? ................................................................. 23

5.7 Test setup beacons ................................................................................................. 26

5.7.1 Acceptance limit ............................................................................................. 26

5.7.2 Delineation ........................................................................................................ 26

5.7.3 Configurations .................................................................................................. 28

5.7.4 Test environment .............................................................................................. 30

5.8 Test results Beacons ................................................................................................. 33

5.8.1 Operating system in combination with iBeacon technology ................... 33

5.8.2 Effect of the interval on accuracy ................................................................ 35

5.8.3 Effect of the power on accuracy .................................................................. 37

5.8.4 Most accurate settings for Estimote Beacons .............................................. 40

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5.8.5 Overall conclusion test results ........................................................................ 44

5.9 What are the requirements for indoor positioning with iBeacon technology? .. ................................................................................................................................... 45

5.9.1 Surroundings ..................................................................................................... 45

5.9.2 Placement ........................................................................................................ 45

5.9.3 Obstacles .......................................................................................................... 45

5.9.4 Electronic devices and signals ....................................................................... 45

5.9.5 Electric and magnetic radiation shielding materials .................................. 45

5.9.6 Hardware requirements .................................................................................. 46

5.9.7 Software requirements .................................................................................... 46

5.10 What are the advantages and disadvantages of iBeacon technology for indoor positioning? ............................................................................................................. 47

5.10.1 Advantages ...................................................................................................... 47

5.10.2 Disadvantages ................................................................................................. 47

5.11 What possibilities does precise indoor positioning using iBeacon technology provide? .............................................................................................................................. 48

5.11.1 Retail .................................................................................................................. 48

5.11.2 Other examples ................................................................................................ 49

6 Conclusion ................................................................................................................... 50

7 Recommendation ...................................................................................................... 50

8 Definitions ..................................................................................................................... 51

9 References ................................................................................................................... 52

10 Attachments ................................................................................................................ 55

10.1 Attachment 1.1 – Test environment ...................................................................... 55

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1 Introduction This report lists the description, results and conclusion of the study to several indoor positioning technologies. This topic was initiated in the minor Mobile Application Development from the HAN University of Applied Sciences, Arnhem.

The purpose of this study is to investigate different localization techniques and determine which technology produces the best results for indoor positioning.

This report proposes the following hypothesis: "With beacons you can determine indoor location with deviations of less than ten percent of the actual distance, which makes an indoor navigation system with beacons a useful technology."

The above hypothesis is the theme of this report. This hypothesis is tested by answering the following questions:

What techniques are currently available for indoor positioning? What are the differences and similarities between the positioning techniques? What are the advantages and disadvantages of the positioning techniques? Why iBeacon technology? What is iBeacon technology? How does iBeacon technology work? What are the requirements for indoor positioning with iBeacon technology? What are the advantages and disadvantages of iBeacon technology for indoor

positioning? What possibilities does precise indoor positioning using iBeacon technology

provide?

By gathering information answers are obtained about indoor localization using beacons. Also, tests are setup and executed with the aid of Estimote beacons and the results are analyzed.

From all the information gathered in this report, a conclusion is made and the hypothesis is tested.

Finally, a recommendation is written on basis of the conclusion, if the iBeacon technology is a useful indoor navigation technology.

1.1 Over SPWNED (spawned)

This group consists of Shirley, Peter, William, Nick, Eric and Dennis, which abbreviated spells SPWNED. This can be seen as the past tense of "to spawn", defined below. Our goal is to eventually spawn a mobile application and a research paper.

The section "NED" also indicates we are from “Nederland”, The Netherlands. to spawn [spôn] (Houghton Mifflin Company, 2000) 1. To produce or deposit (spawn). 2. To produce in large numbers. 3. To give rise to; engender: tyranny that spawned revolt. 4. To cause to spawn; bring forth; produce: a family that had spawned a monster. 5. To plant with mycelia grown in specially prepared organic matter.

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2 Problem "The current technologies for positioning, such as (A-)GPS, are too inaccurate for precise indoor positioning."

In today's society, mobile devices are a part of life (Langeveld & Savalle, 2010). Look around you on the street and you see several people staring at the device in their hands, looking for a particular street or bus stop. At a concert you will see a light show of mobile phones (see Figure 2.1) pointed towards the stage. In other words, mobile devices are taken everywhere and form a connection with more than just your immediate surroundings.

One wants to be connected, to find things quickly. But not only online, in the real world too. With indoor navigation one can spend their time more useful and efficient because less time is spent searching.

Moreover, companies (think of stores, retail) can point their customers to certain products. Also, they can display targeted commercials and special offers, based on a customer’s location, also to the benefit of the customer.

Obviously there are multiple applications for indoor navigation. These will be discussed later in this document.

The iBeacon technology seems to be a good option to make indoor navigation possible. But what are the conditions for reliable and accurate (indoor) positioning with iBeacon technology?

3 Objective The objective of this project is to investigate the different localization techniques and determine which technology produces the best results for indoor positioning.

If a suitable technology is found, it can be used by the client to let visitors, students and / or employees of the HAN navigate the school, for example at ICA Presents or an Open Day, and display useful information when they are at a stand or presentation. However, this is not within the scope of this project.

4 Hypothesis With beacons you can determine indoor location with deviations of less than ten percent of the actual distance, which makes an indoor navigation system with beacons a useful technology.

With some tests this assumption is tested. In this study it is tested with multiple locations and devices, and average, minimum and maximum deviation of the virtual to the real location are easily determined. Up to one meter deviation falls within the acceptance range. For an explanation of the acceptance range, see chapter 5.7.1. If the deviations exceed the acceptance range, this technology is not suitable for indoor location.

Figure 2.1 – A common image at concerts

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5 Questions 5.1 What techniques are currently available for indoor positioning?

There is not yet a standardized technique for an Indoor Positioning System (IPS), but there are several techniques that provide a good possibility.

5.1.1 Light Field Communication (LFC)

Existing light sources can be used to make navigation possible. LEDs flash at a frequency that is imperceptible by the human eye. These frequencies, however, can be manipulated and used to give each LED its own frequency, and thereby identify them. Among others, Philips (Philips, 2014) and Bytelight (ByteLight, 2013) use such a technique. 5.1.1.1 Philips

Philips is currently focusing primarily on retail (Figure 5.1), because of the (often) dense grid in which the lighting is installed. With their 'intelligent lighting' a smartphone can determine its position using an app. This detects the frequency of an LED and knows where that LED is located. Then the current position can be displayed on a map and the user is guided to the desired location.

Figure 5.1 - Philips' LED positioning system

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http://www.newscenter.philips.com/nl_nl/standard/about/news/press/2014/20140217-Intelligente-LED-winkelverlichting-communiceert-met-smartphone.wpd

http://www.bytelight.com/


5.1.1.2 Bytelight

The Bytelight implementation is almost the same as the Philips technique. A chip modulates the frequency of the LED, a mobile application knows and recognizes these frequencies en associated locations. Bytelights implementation though appears to have a more ‘free’ distribution of the lighting. As seen in Figure 5.2, there is lighting in different locations, not placed in a grid.

Figure 5.2 - Bytelights LED positioning system

5.1.2 Infrared (IR)

The infrared technology is cheap and currently available for many mobile devices, ranging from smartphones to notebooks. Infrared (IR) is electromagnetic radiation that is invisible to the human eye. In order to work properly, there must be a clear line of sight between the IR transmitter and receiver (targeted communication) and no other strong lighting (Farid, Nordin, & Ismail, 2013). Because the range of a transmitter is about a few meters, depending on the battery and the number of built-in LEDs, this is a relatively accurate technology. But it is very difficult to apply on a larger scale because there are a lot of transmitters required (Schmitt & Kaufmann, 2005). 5.1.3 Radiofrequencies (RF) 865 MHz (UHF) – 10.6 GHz (SHF)

Radio Frequency (RF) based systems are widely used because they overcome many of the shortcomings of infrared (IR). The signals can penetrate walls and obstacles, so they have a better coverage of the building, reducing the amount of RF receivers needed. (Farid, Nordin, & Ismail, 2013)

Disadvantages of RF are that it requires more power and isn’t targeted communication. In addition, the used frequencies often fall under license. Systems with high precision (~ 10-30 cm) use Time Difference of Arrival (TDOR) or Angle of Arrival (AOA), but require synchronization of the receivers. The disadvantage of this system is its price. Systems which depend on the measurement of signal strength are less

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complicated and therefore cheaper, but also less accurate (~ 1-3 m).

Positioning with RF signals is possible with the following four methods:

• Receive Signal Strength Indication (RSSI) - position is determined by measuring the received signal strength from one or more signal sources, using the fact that signal strength is reduced over distance. This is the least accurate of all methods because any blockage or reflection causes an error.

• Time Difference of Arrival (TDOA) - position is determined by measuring the relative delay of at least two signal sources, and in the physical fact that the speed of light times the differential time is equal to the differential distance. This may be the most accurate method, but it requires a complex infrastructure to achieve high performance.

• Angle of Arrival (AOA) - position is determined by the relative angle of arrival of at least three sources in known locations and measure the estimated position using geometry. Not widely used because it is difficult to implement directly in the sensor.

• Dead Reckoning / Doppler Relative Displacement - position is determined by measuring relative displacement and direction from a known point using a hybrid technology that combines inertial sensors with RF Doppler data. This technique does not require any knowledge of the location of a signal source.

(Loctronix, 2013)

5.1.3.1 Wi-Fi (or WLAN)

WLAN positioning uses the signal strength of the access points in the neighborhood to calculate the position. There are two ways to determine the position. One way, the empirical model (Dictionary.com, sd), is based on comparing the current signal strength with a database of pre-recorded measurements. Before the system can be used, (one-time) calibration is required, so you know which signal strengths apply to which position. The second method is known as the propagation model and is based on mathematical equations. These equations describe the degradation of the signal strength of a radio wave in the room. Using these equations, an estimated distance of the WLAN card (read: user) to the access point can be calculated and through triangulation (three-point measurement) an absolute position can be determined. For this method at least three access points are required. (Mazuelas, et al., 2009), (Großmann, Röhrig, Hakobyan, Domin, & Dalhaus, 2006)

The advantage of WLAN positioning is that the infrastructure already exists and thus easily used as IPS. You also have an infrastructure that is used for other applications (and therefor maintained), so the infrastructure is relatively reliable.

However, if there is a power failure in the building, then the IPS will no longer be usable. Another disadvantage is that the signal levels are constantly changing, not only by the movements of the recipient, but also by other persons or objects in the area. This affects the precision of the measurements in such a way that an exact location can be difficult to determine.

In both cited studies above deviations from 1.25 to 4.0 meters, but also values (well) above are mentioned.

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5.1.3.2 Ultra Wide Band (UWB)

Ultra Wide Band uses short pulses over a large part of the frequency range. Due to the short duration of UWB pulses, there is a much smaller probability of interference, and it is easier to filter the reflected signals from the original signal. This results in a higher accuracy (~ 15 cm). This technology is much less affected by obstructions such as walls objects than for example WLAN. However, it is a relatively new technology that is not yet standardized. Problems mainly include the impact of this technology on existing systems (more noise), but also the developments are slow and the costs are high.

DecaWave has developed a chip (decaWave, 2013) based on the IEEE802.15.4-2011 standard. This chip can transmit data (albeit at relatively low speeds) and determine both inside and outside the location of tagged objects with an accuracy of up to 10cm.

TU Delft also researched (TU Delft, sd) an IPS based on UWB. They too indicate positioning with an accuracy of mere centimeters is possible. Other researchers (Leitinger, Froehle, Meissner, & Witrisal, 2014) measured, with a floor plan and just one UWB signal, a maximum deviation of 5 cm in 90% of the measurements.

This technology appears to be a very good option as IPS.

5.1.3.3 GPS

The Global Positioning System is currently the most widely used positioning system. It measures the delay in signals from multiple satellites moving in known orbits. To work properly, at least 4 satellites must be visible. If there are more, that increases the precision. This technique is unfortunately not very usable indoors, because there is always a line-of-sight (a direct line between sender and receiver) required between the receiver and the satellite.

There are solutions to receive GPS signals indoors. These consist of repeaters that receive the signals via an antenna on the roof and re-emit them in the building. The disadvantage of this is that the GPS receiver then always measures the position of the antenna, and not of itself. (Roger GPS repeater, 2009)

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5.1.3.4 Radio frequency identification (RFID)

Radio frequency identification is a technology to store information in and to read from so-called RFID tags from a distance. These are often found in sticker form (see Figure 5.3), for example on products in stores to prevent shoplifting.

Systems that are built to navigate indoors often produce errors in the positions, especially in low-cost systems. One solution would be to regularly calibrate the system at points where people often pass. This can be done manually but also automatically by means of an RFID reader. This device reads the identification numbers of RFID chips installed in the building. The number is linked to the location of the chip, so the reader knows where it is in the building. RFID chips are small and require no maintenance. They can be applied on walls, floors and ceilings.

There is however a difference between active, passive and semi-passive RFID chips. The active chips can emit a signal themselves (and thus require a power source), the passive chips will only modulate the signal that they receive from an RFID reader and send it back for identification and thus receive their energy from that same signal. These passive RFID chips are the most maintenance-free, since they need to be installed only once and don’t have to be fitted with new batteries their entire lifetime. However, the passive chips also provide the least accurate signal. Semi-passive chips do have their own power source, but only transmit a signal when receiving a signal.

In a study by Samer Saab and Zahi Nakad (Saab & Nakad, 2011) the accuracy of the tags is quite high, with average deviations of only 0.1m, if the RFID tags are placed 1.2m apart.

5.1.3.5 Bluetooth Low Energy

Bluetooth Low Energy (also called Bluetooth Smart or BLE) is a part of the Bluetooth 4.0 specification. Unlike the older

version of Bluetooth, Bluetooth Low Energy is specially designed to use much less power but also offer a similar

range. BLE was first introduced under the name Wibree, but merged with the Bluetooth 4.0 specification in 2010. BLE is not backwards-compatible with older versions of Bluetooth:

• Bluetooth: supports only classic Bluetooth • Bluetooth Smart Ready (Figure 5.4): supports classic Bluetooth and Low Energy • Bluetooth Smart: supports only Low Energy

New smartphones (iPhone 4S and newer, Android devices with at least version 4.3), laptops and tablets often have full support for Bluetooth 4.0 and Smart Ready.

Figure 5.3 - RFID-tag, often in form of a sticker

Figure 5.4 – Bluetooth Smart Ready logo

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Beacons only support the Low Energy Protocol (so they can operate very long on a single CR2032 battery). Older devices such as computer equipment and old phones only support the classic Bluetooth protocol.

The main purpose of Bluetooth Low Energy is to use little energy. Some beacons can transmit a signal for two years on a single battery charge. This does depend on many factors such as:

• Power (with which the signal is transmitted) • Advertising Interval (the interval at which the signal is transmitted)

The classic Bluetooth protocol and the new variant BLE both use the same frequency (2.4 GHz - 2.4835 GHz), but Low Energy use different channels. BLE has lower a throughput speed and is therefore not intended to send and receive large files, but to discover devices and communicate with them.

The range of BLE and the old protocol is up to 100 meters. This is the most ideal situation, the range is usually between 50-70 meters.

At this time the following operating systems support Bluetooth Low Energy:

• iOS 5 and higher • Windows Phone 8.1 (not yet released) • Android 4.3 and higher • BlackBerry 10

Table 1 - Technical specifications Bluetooth

Technical specifications Bluetooth Bluetooth Low Energy Distance Max 100 m Max 50 m Speed 0.7-2.1 Mbit/s 0.27 Mbit/s Delay ~ 100 ms. ~ 6 ms. Voice support Yes No Power consumption 1.0W 0.01 - 0.5W(varies) Peak power < 30 mA <15 mA Encryption 56/128-bit 128-bit AES

5.1.3.5.1 Proximity UUID

Each beacon can be uniquely identified by its own unique proximity UUID. This identifier is 20 bytes long and is divided into 3 sections:

• ProximityUUID (16 bytes) • Major number (2 bytes) • Minor number (2 bytes)

The Proximity UUID is an identifier which is used to distinguish beacons. If for example the beacons are used to display a special offer in a store with multiple physical locations then the ProximityUUID for all these beacons is the same. The mobile application of the store then scans in the background for all beacons with this UUID.

The major number is used to identify a specific store. Each of the retail store will receive its own major number.

The minor number is to distinguish individual beacons. Each beacon in a store has a different minor number, so the app knows exactly at which beacon the customer is.

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To see which beacons are in the vicinity, different applications can be used. These scan the area for Bluetooth signals and when beacons are found, the data of all beacons are displayed. 5.1.3.5.2 Support in iOS / Android

In order to use beacons, an app needs to be installed on a device and configured with certain beacons in the area. The application does not need to be started to react to the presence of beacons. The OS constantly scans for beacons in the area in the background. If the phone is in the vicinity of a beacon, the OS sends a notification to the application, which is then started.

Requirements iOS To make use of beacons on an iPhone, current applications must be updated with this technology. When an application is started after the update, the user is given the opportunity to make use of beacons.

To use the technology on an iPhone, a number of requirements must be met:

• Bluetooth must be enabled • Background app refresh must be enabled • iPhone 4S or newer model

Requirements Android

To use the technology on an Android device, a number of requirements must be met:

• Bluetooth must be enabled • Android 4.3 or newer OS version • Device must support Bluetooth 4.0

5.1.4 Dead-Reckoning

Dead-reckoning is the process of estimating the current position, based on the last known position and displacement of said position based on known or estimated velocities and directions within the elapsed time. Dead-reckoning uses an inertial navigation system that provides highly accurate directional information. One of the drawbacks of dead-reckoning is that the inaccuracy of the process is cumulative, so that the deviation of the true position grows with time. The reason is that new positions are calculated in full from the data of previous positions.

(Farid, Nordin, & Ismail, 2013)

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5.2 What are the differences and similarities between the positioning techniques?

The different techniques differ considerably in terms of operation, but there are also some similarities to be found. Below these differences and similarities will be briefly explained.

5.2.1 Similarities

Among the techniques, there are some similarities to be found. GPS, Wi-Fi, BT4.0, UWB and RFID all use radio waves. Also, all these techniques have of a range of at least a few meters, mostly suitable for indoor. Bluetooth and Wi-Fi are also in the same frequency band (2.4GHz), so they may influence each other. This could affect the accuracy.

Light Field Communication (LFC) and IR both use light, visible or not. The accuracy depends on the number of lights used. With two lamps in a large space, the accuracy is logically less than when in the same room a grid of twelve lamps is mounted. This also applies to most other techniques. More reference points means higher accuracy.

5.2.2 Differences

The techniques that use radio frequencies differ mainly in the used frequencies. GPS uses relatively low frequencies so as to realize global range. The downside is that these frequencies are not low enough to penetrate buildings very well.

Wi-Fi and Bluetooth use frequencies in the gigahertz range to ensure a high data throughput in relatively short distances. The difference between the two techniques as IPS is great. Where Wi-Fi as existing infrastructure is also used for internet / network access, the Bluetooth technology is to be installed as a separate infrastructure. This requires separate maintenance whereas Wi-Fi needs maintenance anyway. However, the bluetooth modules have their own power supply (good for a continuous operation of two years), where the Wi-Fi network is dependent on the power grid.

UWB makes use of even higher frequencies, with the result that the range is somewhat low. Also, the technique is relatively new, so the costs are still high. More research and development is still needed.

With RFID for this application tags are used that operate at (relatively) low frequencies around 865 MHz. This gives them a range of one to twelve meters. Due to the low price of the tags, they can be applied in large quantities, which also makes a high accuracy possible. There is however a fine grid - compared to other techniques - of tags required.

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The difference between the aforementioned techniques and LFC or IR is essentially the form of communication. Instead of radio frequencies, light is used. This also has a frequency, but in the terahertz range. The big difference between the techniques themselves is this frequency. Where LFC uses visible light – and can therefore be used as standard lighting - IR light is invisible to the eye. A second infrastructure is needed in addition to the existing lighting. However IR suffers from ambient light, making it work especially well in dark or less well-lit areas. LFC on the other hand just needs a (cheap) adaptation of existing lighting.

Then there is the odd man out: dead-reckoning. This is a technique that does not use an infrastructure. With a compass and / or a gyroscope and accelerometer this technique can calculate the speed and the direction in which the user moves. For short distances it can work well (think of a car navigation system, when in a tunnel without GPS signals), but long distances a small deviation soon causes disastrous deviations. Also, this requires very accurate equipment.

5.2.3 Summary Table 2 - Specifications different techniques

Technique Frequency Signal type Signal range

GPS 1575.42 MHz

1227.60 MHz

Radiofrequency (UHF)

Worldwide, outside

Dead-reck. - - -

Wi-Fi 2.4 / 5 GHz Radiofrequency (UHF/SHF)

35-100m

BT 4.0 2.4GHz Radiofrequency (UHF)

~100m

UWB 3.1-10.6 GHz Radiofrequency (SHF) ~10m

RFID 865-868 MHz* Radiofrequency (UHF)

1m-12m**

LFC Unknown Light Depends on lamp

IR 430 THz - 300 GHz Light Depends on lamp and ambient light

* Most suitable for this application

** At mentioned frequency

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Accuracy Estimated cost Maintenance infrastructure

GPS 3m or more GPS module: ~€50 none

Dead-reck. <50m - -

Wi-Fi 1,25 – 4m (or more) €50 - €800 per AP, often multiple

Hardly, replace faulty equipment

BT 4.0 Nearby: 5-6cm

Far: 2-3m

~€30 per beacon, multiple needed

Replace beacon every two years

UWB 5-15cm High / unknown Unknown

RFID ~10cm (if sufficient tags used)

From €0,05 per (passive) tag

Virtually none

LFC Depends on amount of lights

~€0,10 extra per LED-light (decaWave)

Replace defective lights

IR Depends on amount of lights

Unknown Replace defective lights

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5.3 What are the advantages and disadvantages of the positioning techniques?

Each technique has its positive but also negative points, in relation to indoor positioning. Below, the positive and negative points will be briefly explained.

5.3.1 Positive points

Each technique has its advantages for indoor positioning. The techniques for Infrared, GPS and Wi-Fi can be used on almost any mobile device. The LFC and Wi-Fi infrastructure is generally already present and therefore it’s easy to implement these techniques.

The signals from the radio frequency techniques will not be stopped by walls and / or obstacles. This is very positive for an indoor positioning technique, because less transmitters and receivers are needed.

5.3.2 Negative points

Besides advantages, each technique has its disadvantages when it comes to indoor positioning. The techniques Infrared and GPS require a direct line of sight between the transmitter and receiver, which is difficult to achieve indoors for GPS.

LFC will consume a lot of unnecessary power when it is used in areas where lots of natural light is present. Infrared is also not ideal in well-lit areas (natural or artificial) because the light can disrupt the signal from the infrared light.

Wi-Fi is very disadvantageous in case of a power failure, because access points typically have no separate power source (for example batteries). Also, the Wi-Fi signal is not constant: as more people log on to the network, signal strength will redistribute and decrease.

Dead-reckoning calculates your position based on the previous position, causing a deviation growing with time. As a result, this technique is not precise enough to use indoors.

Bluetooth Low Energy is only supported on devices running iOS 5 and higher, Windows Phone 8.1 (not yet released), Android 4.3 and higher and BlackBerry 10. This means that only the newest devices support this technology, which excludes a large part of the devices.

Table 3 – Advantages and disadvantages infrared

Accuracy Advantages Disadvantages Infrared Unknown Inexpensive Line-of-sight required

between sender and receiver

Usable on many mobile devices

Many transmitters required

No strong ambient light allowed

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Table 4 - Advantages and disadvantages GPS

Accuracy Advantages Disadvantages GPS 3 meter or more Available on many

mobile devices Line of sight between satellite and device needed

Table 5 - Advantages and disadvantages Wi-Fi

Accuracy Advantages Disadvantages Wi-Fi 1,5 – 4,0 meter Infrastructure often

already available In case of power failure unusable

Multiple functions Signal strength not constant

Available on many mobile devices

Table 6 - Advantages and disadvantages dead-reckoning

Accuracy Advantages Disadvantages Dead-reckoning

< 50 meter Not dependent of external signals

Deviation grows with time

Not accurate enough for indoor positioning

Table 7 - Advantages and disadvantages Bluetooth Low Energy

Accuracy Advantages Disadvantages Bluetooth Low Energy

Nearby: 5-6cm Far: 2-3m

Energy efficient Is only supported on iOS 5 and higher, Windows Phone 8.1 (not yet released), Android 4.3 and higher and BlackBerry 10

Relatively inexpensive transmitters

Table 8 - Advantages and disadvantages UltraWideBand

Accuracy Advantages Disadvantages UWB < 1 meter Small risk of interference High costs Little affected by walls

and obstacles Early stage of development

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Table 9 - Advantages and disadvantages Radio Frequency IDentification

Accuracy Advantages Disadvantages RFID < 1 meter Small Device must constantly

emit a signal Maintenance free

Table 10 - Advantages and disadvantages Light Field Communication

Accuracy Advantages Disadvantages LFC < 1 meter Infrastructure often

already present Unnecessary power usage if no light needed

Multiple functions

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5.4 Why iBeacon technology?

In this research the iBeacon technology was chosen because it is a relatively new technique, which could be very interesting. There were some beacons available to test the propositions, of which the results could underline the outcome of this research.

With these reasons in mind, the following hypothesis is established: With beacons you can determine indoor location with deviations of less than ten percent of the actual distance, which makes an indoor navigation system with beacons a useful technology.

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5.5 What is iBeacon technology?

The term 'iBeacon' is a trademark of Apple (Apple Inc., 2014). It stands for a technology (patent pending), which makes it possible to determine the distance between a device and a beacon. This technology is not only used for iOS devices. Latest Android devices support this technology too. (Cavallini, iBeacons technology in a few words, 2013).

Figure 5.5 - Beacons from Estimote

In Figure 5.5 two beacons of Estimote are shown. A beacon is an inexpensive, small device that constantly emits Bluetooth Low Energy (BLE) signals. A mobile device can then receive these signals and to calculate its distance to a beacon, on the basis of these signals. The signal that the beacon emits, contains an identification code (UUID). This UUID is not guaranteed to be unique, but is useful because of the wide range of possible UUIDs (Cavallini, iBeacons IDs, 2013).

Because the signals a beacon emits, can only bridge a maximum distance of (about) 70 meter, iBeacon technology is not suitable for use on large distances, but rather in small, local areas (Estimote, 2012). This is also called micro-location (Cavallini, iBeacons technology in a few words, 2013).

A beacon can interact with a mobile device by starting a specific application or show a push notification. With this functionality, a developer can convey specific information to a mobile device when it is within range of a specific beacon. (Cavallini, iBeacons technology in a few words, 2013).

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http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.htm&r=11&p=1&f=G&l=50&d=PTXT&S1=(455%2F456.1.CCLS.+AND+20140415.PD.)&OS=ccl/455/456.1+and+isd/4/15/2014&RS=(CCL/455/456.1+AND+ISD/20140415)


5.6 How does iBeacon technology work? 5.6.1.1 Bluetooth low energy in beacons

BLE by default consists of four modes that can be used for communication. These are: the master device mode, slave device mode, advertising mode and scanning mode. Beacons use the advertising mode of BLE.

Advertising is a mechanism that broadcast data packets in a certain frequency to make a device discoverable for other devices. The interval can be set from twenty milliseconds up to two seconds. The shorter the interval, the shorter the battery life, but the faster the device can be found. The packets can contain up to 47 bytes of data and consist of:

• one byte opening • four bytes access address • two to 39 bytes advertising channel PDU (protocol data unit) • three bytes CRC (cyclic redundancy check)

In Figure 5.6 the advertisement package is visually depicted.

Figure 5.6 - Visual representation of an advertisement packet

This means that a beacon can transmit data without a connection. In Figure 5.7 the advertisement packet of a beacon from the supplier Estimote is displayed. However, this protocol is standard for iBeacon technology.

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5.6.1.2 Example

Figure 5.7 – An example of an Advertising Packet

(Puchta, 2014)

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5.6.1.3 Measuring distance with beacons.

Through the BLE protocol data arrives. This data is displayed in Table 11. This data is sent by the beacon and is collected by a mobile device. Table 11 – Data sent by a beacon

Name Description iBeacon prefix A prefix as an advertisement for Apple's patent on iBeacons

UUID The unique identification of a beacon

Major number A number that groups the beacons

Minor number The beacon sequence number within the group

TX power Indicates how strong the signal is at one meter distance from the beacon.

Based on the RSSI (Received Signal Strength Indication), the strength of the signal can be determined. If the device is further away from the beacon, the RSSI will be lower.

Since it is known how high the TX power will be one meter from the beacon, it is possible to calculate how far the device is placed from the beacon, using to the power and RSSI. This is also how it’s carried out in the test.

Zones

The area around the beacon is divided into four zones: "unknown", "far", "near" and "immediate" (Figure 5.8). When a beacon cannot be reached because the beacon is too far removed from the mobile device or when it is disabled, then it falls under the "unknown" zone. The zone between 30 m and about two meter falls into the "far" zone. Two meter to about half a meter is registered under the "near" zone. Closer than half a meter beacon falls under the "immediate" zone. These zones makes it easy for a developer to transmit specific information at a selected distance.

Figure 5.8 - Zones used by beacons

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5.7 Test setup beacons

To check whether Estimotes claims (Estimote, 2014) on the functioning of the Estimote beacons are correct, a test setup is devised. Here the beacons are placed on the floor at different distances of a mobile device. Subsequently, on the mobile device, the distance is calculated. This data is then sent to a server where graphs are generated. The tests are carried out on Android and iOS, and there are various configurations set on the beacons. During testing two devices are used. The first is an iPod Touch with iOS 7. The second is an Asus Nexus 7 with Android 4.4. We deliberately chose to use those two operating systems because both operating systems have a large share of the market (Oost, 2014). The iBeacon technology is designed for iOS devices by Apple but Android also supports iBeacon technology since Android 4.3 (Burke, 2013). It is important to test with both devices for accurate test results. 5.7.1 Acceptance limit

Within this study, the research team established an acceptance limit for the tests that determines when a measurement is accurate enough to be accepted.

The acceptance range for this project is ten centimeters per meter. Ten centimeter was chosen because devices differs in size. This amounts to 10% clearance on the average deviation. In order to obtain the results, on each measurement the average deviation is calculated in a percentage, by measuring all deviations of each measuring point. The results of the tests will be compared with the acceptance limit. This shows whether indoor positioning with iBeacon technology is acceptable. 5.7.2 Delineation

As there is limited time and resources to work with, there are different delineations used to restrict the investigation. The following delineations apply: • Only Estimote Beacons are used.

o Beacons from other manufacturers may produce better results.

• For each test with Android, three beacons are used.

o The signals from the beacons might affect each other.

• For each test with iOS two beacons are used (one is no longer available).

o Because of force majeure one beacon was no longer available, which may

affect consistency between the comparison of Android and iOS.

• An in-house made application is used in order to receive the measurements.

o The test results may be affected by the method of programming.

• Only Estimote SDK version 2.0 is used.

o In other versions, the devices may react differently.

• Only Android 4.4 and iOS 7.1 are used.

o With other versions, the devices may react differently.

• Each measurement had a duration of exactly 30 seconds.

o It is not measured if longer measurement periods yield different results.

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• One device per operating system (Android, iOS) is used.

o Results of different devices with the same operating system are not measured.

• Possible interfering signals are not taken into account.

o Signals such as Wi-Fi, Bluetooth etcetera are ignored during testing. This means

that the tests at times might suffer from interference, which could affect the

test results.

• The distances that are most applicable are examined. Other distances are not

measured.

o Test results above 50m are unknown for this study.

• The battery percentage of beacons is not taken into account.

o The battery life can affect the strength of the signal.

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5.7.3 Configurations

The tests for the iOS and Android applications are carried out with the configurations and distances as listed in Table 12.

Table 12 - Configurations for the tests

Test Real distance (m) Power (dBm) Interval (ms.) 1 0.5 4 50 2 1 -30 1000 3 1 -30 2000 4 1 -30 50 5 1 -16 1000 6 1 -16 2000 7 1 -16 50 8 1 4 1000 9 1 4 2000 10 1 4 50 11 2 4 50 12 5 4 50 13 10 -30 1000 14 10 -30 2000 15 10 -30 50 16 10 -16 1000 17 10 -16 2000 18 10 -16 50 19 10 4 1000 20 10 4 2000 21 10 4 50 22 50 0 (iPhone only) 50 23 50 4 50 24 1 -16 (single beacon) 50

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In addition to testing different distances with different power and interval, tests are carried out with various objects between the beacon and the receiver (see Table 13). From this we can conclude whether objects interfere with the signals. The objects are placed in the middle of the distances every time to ensure consistency. The following tests are only done with an iOS application, for the Android test results are so inaccurate that it was decided to disregard Android.

Table 13 - Configurations for the tests with possible interfering objects

Test Real distance (m) Power (dBm) Interval (ms.) Object 1 1 4 50 Lunchbox 2 0.5 -16 50 Lunchbox 3 4 50 2 Lunchbox 4 4 50 5 Lunchbox 5 5 -16 50 Lunchbox 6 0.5 -16 50 Hand 7 1 -16 50 Hand 8 5 -16 50 Hand 9 2 -16 50 Hand in pocket 10 1 -16 50 Hand in pocket 11 1 -16 50 Body 12 2 -16 50 Body 13 5 -16 50 Body 14 2 -16 50 Plaster wall 15 5 -16 50 Plaster wall 16 1 -16 50 Phone 17 2 -16 50 Phone 18 5 -16 50 Phone

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5.7.4 Test environment

The tests are conducted on HAN University of Applied Sciences, Ruitenberglaan 26 in Arnhem. In the room as shown in Figure 5.9 the test in which objects are used are conducted. In this test environment the beacons and the mobile device are placed on the ground. In Attachment 1.1 – Test environment the entire open space is visible, which includes multiple access points. Some of those access points may affect the Bluetooth signals:

Access point 1

• Eight meters from the beacons.• An archive cabinet of half a meter deep between the access point and the

beacons.• 2.4 and 5 GHz frequencies.

Access point 3

• Four and a half meters from the beacons• A single wall between the access point and the beacons.• 2.4 and 5 GHz frequencies.

There are several other access points in the surrounding classrooms which might also affect the signal from the beacons.

Figure 5.9 - Floor plan test environment

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The test environment of the tests with objects is located in another room in the same building. In Figure 5.10 the test setup is shown. The beacons are located at the end of a table in the room. The device is placed on another table. The table with the device is moved in the y-axis to the number of meters defined for each test.

Access point 1

• Three meters from the beacons.• 2.4 and 5 GHz frequencies.

Figure 5.10 – Floor plan test environment

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On the ceiling of the test room some aluminum tubes are mounted. Aluminum weakens and blocks signals (Dusyjopa, 2013). This applies to Wi-Fi signals, as well as the beacon signals. The tubes are four meters from the ground.

The devices tested were within range of the access points. But because different distances are measured, the signal intensities were different. The devices were located in the same space, beneath the aluminum tubes and at room temperature.

The tests conducted at 50 meters differ from the other tests. Because space is limited, these tests are performed in the open air. These tests did not suffer from Wi-Fi signals or aluminum. The temperature of the 50 meter tests is on average approximately twelve degrees Celsius (outside).

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5.8 Test results Beacons

Some questions are prepared for these tests. In this chapter the questions are answered by the test results.

The questions are mainly intended to clarify the following points:

• The accuracy of the beacons.• What factors affect the accuracy.• On what operating system the most accurate results are achieved.

The power and interval of the beacons are adjustable. To confirm that these settings affect the accuracy of the beacons, the tests are executed changing one value with conditions being equal or held constant (ceteris paribus).

5.8.1 Operating system in combination with iBeacon technology

The tests were performed on two operating systems, iOS 7.1 and Android 4.4. In terms of accuracy of the measured distance, there is a significant difference between the operating systems.

In Figure 5.11 one of the Android tests is shown. A distance of six meters is measured while the actual distance is one meter. The next measurement jumps to a meter and the results continue to fluctuate. Therefore the standard deviation is very high.

Figure 5.11 – Test results Android 4.4 at 1m.

Distance (m)

Interval (ms.)

Power (dBm)

Device Avg. deviation (%)

Variance Standard deviation

1 50 -16 Android 128.86 1.54 1.24

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The iOS tests are much more accurate when looking at the average and standard deviation. In Figure 5.12 one of the iOS tests is shown. All test results deviate approximately 0.2 meters from the actual distance of one meter. This means that the measurements are much more stable and thus the standard deviation is lower.

Figure 5.12 – Test results iPhone (iOS 7.1) at 1m

Distance (m)

Interval (ms.)

Power (dBm)

Device Avg. deviation (%)

Variance Standard deviation

1 50 -16 iPhone 17.86 0.04 0.19

The reason that the tests in Android vary much and have a high standard deviation, is caused by the bluetooth stack of Android. It has not yet been optimized for iBeacon technology which makes the calculation of the distance to be inaccurate. The reaction of Estimote, when the results were fed back to them is as follows:

Since iOS is much more developed for iBeacon technology, further tests are performed on an iOS device and Android is excluded.

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5.8.2 Effect of the interval on accuracy

In order to investigate the effect of the interval to the average deviation and the standard deviation of the measured distances, the interval is tested ceteris paribus. 5.8.2.1 Average deviation

Figure 5.13 shows that the average deviation at a distance of one meter in two tests (with a power of -30 dBm and -16 dBm) decreases when the interval is changed from 50ms to 1000ms. When the interval is changed from 1000ms to 2000ms, the average deviation increases.

At a distance of one meter at 4 dBm power the average deviation remains the same from 50ms to 1000ms, from 1000ms to 2000ms the average deviation declines.

The patterns described in the previous sections are not consistent, so no causal relationship has been found between the interval and the average deviation.

Figure 5.13 - Effect of interval on average deviation

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5.8.2.2 Standard deviation

There is a causal relationship between the interval and the standard deviation. This relationship is shown in Figure 5.14. It is clear that the standard deviation increases, as the interval increases.

Figure 5.14 – Effect of interval on standard deviation

5.8.2.3 Conclusion

The interval has a clear causal relationship with the standard deviation. The interval determines the amount of packets sent within a certain time frame. When this interval is high, the time between packets is longer. In this period, other factors are potentially affecting the signals causing different measurements yielding different results. A short interval is recommended when stable results are desired. If this is not of importance, a longer interval may be selected for improved battery life of the beacons.

No clear link is found between the interval and the average deviation. An explanation of the different test results could be sought in other factors such as Wi-Fi interference or the beta status of the Estimote SDK.

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5.8.3 Effect of the power on accuracy

In order to investigate the effect of the power on the average deviation and standard deviation of the measured distances the power is tested ceteris paribus. 5.8.3.1 Average deviation

Figure 5.15 shows the effect of the power on the average deviation of the beacons.

The average deviation appears to be smaller when the power is higher. The average deviation is smallest at a power of -16 dBm. In all three tests, however, the average deviation becomes higher again when the power is higher than -16 dBm.

It is therefore concluded that there is a causal link between the power and the average deviation.

Figure 5.15 - Effect of power on average deviation

It is curious how there is a V-shape to be seen in the deviation. To identify the cause, it is important to clearly understand how the measured distance is determined.

The beacons include the original power in their message. The signal from the beacon weakens in the air and reaches the device with a certain strength. The device calculates the distance out of the measured signal strength and the original strength.

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In Figure 5.16 it can be seen that at a power of -30 dBm, the device calculates the beacon is located at about one and a half times the actual distance.

Figure 5.16 - iPhone, 1m, -30dBm, 50ms interval

In Figure 5.17 it can be seen that at a power of -16 dBm, the device calculates the beacon is located at about the actual distance.


In Figure 5.18 it can be seen that at a power of 4 dBm, the device calculates the beacon is located more or less halfway the actual distance.

Figure 5.18 - iPhone, 1m, 4dBm, 50ms interval

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5.8.3.2 Standard deviation

There is a causal link between the power and the standard deviation. This relation is shown in Figure 5.19. It can be seen that the standard deviation decreases, as the power increases.

Figure 5.19 - Effect of power on standard deviation

5.8.3.3 Conclusion

Clearly there is a causal relationship in both the average deviation as the standard deviation. The standard deviation is smaller when the power is higher.

However, the power does not have this effect on the average deviation. There the average deviation is smallest at the half of the available power range. When the power is higher, the calculated distance is less than the actual distance. When the power is lower, the calculated distance is greater than the actual distance.

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5.8.4 Most accurate settings for Estimote Beacons

Since it is now known which factors (power and interval) influence the accuracy of the measured distance, a top five of tested configurations during the research was listed. The top five is based on the lowest average deviation. The average deviation is determined per test over all tested distances.

Nr. Power (dBm) Interval (ms.) Device Avg. deviation (%)

1 -16 50 iPhone 17.86

2 -16 2000 iPhone 31.82

3 -30 1000 iPhone 32.50

4 -30 50 iPhone 37.99

5 4 1000 iPhone 39.05

For iOS the lowest average deviation is achieved with a power of -16 and an interval of 50 milliseconds.

The top five configurations for Android is also listed.

Nr. Power (dBm) Interval (ms.) Device Avg. deviation (%)

1 -30 1000 Android 79.41

2 -30 50 Android 86.05

3 -30 2000 Android 86.10

4 4 1000 Android 94.52

5 4 50 Android 96.22

For Android, the differences in the average deviation is too small to make any meaningful statements.

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5.8.4.1 Interference caused by objects

In the measurements without objects (ideal conditions) a power of -16dBm is most accurate. These settings are used as a basis for testing with objects.

In Figure 5.20, the average deviation is recorded for different objects attenuating the signal from the beacons.

When the bluetooth signal is attenuated by objects, the average deviation is higher. Figure 5.21 and Figure 5.22 show that the change in the deviation is caused by the measured distance on average being higher than the measured distance in perfect conditions.


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Figure 5.20 - Average deviation with objects.

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Figure 5.22 - iPhone in hand, 1m, -16dBm, 50ms interval

This difference is logical because the distance is calculated by the strength of the signal. When the signal is attenuated, the device simply calculates a higher distance.

The objects also have an effect on the standard deviation. It increases when objects attenuate the signal. In Figure 5.23 the standard deviation caused by the different objects is displayed.

Figure 5.23 – Standard deviation with objects

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5.8.4.2 Conclusion

Objects have a major impact on the accuracy of the beacons. This is mainly because the devices calculate the distance based on the signal strength. When the signal is attenuated by objects, the calculated distance is larger.

In order to improve the accuracy of the beacons in combination with objects the power of the beacons can be set at maximum. When the signal is attenuated by objects, the measured distance with a maximum power is closer to reality. This is because at ideal conditions with no objects, and with a maximum power, the measured distance is approximately half of the actual distance.

When an object is placed between the device and the beacon this weakens the signal so that the device will calculate a greater distance. By adding this derogation together with the measured distance from the ideal conditions measured values come closer to the actual distance. This will be one of the reasons to change the power of a beacon.

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5.8.5 Overall conclusion test results

The iBeacon technology is still immature, which is reflected in the test results. The acceptance limit of an average deviation of ten percent, as stated in the test setup, was not achieved. The best average deviation achieved during these tests, was 17.86 percent.

The beacons use bluetooth signals that cannot move well through objects. As a result, the problem remains that objects and especially the human body greatly affect the signal. This is not because the technique is immature, making it most likely dealing with objects will not improve in the future.

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5.9 What are the requirements for indoor positioning with iBeacon technology? 5.9.1 Surroundings

To use beacons in a room or area it is recommended to keep the following guidelines in mind:

• The beacons are placed on the ceiling• There is little to no obstructions between the beacons and the users• The beacons are not placed next to disruptive electronic devices• The beacons are not placed next to electrical and magnetic radiation shielding

materials

5.9.2 Placement

By placing beacons on the ceiling, the beacons have a direct connection with the user, as there is little to no obstructions in-between. For example, if the beacons are placed at eye level in the room, it is more likely that the signals are disturbed by various obstacles or other people in the room.

5.9.3 Obstacles

Bluetooth Low Energy emits a low power signal and therefore an obstacle can disrupt the signal, so that the beacons do not work properly. Our tests showed that even the smallest obstacle can affect the signal.

5.9.4 Electronic devices and signals

Bluetooth Low Energy emits its signal on the same frequency as Wi-Fi. If too many devices are put in the same room as the beacons, the reliability of the beacon signal might be reduced.

5.9.5 Electric and magnetic radiation shielding materials

A number of materials shields electric and magnetic radiation. When a beacon is placed between these materials, it may affect the signal strength of the beacon and the receiving device a lot. The following materials shield the most: Table 14 - Materials and their shielding of electric / magnetic radiation

Material Shielding Aluminum foil (cladding) 99,9 %

Zinc or copper roof 99,9 %

Fine mesh copper film 99,9 %

Light concrete 300 mm 90-95 %

Light concrete 100 mm or reinforced concrete 160 mm

70-90 %

Chicken wire 2 cm mesh 90-95 %

Shielding may enhance the radiation. For example, if a window is shielded (ferrous curtains) and another window is not, then it may be that the reflectance of the second window on the curtains of the first amplifies the radiation (Dusyjopa, 2013).

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5.9.6 Hardware requirements

To use beacons on iOS, the following requirements apply: Table 15 - Hardware requirements for use of beacons with iOS

Device iPhone 4s or newer

iPad (3rd generation or newer)

iPad mini or newer

iPod Touch (5th generation or newer)

Beacons Beacons as described, like:

• Estimote• Kontakt.io• SmartBeacons

To use beacons on Android, the following requirements apply: Table 16 - Hardware requirements for use of beacons with Android

Device Every device with support for Bluetooth Low Energy

Beacons Beacons as described, like:

• Estimote• Kontakt.io• SmartBeacons

5.9.7 Software requirements

To use beacons on iOS, the following requirements apply: Table 17 - Software requirements for use of beacons with iOS

Software version: iOS 7 or higher

Other requirements Bluetooth must be enabled

There must be an application installed able to communicate with the beacons.

To use beacons on Android, the following requirements apply: Table 18 - Software requirements for use of beacons with Android

Software version: 4.3 (Jelly Bean) or higher

Other requirements Bluetooth must be enabled

There must be an application installed able to communicate with the beacons.

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5.10 What are the advantages and disadvantages of iBeacon technology for indoor positioning?

To bring the advantages and disadvantages of iBeacon technology for indoor localization to light, two test applications are written for Android and iOS. In addition, the researchers have three Estimote beacons at their disposal. The strength of the signal and the interval at which the beacon emits that signal can be adjusted using the iOS application developed by Estimote.

The test applications for iOS and Android use the API provided by Estimote. These test applications measure the accuracy of the beacons. The accuracy has been measured at different distances. In addition, it is investigated whether there is a difference in accuracy at different intervals or power of beacon signals. This results in the following.

5.10.1 Advantages The beacons in general have a number of advantages, namely:

• The technique uses Bluetooth low energy, which most new mobile devices support.• The beacons are small, therefor you can place them almost everywhere.• They consume little energy, thanks to Bluetooth Low Energy.• Relatively large range up to 100m.• No application needs to be running to receive notifications.

Thereby claiming the beacons of Estimote some advantages:

• With nanomaterial these beacons simply stick to nearly every surface.• The beacons are waterproof.

5.10.2 Disadvantages

However, there are also disadvantages to be found in this technique:

• After about two years the battery is empty. Replacing it is not easy (yet).• The Bluetooth signals, and therefore the accuracy, are easily disturbed by (mostly)

people, other objects or walls.• Each devices accuracy is different (iOS devices appear to be more accurate than

Android devices).• Not all mobile devices support Bluetooth (4.0) Low Energy technology.• Older Android devices with an OS version lower than 4.3 do not support BLE.• Different beacons have different signal strength.• The security of Estimote beacons is currently very weak, the ID can be changed

without authentication.• Trilateration (precise location using three beacons) is not accurate (see deviations

in test results).

It should be noted that Estimote is working on a new version of their beacons that should bring some improvements.

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5.11 What possibilities does precise indoor positioning using iBeacon technology provide?

Over the past 100 years, the shopping experience little changed from the customers. A customer walks into the store, pick up the product, pay for it at the box office and walks outside (Cavallini, iBeacons technology in a few words, 2013). The shopping experience could change much now using beacons. The possibilities of the beacons are described below.

5.11.1 Retail

The beacons are primarily usable for retail. It is a way to change interaction between the customer and vendor and improve the buying experience of customers. The following use cases are examples of the use of beacons in retail. 5.11.1.1 Personalized advertising

The iBeacon technology makes it possible to display personal advertisements to customers based on, for example, date, location, or purchase history. Conditions apply: the customer must be in the store to get ads. The aim is to motivate customers to roam the store and display products or discounts they are interested in. In this way, customers are encouraged to buy the product. 5.11.1.2 Mapping the behavior of customers

In addition, the iBeacon Technology makes it possible to analyze the behavior of customers within the store. This allows the shopping behavior to be easily analyzed. The merchant can then optimize his store. 5.11.1.3 Multi-channel integration

Multi-channel integration is the parallel or integrated use of various distribution channels to get in touch with customers and / or sell products. The use of multi-channel integration with beacons is that online and offline shopping are merged (Cavallini, iBeacons technology in a few words, 2013). For example, a customer may have searched online for products of the store and to find the product in-store using beacons without the customer even asking for it. Another possibility is that the customer can buy a product in the online store and the next day beacons help to pick up the product in the store. That way the two factors are combined in order to enhance the customer experience. 5.11.1.4 Small businesses

For small businesses, there are many options with beacons. For example, a retailer can create beacons with his own Apple products, such as a Mac or iPad. This can be done with an application of Estimote which is downloadable from the Apple App Store (Estimote Inc., 2014). This way the retailer can still send notifications to reach customers without additional investment.

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5.11.2 Other examples

In addition to the retail trade, the concepts of beacons can also be used in other specific situations. 5.11.2.1 Hospital

To help patients in a hospital quickly, it is convenient to obtain all information of a patient as soon as possible without error. Using beacons, a doctor entering the room can immediately obtain all the patient information the on his device. 5.11.2.2 Museums / Exhibitions

Visiting a museum is a whole different experience with beacons. Micro-location and interactivity give visitors more information about the item that they’re observing. Visitors can also get notifications on events, sessions, workshops and the like (InformatieProfessional, 2014).

It is also possible for the organizers to see where most people walk in the museum, also which is the most viewed item. 5.11.2.3 Public transport

The beacons can also be used in public transport. A PT-application can see exactly which train or bus a user is in, therefor the application can show relevant travel information. 5.11.2.4 Sporting events

In large sports stadiums beacons can help people to quickly navigate directly from the parking lot to their seats. 5.11.2.5 Parking

beacons can be very useful in large parking garages. Using this technology your phone can tell you exactly how many and which spaces are still available. If you’re already parked, your phone can indicate where your car is.

(Cavallini, iBeacons technology in a few words, 2013)

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6 Conclusion The objective of the project is to investigate the different positioning techniques and determine which technology produces the best results for indoor positioning. From examining the possible techniques for indoor positioning, iBeacon technology emerged as the most interesting option. Next, the hypothesis below was drawn.

With beacons you can determine indoor location with deviations of less than ten percent of the actual distance, which makes an indoor navigation system with beacons a useful technology.

Several tests are performed in which the deviations of distances were measured with both a Nexus 7 (Android 4.4) as well as a iPod Touch 5G (iOS 7.1). It can be concluded from the test results that the beacons are too inaccurate on both devices for indoor positioning relative to the acceptance limit.

In addition, looking at the results it can also be concluded that iBeacons give better results on the iPod Touch than the Nexus 7. Estimote has, in response, indicated that the iBeacon technology is better developed on iOS than Android.

Finally, it can be said that iBeacons are suitable to indicate whether an Android or iOS device is in the vicinity of a store or a product. To actually navigate to a location, the iBeacon technology is still insufficiently developed.

Based on the acceptance limit combined with the measurement results it can be concluded that as a result of this study, the hypothesis is refuted.

7 Recommendation The study revealed that iBeacon technology is insufficiently accurate as indoor positioning technology. Nevertheless SPWNED sees a future in this method of navigation. Since the measurement results are inaccurate, further development of the iBeacon technology must lie mainly on improving the determination of the distance.

Besides, most alternatives are not sufficiently developed. Most alternatives must be calibrated, such as WLAN and UWB. GPS is not received indoors and for the use of IR many transmitters must be placed. An interesting alternative is Light Field Communication, but this is still in development by, amongst others, Philips. Because the iBeacon technology has shown to be insufficient, the development of alternatives like LFC can only be welcomed.

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8 Definitions Abbreviation In full

AES Advanced Encryption Standard A-GPS Assisted Global Positioning System AOA Angle of Arrival BLE Bluetooth Low Energy BT Bluetooth CRC Cyclic Redundancy Check dBm Decibel-milliwatts DR Dead-reckoning GHz Gigahertz – a billion hertz GPS Global Positioning System HAN Hogeschool van Arnhem en Nijmegen

(HAN University of Applied Sciences) Hz Hertz – the unit of frequency ICA Informatics and Communication Academy IEEE Institute of Electrical and Electronics Engineers IPS Indoor Positioning System IR Infrared led Light Emitting Diode LFC Light Field Communication MHz Megahertz – a million hertz NFC Near Field Communication OS Operating System PT Public Transport PDU Protocol Data Unit RF Radiofrequency RFID Radio Frequency Identification RSSI Receive Signal Strength Indication SHF Super High Frequency TDOA Time Difference of Arrival THz Terahertz – a trillion hertz TU Technical University UHF Ultra High Frequency UUID Universal Unique Identifier UWB Ultra Wide Band VHF Very High Frequency Wi-Fi Wireless Fidelity WLAN Wireless Local Area Network

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Sullivan, J. (2013, november 19). Apps That Know Where You Are: Our Experimentation With Apple’s iBeacon Technology. Retrieved maart 2014, from Nerdery.com: http://blog.nerdery.com/2013/11/nerdery-labs-ibeacon-experiments/

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Beacons

x meters

3m

7m

3m

26m

7m

2m

8m

7m

3m3m

8m

7m

7m

8m

7m

Arch

ief

2m

Arch

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AP 1.

AP 3.

AP 2.

1m

3m

10 Attachments 10.1 Attachment 1.1 – Test environment

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SPWNED - iBeacon Technology

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