Comparison of Developer Tools for Indoor Positioning. Gecko v1.0.1 and Ekahau Site Survey v4.6

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1 Comparison of Developer Tools for Indoor Positioning Gecko v1.0.1 and Ekahau Site Survey v4.6 Report prepared by Mikael Larsson & Henrik Hedlund Qubulus AB 1 24/01/2011

2 Abstract The purpose of the comparison was to evaluate and compare the behaviours of the Ekahau Site Survey tool from Ekahau (ESS v4.6) and the Gecko developer tool from Qubulus (Gecko v1.0.1.) Wi Fi measurement capability, measurement visualization and live positioning were the main criteria examined. To get the most accurate and comprehensive results, measurements were taken in tests performed at three different reference locations. Disclaimer The content and findings expressed in this document are based on live tests performed by Henrik Hedlund and Mikael Larsson at three different reference locations, during four days in December Both Henrik Hedlund and Mikael Larsson represent Qubulus AB, from where the Gecko tool originates. The content of this document does not have the intention of presenting Gecko in an incorrectly favorable way, but instead to evaluate and present the Ekahau and Gecko tools as separate entities in an objective study. Henrik Hedlund, Mikael Larsson, Qubulus AB 2 24/01/2011

3 Table of Contents 1. Purpose & Scope of Comparison 2. Comparison 2.1 General 2.2 Measurement Methods 2.3 Measurement Presentation 2.4 Positioning 3. Summary Qubulus AB 3 24/01/2011

4 1. Purpose & Scope of Comparison The purpose of the comparison was to evaluate and compare the behaviours of the Ekahau Site Survey tool from Ekahau (called ESS v4.6) and the Gecko developer tool from Qubulus (called Gecko v1.0.1). The ESS v4.6 is part of a tool suite from Ekahau that also includes tools such as Ekahau Positioning Engine (EPE), Ekahau Vision and Ekahau Activator. Both solutions provide possibilities for enabling accurate indoor positioning. Additionally, both solutions provide capabilities of performing radio signal measurements that give information about the behaviour of the local radio access environments. Gecko v1.0.1 has the capability to handle multiple radio access technologies as opposed to ESS v4.6. To get the most accurate and comprehensive results, measurements were taken and tests performed at three different reference locations. These reference locations are major shopping malls located in Malmö, Sweden and a customer pilot site in the Netherlands. In total, several hundred square meters were surveyed. The evaluation spanned over in total four days in December The tested configurations were: Ekahau Site Survey tool v4.6 (ESS v4.6) installed on HP ProBook laptop (Windows 7) Gecko tool v1.0.1 (Gecko v1.0.1) installed on HTC Desire (Android 2.1) 2. Comparison 2.1 General The ESS v4.6 is PC based software while the Gecko v1.0.1 runs on Android smart phones. Due to this, it is not very meaningful to compare the installation procedures, but it can be mentioned that they both ran smoothly. Once properly installed, both tools were easy to use and the map display management with zooming functionality worked well. Due to its more comprehensive feature set, the ESS v4.6 took a few more moments to get started with but was convenient to use once the basic features were found. The Gecko v1.0.1 has a recording mode and a localization mode, where the latter one only can be accessed after having recorded data and so called fingerprints are created. The ESS v4.6 has a similar setup, where positioning only can be done after having recorded two surveys, i e a calibration survey and a test survey. Both tools require the input of a valid map. The Gecko v1.0.1 automatically calculates the scale of the map, while the scale information has to be manually entered into the ESS v4.6. The help sections are supportive and available as PDF documents for both tools. In addition, the Gecko v1.0.1 comes with a few demonstrative videos. Qubulus AB 4 24/01/2011

5 A notable difference between the tools is that the features of the Gecko v1.0.1 is focused on positioning functionality, whereas the ESS v4.6 is more focused on survey functionality, with a positioning (tracking) feature included in the tool. Gecko v1.0.1 ESS v4.6 Comment Device Smart Phone PC Installation & basic Easy Medium Easy, Medium, Hard usage Map scale Auto* Manual * Map NW & SE GPS coordinates required Help section PDF + Videos PDF 2.2 Measurement Methods Both tools measure the number of radio sources (access points, etc) and their signal strengths for different locations. Recordings with the Gecko v1.0.1 are made every 5 th square meter for the area surveyed. The recording for each position takes approximately one minute. To collect radio access data and get the most detailed information with the ESS v4.6, it is necessary to walk around the location with the laptop in two separate sequences, with continuous measurements of signal strengths. The first sequence is a calibration survey and the second is a test survey. Both of surveys are needed to get proper data measurement visualizations, one is needed to perform basic positioning. Considering the device weight and the preparation time needed, collecting data is a more convenient but a somewhat slower process with the mobile Gecko tool, compared with the PCbased Ekahau tool. Gecko v1.0.1 ESS v4.6 Comment Device weight ~150g ~3kg Data collection time* ~120 min ~40 min (2x20min) Example location of 1000m 2 Qubulus AB 5 24/01/2011

6 Example of recording mode in the Gecko tool (v1.0.1). 2.3 Measurement Presentation In the ESS v4.6 the results of the site survey is displayed in a number of colourful map images, displaying the level of signal strength etc. The image maps are nicely presented in gradients of green (Excellent), yellow (Good) and red (Bad). The presented data, e.g. calibration quality and location accuracy, is not always useful for analysis outside the ESS v4.6 tool. The location accuracy gives information valid for positioning with the Ekahau tool only, since other positioning tools likely have implemented different positioning methods and algorithms. The signal strength visualization can be meaningful and gives guidance on where to install additional Wi Fi access points to improve coverage of a certain location. Additionally, in the ESS v4.6, the AP list measurements can be exported as an XML file and the measurement visualizations can be exported as image files in various formats. The Gecko tool can export the collected data to a text file that is stored on the memory card, but does not present the data in any other way. Instead, the data collector will need to contact Qubulus for a detailed analysis of the data. Gecko v1.0.1 ESS v4.6 Comment Export collected data YES, Text file NO Export AP NO YES, XML file measurement list Export of data visualizations N/A YES, image file* PNG, JPEG, GIF and BMP Visual presentation of collected data in tool NO YES Qubulus AB 6 24/01/2011

7 Example of visualizations from the ESS v4.6. Location coverage (left) and signal strength (right). 2.4 Positioning Once data has been collected, positioning can take place. The Gecko v1.01 and the ESS v.4.6 use the same radio access metrics (RSSI values from different radio access technologies) but different positioning algorithms to retrieve location estimates. The ESS v4.6 has a tracking/positioning feature in the site survey tool that allow for tracking of specific objects. There are many aspects on how to assess the quality and accuracy of the positioning. In this comparison, only one aspect has been examined, namely perceived positioning accuracy. The perceived positioning accuracy was based on ocular estimates at different spots in the three reference locations, covering hallways, corridors, open spaces and areas with both strong and weak Wi Fi coverage and signal strengths. The accuracy estimation was based on knowledge of distances between walls and other reference lengths, determined from physical measurements and from the scale in the indoor map. The ESS v4.6 feature rails were used in hallways and corridors, which narrowed down the possible positioning locations in those areas. Additionally, the ESS v4.6 open space feature was used for relevant locations. The testers experiences were that the rails functionality worked well, and supported the positioning accuracy more than it limited the user experience. That is, given that the rails are drawn properly. In the simple but time efficient map preparation procedure for the Gecko tool, there is no possibility to draw rails, open spaces etc. The perceived positioning accuracy ranged 3 15 meters for the ESS v4.6 and 3 10 meters for the Gecko v1.0.1, based on a number of measured spots at the three reference locations. At occasions, both tools presented very high accuracy of 0 1m. The Gecko v1.0.1 generally performed better in open spaces and in spots with poor Wi Fi coverage, whereas the ESS v4.6 (with help from the rails) performed better in hallways and corridors. Qubulus AB 7 24/01/2011

8 A good performance of Gecko v1.0.1 at poor Wi Fi coverage is secured by a unique processing of radio signals available at the reference locations. Gecko v1.0.1 ESS v4.6 Comment Perceived positioning accuracy 3 10m 3 15m Three reference locations Hallways, Corridors Medium accuracy (5 10 m) High accuracy (0 5 m) * * At occasions 0 1 m accuracy Open spaces High accuracy (0 5 m) * Medium accuracy (5 10 m) * At occasions 0 1 m accuracy Weak Wi Fi spots Medium accuracy (5 10 m) Low accuracy (10 15 m) Area definition functionality NO YES Possibility to define rails, open spaces etc 3. Summary The tools differ in a large number of aspects, which makes it difficult to distinguish the Gecko v1.0.1 and the ESS v4.6 based on any performance measures. The ESS v4.6 tool provides some useful features for site surveys, presenting the data in a nice and clear way. If you are a network technician that needs to get details and measurements of your network, ESS v4.6 is the most convenient tool out of these two. The drawback of the Ekahau tool is that it is not so easy to get started with and the positioning feature set is limited. The Gecko v1.0.1 tool is very easy to get started with, provides accurate positioning and a number of useful positioning features. On the other hand, it lacks the visualization of collected data. The benefits of having the capability to use different radio access technologies together with the fact that the Gecko tool is available for free, are key advantages of the Gecko v1.0.1 in this comparison. The perceived positioning accuracy gives comparable measures for the two tools within a range of 3 15 m for the ESS v4.6 and of 3 10 m for the Gecko v The ESS v4.6 tool performed better in hallways and corridors and the Gecko v1.0.1 tool performed better in open spaces and in areas with poor Wi Fi coverage. Qubulus AB 8 24/01/2011