Hint on Drive test work

[ayomm86]

Every good RF design, after its implantation should be evaluated. There are few ways to do this, for example through analysis of KPI (Key Performance Indicator) or through prediction tools and signal interference. Other very common and efficient way to evaluate the network is conducting a Drive Test. But what is it? The name is intuitive: take a drive test. The Drive Test is a test performed in cellular networks regardless of technology (GSM, CDMA, UMTS, LTE, etc. ...). Means collecting data on vehicle movement. Its variation has also intutive: Walk Test, ie, collect data by walking areas of interest.The analysis of drive test are fundamental for the work of any professional in the field of IT and Telecom comprising two phases: data collection and data analysis.Although through the analysis of KPI's we can identify problems such as dropped calls, among others, the drive tests allow a deeper analysis in field. Identifying areas of each sector of coverage, interference, evaluation of network changes and various other parameters.Then let's know more about this technique, and know what we can do with it?

[ayomm86]

Drive Test routes are the first step to be set, and indicate where testing will occur. This area is defined based on several factors, mainly related to the purpose of the test.The routes are predefined in the office.A program of a lot of help in this area is Google Earth. A good practice is to trace the route on the same using the easy paths or polygons. The final image can then be brought to the driver. Some software allows the image to be loaded as the software background (geo-referenced). This makes it much easier to direct routes to be followed.It is advisable to check traffic conditions by tracing out the exact pathways through which the driver must pass. It is clear that the movement of vehicles is always subject to unforeseen events, such as congestion, interdicted roads, etc.. Therefore, one should always have on hand - know - alternate routes to be taken on these occasions.Avoid running the same roads multiple times during a Drive Test (use the Pause if needed). A route with several passages in the same way is more difficult to interpret. Drive Test ScheduleAgain depending on the purpose, the test can be performed at different times - day or night. A Drive Test during the day shows the actual condition of the network - especially in relation to loading aspect of it. Moreover, a drive test conducted at night allows you to make, for example, tests on transmitters without affecting most users.Typically takes place nightly Drive Test in activities such System Design, for example with the integration of new sites. And Daytime Drive Test apply to Performance Analysis and also Maintenance.Important: regardless of the time, always check with the responsible area which sites are with alarms or even out of service. Otherwise, your job may be in vain. Types of CallsThe Drive Test is performed according to the need, and the types of test calls are the same that the network supports - calls can be voice, data, video, etc.. Everything depends on the technology (GSM, CDMA, UMTS, etc. ...), and the purpose of the test, as always.A typical Drive Test uses two phones. A mobile performing calls (CALL) for a specific number from time to time, configured in the Collecting Software. And the other, in free or IDLE mode, ie connected, but not on call. With this, we collect specific data in IDLE and CALL modes for the network.The calls test (CALL) can be of two types: long or short duration.Short calls should last the average of a user call - a good reference value is 180 seconds. Serve to check whether the calls are being established and successfully completed (being a good way to also check the network setup time).Long calls serve to verify if the handovers (continuity between the cells) of the network are working, ie calls must not drop.

[ayomm86]

But what is a Drive Test Drive Test, as its name suggests, is the procedure of conducting a driving test. The vehicle does not really matter, you can make up a test drive a motorcycle or bicycle. What matters is the hardware and software used in the test. Basically, to hold a test drive we need a Notebook (1) - or other similar hardware - with a Software Collection (2) installed, a Security Key (3) - Dongle - common to these types of software, at least one Mobile Phone (4), a GPS (5), and a scanner (6) - optional. Also common is the use of adapters and / or hubs to enable proper interconnection of all equipment.
http://www.telecomhall.com/Data/Sites/1/siteimages/blog/008/blog_008_b.JPG Note: some figures shown in this tutorial (as above) are representations of diagrams as a blackboard. Of course we want to do professional illustration, vector with software, etc.. But remember that telecomHall team consists of engineers, and our focus is learning. We believe that the content presented stands the lack of perfection in the diagrams. Anyway, if you have skills with drawing, and would like to contribute, your contact will be very welcome! Contact. The main goal is to collect test data, but they can be viewed / analyzed in real time during testing, allowing a visualization of network performance on the field. The data of all equipment are grouped by collection software and stored in one or more output files (1).
http://www.telecomhall.com/Data/Sites/1/siteimages/blog/008/blog_008_c.JPG

GPS : collecting the data of latitude and longitude for each point / measure data, time, speed, etc.. It is also useful as a guide for implementing the correct routes.
MS : mobile data collection, such as signal strength, best server, etc ... They are typically used two phones. A performing mobile calls (CALL) for a specific number from time to time, configured in the Software Collection. And the other free or IDLE mode, ie connected, but not on call. This is to collect specific data and IDLE modes CALL.
SCANNER : collecting data across the network, since the mobile radio is limited and does not handle all the necessary data for further analysis complete.

The minimum necessary to carry out a test drive, as we shall see, is a mobile device with a collection of software and a GPS. Currently, there are already mobile phones that do it all. They have an internal GPS and a collection of specific software. They are very practical, but are still quite expensive. In addition to providing voice call may be carried out other types of calls such as data, video etc.. Will depend on the technology (GSM, CDMA, UMTS, etc. ...), and the need to analyze such data or not. Anyway, whatever the equipment, software and procedures used, the end result is always the same, the output file. The vast majority of software collection (or processing) do or have together some software which also makes analysis. These are called post-processing software. Each post-processing software has its own specific analysis, and how much data (measures) is huge, they can be of great help to solve specific problems well. Note: It is our goal today we extend a lot about drive test, and we will stick to the generic procedures for plotting to carry out the analysis. If you have any questions, just contact us. Regardless of what the post-processing software, have all the functionality to export data in tabular form, in plain text or CSV. And that's what we use. One advantage of working with the data this way is that no matter how they were collected, but its content. So for example we can, even if a team has run half the route with a type of software, and another team of drive test with another shot the rest, we can plot the data from our network on a single desktop. That's where for example the generic software analyzes geo-referenced, such as Mapinfo and Google Earth. Another advantage is that the analysis available in Mapinfo and Google Earth is generally a better use, since they are more familiar to most professionals, and not specific to those who only performs / looks drive test. This can be understood in not having to acquire multiple software licenses post-processing, one usually sufficient for deeper analysis. Plotting the data in Mapinfo As always, our data are fictitious. Thus, we create a file with random points around our network, like a test drive it, except that you may notice that the streets do not match exactly with the images of Google Earth. The parameters are not even real. In this case, we use two dummy parameters, one containing the signal level collected (we'll call signal_level) and another containing the information sector of the call server at each point (best_server). This file is like the file exported by the team that made the data collection, and call log_exported.txt, located in the C:\Hunter\MI\DriveTest\Data.
http://www.telecomhall.com/Data/Sites/1/siteimages/blog/008/blog_008_d.JPG Sure, we have the files in tabular format. The first step is to open this file in MapInfo. We have seen how to open an Excel file format in MapInfo. We will now open up our data in tab-delimited text format. To do this, go to Menu File -> Open, select Files of type display *. txt (1) and select our archive (2). Click the Open button (3).
http://www.telecomhall.com/Data/Sites/1/siteimages/blog/008/blog_008_e.JPG Our file was exported using tab as delimiter, so the dialog box select this option (1). And the first line has the column headings, then check this option (2). Click the OK button (3).
http://www.telecomhall.com/Data/Sites/1/siteimages/blog/008/blog_008_f.JPG With the file open, the next step is to create points for himself, and create a new map with the data. Also as seen previously in another tutorial how to do this, and the result is seen below.
http://www.telecomhall.com/Data/Sites/1/siteimages/blog/008/blog_008_g.JPG Note: soon, Hunter Drive Test Mapinfo tutorial we will see how these and other tests on an automated (scripted MBX). We suggest that you open (and leave open) the window while you are doing manually Mapbasic commands Mapinfo. This is because you can get more familiar with the syntax of the scripts that will receive Mapbasic Note that the map with the data just opened in Mapinfo not bring us any interesting information (even if for example we can verify the extent of each section by clicking on it). We need to create thematic maps, according to each parameter measured. A thematic map is a map with symbols and colors specific to pre-defined values of each parameter in each point. For instance, we color all points of the map that have the information signal level greater than -65 dBm with the color green. So, visually we have the area (green) where the signal is very strong. This is the case of Thematic Map using Ranges. (The unit dBm refers to signal intensity, and we'll talk in detail later). We can also color in a new thematic map information from the best server for each point using a single color for each server, and so we see the coverage area of each sector. To do this we create a Thematic Map-based Points - Individual. Ranges of Thematic Map First, we view the signal strength of geographically distributed in the area where we performed the test drive. For this, we will create a Thematic Map by Ranges. The creation of thematic maps is one of the most important commands of MapInfo, which enables a huge amount of changes. Today we use the standard symbols suggested for each type of information present in the data table. Later we will see settings that give a better presentation of data. Access Menu: Map (1) -> Create Thematic Map ... (2). Or press F9.
http://www.telecomhall.com/Data/Sites/1/siteimages/blog/008/blog_008_h.JPG In the new window that will appear, select the type Ranges (1) and choose a type of range, for example Red, Orange, Light Green, Green (2). Click the Next button (3).
http://www.telecomhall.com/Data/Sites/1/siteimages/blog/008/blog_008_i.JPG In the next window, select the table and field that will create the thematic map. In this case, choose Table log_exported (1) and field signal_level (2). Click the Next button (3).
http://www.telecomhall.com/Data/Sites/1/siteimages/blog/008/blog_008_j.JPG In the next window we have a few options that can and will be used later. You can see some of these options by clicking the appropriate button. Below is the window that opens when clicking the button Ranges ... allowing for example change the number of ranges and methods. Click the Cancel button (1).
http://www.telecomhall.com/Data/Sites/1/siteimages/blog/008/blog_008_k.JPG At the moment, as we are learning how to plot the data thematic ranges, so we'll just accept the standards proposed by Mapinfo and click the OK button (1).
http://www.telecomhall.com/Data/Sites/1/siteimages/blog/008/blog_008_l.JPG The result is a thematic map plotted.
http://www.telecomhall.com/Data/Sites/1/siteimages/blog/008/blog_008_m.JPG


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