Percepción de amenazas climáticas y de la cadena de valor

Like with all other R&S ViCom APIs, a demo application is packaged with the GSM measurements. The interface is similar to the other demo applications. To start the application double click the

C:\RuS\ViCom_<version>\bin\SampleForViComGSM.exe file in the bin folder. Refer to Sample Application.

The application window is a dialog that is organized in columns.

The left-most column is similar to the one from other demo applications. It contains the control center in which buttons are provided that relate to the methods in the

CViComGsmInterface class (and their base interface). The order of the buttons implies the logical order in which they should be executed.

The middle column provides fields for setting the measurement and technology specific properties. In the frequency list, the channels that shall be measured must be speci- fied. This is the only setting that must be done before starting the measurement. For each frequency, the automatic demodulation of SI messages can be specified upfront, as well as the frequency index (which must be ascending, starting by 0 and unique). The right column contains a mixture of functions, like settings management, basic set- tings and result evaluation (i.e. showing the results which are written into a text-file in an editor).

Figure 7-11: R&S ViCom GSM technology demo application

● Basic Channel Configuration...95 ● Specifying Measurement Details...96 ● Requesting System Information Type...98

7.2.1 Basic Channel Configuration

The first step when using the application is to define the list of frequencies that shall be scanned. Therefore, the following steps must be done:

● Load the R&S TSM Instrument (click "Load GSM NWS"). Set the initial values for Time Base, Result Buffer and Measurement Rate by clicking the related buttons. This is not really necessary when the application is started for the first time or the value has not been changed, but once a setting has been modified it is required to update the parameters in the R&S TSM instrument.

● Put the list of frequencies into the list in the middle column. You don’t have to enter the auto-demodulation settings and frequency index; they are added automatically with default values. A line in the edit control contains up to three elements, each separated by a white space:

– Channel center frequency in MHz (decimals follow a period)

– Auto-Demodulation settings for System Information messages. You must spec- ify which shall be enabled by entering the numbers in one block. For example, if the SI Type 1 and 4 shall be decoded, enter 14.

– Frequency index to be used later in the result. This is not mandatory and will be filled automatically when you enter the frequencies.

You can enter new lines by clicking <Ctrl>+<Enter> when the focus is in the list control.

● Click the "Set Frequencies" button to transfer the settings to the R&S TSM Instru- ment.

● Optionally, a more detailed setup of the measurement can be made. Therefore, click the "Setup measurement details for start of measurement" button below the frequency list. See the section below for a more detailed discussion. By default, only SCH measurements are enabled.

● To start the measurement, click "Start Measurement"

● To fetch some results, check the number of result available and transfer some of them to the PC (using the "Get Result Counter" and "Get Results" buttons).

7.2.2 Specifying Measurement Details

Most of the settings necessary to define the different measurement tasks which have been explained in the previous chapter must be setup in a special dialog that is shown in Measurement details dialog. The same dialog is used to initialize the measurement details before a measurement is started and when the measurement configuration is changing while the R&S TSM Instruments are active. Slight differences concerning the buttons at the bottom of the dialog can be seen when comparing the dialogs, but the major part of the dialog is consistent.

To show the dialog, click "Setup measurement details for start of measurement" before you click the "Start Measurement" button. Once the measurement is active, the button "Redefine measurement details during measurement" can be used.

The configuration should be straightforward after the previous chapter has been read. The input fields reflect the fields in the C-structures for many parts of the

SMeasurementDetails. Besides the settings for the spectrum and channel power measurement modes, the dialog also provides a way to enable and disable the mea- surement tasks.

One important aspect is that the configuration can be applied to a different scope of channels. It’s possible to modify the details for a single channel, for all channels or to

settings. The behaviour can be defined in the lower part using the different radio but- tons.

Figure 7-12: Measurement details dialog

Even a subset of the measurement frequencies can be configured. Click the "Press button for individual setup" button that appears, if the radio button "Individual setup for a list of frequencies" is active. In the upcoming dialog, the active measurement tasks can easily be defined per each configured frequency.

The spectrum and channel power measurement settings cannot be defined on a per- channel basis, as the dialog illustrates. Both configurations are valid for all channels that perform that measurement tasks. Each modification always concerns all active measurements.

Figure 7-13: Measurement mode specification

7.2.3 Requesting System Information Type

Once a measurement has been started, you can request the System Information type 1 to 4 for a specific BTS. Therefore, the lower part of the main dialog offers the appro- priate controls.

Before such a request is sent, it is required that the SCH has been demodulated suc- cessfully. This is due to the fact that the SCH contains information required to syn- chronise and demodulate the BCCH (namely the BSIC).

For each message type, a user-managed request id can be specified. This helps iden- tifying to which request a result belongs. The dialog also allows setting a timeout, after which the demodulation request is stopped. A currently active demodulation request can also be cancelled again. The related checkbox has to be selected when the request is sent.

Figure 7-14: System Info type demodulation request

For all requests the channel (identified by its center frequency index), the indicator of the SCH Info (taken from the SCH demodulation result) and the BTSs BSIC have to be given to the network scanner.