File operations

The file operations necessary for this application are handled in the SaveStore class. The key features are to be able to create a new file and append data from the network data gatherer and the GPS location. Also error prevention and basic file operation assistance such as naming a file with a desired file name is handled here.

This class is directly attached to the AppUi class and can therefore easily be accessed from menu options and such. Although it is not included in the Engine class as proper Symbian C++ coding paradigm would have suggested it is still easily managed.

In order to be able to create a usable file, the data from the network data gatherer and the GPS location module has to be combined. This can prove to be problematic in the sense that both modules have to be able to deliver results to the SaveStore at the same frequency. We would not want to have the same location for two different readings from the network data gatherer unless we are not moving.

It is also necessary to have a correct file format in the output if the RAT PC application is to be able to process the data and analyze it. In our file format we statically add the parameters from 2G and 3G together with a GPS location and a time stamp. The static nature of this solution means that we are going to have empty fields for the columns that are not in use leading to an unnecessary large file size. A dynamic solution is briefly discussed in the future work section 7.3.

4.3. SYSTEM OVERVIEW 25

4.3.6

Graphical User Interface

The graphical user interface plays an important role in the overall user experience. It is the single entity that supplies the end user with information and naturally has to be able to present the relevant data so that it is easy to understand it. The application will utilize many of the standard Symbian S60 visual elements, such as tabs, label texts and menus.

To better accommodate the different types of data from the network data gatherer a set of views will be used. These are incorporated into the tabs so that switching between the views will be as simple as possible. The main view will contain general information about the phone and the primary cell to which the phone is communicating with. In an additional view the neighbor list will be displayed and in a third there will be general application information such as version number etc.

Chapter 5

Results

In this chapter I show the final RAT-UE application and what it is capable of. I will present how the implementation actually turned out. The short comings that were not implementable and the reasons for them not being implemented are discussed.

5.1

The application

The final application that was designed and implemented in the previous chapter is a tool for gathering data about the cellular network to which one is connected. This can be either a GSM or UMTS network and the application can be used either as a standalone device for engineers that is using it when they are out in the field, but it can also be used in conjunction with the RAT PC application for advanced post processing. Depending on the SIM-card used it will show the information for that operator’s network and should the engineer want to acquire information about another network a corresponding SIM-card has to be used.

5.1.1

First screen

Since the application is built for the Symbian S60 operating system it is similar to other such applications. It has a set of tabs for navigation and menus for options. To switch between the tabs the Right or Left button is pressed. The first screen shows the user relevant information about the hand set status and its directly connected neighbor. The application automatically switches between UMTS and GSM operational mode once it detects it. If one technology is preferred this has to be set in the Symbian OS itself, a feature that is not always available. The parameters that are shown on the first view of the application for UMTS are presented in Table 5.1.

For GSM operations the same fields are used and mapped according to the design in section 4.3.3 The corresponding parameters are shown in Table 5.2.

There are also two graphs displayed on the first tab when in UMTS mode. They respectively display recent EcNo and RSCP activity for the last 24 entries and are color coded. The color codes are taken from an arbitrary color gradient ranging from green to red as the values deteriorate. Since the application gathers a new value every second, the graphs show a new value each second as they get

28 CHAPTER 5. RESULTS

Table 5.1: UMTS parameters listed on the first screen.

Label name Parameter

Technology GSM or WCDMA indicator

RSSI Signal Strength on whole frequency scope

MCC Mobile Country Code

MNC Mobile Network Code

LAC Location Area Code

CellID Cell Identificaiton

PSC Primary Scrambling Code

UARFCN UTRA Absolute Radio Frequency Channel Number

EcNo Energy to Chip over Noise ratio

RSCP Received Signal Code Power

Lat Latitude

Long Longitude

Saving Save indicator

Table 5.2: GSM parameters listed on the first screen.

Label name Parameter

Technology GSM or WCDMA indicator

MCC Mobile Country Code

MNC Mobile Network Code

LAC Location Area Code

CellID Cell Identificaiton

BSIC Base Station Identity Code

ARFCN Absolute Radio Frequency Channel Number

RxLev Received Signal Level

Lat Latitude

Long Longitude

Saving Save indicator

updated. When new values are showed old ones are pushed to the side, and once they get past the final position in the graph it will be removed. This allows the user to see the values for the last 24 seconds and it simplifies the process of identification and to assess recent activity or hotspots. These graphs are not available in GSM mode.

The options available from the options menu are accessible with a press on the left options button. There are options for starting and stopping the saving of the data and the option of naming the save file. There is also an option for including a Filemark into the save file which works as a personal note if the user wants to save a note for later referral. The filemark will be saved together with the other data, so the application has to have started to save before it can be used. Other options for the save operations include which drive that is going to be used and information about how much memory is remaining. Through the Graph option menu the user can choose whether to show the graph or not. From the GPS option menu the user can choose to reinitialize the GPS acquisition.

5.1. THE APPLICATION 29 Finally there is an exit option that exits the application. Exiting the application will also stop the saving process so the user does not have to manually stop to save.

5.1.2

Second screen

The second screen shows the neighboring cells. The data is presented in a list and the values are updated every second from the Network Data Gatherer module. This view is particularly interesting for field engineers as it displays the currently active neighboring cell on top and the rest of the cells sorted according to best EcNo value. In UMTS mode, one can see for instance if there is a lot of interference on our primary neighbor coming from other neighbors. The general network information from the first screen is also displayed on this screen. The parameters that are presented on this screen in UMTS mode is presented in Table 5.3. There are no options in the option menu on this screen.

Table 5.3: UMTS parameters listed on the second screen.

Label name Parameter

Technology GSM or WCDMA indicator

RSSI Signal Strength on whole frequency scope

MCC Mobile Country Code

MNC Mobile Network Code

LAC Location Area Code

CellID Cell Identificaiton

UARFCN column UTRA Absolute Radio Frequency Channel Number for every neighbor

SC column Scrambling Code for every neighbor

EcNo column Energy to Chip over Noise for every neighbor RSCP column Received Signal Code Power for every neighbor Cell count Number of observed cells in the vicinity

The GSM mode is again handled similarly with the general network information remaining and the other parameters mapped according to the design in section 4.3.3. Table 5.4 shows the available parameters on the second screen.

5.1.3

Third screen

The third and final screen displays general information about the application. The contents are listed in Table 5.5.

When the application is first started the user is prompted whether to start saving or not. If choosing to do so, the saving of network data and the GPS modules will be started. This can also be started manually later. Since initial GPS acquisition can take some time the user is alerted to this. The user is graphically shown on the first screen whether or not the saving is initiated with a color bar. Similarly a bar indicates whether or not the GPS is in use.

30 CHAPTER 5. RESULTS

Table 5.4: GSM parameters listed on the second screen.

Label name Parameter

Technology GSM or WCDMA indicator

RSSI Signal Strength on whole frequency scope

MCC Mobile Country Code

MNC Mobile Network Code

LAC Location Area Code

CellID Cell Identificaiton

ARFCN column Absolute Radio Frequency Channel Number for every neighbor

BSIC column Base Station Identity Code for every neighbor RxLev column Received Signal Level for every neighbor Cell count Number of observed cells in the vicinity

Table 5.5: Information available on third screen

Label name Meaning

Version Current version number

GPS The status of the GPS module. Indicates either

”Active” or ”Not active”.

No. of Saved Entries Number of saved entries since start of a new file. This will be reset once a new file is started

MemCard Remaining

Remaining memory on the memory card (if present) Phone memory Re-

maining

Remaining memory on the phones internal memory

5.2

Fields of use

There are two primary fields of use for the RAT-UE application. The first one is for field use when an engineer actively analyses the information displayed through Graphical User Interface. The second is for post processing in the RAT application in which case the device does not have to be monitored when gathering data.

5.2.1

Standalone

As a standalone application the RAT-UE allows the user to quickly gain access to information about the cellular network. Depending on the SIM-card used the monitored network can be changed. The engineer can then easily observe the status of the network at the current location. Hotspots can be saved with the use of filemarks so that the interesting spot is not forgotten. The graphs will pedagogically allow even untrained users to assess whether the current signal quality and signal strength is good or bad. For the more advanced users and for the field technicians the cell listing on the second screen will allow the user to detect areas that may need attention and further cell optimization. If during a field test the engineer deems the hotspot to be of interest he can order a more

5.2. FIELDS OF USE 31 extensive cell analysis.

The tool is also useful for assurance of adequacy in locations with ques- tionable quality. This can be done within a company’s own premises or at a customer’s location. By just bringing the RAT-UE enabled device to the questionable location one can promptly see if the quality is adequate or not.

When utilizing RAT-UE in this manner the GPS feature might not be considered to be a fundamental part as the user normally knows where he or she is. But for further analysis with the RAT pc application it is essential.