Macao Polytechnic InstituteSchool of Public Administration Computer Studies Program

MCCS 391 Graduation Project I

GSM Cell Location

Supervised by:

Philip Lei P-02-0377-2 P-02-0412-2

Group Members: Roy Lei Ricky Tam

Date: 29-Jun-2005

Table of Content1. Abstract -----------------------------------------------------------------------2 2. Introduction ------------------------------------------------------------------3 2.1 Project Equipment------------------------------------------------------3 2.2 Cell ID location VS existing location software---------------------3 3. Cell ID background----------------------------------------------------------4 3.1 What is Cell ID ---------------------------------------------------------4 3.2 Cell IDs contents ------------------------------------------------------5 3.3 Cell IDs theory---------------------------------------------------------5 3.4 Cell selection and reselection -----------------------------------------6 3.5 Obtain Cell ID ----------------------------------------------------------7 3.6 Cell ID analysis---------------------------------------------------------8 4. Application Development --------------------------------------------------9 4.1 Design algorithm of using Cell ID -----------------------------------9 4.2 Solution------------------------------------------------------------------9 5. Future works --------------------------------------------------------------- 10 5.1 More user friendly---------------------------------------------------- 10 5.2 Functional Application ---------------------------------------------- 10 5.3 Other application ----------------------------------------------------- 10 6. Conclusions ---------------------------------------------------------------- 11 7. Job distribution------------------------------------------------------------- 11 8. Installation guide --------------------------------------------------------- 12 8.1 Download SDK for Python ----------------------------------------- 12 8.2 Installing Python for Series 60 ------------------------------------- 12 8.3 Installing on a Series 60 Mobile Device ---------------------- 12-13 8.4 Running GSMCellLocation.py ------------------------------------- 13 8.4.1 Applications flow chart --------------------------------------- 13 8.4.2 Start Program ----------------------------------------------- 14-16

AppendixGSMCellLocation source code ----------------------------------------- 17-18

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1. AbstractNowadays, mobile phone becomes more and more common, wireless network becomes mature, there are many researchers have already figured out different kinds of issues for location services, including positioning methods and location information exchange protocols. Although there are many methods can provide a accuracy information for location, but they often require extra cost to existing network, special hardware and telecom company support (e.g. GPS, A-GPS), Ordinary mobile handset or PDA cannot enjoy the location services. But we find that we have another method to provide simple location information through GSM signal. We will simply introduce our development tools; next step is compare with other location software. The following will introduce Cell ID, its background, theory, how to obtain Cell ID and implement it, cell reselection and the development a location software try to show user location. This project aims to adopt simple GSM cell information positioning method which can be applied into ordinary Symbian mobile phones without extra cost and hardware upgrade, but lack of accuracy of area GSM cell ID positioning will still be a great problem.

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2. Introduction2.1 Project EquipmentCell ID based mobile positioning systems are the most cost effective way to locate mobile stations and are very easy to implement in existing mobile networks and handsets. However, cost effective solutions based on Cell ID lack accuracy compared to other location technologies that are available; therefore, other more expensive technologies were selected for accuracy sensitive applications. Besides general PCs, this project involves a Symbian mobile phone, Python for series 60 development tools, and we are using Nokia 7610 which is equipped with Symbian OS 7.0. (Python for series 60 Platform required Symbian OS at least 6.0 or above), besides normal telephone functions, it consists of Bluetooth connectivity and it can browsing a text file which with a specific photo, it is because our project will through Bluetooth to transmit program coding and using browser to display some photo.

2.2 Cell ID location VS existing location softwareThe following is cell ID compare with different kind of location software result: Technology Cell ID TDOA EOTD GPS/A-GPS Networks All All GSM All Handset change None None Yes Yes Accuracy Depends on the size of the cell 100m 3km 100-200m 50-200m 5-30m

TDOA (Time Difference of Arrival); EOTD (Enhanced Observed Time Difference); GPS (Global Positioning System); AGPS (assisted GPS);

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3. Cell ID background3.1 What is Cell ID?GSM signal includes a lot of contents; Cell ID is one kind of them from Base Transceiver Station (BTS) signal. It is used to verify that Mobile phone is connected with BTS or not, BTS is set up at the top of building, a different telecom company has different BTS, on this project we choice CTMs BTS to implement the experiment because it has built up many BTS in Macao.

Fig 1: a simple BTS model

* BTS: Base Transceiver Station * MS: Mobile system

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3.2 Cell IDs contentsFor each telecom company, they have a same MCC (Mobile Country Code), but each telecom company has a set of unique no for each BTS, it is MNC (Mobile Network Code), lac (Location Area Code), and cellid (Cell ID).

Area: Y Lac: [1] Cell ID: [210]

Area: X Lac: [1] Cell ID: [1085]

Area: Z Lac: [1] Cell ID: [128]

Fig 2: A BTS signal contents

3.3 Cell IDs theory

Telecom Company signal

Fig 3: Mobile Phone connecting with a BTS

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3.4 Cell selection and reselectionA mobile phone must periodically measure the strength of the signals emitted from the base stations nearby. Base on the measurement a mobile phone select a cell which gives the best reception. After connected to a cell, accessing a service become possible. However, when the mobile phone moves along a path, the strength of signal received from the base station that it is connected to may drops, which may due to several reasons like it is moving away from that base station or there is some environmental factor that distort the reception. In this case, a mobile phone must reselect another cell which gives a better strength of signal. This process is called the cell reselection. Cell reselection is very common, when we travel around some place we usually experience quite a number of cell reselection event, since cell are of limited size. When we reach the edge of a cell, a mobile phone will reselect another cell that gives a better reception in order to guarantee the quality of service provided to a user. When a cell reselection event occurs, the mobile phone will transit from one cell to another cell, thus receiving signal from another cell which is of different lac and cellid.

Fig 4: Cell selection and reselection

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3.5 Obtain Cell IDReclaimed Land Zone() (Fig 5) is our testing area, we go through all bus stop round there, for each bus stop, we use at least 5 minutes to take sample.

Fig 5: Sample area

Method A

Method BFig 6: Getting Cell ID method

Method C

Method A : Stand in a place, dont move mobile. Method B : Around a building one time. Method C : Move mobile from area A to Area B.

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3.6 Cell ID analysisIn order to obtain the position of Cell ID, so we develop a software named CellFinder help us to chase the position of Cell ID. After several days collect process, some result is as follows: IPM Kingsway Hotel Centro A. A. Turisticas New Yaohan Centro Cultural Hotel Lisboa [ 35, 128, 1085 ] [ 35, 128 ] [ 35, 1084, 1085 ] [ 30, 156, 1608, 1609 ] [ 209, 210, 215, 292, 1401 ] [ 20, 70, 134, 1067, 1106 ]

We find that in same place we can collect one or more Cell ID, and the same Cell ID will appear in different places, finally we found that the it signal broadcast like the below:

Cell 35

Cell 128 Cell 1084

Cell 30

Cell 1085

Area: IPM Lac: [1] Cell ID: [35,128,1085]

Fig 7: mobile phone getting cell ID

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4. Application Development4.1 Design algorithm of using Cell IDDuring the process of designing algorithm, do not support chinese system is our first problem, and cant open database with general software which created by Python is second, so we can not be direct enter data into database, even if input the data reluctantly, we can't also open the database and look over whether the content is correct.

data

? ?

4.2 SolutionDuring the developing, we find that Symbian OS and Python Series 60 support text file, and it can call a HTML file to display (HTMLs content can be chinese or photo), so we decide to develop the database toward this way.After testing, we decide to give up using database which created by Python, and substituted by text file, and this solution also obtain affirmation finally. Finally we have built up a Application which is called GSM Cell Location. Its major function is tracking Cell ID which broadcast from BTS and display scency nearby the mobile holder.

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5. Future worksWe would consider more about the development of Cell ID on this project in the next semester or in the future.

5.1 More users friendlyWe would try to load a map in background on mobile screen, after tracking; it will point out users position in flashing. Besides that we would add more useful information (e.g. restaurant, theatre, public place of entertainment, etc;).

5.2 Functional ApplicationGSM Cell Location can be developed into a kind of control and monitor software e.g. The localization of motorcades, such as the bus, taxi, lorry etc; to monitor its position.

5.3 Other applicationAs it is found that GSM cell change method perform well in one-dimensional path. It is possible to apply the same method on path-based scenarios, including bus route or tram route(for future). The challenge is that all surroundings are open area, where performance would be slightly degraded. If the requirement is modified a little bit into just notifying the tourists that they enter a new district, say Reclaimed Land Zone()or Praia Grande(), and showing them with different information that is interested by tourists, the offered service can be more reliable than bus stop or tram stop positioning.

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6. Conclusions6.1 After discussion, we find that Cell ID is not very suitable for smaller area, because the BTS range may be very far (from 15 m to 20 km ), so it is suit for a large area and low level request of accuracy. 6.2 Because of Cell ID must be granted by BTS, so only suitable for the area which covering with GSM signal. When you in plain , virgin forests and ocean etc, your mobile cant received any signal, so it can't use, this point is weaker than GPS. 6.3 Because there may be many of telecom company in a same place, so a telecom company s Cell ID data can not be use for another companys user, programmer should be set up many sets of database of Cell ID for using. 6.4 Although Cell IDs accuracy does not high, but it dont need to develop , free, and can be used on general handset, it feasibility is still worth studying. 6.5 If we know the distribution of the BTS, locating will be more accuracy.

7. Job distributionPython is a kind of new language for us, and using Cell ID to show position is a new technology, so to the development of the whole application, we have done a lot of research, data's collection, discuss and analyze Cell ID together, analyze the feasibility of argument and summarize the result that is received, so unable to separate each person's work clearly, so the following work is distributed only for referential, This is because the purpose of this project's is greater than coding, so we use more time as analysis. Ricky Tam Responsible for the collection of the data in earlier stage, analyze GSM signal and Cell ID operation principle, function CellFinder, handle_browser(), handle_browser_select() and html file was design by him Roy Lei Responsible for analysis and feasibility of designing program, analyze the application of Cell ID. Develop GSM Cell Location.py

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8. Installation guide8.1 Download SDK for PythonFirst you have to go here http://www.python.org/ to download a Python SDK installer. When you download the SDK from the Internet, note that you must choose a Nokia, Borland, or Microsoft edition of Series 60 SDK for Symbian OS 6.0 or above. The current release does not support CodeWarrior editions.

8.2 Installing Python for Series 60This is for preparing the environment to run Python for Series 60 and the installation of the Python execution environment. To ensure which Python for Series 60 package to install, see Table 1. Phone model Nokia 6600 Nokia 6630 Nokia 7610 Nokia N-Gage QD Python for Series 60 package PythonForSeries60.SIS PythonForSeries60_pre_sdk_20.SIS

8.3 Installing on a Series 60 Mobile DeviceClose all applications in your device before you start the installation. After installation, an application called Python, which launches the Python execution environment, is visible in the phones (or an emulators) main menu. There are two ways of installing the Python for Series 60 files on a Series 60 device: Nokia PC Suite software, see http://www.nokia.com/ Web site for more information. Infrared or Bluetooth If you use Nokia PC Suite and have associated files of SIS type with the PC Suite application, click the PythonForSeries60.SIS. or PythonForSeries60_pre_sdk_20.SIS. The execution environment is installed automatically (you may have to confirm the file transfer from the phone). You can also install Python for Series 60 directly from a PC using the

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Infrared port or Bluetooth. To install Python for Series 60: 1. Establish an Infrared or a Bluetooth connection between your PC and your phone. For more information, see the appropriate Infrared or Bluetooth documentation in your phone manual. 2. Right-click PythonForSeries60.SIS or PythonForSeries60_pre_sdk_20.SIS according to the model of your phone, and send the file to your phone. 3. Select whether Python for Series 60 should be installed on the Phone memory or Memory card. A progress bar indicates the status of the installation. The Installation complete pop-up note indicates that the package has been installed on the phone and that the Python icon is available on the main menu. 4. Send the GSMCellLocation.py through Bluetooth or SMS to your mobile phone and then save it.

8.4 Running GSMCellLocation.pySelect the Python icon to start Python. Select Options > Run script to run GSMCellLocationi.py on your phone.

8.4.1 Applications flow chart

Fig 8: Flow Chart

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8.4.2 Start Program1) After running this software, you will see a welcome screen. When you press Option > Start Tracking, you will see the below screen.

2) Press Start Tracking, software will getting Cell ID automatically, if obtain Cell ID and it has record in our Database, you can see the below screen.

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3) At this moment Press Option > Stop Tracking, to terminate searching Cell ID, and then press Option > Browser

4) When you press Browser, it will show a places name to inform you that where you are.

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5) After choice a places name, mobile screen will show information as below:

6) If there is no GSM signal or Cell ID not in database, it will show as below:

,

~~ The End ~~

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