Integration of Cellular Mobile Networks using gsm

Recently GSM Networks have spread widely because of it vast coverage. Also number of service providers is rapidly increasing. So in this project we basically integrate all running cellular mobile networks with the single GSM modem. The task begins with the user who first selects the network via Keypad and then gets connected with that network within some seconds. The purpose of this project is to use the facility of EASYLOAD from one device rather than keeping different mobile for different networks. The GSM modem is interfaced with Microcontroller ATMEGA16. Another Feature of this project is its battery Backup system, which will keep this device always ON. Moreover, this work has never done in Pakistan. This is one of the best electronics projects and gsm based projects for students in pakistan.

Cellular Mobile Network

Recently GSM Networks have spread widely because of it vast coverage. Also number of service providers is rapidly increasing. Normally a single user uses more than one cellular network. So he/she must have a mobile phone for each cellular network.

Problem of a consumer

As there are number of network increases and user wants to use the service of different cellular companies so he has to use a mobile phone for each network and as a result overburden of mobile phones.

A Solution of a Problem

A need was realized to make a mobile phone which can accommodate the SIMs of the entire cellular network and user can get rid to use each mobile set for each network. This was a positive development and also the need of every consumer who uses more than a single mobile phone.

Integration of Cellular Mobile Networks objective

In our project we integrate the entire GSM networks which are currently available in Pakistan. Basically we are running the entire cellular network by using a single GSM modem i.e. SIM300D. The process is done by switching from one network to another. The worst case scenario of switching from one network to another is 15 seconds.

Technology uses for the Integration

We are using SIM300D GSM modem. This modem is controlled by a controller AVR ATmega16. After giving an input to the controller, the controller interprets the command and sends the desired readable request to the GSM modem. The GSM modem performs the action by transferring the signal to the cellular network which we selected at the star

Integration of Cellular Mobile Networks applications

Instead of making a Simple mobile phone we gave a flavor to our project. We relate our project with the daily life routine. In market easy load service is provided by all the cellular networks. So a shopkeeper must have a mobile set for each network and he may confuse while the using of 4-5 handsets. So we made a product which a shopkeeper takes and get rid form number of sets. This module (includes GSM modem and controller) provides authentication of user’s number on which he/she want to make an easy load and also customer’s satisfaction.

Benefits of Integration of Cellular Mobile Networks

This project has several advantages which give it an edge over existing practice. The main benefit is that it saves the cost of keeping multiple phones as each SIM require separate mobile phone. Similarly wear and tear cost is also reduced because extensive use of keypads results in need of frequent change. As our device has the facility of rechargeable battery so it works for long time even if electricity is not available and this also eliminates the tension of charging several mobile phones.

Working of a module- A

In this Integrated of Cellular Mobile Networks user (a consumer) basically give the input through keypad. This input would may be the selection of network i.e. user want to use. After selecting the appropriate network by the microcontroller the control transfers to the second user (a shopkeeper). The shopkeeper enters the password which is for the authentication. After entering the password control again moves to the first user (a consumer) who enters the amount and then shopkeeper send this string to the GSM modem. The GSM modem then transfers the message to the selected network. Flow is shown in figure below:

Integration of Cellular Mobile Networks flow diagram
Integration of Cellular Mobile Networks flow diagram

The design of Integration of Cellular Mobile Networks consists of three modules each comprising a separate part.

  These modules are:

  • Module A consists of devices which are interfaced with the microcontroller
  • Module B consists of the GSM modem and multiplexing of SIMs
  • Module C is the battery Backup circuit

 Integration of Cellular Mobile Networks Module A

Integration of Cellular Mobile Networks Module A
Integration of Cellular Mobile Networks Module A

Module A consists of 4 different components which are integrated with each other.These components include 4×4 keypad, 16×4 LCD, microcontroller ATMEGA 16 and MAX232.

  • Keypad is interfaced on PORTA of avr microcontroller, utilizing all
  • LCD interfacing with avr microcontrollers on PORTC , PC0-PC3 are used as data bit, PC5 for enable and PC7 is the R/S pin of the LCD, whereas the R/W pin is connected to
  • MAX232 is used for the serial transmission between the Microcontroller and the GSM module. serial comunicaton with microconttoller is performed. The RXD and TXD of the microcontroller are integrated with one channel of MAX232. The purpose of integrating the RXD and TXD with the MAX232 IC is to covert voltage level and to send data serially (bit by bit). MAX232 is further connected to the DB9 connector. The RTS (Ready to send) pin of the DB9 connector needs 12V for transmission, which is arranged from the second channel of the
  • Gsm interfacing with microcontroller is used. PORTB of the microcontroller is used for handling multiple SIMs(shown in module B).By sending ‘1’ on any control signal will ON the respective SIM integrated with the GSM module

 Integration of Cellular Mobile Networks Module B

Integration of Cellular Mobile Networks Module B
Integration of Cellular Mobile Networks Module B

Module B consists of GSM Modem Sim300z and MC14066B (Quad Analog Switch/Quad Multiplexer).

  • The GSM Modem is integrated with the microcontroller with a 4 wire cross cable (RX, TX, RTS, and GND)
  • One GSM Modem is used for multiple SIMs, these SIMs are multiplexed using For each SIM one MC14066B is used. Only two SIMs are multiplexed in the above design, as the others are its replica’s. AT commands are used to communicate between gsm and microconttoller
  • MC14006B has four in/out pins and four control signals for these pins. SIM_VDD, SIM_CLK, SIM_RST are send from the module, in other words are send on the IN pin of the MC14006B, whereas the SIM_DATA is received by the All 4 control signals are handled with one signal sent from PORTB of microcontroller. For example as the control_sim1 is set to high, all four control signal will get high and only SIM1 will communicate with the GSM modem and the other SIM will remain off. How to send sms using gsm module will help you to get clear understanding.

Integration of Cellular Mobile Networks Module C

Integration of Cellular Mobile Networks Module C
Integration of Cellular Mobile Networks Module C

Module C can also be called a Battery Backup circuit. This battery backup circuit consists of a battery (6.2V & 4Amp), LM317 (regulator), capacitors and resisters.The voltage given to this circuit will be 9V from power supply and the remaining modules will get the power from this circuit.The circuitry shown around LM317 is to convert the voltage which is desired. This circuitry is repeated twice. you may check power supply for electronics projects article.

  • Firstly, our input voltage is 9V which is to be converted to 7V for battery. More than 7V can damage the
  • The second circuitry is the convert 6.2V to 5V, as our Module A and Module B are working on The Value of R2 is set with respect to the output voltage. This value is calculated by LM317 calculator.The purpose of capacitors is to filter noise factor.

 Results of Integration of Cellular Mobile Networks

“Integration of cellular mobile networks” is in the preferred working condition, the results are achieved the way they were desired. Finally our device is sharing load (EASY LOAD) on desired networks. This appliance provides all the facilities on single machine that customer and shopkeeper previously enjoyed using different cellular phones. And along with it has a battery backup, which will make the device run for eight hours. The piece of equipment is made while taking all the safety and security measures into consideration. In short the device is safe and easy to use.

 Integration of Cellular Mobile Networks Enhancements

Every project has some deficiencies and their completion is named as enhancements. Similarly our project needs enhancements. The enhancements which can be made in this project are:

  • Using an external memory, e. SD card to store all the transaction in database and can view on computer.
  • Interfacing EPROM, to store all the transaction and delivery reports and can be viewed on the
  • The device can also be used for a service provided by Telenor “EASY PAISA”, by making some changes in
  • The device can also be enhanced for Credit card For security purpose the owner will enter the password before the transaction.

Integration of Cellular Mobile Networks Conclusion

The project “Integration of cellular mobile networks” can be concluded by using the word ‘success’ in integrating all telecommunication networks of Pakistan (Warid, Telenor, Zong, Ufone and Jazz).Integration of cellular mobile networks is a market oriented project. The purpose of this project was to develop a device that could be used by retailer/shop owners who do a side business of EASYLOAD. So instead of keeping different mobiles for different networks, there is a now a device that consisted of all networks.These networks are working through only one GSM modem (SIM300z). SIM300 is a Tri- band GSM/GPRS engine that works on frequencies EGSM 900 MHz, DCS 1800 MHz and PCS1900 MHz. The telecommunication networks working through this modem lie in the 1800MHz range.

The big advantage of SIM300z was that it had specific pins for the SIM .i.e. SIM is externally attached with the modem. So through multiplexing different SIM are attached to the modem but only one SIM is working at the current time. The disadvantage of the Modem is its hot removal deficiency .i.e. the modem cannot change the network in its ON state. The modem needs to get OFF before switching to another network.

Our aim was to give a better product than the existing one, so a battery backup circuit is attached to the device, which will make our device continue to work for eight hours.Security issues are also taken into consideration, the device gets ON on entering the password by the owner, and also the facility to change the password.There were many problems and issues to complete this project, but were solved through hard work, effort and will power.

Note: This project is presented by usman shahzad from comsats university islamabad.

Categories GSM

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