Sniffer for Detecting Lost Mobile Created By:

Contents Introduction What Sniffer is ? IMEI Design Working Advantages Conclusion References

Introduction Each and everyday thousands of mobile get misplaced or lost, through effective way for the blocking of the lost mobile to prevent unauthorized person from making and receiving the calls has been done by the manufacturers of the mobile with the help of International Mobile Equipment Identifier (IMEI) has been done but however there has been no development or very little progress for the detection of the misplaced mobile phone. For the detection of lost mobile SNIFFER plays a vital role.The sniffer device has to be designed precisely and size should be reduced for easy mobility for the purpose of detection.

What Sniffer is ? The device include a mobile Base station that includes Sniffer Base station, Unidirectional antenna, Tracking software. The sniffer is a small base station that includes transceiver section. It should operate at a frequency which is much different from the frequency of the current cell in which the operation of detection is being carried out. The directional antenna is an important device that is to be designed and used as it plays a major role.

IMEI International Mobile Equipment IdentityUnique number embedded in the mobile phone. Used for blocking of call made by unauthorized person Numbering system is a 15 digit unique codeIdentify-GSM/DCS/PCMCheck EIR (Equipment ID Register)

Design The sniffer device has to be designed precisely and size should be reduced for easy mobility for the purpose of detection. The device can be called as a mobile base station that includes the following important components: Sniffer base station Unidirectional antenna Tracking software

Sniffer Base Station Small base stationInclude transceiver sectionOperated at frequency (900mhz which is VHF range)OSCILLATOR circuit-for frequency rangeCooling is Important that has to be provided to the circuitLow power transmitter (help in nature)

Unidirectional Antenna Act as a eyes for the snifferAntenna is a device works at specified frequencyTransmitting & receiving data signalTransmit powerUsed to show radiation pattern

Radio Pattern The Unidirectional Antenna Radio Pattern

Tracking software Feature: help to create database using RAMIMEA - embedded in a chipRAM stores - IMEI no.Act as a database

Tracking software RAM Signal Information IMEI Number I/P Lost Mobile

Working of Sniffers The Working of sniffers is of two phases  Before Sniffer increases the frequency  After Sniffer increases the frequency

Before Sniffer Increases the Frequency

Before Sniffer Increase the Frequency In this a base station is used that works as a middle point of mobile phone and MSC (Mobile Switching centre). There is two way communication between devices. Before the communication establishment, the authentication of SIM card (Using IMEI) and handset (Using EIR) is done. The EIR is located at MSC and it contains the contains the IMEI of the lost mobile.

After Sniffer Increases the Frequency The information from this communication is fed to sniffer device and start to locate the mobile phone. The connection between BTS and device is lost due to EIR request. The lost device search the device to get locked and send the signal which is received by sniffer device and connection between them is established. Now IMEI of lost device is validated with stored IMEI and then connection is established.

Contd.. After that the location is traced. During this process, if another device try to connect with sniffer then the connection is denied. This can’t be done with the GPS because the sniffer can only work with frequency only used with operators. Now the antennas are used to track different positions of the lost device.

After Sniffer Increases the Frequency

Advantages This method is used for finding the lost mobiles effectively Cost effective Low power consumption Easy to design

Conclusion “Sniffer for the detection of lost Mobile phones” paves a way by means of which the lost mobile phones can be recovered. But the process of detection is yet to be developed through the software. There are certain boundary conditions or criteria that have to be qualified for the identification of the lost mobile like the power of the mobile should be good enough, the mobile phone should not be in the shadow region etc., but however this method can be improved by using modern technologies and devices.

References Schiller, “Mobile Communication", Pearson Education 1 Edition, 7th reprint John D Kraus, “Electromagnetics", MH, Jordan et al, “Electromagnetic waves and radiation system”, Prentice Hall