29-11-2012, 06:20 PM
Abstract of Sniffer for Detecting Lost Mobiles
Abstract of Sniffer for Detecting Lost Mobiles.doc (Size: 722.5 KB / Downloads: 21)
The sniffer is a small base station, it includes transceiver section. It should operate at a frequency that is much different from the frequency of the current cell in which the operation of detection is being carried out. Some of the main important things are the frequency that has to be generated by the transceiver section is around 900MHz range which is a VHF range and it is necessarily to design the oscillator circuit for that frequency range .Another important is the cooling that has to be provided to the circuit while designing the circuit that is to be operated at 900MHz range of frequency. Hence proper design of base station is an important thing in the design of the sniffer. Mobile phones as well as the base station has low power transmitter is also transmitting at low power. The transmitter of the sniffer has to be a low power transmitter. This helps in the process of reducing the interference of the device with the devices that are in the other cells.
I. INTRODUCTION
One of the most interesting things about cell phone is that it is really a radio an extremely sophisticated radio, which uses some band of frequency that has the basic working similar to the ordinary cordless phone. The mobile cellular communication has been appreciated since its birth in the early 70’s and the advancement in the field of VLSI has helped in designing less power, smaller size but efficient transceiver for the purpose of communication. But however the technology has not yet answered the loss or misplacement of the lost mobile phone which is significantly increasing. In this paper we discuss the problem and the probable solution that could be done. The IMEI number is a unique number that is embedded in the mobile phone the main purpose of which is the blocking of calls that is made by unauthorized person once the mobile is reported as stolen but here we use it effectively for the purpose of detection.
II. ABOUT IMEI
The GSM MoU’s IMEI (International Mobile Equipment Identity) numbering system is a 15 digit unique code that is used to identify the GSM/DCS/PCS phone. When a phone is switched on, this unique IMEI number is transmitted and checked against a data base of black listed or grey listed phones in the network’s EIR (Equipment ID Register). This EIR determines whether the phone can log on to the network to make and receive calls. To know the IMEI number the *#06# has to be pressed, the number will be displayed in the LCD screen;
it is unique to a mobile phone. If the EIR and IMEI number match, the networks can do a number of things.
For example grey list or blacklist a phone:
1. Grey listing will allow the phone to be used,but it can be tracked to see who has it (via the SIM information).
2. Black listing the phone from being used on any network where there is an EIR match.
III. DESIGNING FOR THE SNIFFER
As stated this proposal is about the detection of lost mobile phone and for this purpose we are designing a new device called the Sniffer. 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:
1. Sniffer base station
2 .Unidirectional antenna
3 .Tracking software
3.1 SNIFFER BASE STATION:
The sniffer is a small base station, it includes transceiver section. It should operate at a frequency that is much different from the frequency of the current cell in which the operation of detection is being carried out. Some of the main important things are the frequency that has to be generated by the transceiver section is around 900MHz range which is a VHF range and it is necessarily to design the oscillator circuit for that frequency range .Another important is the cooling that has to be provided to the circuit while designing the circuit that is to be operated at 900MHz range of frequency. Hence proper design of base station is an important thing in the design of the sniffer. Mobile phones as well as the base station has low power transmitter is also transmitting at low power. The transmitter of the sniffer has to be a low power transmitter. This helps in the process of reducing the interference of the device with the devices that are in the other cells.
3.2 DESIGN OF UNIDIRECTIONAL ANTENNA:
Though the transceiver in a sniffer plays an important role in the detection of the mobile phone but however it is the directional antenna that has a major role in the design of the transmitter. The directional antenna acts as the eyes for the sniffer for the purpose of the detecting the lost mobile phones. Hence the proper design of the directional antenna is required. Antenna is a device which works at specified frequencies range for transmitting or receiving the data signal. In general, antennas transmit power depending on lobe pattern which varies from one antenna to the other.