1- Passive Receivers for Cellular Networks

1- Passive Receivers for Cellular Networks

Passive reception systems for digital and analogical cellular networks, expandable, with triangulation functions (physical location of the target, with and error from 2 to 10 meters). These equipments are specific developments for monitoring cellular targets without being detected, because they don´t transmit any signal, they just receive the communications from the air. This feature is the big difference from others equipments that you can find in the market, which design is based on cellular telephones, that receive and transmit, and can be detected as any telephone device.

Available Standards:  

• TDMA
• N-AMPS
• AMPS
• GSM

Analogical and Digital Bandwork:

      GSM

• 800 Mhz
• 900 Mhz
• 1800 Mhz
• 1900 Mhz

The equipments receive one target per cell or one target per channel, depending on the programming and the data´s configuration you wish to obtain. Our systems work with a in-house developed software, totally made in Argentine by Maxx Technology S.A.

Software pictures:

• Channels Configuration Screen
•  TDMA/AMPS/N-AMPS Digital Equipment Screen
• AMPS/TDMA/GSM Multistandard Equipment Screen

Systems have no expansion limits, all equipments can be increased in capacity of target´s monitoring. They can be installed from 1 cell (2 channels) up to 33 cells (66 channels), providing a total range of interception, efective in 100%, depending on the number of channels of each equipment. 

What’s more, they can work in networks, through microwaves radiolinks, which allows the loading of targets and the downloading of the recorded data with no need of another available operator.  This is a very important feature when you have several devices for electronic surveillance and you need a remote monitoring of them. In this way, a 2 cells (4 channels) passive receiver called “Master system” works as control centre, for remote supervision of others smaller devices for cellular surveillance, reception of analogical/digital microphones for fixed phones and environments, etc.-

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2- Localization System of Independent Cellular Telephony. 

Objetive: Learn with relative precision the location of a cell phone with the possibility to intercept the communications that are generated in the same one.

Description: The operation is based on the location of receivers in strategic places of each cellular cell. The receivers, besides having the possibility of decoding the control channel and intercepting the different communications, have additional directional receiver antennas which allows to calculate approximately the position of the cell phone through a joint triangulation.

The data are processed and transmitted to a central unit that is in charge of the joint triangulation and it's the one that has the total control of the system. The user´s interface runs over that central unit. The third element that composes this system is a mobile receiver for the approach to the cell equipment achieving to decrease the error of search.

3- Location and interception system for cellular telephony mobiles at national level.

The system allows to carry out the reception and location of the mobile units from a surveillance center destined for that purpose . The performance is based on the triangulation, in environments of great urban density, by means of the measurement of the channels of control of the businesses suppliers.

Observations: this system will be able to be acquired only by government agencies and its implementation is carried out agreeing to the infrastructure of the suppliers companies whose contribution should be obtained for the contracting government agency.

Basic plan: Each mobile is taken by a Radio Base (normally the most nearby one). Once the radio base´s position is known, the position of the nearby radio bases, the density of distribution and a referenced cartoghaphic map, the information is crossed and processed by an algorithm that aproximately locates the mobile on the map. The following figure shows the process.

A machine connected to the Cellular central downloads the data of cell and channels that the loaded mobiles take. This data is sent through a IP Network to the different visualization interfaces, in which the information is shown in the following way:

 

Main advantages:
1- Profit of Network installed.
2- Location on line.
3- Intercept in direct or in differed.
4- Open to new implementations of software for automation of processes.
5- Very good approximation in zones of high density of Bases Radio.
6- Historic Registration and statistical capacity of prosecution.
7- Additional Possibility of information as incoming and outgoing calls.