Purdue university graduate school

Party on IT Crime, 2006). 
With all the potential evidence available on mobile phones it is no surprise how 
much importance is placed on isolating mobile phones in order to preserve the evidence 
found on them. However, all the proper intentions and efforts are for naught if the 
devices being relied upon have unknown failures that might allow the evidence to be 
changed. It is for this reason that the tools must be tested and validated. 
1.3 Statement of Purpose 
There are a myriad of conditions in which shielding devices can be used that will 
cause them to fail. For this research the devices will be used appropriately and vendor 
instructions will be followed when applicable. This research tested several of the 
shielding devices that are currently available to investigators for use with mobile phones. 
The experiment determined if distance from a tower, the type of information being 
transmitted, and the network being used effect the isolation capabilities of the shielding 
devices. The success or failure of the shield to isolate the phone was recorded. This will 
allow users of the devices to know where they can expect faults to occur. For researchers 
and manufacturers the results will also provide insight into where and how improvements 
can be made into RF shielding tools. 
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1.4 Definitions 
BlackBerry Enterprise Server (BES): A software administration suite from RIM that 
allows an administrator to manage multiple phones
Code Division Multiple Access (CDMA): A method for dividing bandwidth into 
segments in order to allow multiple signals to be broadcast on a carrier channel. 
Sprint and Verizon are the largest NSPs in the U.S. that utilizes CDMA. 
Decibel (dB): A dimensionless ratio unit used to measure the signal strength in mobile 
phones from a predetermined reference point. 
Exchangeable Image File Format (EXIF): metadata embedded in a photograph when the 
picture is taken that contains information that can be used to distinguish when, 
where, and what took the picture. 
Faraday Cage: An enclosure developed by scientist Michael Faraday that can be used to 
spread incoming electrical signals out over its outer shell while signals that 
originate from the inside are spread across the interior. This in effect electrically 
isolates any device inside it from the outside world. 
Global Positioning System (GPS): A series of computers and satellites designed to 
determine the latitude and longitude of a receiver on Earth. 
Global System for Mobile Communications (GSM): Standard for mobile telephone 
systems. It originated in Europe and is the most common standard worldwide for 
mobile phones. GSM makes use of SIM cards to identify devices on the network. 
AT&T and T-Mobile are the largest NSP providers in the U.S. that operates with 
GSM. 
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Isolation: Normally meaning a device is unable to recieve any source of radio 
communication. When used in this paper it means that a mobile phone has been 
placed in a shielding device that attenuates RF signal enough to prevent any 
meaningful communication on the network. 
Location Area Information (LAI): A list generated by some mobile phones to store 
recently used towers in order to increase communication efficiency 
Location Information (LOCI): Unique codes that identify which tower a mobile phone 
was last using. This information is updated as the phone communicates with new 
towers. 
Multimedia Message Service (MMS): A standard way to transmit messages that include 
multimedia content to and from mobile phones