Short-Range Detection of Radio Transceivers for Physical Security

Identification and Significance of the Problem In the last 20 years, the use of personal, wireless communications devices by society has exploded. Nearly every adult (and many children) in developed and developing countries carries at least one communications device usually in the form of a mobile phone. In addition to mobile phones, a host of other wireless technologies such as Bluetooth, FRS/GMRS radios, and Wi-Fi have widespread deployment such that the world population has multiple paths to achieving a nearly constant wireless connection for voice and data traffic. Besides the ability to provide voice and data connectivity, many mobile phones have digital camera functions. This universal connectivity and photographic capability poses a significant challenge to the task of providing both information and physical security within sensitive facilities. At risk facilities include military installations, prisons, national intelligence centers, government and corporate research facilities, and places where confidential business meetings occur. Whether intentional or unintentional, malicious or benign in nature, the act of personnel bringing wireless devices into a secure area represents a potential breach of security. Depending on the facility, this breach could result in loss of national security information or the conduction of criminal activity. Current security measures to address this issue rely primarily on posted signs and personnel queries to control the entry of RF communications devices into a secure area. These measures do not provide an active deterrence capability, thus limiting their effectiveness. Development of an Active, RF Transceiver Detection System The ability to rapidly and unobtrusively scan individuals entering a facility or moving through a constrained area (hallway, doorway, etc.) to determine if they possess a wireless device would be a valuable tool for security personnel. In the proposed effort, Vadum will develop a prototype active RF transceiver detection system based on an existing internal program in addition to the results obtained from the ongoing Phase I activities. The key goal of Phase I was improving the transceiver sensing function through hardware architecture choices. Additional benefits to be gained through signal processing can only be achieved after maximizing the performance of the hardware component of the proposed detection technique. The objectives of the proposed program focus on the implementation and test of the prototype system architecture developed during Phase I. Tests of the prototype system will utilize representative RF targets including mobile phones and two-way radios under realistic scenarios for personnel transiting through a walk-through portal form-factor implementation. An important element of the proposed program will consist of a brief target characterization study to enable the estimation of statistics of target responses to the active detection technique employed. This study will aid the refinement and optimization of the prototype design to meet the objectives of a low-cost, human-safe system that has a development path from fixed stand-alone portal, to unobtrusive emplacement, to a man-portable unit for mobile detection applications. The Phase II effort will leverage Vadum’s experience in developing the active detection technique and the initial pre-production mobile phone detection prototype developed prior to the Phase I program. Vadum rapid electronics prototyping and electronic test equipment resources will be employed to realize the prototype implementation and validate successful construction. The detection prototype application testing and mobile phone characterization efforts will utilize Vadum’s large inventory of mobile phone and personal wireless communications devices to thoroughly map the target response space and prototype performance for the selected architecture and detection technique embodiment. The test and characterization activities will reduce the risk of developing a successful detection system that can transition readily to government and commercial applications.