An optimal detection technique for mobile radio freqencies

Cellular phone technology is rapidly changing. Features like Bluetooth, USB, high resolution cameras, microphones, Internet, 802.11 wireless, and memory cards are added every year. Also, the communication technology a cellular phone uses such as CDMA, GSM, 3G, and 4G are rapidly changing. To get a good grasp on what is available today let's take a close look at some off the shelf cellular phone detectors. Most detectors are manufactured with the intent that the cellular phone is stationary and powered on. They generally have the same features and it is questionable whether or not they actually detect a cellular phone.

The two most popular cellular phone detectors available on the market today are produced by Berkeley Varitronics Systems and Mobile Security Products. These companies produce the wolfhound cellphone detector and Cellbuster respectively. This study examines detecting cellular phones when a person is entering a secure facility or cellular phone restricted area. The detection technique studied requires measuring a cell phone's electromagnetic properties and determining an identifiable signature. Measuring the RF spectrum around 240 -400MHz(outside the cellular phone band) shows the most potential. The main problem with ensuring that a cellular phone isn't in a secure facility is that an accurate method for detecting them doesn't exist. The only way to be certain is to perform full body searches on a regular basis. Most cellular phone detectors available today only alarm if there is a cellular phone or transmission device in the general area. They appear to alarm randomly and aren't very accurate. Detecting a cellular phone signal using an accurate signal detection technique is the focus of this research and can be solved by using a down converter in conjunction with a bandpass filter. The technique is more accurate and provides signal detection at a lower frequency, making it easier to work with. If this solution was implemented, it would greatly reduce the risk of cellular phones getting into secure facilities. Businesses and government would save a lot of money on security. The solution would also greatly reduce the risk of their data leaking to the general public and losing even larger amounts of money.