International Journal of Scientific & Engineering Research, Volume 4, Issue 5, May-2013 1658 ISSN 2229-5518 IJSER © 2013 http://www.ijser.org Multism development of unauthorized cell-phone signal detector for multiple users Lawal W. and Ogunti E.O. Abstracts The use of mobile phones (GSM) by all categories, classes and ages of people has become widespread. While this is laudable, the abuse of this technology has however been on the high side in recent times. People often tend to forget and sometimes deliberately use their phones in unauthorized places such as examination halls, correctional facilities (prisons and cells), religious places (mosques), banking halls, and confidential meetings. The micro- miniaturization of these devices increases the risk to exploit and misuse this technology for diabolical and illegal purposes. For example, cell phones hidden in a meeting room, or on a person, allows a competitor to listen in or record illegally vital protected information. In hospital settings, Electromagnetic Interference (EMI), due to the presence or use of cell phones near sensitive electronic equipment may cause important patient-care equipment to fail to perform properly, putting patients at risk. The use of mobile phones as aids for cheating in examinations has somewhat become a menace in Nigeria. Consequently, a very real need exists today for individuals, businesses, institutions and the government to take measures to detect and identify the unauthorized use of cell-phones within the bounds of any controlled premise. In this work, attempt is made to provide a mechanism to forestall adverse consequences of unauthorized usage of cell phones in public buildings. Multism 11.0 version was used as appropriate CAD tool for the development of a phone signal detector for multiple users. Any cell phone activity such as making or receiving calls, sending or receiving SMS will be detected within the range of 5.8m. Keywords: Signal detector, micro- miniaturization, Multism, active mode, correctional facilities, multiple users and buzzer alarming. INTRODUCTION Unauthorized mobile phone usage in both private and public places has become a problem that may be difficult to solve. [7].The technology added to cellular phones in the last 15 years has made them a jack-of-all -trades for information storage and transmission. Features like Bluetooth, USB, micro USB, high resolution cameras, microphones, internet, and 802.11wireless technology make cellular phones perfect for stealing data. The only way of ensuring that a cellular phone is not in a secure area is to have an accurate method for sniffing (detecting) them. Most cellular phone sniffers available today only alarm if there is a cellular phone or transmission device in the general area.[1],[2],[3],[4]. They appear to alarm randomly and are not very accurate. Detecting a cellular phone signal and location has been a little problematic. The technique in this work provided signal detection as well as signal location. A cell phone detector can detect the signals use in the GSM band at about 900 MHz and Digital Cellular System (DCS) at about 1800MHz.[1],[11],[12]. Since the signals are digitally encoded, the sniffer can only detect the signal activity, and not the speech or the message contents of the signal. The sniffer only receives and doesn't transmit, making it great for areas sensitive to cellular phone usage. Over the last three decades, the number of cell phones, laptops and other electronic mobile devices has increased tremendously [13],[ 6], [8]. In the last few years, these mobile devices have started to be equipped, besides cellular interfaces (GSM), with peer-to-peer communication technologies, such as Wi-Fi or Bluetooth. They enable new services and applications such as context-aware applications. In France, a service that will allow a person passing in front of a movie advertising board to download the trailer on his mobile phone via Bluetooth or Infrared is currently under development. In front of a car billboard, buyers will be able to receive the address of the closest car dealer by SMS. Another benefit provided by these new communication technologies is the possibility given to friends to automatically detect friend’s location and exchange information through mobile social networks [13]. The Cellular telephone (commonly mobile phone, cell phone or hand phone) is a long-range, portable electronic device used for mobile communication. In addition to the standard voice function of a telephone, current mobile phones can support many additional services such as SMS for text messaging and mail delivery, packet switching for access to the Internet, and MMS for sending and receiving photos and video. Most current mobile phones connect to a cellular network of base stations (cell sites), which is in turn interconnected to the public switched telephone network (PSTN) except satellite phone [1],[9]. Cellular telephone is also defined as a type of short-wave analog or digital Telecommunication in which a subscriber has a wireless connection from a mobile telephone to a relatively nearby transmitter. The transmitter span of coverage is called a cell. Generally, cellular telephone service is available in urban areas and along major highways. As the cellular telephone user moves from one cell or area of coverage to another, the telephone is effectively passed on to the local cell transmitter. MATERIALS AND METHODS The first stage in the design of this sniffer system involves the use of a CAD tool, Multism. Here a circuit was design using Op-Amp and RC filter for signal sniffing. The stability of the circuit was established using S-parameter and the K factor of the Op-Amp., else the amplifier may turn into an oscillator. Different sniffing circuits were evaluated through simulation in Multism. The various circuits simulated were shown in fig.1 to 6. A sniffer circuit [1], available commercially was simulated using Multism to confirm its performances. The maximum range cover by this circuit is 1.5m. Since the goal of this research is to exceed 1.5m, efforts were made to redesign the circuit to allow coverage of larger area such as correctional facilities, examination halls and big banking halls, i.e., to have coverage of about 6m in radius. Following design procedure, the circuit of fig1 was developed. Simulation of the design in fig 1 in the GSM frequency of 900MHz and 1800MHz was done. IJSER