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    • The History of Cell Phones

      The History of Cell Phones

      Cell phone technology  is based on radio technology that was developed from the 1940’s onward. For instance, the beginning of cell phones can be traced to the innovation in taxi cabs, police cars, and other service vehicles where two way radios allowed taxi drivers or police officers to communicate with one another or with a

    • Cell Phone Cloning

      Cell Phone Cloning

      Cell phone cloning refers to the act of copying the identity of one mobile telephone to another. This is usually done to make fraudulent telephone calls. The bill for the calls go to the legitimate subscriber. This made cloning very popular in areas with large immigrant populations, where the cost to “call home” was very

    • IS-95: CDMA

      IS-95: CDMA

      IS-95 is a standard for CDMA (Code Division Multiple Access) Digital Cellular. Mobile Frequency Range Rx: 869-894; Tx: 824-849 Multiple Access Method CDMA/FDM Duplex Method FDD Number of Channels 20 (798 users per channel) Channel Spacing 1250kHz Modulation QPSK/OQPSK Channel Bit Rate 1.2288Mb How CDMA Works In a CDMA system, your encoded voice is digitized

    • How to Dry Out a Cell Phone

      How to Dry Out a Cell Phone

      When dealing with a wet phone, it is important to act quickly. Few phone companies offer a warranty on wet phones and have gone as far as to place a "wet strip" on the phone that changes colors when it has gotten wet. What this means is that the wet strip will allow the company

    • Tumbling

      Tumbling

      Tumbling exploits a weakness in the AMPS/NAMPS roaming system. In tumbling, you first configure the SIDH in your mobile telephone to pretend to be from another cellular carrier. If you are in Colorado, for example, you would configure your mobile telephone as if it were subscribed to a cellular carrier in Texas. Next, you modify

    • AMPS (EIA/TIA-553) and NAMPS (IS-91)

      AMPS (EIA/TIA-553) and NAMPS (IS-91)

      Mobile Frequency Range Rx: 869-894; Tx 824-849 Multiple Access Method FDM Duplex Method FDD Number of Channels 832 Channel Spacing 30kHz Modulation FM AMPS AMPS (Advanced Mobile Phone Service) was the first cellular mobile system in the United States. AMPS operates as an analog system using 30 kHz wide channels. NAMPS AMPS was later enhanced

    • ESN (Electronic Serial Number)

      ESN (Electronic Serial Number)

      ESN (Electronic Serial Number) An Electronic Serial Number is a code created to identify mobile devices. An ESN is 32 bits long, and the distribution of information in those bits has changed as the standard has evolved. The first 8 bits originally represented the manufacturer code, leaving 24 bits for the manufacturer to assign codes

    • SIM Card

      SIM Card

      A SIM (Subscriber Identity Module) card is a type of interface card that is found in most modern cell phones and contains the user’s account information as well as some types of media, such as contacts, pictures, and sometimes ringtones. A SIM card contains an ICCID, or Integrated Circuit Card ID, number that identifies the

    • How to Unlock a BlackBerry

      How to Unlock a BlackBerry

      Many wireless providers across the globe, including AT&T/Cingular, T-Mobile, Vodafone, and Verizon sell Blackberries. When these companies sell a BlackBerry, they do so at a discount in order to attract customers. The providers then make up the lost profits over the lifetime of their contract with the customer. To protect those profits, the wireless providers

    • PCS (Personal Communications Service)

      PCS (Personal Communications Service)

      PCS (Personal Communications Service) is a set of standards. Most PCS standards are based on an existing standard. PCS is little more than the operation of these standards on the frequency bands of 1930-1990MHz for receiving and 1850-1910Mhz for transmitting. PCS StandardBase Standard PCS TDMA IS-136 PCS CDMA IS-95 PCS 1900 GSM PACS PHS cordless

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