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    • 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

    • Country Direct Numbers

      Country Direct Numbers

      Country Direct numbers are used so that you may connect to an operator from a foreign telephone network, without incurring long distance charges. These numbers may be useful in blue boxing, as many countries still have older switching equipment in use. List of Country Direct Numbers Australia (Telstra) (800)682-2878 Austria (Telecom Austria) (800)624-0043 Belgium (800)472-0032

    • Numbers that always Ring Busy

      Numbers that always Ring Busy

      In the following listings, "xxx" means that the same number is used as a constantly busy number in many different prefixes. In most of these, there are some exchanges that ring busy and some exchanges that are in normal use. ALWAYS test these numbers at least three times during normal business hours before using as

    • Cell Phone Frequencies

      Cell Phone Frequencies

      Cell phone frequencies are the frequency ranges within the Ultra High Frequency (UHF) band that are designated for cell phone use. Bluetooth devices, wireless networks, and television signals also use this frequency band. Although cellular phone systems divide cities and geographic areas into smaller cells of coverage, it allows for a fair amount of frequency

    • Unlocked Cell Phones

      Unlocked Cell Phones

      To understand what an unlocked cell phone is, it is important to first understand what a locked cell phone is. A locked cell phone is one that can only be used with one cellular service provider. In contrast, an unlocked cell phone can be used with any cellular service provider. When a cell phone is

    • How to Activate a TracFone

      How to Activate a TracFone

      TracFone is the 6th largest mobile network operator in the United States. It allows its customers to purchase airtime usage when they purchase phones that companies like Nokia, LG, and Motorola make. A TracFone customer has to activate the cell phone before using it. It can be activated via the TracFone website or TracFone customer

    • 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

    • SS7 (Signaling System 7)

      SS7 (Signaling System 7)

      SS7 (Signaling System 7) is a standard for control signaling in the PSTN (Public Switched Telephone Network. SS7 signaling is done out-of-band, meaning that SS7 signaling messages are transported over a separate data connection. This represents a significant security improvement over earlier systems which used in-band signaling. The first CCS protocol was the Signaling System

    • CLLI Codes

      CLLI Codes

      CLLI codes, or Common Language Location Identifier, pronounced “silly codes”, are codes used by telecommunication companies to identify specific industry equipment. CLLI codes are 11 characters long, may be comprised of a combination of letters and numbers, and are used by all telecommunication companies in North America. While CLLI codes were first created and used

    • Call Back Security

      Call Back Security

      Call back security, also known as dial back security, is a security mechanism used to authenticate users over dialup lines. The way call back security works is the dialup user calls into the system and enters his username and password. The system then hangs up on the user and calls the user back at a

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