Dr. Martin Cooper is the person credited with both inventing the modern cell phone as well as making the first cell phone call in New York City, New York in April 1973. A related invention is the cave radio phone invented by Nathan Stubblefield who was awarded a patent for the idea in the early …
A smartphone is a mobile phone with a considerably greater amount of functionality than an ordinary mobile phone or a feature phone. Smartphones can be considered a blend between a mobile phone and a full featured mobile computer, similar to the PDAs (Personal Digital Assistants) of the past, but even more capable. They typically include …
Loop start is a a signaling technique in which a party gets a dial tone by closing (shorting) a DC current loop. In a loop start signaling system, the electrical loop between your telephone and your central office (CO) is normally open. When you pick up the telephone handset, it causes a circuit to be …
SMS, or Short Messaging Service, is a text-based messaging service that is used by over 2.4 billion mobile phone users worldwide. SMS allows users to send and receive text-based messages, pictures, videos, and audio clips from other mobile phone users and desktop computer users who have applications that can interact with mobile phones. SMS differs …
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 …
Telephone voltage is actually related to the physical distance at which you can operate the telephone. If the voltage is high, it can signal to great distance. However, higher voltage carries certain risks. 48 V is a compromise between distance and safety. 50-52 V is used in central office common batteries, but designations and documents …
A CLEC, or Competitive Local Exchange Carrier, is a type of telecommunications provider that was formed after the breakup of AT&T. CLECs are usually smaller telecommunications providers that compete with ILECs, or Incumbent Local Exchange Carriers, which were already in place before AT&T’s separation. While CLECs generally provide the same services as ILECS for less, …
This is the “right hand” of both the professional and the amateur lineman. Basically, it is a customized portable telephone which is designed to be hooked onto raw cable terminals in the field and used to monitor the line, talk, or dial out. The monitor function is usually the main difference between the “butt-in” test …
An IDEN, or Integrated Dispatch Enhanced Network, is a radio service provided by some mobile telephones that allows subscribers to talk to nearby subscribers who have similar phones without dialing their individual numbers. IDENs are often provided as a free service on modern mobile phones, such as Nextel, or as a premium service that can …
RBOC (The Regional Bell Operating Companies) were created as the result of a legal dispute between the US Justice Department and the AT & T Corporation. In 1984, the American Telephone & Telegraph Company split its local operations into 7 autonomous RBOCs that became known as “Baby Bells”. In the beginning, these companies were called …