Mobile Phones

Question: What does VoIP stand for?

Answer: VoIP stands for Voice over Internet Protocol, the system guidelines for voice communication over the Internet and similar networks that use Internet protocols.

Question: What does the “SIM” in SIM card stand for?

Answer: SIM stands for Subscriber Identity Module. A SIM card contains a key that identifies a user’s mobile phone with a specific carrier subscription and account.

Question: Which manufacturing company produced the first camera phone, called the J-Phone, that could send photos over a cellular network?

Answer: Sharp, an electronics manufacturer, was the first company to produce a camera phone with the capability to send photos electronically. The phone was equipped with a 0.1-megapixel camera.

Question: Which telephone company introduced the first mobile telephone service (MTS), in 1946?

Answer: In 1946 AT&T introduced the first MTS in the United States. The service was similar to a walkie-talkie, with a simplex radio system that allowed only one user to speak at a time in a phone call.

Question: The biggest difference between 3G and 2G mobile-data-transfer technology is the use of packet switching over circuit switching.

Answer: Packet switching in 3G cellular technology allows data to be transferred between two locations in a network in separate small packets that are reassembled when they reach their destination. 2G circuit switching requires an established connection before data can be transferred between two locations.

Question: Motorola was the first telephone company to create a handheld mobile phone.

Answer: In 1973 the first-ever call from a handheld mobile phone was made by an executive at Motorola.

Question: What is the name for the mapped hexagonal geographic areas that make up the cellular phone grid?

Answer: The hexagram mapped areas that make up a cellular phone grid are called cells. Each cell contains a radio transmitter that sends a signal to the surrounding area.

Question: Which band of radio wave frequencies do cellular phones use for telecommunication?

Answer: Cellular phones initially used the 800–900-MHz band of radio frequency, which allows a signal to be transmitted over large geographic areas.