Mobile Technology

Here are some dictionary isitilah we often hear in wireless technology, particularly mobile technology.

AMPS

AMPS (Advanced Mobile Phone Service) is the name of origin for cellular phone service, developed by Bell Labs and was released in 1978 in Chicago. Show AMPS analog cellular phone service.

CDMA

CDMA (code division multiple access) modulation technique is spectrum-spread (spread-spectrum) used in digital personal communication devices such as mobile phones. Unlike TDMA technique is used for GSM, CDMA does not use a specific frequency to each user, but every channel uses the available spectrum. CDMA technique to change the conversation data into digital form and add to it a special frequency code. This data is then distributed into frequency ranges with pseudo-random pattern (pseudorandom) and data receiving devices instructed to decipher only the data associated with a particular code to reconstruct the signal. CDMA was originally a military technology used during World War II by English allies to foil German attempt to interrupt transmission. The British allies decided to use multiple frequencies to complicate german take a complete signal.

FDM

FDM (frequency division multiplexing) is a multiplexing technique that uses different frequencies to combine multiple data streams for transmission via a communications medium. FDM provides discrete carrier frequency to each data stream and then combine several carrier frequencies are modulated for transmission. For example, television transmitters use FDM to transmit several channels at once.

GPRS

GPRS (General Packet Radio Service) is a wireless communication standard that works at the speed of 150 kilobits per second. GSM system (Global System for Mobile Communications) is only able to transmit data up to 9.6 kilobits per second. GPRS supports a variety of bandwidth is, is an efficient way to utilize the limited bandwidth, especially to send and receive data much like e-mail and while browsing the Web.

GSM

GSM (Global System for Mobile Communications) is the standard used for mobile communications are widely used in Asia and Europe. GSM was first introduced in 1991, and the GSM service is now available in over 100 countries worldwide. GSM uses narrowband TDMA which allows eight simultaneous calls on the same radio frequency.

TDM

TDM (time division multiplexing) is a type of multiplexing that combines data streams by giving each stream a different time slot to another. TDM repeatedly transmits a series of fixed time slots through a single transmission channel.