Glossary (C-D)

CDMA- (Code Division Multiple Access)
An air interface technology that was developed by the U.S. military and commercialized by the U.S. company Qualcomm. CDMA supports SMS with a message length of 120 characters. With CDMA, each conversation is digitized and then tagged with a code. The mobile phone receives a signal to locate that particular code and it then deciphers the conversation off the airwaves. It codes each conversation expanding it 128 times, making it easy to decipher at the receiving end.

CDMA2000
3G CDMA evolution from cdmaONE supported by cdmaONE operators. Phase 1 provides 144 Kbps data rate and Phase 2 up to 2 Mbps. See Third Generation.

CDMAONE
The name used by the CDMA Development Group (CDG) for CDMA networks (IS-95) using 2nd-generation digital technology.

CDPD- (Cellular Digital Packet Data)
An enhanced packet overlay on analog cell phone networks used to transmit and receive data. This technology allows data files to be broken into a number of packets and sent along idle channels of existing cellular voice networks. CDPD provides 19.2 Kbps and is deployed by AT&T among several other carriers.

Coverage
Refers to the region within which a paging receiver can reliably receive the transmission of the paging signals.

Digital
A digital signal is composed of electrical pulses representing either zero or one. Because digital signals are made up only of binary streams, less information is needed to transmit a message. Digital encoding therefore increases the capacity of a given radio frequency. Furthermore, only digitized information can be transported through a noisy channel without degradation. Even if corruption occurs, as long as the one zero pattern is recognizable, the original information content can be perfectly replicated at the receiving end.

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