Smart Phone and Next Generation Mobile Computing

132 Smart Phone and Next-Generation Mobile Computing

while upgrading GSM/GPRS to EDGE or to 3G UMTS/WCDMA is

to make the most out of the existing GSM infrastructures. GPRS

and EDGE are considered intermediate solutions for early adopters

before 3G.

3.5 Code-Division Multiple Access

The notion of CDMA has two distinct meanings: It can refer to the

multiplexing scheme of code-division multiple access, or it can refer

to second-generation cellular systems that use DSSS as the spread

spectrum scheme and code-division multiplexing as the underlying

multiplexing technology. Unlike GSM, which is also the name of the

standard, the standard for CDMA cellular systems is IS-95.

3.5.1 Code-Division Multiple Access Concept

Section 3.2 introduced CDM. CDMA is actually ...