Digital systems offer considerable advantages in terms of capacity and security and introduce
new possibilities for data traffic.
• Uses digital modulation
• Variety of multiple access strategies
• More efficient use of radio spectrum
• Voice and low rate circuit switched data
• International roaming capability
• Secure air interface
• Compatibility with ISDN
While first generation systems used a cellular structure and frequency re-use patterns, digital
systems developed this concept to include multi-layer cellular patterns (microcells and
macrocells). The greater immunity to interference inherent in digital transmission allowed
tighter frequency re-use patterns to be implemented.
• Derived from Qualcomm IS-95 air
interface
• Largely American subscriber base with
some Asian networks
• Code Division Multiple Access
• The closest 2nd generation standard to
many of the 3rd generation standards
• ANSI-41 core network
• Chip rate of 1.2288Mcps
cdmaOne phones
• North American TDMA/FDMA based
standard based upon AMPS
• Predominantly used in North and
South America
• ANSI-41 Core Network
• Planning Similar to GSM
• PDC
• Japanese TDMA/FDMA based
standard
• Predominantly used in Asia
• Planning Similar to GSM
new possibilities for data traffic.
2nd Generation Characteristics
• Widespread Introduction in 1990’s• Uses digital modulation
• Variety of multiple access strategies
• More efficient use of radio spectrum
• Voice and low rate circuit switched data
• International roaming capability
• Secure air interface
• Compatibility with ISDN
While first generation systems used a cellular structure and frequency re-use patterns, digital
systems developed this concept to include multi-layer cellular patterns (microcells and
macrocells). The greater immunity to interference inherent in digital transmission allowed
tighter frequency re-use patterns to be implemented.
cdmaOne Characteristics
• First networks in 1996• Derived from Qualcomm IS-95 air
interface
• Largely American subscriber base with
some Asian networks
• Code Division Multiple Access
• The closest 2nd generation standard to
many of the 3rd generation standards
• ANSI-41 core network
• Chip rate of 1.2288Mcps
cdmaOne phones
D-AMPS/PDC Characteristics
• TDMA (D-AMPS)• North American TDMA/FDMA based
standard based upon AMPS
• Predominantly used in North and
South America
• ANSI-41 Core Network
• Planning Similar to GSM
• PDC
• Japanese TDMA/FDMA based
standard
• Predominantly used in Asia
• Planning Similar to GSM