Summary of Mobile Networks Evolution from R99 upto R4. What are the architectures and objectives of these various phases.

1. http://www.3gpp.org/technologies/tutorials-tools
UMTS R99
UMTS R4 Focus is on CS Core – Split Architecture separate Costly Control Plane from Cheaper user Plane in CS CORE network

2. UMTS R5
Objective is to get rid of the CS CORE Network and have with an All IP Network without compromising real-time services like Voice.
Introduction of IMS
Control : So that an operator can bill the customers
QoS : Voice is sensitive to Delays
Apps : Services can be provided by 3rd parties

3. UMTS R6
Emphasis on HSUPA
UMTS R7
Emphasis on HSPA+