SAE/EPC

SAE, or System Architecture Evolution, is synonymous with EPC, or Evolved Packet Core. SAE/EPC is defined by 3GPP in Release 8 as an entirely new core network with a flatter all-IP architecture enabling a higher-data-rate, lower-latency packet-optimized system that supports multiple radio-access technologies, focusing on the packet-switched domain, with the assumption that the system will support all services—including voice—in this domain.

3GPP has made significant progress in Rel-8 towards the standards development and definition of a new flatter-IP core network to support the EUTRAN through the System Architecture Evolution (SAE) work item, which has recently been renamed the Evolved Packet Core (EPC) Architecture. In parallel, 3GPP has made significant progress towards the standards development and definition of a new OFDMA based technology through the Long Term Evolution (LTE) work item. This new OFDMA based air interface is also often referred to as the Evolved UMTS Terrestrial Radio Access Network (EUTRAN). Note that the complete packet system consisting of the EUTRAN and the EPC is called the Evolved Packet System (EPS).

The combination of LTE and SAE provides the long-term vision for 3GPP to an all-IP, packet only wideband OFDMA system expected to further improve performance by providing higher data rates, improved spectral efficiency and reduced latency. The ability of LTE to support bandwidths wider than 5 MHz is of particular importance as the demands for higher wireless data speeds and spectral efficiencies continues to grow.

EPC will use IMS as a component. It will also manage QoS across the whole system, which will be essential for enabling a rich set of multimedia-based services. EPS will be optimized for all services to be delivered via IP in a manner that is as efficient as possible—through minimization of latency within the system, for example.

Although it will most likely be deployed in conjunction with LTE, EPC could also be deployed for use with HSPA+, where it could provide a stepping-stone to LTE. It will support service continuity across heterogeneous networks, important for LTE operators that must simultaneously support GSM/GPRS/EDGE/UMTS/HSPA customers.

The key features and capabilities of SAE/EPC include:

• Reduced latency and higher data performance through a flatter all-IP architecture.
• Support for both LTE radio-access networks and interworking with GSM/UMTS radio-access networks.
• The ability to integrate non-3GPP networks such as WiMAX.
• Optimization for all services provided via IP.

Additional Information

Questions and Answers

UMTS Evolution from 3GPP Release 7 to Release 8: HSPA and SAE/LTE