Overview:

SON concepts are included in the LTE (E-UTRAN) standards starting from the first release of the technology (Release 8), and expanding in scope with subsequent releases. A key goal of 3GPP standardization is the support of SON features in multi-vendor network environments. 3GPP has defined a set of LTE SON use cases and associated SON functions.1 The standardized SON features effectively track the expected LTE network evolution stages as a function of time. With the first commercial networks to be launched in 2010, the initial focus of Release 8 has been functionality associated with initial equipment installation and integration. The scope of the first release of SON (Release 8) includes the following 3GPP functions, covering different aspects of the eNodeB self configuration use case:

• Automatic inventory
• Automatic software download
• Automatic Neighbor Relation
• Automatic Physical Cell ID (PCI) assignment

The next release of SON, as standardized in Release 9, will provide SON functionality addressing more maturing networks. It includes these additional use cases:

• Coverage & Capacity Optimization
• Mobility optimization
• RACH optimization
• Load Balancing optimization

Other SON related aspects that are being discussed in the framework of Release 9 include improvement on the telecom management system to increase energy savings, a new OAM interface to control home eNodeBs, UE reporting functionality to minimize the amount of drive tests, studies on self-testing and self- healing functions, and minimization of drive testing. It should be clear that SON-related functionality will continue to expand through the subsequent releases of the LTE standard.

The SON specifications have been built over the existing 3GPP network management architecture, reusing much functionality that existed prior to Release 8. These management interfaces are being defined in a generic manner to leave room for innovation on different vendor implementations.

Femtocells were the original commercial use cases for SON.