The 3GPP System consists of UEs and Network Infrastructure. The System is designed to support a wide variety of
services and UE types. Due to this diversity of applications there are many options within the 3GPP specifications.
This TR identifies the implementation requirements for the sub-set of options (referred to as baseline
capabilities) that are required in 3GPP UEs to allow world-wide roaming of UEs within all 3GPP networks. The
present document also identifies the implementation requirements for specific UE Service Capabilities, in order to help
ensure end to end interworking for UEs claiming to support compatible services.