Technical Specification Group (TSG)
A Technical Specification Group is one of the top-level committees within 3GPP that is responsible for a broad area of the mobile system and approves the specifications in that area.
What is Technical Specification Group (TSG)?
3GPP divides its work into three Technical Specification Groups: radio access networks (TSG RAN), services and system aspects (TSG SA), and core network and terminals (TSG CT). Each is split into working groups that do the detailed drafting, while the TSG itself agrees work items and formally approves the resulting documents.