22.1793GPPMission Critical Push to Talk (MCPTT)Release 17Stage 1TS
The present document covers requirements for Mission Critical Push To Talk (MCPTT) service (represented by the term, MCPTT Service). The MCPTT Service can be used for public safety applications and also for general commercial applications (e.g., utility companies and railways). The specifications contained within the present document can also form the basis for a non-mission critical Push To Talk service (called a PTT service).
Note that further development of mission critical services beyond MCPTT (such as Mission Critical Video and Mission Critical Data) created an opportunity to re-use base functionality documented in the Stage 1 requirements for MCPTT. For example, the ability to communicate mission critical information to groups of users is a common need regardless of service type. Wherever originating MCPTT requirements were found to be in common with other mission critical services, those requirements were moved to a new Technical Specification (3GPP TS 22.280). Each requirement that was moved has been voided in this version of 3GPP TS 22.179, and an informative annex has been created at the end of this specification documenting the location of the originating 3GPP TS 22.179 requirement in 3GPP TS 22.280.