Open Service Access

Open Service Access or Open Service Architecture (OSA) is part of the UMTS network. OSA defines how value-added services are implemented in a UMTS network.

The OSA specification is part of the specification of the 3rd Generation Partnership Project (3GPP) and is published by the 3GPP and ETSI . The programming interface (API) is called Parlay or Parlay / OSA and is being developed in cooperation with 3GPP, ETSI and the Parlay Group.

The terms Open Service Access and Open Service Architecture are often used synonymously, which is confusing in many cases. From the year 2000, all specifications of the 3GPP were published under the term Open Service Access. Older, already published specifications, which used the abbreviation Open Service Architecture, were not adapted. Today you can still find both variants, especially in publications by third parties.

Web links

• TR 23.927 VHE, Open Service Architecture (OSA) - obsolete, has been replaced by TS 23.127
• TS 23.127 Virtual Home Environment (VHE) / Open Service Access (OSA) - successor to TR 23.927
• TS 23.198 Open Service Access (OSA); Stage 2 - successor to TS 23.127