Open Service Architecture (OSA) Application Programming Interface (API) - Part 1
This document specifies the stage 3 of the Open Service Architecture (OSA) Application Programming Interface (API). The concepts and the functional architecture of the Open Service Architecture (API) are described by 3GPP TS 23.127 [2]. This document describes the stage 3 specification of the Open Service Architecture API.
The Open Service Architecture defines an architecture that enables service providers to make use of network functionality through an open standardised interface, i.e. the OSA API. The network functionality is describes as Service Capability Servers. Within the OSA concepts the following Service Capability Servers are identified:
 CAMEL Service Environment (see in 3GPP TS 23.078 [4])
 WAP execution platform (i.e. WAP Gateway & WAP Push Proxy, see in [13] )
 Home Location Register (HLR)
The stage 3 documentation of the OSA R’99 API consists of two parts:
 The API specification (Part 1).
This is a normative stage 3 specification of the capabilities of the OSA R’99 API and describes the OSA API interface classes, containing class diagrams (see section 6), state transition diagrams (see section 7), data type definitions (section 8), and the IDLs (see section 9).
- The Mapping specification of the OSA R’99 API and the network protocols (Part2).
This is an informative specification to provide an example how the OSA API can be mapped on the network protocols (i.e. MAP [7], CAP[8] and WAP[9]). It is an informative document, since this mapping is considered as implementation/vendor dependent. On the other hand this mapping will provide potential service designers with a better understanding of the relationship of the OSA API interface classes and the behavior of the network associated to these interface classes.
The OSA API Stage 3 activity is performed jointly with ETSI SPAN3’s Service Provider Access Requirements activity. The contents of this document is related to the jointly owned 3GPP & ETSI document referred as the API Master document, which contains the API interface descriptions that are common and differentiated between ETSI & 3GPP.