This European Telecommunication Standard (ETS) defines the GSM Application Programming Interface (GSM API) in two parts.
The first part describes, how compatibility to existing application interface ETS 300 838 is covered for the GSM network. So existing PCI applications are able to be used in a GSM environment. For these applications the necessary mapping and local knowledge between application interface and network is described. The only modifications needed in ETS 300 838 to fulfil this requirements are covered by changes of the parameter description. These changes of parameters are defined in clauses 4 and 5 of this ETS.
The second part defines GSM specific features. New GSM API applications need extensions to ETS 300 838 which are defined in section 6 and 7of this ETS.