问题描述：
帮忙翻译一下英文（通信类的）
IN telecommunication services are mainly programmed in procedural languages based on
proprietary hardware and software. The IN service model introduces the concept of service
scripts that specify the logic to form a new service from elementary building blocks. But some important problems still exist. One problem is that the model does not take advantage of modern object-oriented (OO) techniques, as discussed below. Another problem is that the granularity of basic IN building blocks is inconsistent. Some blocks, such as Service Data Management, represent very complex operations that can treat any kind of service data. Other blocks, such as Comparison, represent simple calculation capabilities. The difficulty of reusing these building blocks makes many telephony vendors develop their own proprietary building blocks (Zuidweg 2002).
Modern OO programming techniques have proven to be more modular than procedural
programming techniques. Objects are reusable software building blocks that encapsulate
both data and related processing codes. Objects can be envisioned as service providers
in the sense that they provide services to other objects, and to achieve this, they utilize services from other objects. Well-defined objects have atomic functionalities and maintain a clean interface for controlled access and easy service provisioning. Furthermore, because real implementation is hidden from external access, by keeping the interface unchanged, the implementation of objects can be changed without affecting the overall program. Such characteristics greatly benefit application modification, adaptation, and maintenance.
The service APIs discussed in this chapter mainly use OO techniques. JAIN is specified in Java, so it is OO by design. Parlay is specified in the Unified Modeling Language (UML), so it has the advantage of being language independent. Automatic tools exist to convert the UML to specific Interface Definition Languages (IDLs), like CORBA IDL and Microsoft IDL. Translations from UML to specific programming languages like C++ and Java are also possible. While in principle these translations could be done automatically, the resulting specification is likely to be very hard to read and understand. Nonetheless, translation rules have been devised to make the translation process fairly straightforward.
The various standardization bodies and industrial interest groups have produced a considerable amount of work in this area. This chapter first discusses the strengths and limitations of existing API efforts (for example, Parlay/OSA, JAIN, and OMA) as well as other API approaches that have been suggested for advanced network architectures. Following that is a short description of our approach to developing a layered API model for XG mobile networks. Finally, the chapter concludes with some observations on future work.
IN telecommunication services are mainly programmed in procedural languages based on
proprietary hardware and software. The IN service model introduces the concept of service
scripts that specify the logic to form a new service from elementary building blocks. But some important problems still exist. One problem is that the model does not take advantage of modern object-oriented (OO) techniques, as discussed below. Another problem is that the granularity of basic IN building blocks is inconsistent. Some blocks, such as Service Data Management, represent very complex operations that can treat any kind of service data. Other blocks, such as Comparison, represent simple calculation capabilities. The difficulty of reusing these building blocks makes many telephony vendors develop their own proprietary building blocks (Zuidweg 2002).
Modern OO programming techniques have proven to be more modular than procedural
programming techniques. Objects are reusable software building blocks that encapsulate
both data and related processing codes. Objects can be envisioned as service providers
in the sense that they provide services to other objects, and to achieve this, they utilize services from other objects. Well-defined objects have atomic functionalities and maintain a clean interface for controlled access and easy service provisioning. Furthermore, because real implementation is hidden from external access, by keeping the interface unchanged, the implementation of objects can be changed without affecting the overall program. Such characteristics greatly benefit application modification, adaptation, and maintenance.
The service APIs discussed in this chapter mainly use OO techniques. JAIN is specified in Java, so it is OO by design. Parlay is specified in the Unified Modeling Language (UML), so it has the advantage of being language independent. Automatic tools exist to convert the UML to specific Interface Definition Languages (IDLs), like CORBA IDL and Microsoft IDL. Translations from UML to specific programming languages like C++ and Java are also possible. While in principle these translations could be done automatically, the resulting specification is likely to be very hard to read and understand. Nonetheless, translation rules have been devised to make the translation process fairly straightforward.
The various standardization bodies and industrial interest groups have produced a considerable amount of work in this area. This chapter first discusses the strengths and limitations of existing API efforts (for example, Parlay/OSA, JAIN, and OMA) as well as other API approaches that have been suggested for advanced network architectures. Following that is a short description of our approach to developing a layered API model for XG mobile networks. Finally, the chapter concludes with some observations on future work.
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