**1. Introduction**

Network is the bearer of services and services are the soul of network. The convergent network extends the original communications service type and gradually forms new convergent services which integrate the traditional telecommunication services and a large number of value-added services or contents on Internet (Kolberg et al., 2010). The integrated service is essentially to handle the data and services across heterogeneous networks and service platforms. Facing the heterogeneity and diversity of service resources, integrated services need to run in a multi-terminal, multi-access network and multi-platform heterogeneous environment. These tremendous changes of service environment present a significant interoperability challenge for traditional service provisioning theory. Nowadays, the provision of context-awareness, adaptive personalized services is the development goal of future ubiquitous network (Park et al., 2009). It can enable seamless information exchange between humans, with humans and with entities (e.g., mobile devices), as well as entities and entities at any time, any place and in any way. To meet the development needs of adaptive personalized convergent services, dynamic service discovery and composition technologies are explored widely in the telecommunication service field (Bashah et al., 2010; Niazi & Mahmoud, 2009).

Today, semantic web service (McIlraith, 2001), as an establishing research paradigm, is defined as an augmentation of web service with semantic annotation, to facilitate the higher automation of service discovery, composition, invocation and monitoring in an open environment. Integration of the semantic web technology and telecommunications systems is explored widely in the telecommunication service field (Do & Jorstad, 2005; Vitvar & Viskova, 2005; Qiao et al., 2008a; Gutheim, 2011; Khan et al., 2011; Zander & Schandl, 2011). It is well known that ontology is the semantic interoperability and knowledge sharing foundation for semantic web services matching and context reasoning. Therefore, how to construct the telecommunications service domain ontology is an important factor of successfully applying semantic web services into telecommunication service systems (Veijalainen, 2007, 2008). However, telecommunication service field consists of a large number of concepts/terminologies and relations. How to abstract the sharing domain

Telecommunications Service Domain Ontology:

detail as follows.

**2.1 Domain ontology modeling methodology** 

Fig. 1. Domain ontology modelling methodology.

ontology hierarchy modelling approach is needed.

**2.1.1 Define the scope of telecommunications service domain ontology** 

The first step is mainly to define the scope and border of domain ontology. Telecommunications service domain ontology mainly addresses the semantic interoperability of telecommunications service. This domain ontology mainly provides the shared domain vocabularies and knowledge to support the semantic web applications in the telecommunication service field, such as semantic telecom service description, service discovery, and service context modelling. Therefore, TSDO should involve the servicerelated domain concepts and knowledge. For example, telecom services often involve network type, network carrier, billing policy, user terminal, service quality, service customer, service category, .etc. In fact, telecommunication service field consists of a large number of concepts/terminologies and relations. Some concepts have the higher sharing degree. However, some concepts are only related to concrete application field, such as service context ontology, service description ontology. Therefore, how to abstract the sharing domain concepts and reasonably organize them is a big challenge. The reusability and extensibility are two important ontology modeling factors considered. So an efficient

In practice, we adopted a layered ontology modeling method to organize the domain concepts to improve the reusability and extensibility (see Figure 2). Common ontology, like time and space ontologies, can be shared in the different domains, like telecom, medical domain or any other domains. The concrete domain ontology can be shared by the different domain-related application ontologies. For example, TSDO may be used to create the service context ontology, network management ontology, etc. This method well distinguishes the border of TSDO, common ontology and telecom service-related application ontology.

Semantic Interoperation Foundation of Intelligent Integrated Services 185

Based on our practical experiences in recent years, a concrete domain ontology modeling methodology is summarized as shown in Figure 1. The modelling process is illustrated in

concepts and reasonably organize them is a big challenge. Some related work has been done mainly in applying ontology technology to the mobile service domain. Based on the need for a standardized ontology that describes semantic models of the domains relevant for scalable NGN (Next Generation Network) service delivery platforms, the (Villalonga et al., 2009; Su et al., 2009) provide an overview of Mobile Ontology which comprises a core ontology and several subontologies, and its application examples in the service delivery platform. This work, as a part of IST SPICE project (IST SPICE project, 2008), is a meaningful attempt to establish a standardized ontology for mobile service delivery in NGN. In addition, IST SIMS project explored the semantic interfaces as a new means to specify and design service components and to guarantee compatibility in static and dynamic component compositions. And they also defined a domain-specific ontology, and its main purpose of the ontology is to establish a common description of the SIMS-related concepts and their semantics (Rój, 2008). The (Zhu et al., 2010) introduces a mobile ontology construction and retrieval system architecture. However, there lacks a general domain ontology modelling methodology for telecommunications service and the corresponding engineering approach to support the development work for domain ontology. The (Li et al., 2010) briefly introduced the constructing method of telecommunications service domain ontology (TSDO) proposed by our research team. However, the approach is not perfect at that time and still needs to be further improved. In fact, telecommunication service domain ontology, as the important semantic interoperability foundation of telecom network, still has no significant progress up to now. This has become the biggest obstacle to hamper the applications of semantic web technology in telecom field.

In this chapter, we clearly presented a practical domain ontology modelling approach for telecommunications service field. Under the guidance of this approach, our research team has created an open telecommunications service domain ontology knowledge repository which consists of around 430 telecommunications services-related ontology concepts/terminologies and 245 properties. Based on this domain ontology, we described the telecom network capability services in the semantic level to validate its feasibility. The semantic annotation facilitated the accurate service description, discovery of telecommunication network services and addressed the semantic interoperability problem. The proposed model-driven domain ontology modelling approach separates domain conceptual model from the concrete ontology modelling languages, it enhances the reusability of domain conceptual model and greatly reduces the technical difficulty of domain ontology modelling.

The remainder of this chapter is structured as follows. In Section 2 we presented a general domain ontology modelling methodology for telecommunications service field, and also proposed a specific model-driven domain ontology modelling approach to support the above presented methodology. Section 3 introduced the experimental environment and the demo service to validate the feasibility of domain ontology. Finally, conclusions are drawn.

### **2. Domain ontology modelling methodology for telecommunications service**

Here, technical modelling details for the proposed approach are described, namely telecommunications service domain ontology modeling methodology and a corresponding model-driven implementation mechanism.
