Integrated Service Platform and Its Characteristic Services

With the competition in the telecom market getting fiercer and fiercer, services that traditional intelligent networks provide are far behind the demands of multimedia communications. The next generation network based on Softswitch has realized the separation of call control and service logic. The integrated service platform is used to develop services. And service capability is opened to the third party service providers through open interfaces. These have created conditions for operators to provide flexible and quick services [1, 2]. Using the integrated service platform to develop personalized and integrated services has become a sharp weapon of operators in market competition.

1 Integrated Service Platform

1.1 Characteristics of Integrated Service  Platform
Based on the Softswitch network, the integrated service platform supports services on the Public Switched Telephone Network (PSTN), Softswitch network and 3G network. It can realize the separation of service logic and call control. As a carrier-class application platform that telecom operators and third-party service providers use to create and provide services, it requires the following characteristics:

• Achieving centralized application control and management.
• Having open, standard and secure Application Programming Interfaces (API).
• Implementing services across networks and platforms.
• Accomplishing the separation of service logic and call control and the separation of service logic and bearing.
• Realizing modularization of network service capabilities and standardization of interface protocols.
• Sharing resources, such as media, message and existing network resources.
• Having quick and flexible service creation.
• Using such computer technologies as the object-oriented technology and the distributed application.

1.2 Architecture of Integrated Service Platform
Its architecture can be divided into 4 planes from top to bottom:
  (1) Application Plane
  The application plane presents functions of the platform from the respect of users. It reflects various applications that the platform can provide to end users. The application plane is composed of function entities with one or more service features. Service features can be divided into 2 types by function. One is related to network capability, such as users´ status presentation, instant message providing and serial-parallel addressing. The other is related to service management, such as the Webpage customization of service attributes and users´ data inquiry. From the respect of users, these service features can implement not only traditional voice intelligent services, but also personalized and voice/data combined services.

  (2) Interface Plane
  The interface plane describes the platform from the respect of application developers, and reflects the network capability and service management capability the platform can provide for developers. Relevant services are described by defining various application programming interfaces, i.e., the aggregate of methods and parameters. Interfaces are also divided into 2 types by function. One is related to network capability, such as the service interfaces for call control and user interaction. The other correlates to service management, including the accounting function interface and user account management interface.

  The main technologies currently used for the plane are Parlay and JAIN. Parlay API is specifications defined by the Parlay Group. Its objective is to define a set of external applications to use internal network resources securely and allow third-party service providers or telecom operators to quickly develop various telecom services.

  JAIN API is defined by the JAIN Forum. It is implemented by the JavaBean technology. JAIN is a research forum launched by Sun Corporation in 1998, aiming at the study of how to use JAVA technology to provide intelligent services. So far, over 80 companies have joined the JAIN Forum. The goal of JAIN API is to develop the existing private and closed telecom system into an open system with quick service supply capability. This open system has service transplantability. Its services are independent of bottom telecom networks. It allows service providers to access the networks.
Currently, JAIN and Parlay keep using each other´s technologies for reference and making mutual convergence. The basic trend is that the call control API uses Parlay´s definition and the protocol API adopts JAIN´s definition. Both adopt the JAVA language.

  (3) Distributed Function Plane
  This plane describes the service system from the respect of service platform designers and reflects the overall design a platform. The service platform includes various functional modules, namely service capability servers. Each server implements one or more interface functions at the interface plane. There are two types of service capability servers. One is related to network capability, such as functional entities for call control and user interaction. The other is related to service management, such as the central accounting entity.

  (4) Physical Plane
  The physical plane describes the service system from the respect of service platform users and serves for the physical implementation of the platform. Service capability servers can be implemented in various physical nodes. Physical nodes and service capability servers can be in one-to-multiple or multiple-to-multiple relationships. Possible physical nodes are the application server, database server, Authentication, Authorization and Accounting (AAA) server and call control server.

2 Analysis on Service Demands  and Characteristic Services

2.1 Service Demands
  (1) Traditional Voice Services
  Within a relatively long period of time, fixed telephony services are still the main income source of traditional telecom operators. The fixed network has formed scale economy and can bring good and quick returns.

  However, the equipment capability and processing ability of the program-controlled switch cannot meet the demands of current service development anymore. Fixed telephony services are losing their competence, and their income growth has come down.
Therefore, it has attracted operators´ main attention to develop more new services and look for the potential of existing services by using the Softswitch technology and improving service capability of the PSTN network.

  (2) Broadband Services
  In recent years, the number of broadband users has increased continuously and quickly. It lays a good foundation for the development of broadband services. However, current broadband services are mainly the access services, lacking applicable value-added multimedia services.
The Softswitch network is a service-driven network. Its integrated open service platform helps attract third-party services and content providers to join. Thus service types will be enriched and service applications will be quickened. To introduce the Softswitch technology to broadband networks will infuse vital energy into the development of broadband services.

  (3) Group-User Services
  Fiercer competition in telecom industry forces operators to put the business emphasis on group users, and it is especially true for new operators. Due to their weak foundation and smaller network coverage, new operators usually focus their business attention on group users who may bring them high income and profits.

  In respect of services for group users, future competition will be focused on integrated and personalized services. Telecom operators have to enforce the satisfaction and faith of clients through advanced technologies, diversified and individual package services and service innovation. Demands of various industries for communication are complicated and diversified. Operators have to customize services for users according to the characteristics and scale of a special industry and demands of group users. They also have to further improve services and continuously conduct service innovation to achieve the purpose of attracting and keeping group users to guarantee their sustainable development.
The integrated service platform has the capability of developing integrated open services. According to the demands of group users, the multi-service mixed package and individual services can be flexibly developed on the platform. The extensive services for group users will be consequently upgraded to real personalized services, which helps operators win the initiative in competition.

2.2 Characteristic Services
The features of Softswitch services include:
  (1) Cross-network and cross-terminal communication capability: providing services for all kinds of networks, such as fixed and mobile networks, and multiple terminals.
  (2) Multimedia communication capability: providing voice, video and other integrated services based on broadband packet networks.
  (3) Customized service capability: the openness and flexibility of the service platform make it possible to launch personalized services.
Two services with development prospects are introduced here: IP Centrex service for group users and personal communication portal service for broadband users.

2.2.1 IP Centrex Service for Group Users
To win more group users is the business focus of all telecom operators. The Softswitch technology has incomparable advantages over traditional switch technologies in providing services for group users. Currently, it is a pressing demand for all large operators to use the Softswitch technology to provide group users with the Centrex service.

  Compared to the Centrex service based on the traditional switch, the IP Centrex service based on Softswitch has the following obvious advantages:
  (1) It is difficult for the traditional system to implement Centrex services across different offices and areas. However, with the strong cross-network capability, a Softswitch system can conveniently implement wide-area Centrex services.
  (2) The traditional Centrex service can´t provide users with individual management functionality. But the Softswitch system can achieve the self-management and self-configuration of individual user´s attributes and authority, and real-time accounting information enquiry by providing users with an open management operation interface. Thus it can meet users´ diversified demands well.
The network topology of the IP Centrex service is shown in Figure 1.

  As shown in Figure 1, the IP Centrex service server provides a convenient operation management terminal, so an administrator can easily log on to the system through a Web interface to add, delete and modify users´ data. IP Centrex also has a perfect multi-area-code support function. It can not only map users who are in different geographical areas to the same virtual area, but also map one user to different virtual areas. Thus users in different areas can access the packet network through IP Centrex servers of the Softswitch system, which enables the branches of a nationwide company to enjoy convenient communication services.

2.2.2 Personal Communication Portal Service for  Broadband Users
The services that a Softswitch system can provide for broadband users include point-to-point voice and video communication, conferencing, personalized communication management, unified numbers bound with the existing fixed telephone numbers, Color Ring Back Tone (CRBT) and so on.
When using the personal communication portal service, broadband users access and set their personal communication portals through the Web interface. They can enjoy services such as IP video telephone, users´ personal addresses that can be grouped, built-in click-to-dial, history list of personal incoming and outgoing calls, detailed list of telephone fee, list of unanswered calls, user online status, instant messages and personal communication configuration. The network topology of the personal communication portal service for broadband users is shown in Figure 2.

  As shown in Figure 2, the Softswitch is responsible for call control, while the application server provides service logic, user database and Web services. Broadband users can make a call to another online broadband user through a multimedia terminal and log on to the personal communication portal through a Web browser to manage their addresses and telephone books, call records and other functions.

  The following are the main functions of the personal communication portal service for broadband users:
  (1) User Registration and Log-on
  A user registers through a Web interface and obtains his user name and password for access to a personal communication portal. Then he logs on to the Web and makes configuration for the personal communication portal. After that, the system automatically opens corresponding video terminal software.

  (2) IP Video Telephone
  A user may dial a fixed telephone number via a video terminal software. If the called party is an online broadband user, an IP video call can be made by calling his video terminal software. The user can also choose to use audio communication only. If the called party is not a broadband user or offline, the call will be connected to his traditional telephone.

  (3) Telephone Book
  A user can create his own telephone book, and conveniently modify and manage it. He can also set or cancel call screening and call transfer functions for specific telephone numbers.

  (4) Call Register
  A user can view the list of his received calls, dialed numbers and missed calls. He can delete or restore the history call records in his telephone book. He can select or dial a telephone number from the list, and also calculate call charges by himself based on the call records.

  (5) Click-to-Dial
  A user can input a number and then click to dial. He can also select a number from the telephone book and click to dial.

  (6) Call Forward with No Answer
A user can set a forward number, and turn on/off the function of Call Forward with No Answer.

3 Conclusion
As operators´ Softswitch tests and pilot commercial applications are in progress, the Softswitch technology and services are becoming more mature. However, there are still many problems with its large-scale commercial applications. Firstly, most equipment providers have declared that they can provide integrated multimedia value-added services, but service interoperability between them still needs further improvement because of the capability differences between various service platforms. Secondly, equipment providers and operators need cooperation in theory and practice to set up service quality control systems, plan reasonable IP bearing networks and effectively guarantee the quality of Softswitch services. Lastly, it is expected to do further research in the relationship between Softswitch and existing services, and the profit pattern of Softswitch.

  New technologies need time to grow and mature. Practical applications are necessary for the Softswitch technology to become matured. With the joint efforts of equipment providers, network operators and service providers, the commercial application of Softswitch services is expected to accelerate.

References
[1] Mi Zhengkun. Softswitch Technology and Protocol [M]. Beijing: Posts & Telecommunications Press. 2002, 7.
[2] Chen Jianya. Softswitch and Next Generation Network [M]. Beijing: Beijing University of Posts and Telecommunications Press, 2003, 2.

Manuscript received: 2004-01-08