ZTE´s Unified Service Platform

Currently, telecom operators generally have pre-paid and post-paid subscribers, and adopt real-time billing and hot billing methods. However, the markets are requiring stronger billing functions and faster service update capability.
The Intelligent Network (IN) is the main technical method to realize pre-paid real-time billing. The IN can perform complex service-logic-selection and call-control to conveniently implement online billing, but it is not flexible to provide mixed billing support, service bundling for pre-paid subscribers and
pre-paid/post-paid conversion. Meanwhile, due to the separation in the implementation of
pre-paid and post-paid billing, network operators lack an overall grasp of the subscribers´ usage habits, and suffer from huge initial cost and high maintenance input.

    On the other hand, as the Service Independent Building Blocks (SIB) technology of the IN has a high initiation requirement, the development and commercialization of new services still rely on equipment providers. The result is the less openness and less expandability of service development. In addition, the IN is intrinsically difficult in deploying multi-party call, conference call, service convergence and other services.

1 Architecture and Technical Features
For all the above problems, ZTE embarked on significant and substantial development and exploration in the evolution of the IN towards the Next Generation Network (NGN). Based on the open service structure and the advantages in the conventional IN, ZTE has successfully developed a unified service platform oriented to NGN, which has been massively applied in both domestic and overseas markets. The network structure of the platform is shown in Figure 1.

1.1 Convergence of Pre-paid and Post-paid Services
To implement flexible billing support and enable the convergence of pre-paid and post-paid services, billing is to be separated from the service logic. The billing of services is no longer controlled by the Service Control Point (SCP). Instead, SCP sends a billing request to the dedicated billing unit, and via the related protocol, transfers the billing parameters to the billing unit. The billing unit executes the billing logic, and returns the result to the SCP via the protocol to complete the entire online billing process. By adopting the mode of direct interaction between billing and service control, the billing information can first affect the service provisioning, and then update the account balance in real-time.

    The Diameter Credit Control (CC) protocol is applied in the interaction between the ZTE IN and the online billing unit. The Diameter CC server provides real-time rating and credit control, and through the interaction with the server, the SCP (Diameter CC client) acquires the “credit authorization” and monitors the use of the “credit authorization”. When the subscriber uses the online billing services, the collaboration of server and client can complete the real-time credit control of the subscriber account.

    The Diameter protocol provides a secure, reliable, and easy-to-expand framework for authentication, authorization and billing services. It has the following features:

    (1) With a good failure handling mechanism, it supports failover and failback.
    (2) It has the capability of fast detecting the unreachability of the far end.
    (3) It has a better packet discard processing mechanism and requires acknowledgment of each message.
    (4) It ensures the completeness and confidentiality of the data.
    (5) It supports end-to-end security, Transport Layer Security and IPSec.
    (6) It performs authentication/authorization for each session to ensure security.

1.2 Convergence of Services and Networks
The platform separates the service from the carrying network. Therefore, it facilitates the interconnection of multiple networks and fast service provisioning. The platform adopts the open, standard and unified Parlay/OSA Application Programming Interfaces (API). Through the object-oriented technologies such as Common Object Request Broker Architecture (CORBA), different operating systems and development tools can be applied between the application server and the Parlay gateway.

    The unified service platform has the following strengths:
    (1)The Parlay/OSA API is provided to the external, thereby facilitating the secondary service development and the introduction of services by third-party application developers.

    (2)The following open interface standards are supported:

• Intelligent Network Application Protocol (INAP)
• Customized Applications for Mobile network Enhanced Logic (CAMEL)
• Wireless Intelligent Network (WIN)
• Session Initiation Protocol (SIP)
• Media Gateway Control Protocol (MGCP)
• Short Message Peer to Peer Protocol (SMPP)
• Simple Mail Transfer Protocol/Intelligent Network Application Protocol (SMTP/INAP).
  

    The platform can keep the original access mode intact and lower the operation construction cost. In addition, it conveniently integrates the services. Therefore, the subscribers of different networks can easily use unified services.

    (3) The services of multiple media formats are provided, supporting the conventional fixed telephone network, intelligent services of 2G mobile network. It fully supports 3G, Softswitch, broadband data, video, and other voice and data VAS.

    (4) The unified service platform adopts the service subscription mode to easily implement nested services. Services such as One Number Link You (ONLY) and Coloring Ring Back Tone (CRBT) can be fast deployed.

    (5) The applications can be distributed and operated on multiple application servers, uplifting the system reliability and smooth expandability.

    (6) All services provided on the conventional IN are inherited.

    The platform has an open system structure. In addition, it inherits the advantages of service maturity and excellent system processing capability of the IN. In particular, the OSA module adopts the call control core processing mechanism of the SCP module, leading to a great freedom in processing dense traffic and large signaling processing load.

2 Conclusions
Facing the current fierce competition in the communication market, network operators must provide richly diversified services and flexible service billing policies for pre-paid/post-paid subscribers. The unified service platform of ZTE, leading the IN into the future, is the right weapon for network operators.

Manuscript received: 2005-10-06