Telephone Service is a typical way for individual to get in touch with society. Ringback tone replacement business provides everyone with personalized service, which is in accordance with pursuit for individual style in modern society.

This is an era, which celebrates personality. Commodities without personal styles lack commercial value. CRBT (Ringback tone replacement business) is a business service with commercial attractiveness. It enables users to display his personal style. The figure below is a typical user example of CRBT, which fully illustrated the above features:

System Architecture

KH-PRBT has two main functions: business functions and auxiliary functions. Business function enables customers who have subscribed the CRBT service to change the ordinary “beep… beep” ringback signal into pre-customized, flexible and personalized music, audio and other signals during the calling procedure.

Auxiliary function assists customers to complete application for the business functions, make schemes for the ringback replacement, download and record ringback signal resources, manage roaming users, manage billing, make statistical analysis, manage maintenance and so on. With the help of customized ring tone system and trunk line of existing GSM network, CRBT provides playback of personalized ring tones to users; Via SMS, interactive voice, WAP and WEB, we provide mobile users with auxiliary functions. Meanwhile the platform and related real-time mobile accounting systems connect with each other to implement payment service.

The system design uses open system structure, taking potential future expansions into consideration. The specific design takes use of layered architecture as the following figure , which illustrate various aspects of the structure and contents of each level.

Resource access layer

Mainly used for logical representation of resources and direct management of various resources.

Main access methods include PSTN / PLMN（SS7 ISUP、TUP and so on）， Web，Email，SMS，IVR etc.

Core Service Layer

This is the core part of KH-PRBT, including Core Controlling Function(CCF), user database, ringback repository, business interpreter, billing management, Qos and so on.

Business Layer

This layer provides business functions of ringtones and business logic of auxiliary functions and also graphical service creation environment (SCE), which allows convenient modification of business and quick adaptability to change of business.

System Functions

CRBT call function

When MSC/VLR receives a phone call to a mobile user, who has subscribed the personalized ringback tone service, the mobile terminal will launch the calling procedure of ringback tone replacement service. During the calling process of ringback tone replacement service, the mobile terminal MSC/VLR is no longer connected to the local switch ringback resources, but connections can provide personalized ringback tone resources, which is the CRBT. Currently CRBT supports TMD mode and IP softswitch mode.

Service setting up function

Combined with billing service to achieve service setting up function, i.e. launching service flag of HLR. Use functional interface between RBT and billing system to implement automatic service setting up function. Intelligent network uses intelligent network contract information and service definition to implement automatic service setting up function.

Customized ringback tone function:

CRBT platform implements playback of ringback tone replacement service, and provides customized ringback tone function. Customers can make up his own ringback tone replacement scheme, such as customized ring tone by time, caller group customization, Group ring tones, caller ring tones, single player of ring tones and play of mult-tones randomly and playback.

WEB Interface functions

WEB servers can invoke application components from application servers to accomplish requests for service, and functions such as customize ringback tones and user consultants. 　

　 WAP Interface functions

WEB servers can invoke application components from application servers to accomplish requests for service, and functions such as customize ringback tones and user consultants.

SMS Interface functions

For network structure, we can add a SMS server to the system and other servers. This SMS server is responsible for receiving data from users, manage, analyze and store the data into database and send messages to users via SMS Center. SMS servers implements interface with SMS Center (adopting CNPP, SMPP or SGIP protocol, depending on specific situations of providers for equipment of SMS Center) and implements management of operation and maintenance of system and service based on user interface of web server. Collection of signal instructions can be accomplished by existing equipment of mobile network.

Automatic (or manual) voice navigation function

Customers get access to the system via CRBT platform and via trunk line to SSM part of CRBT. By connecting to controlling nodes, users can launch automatic (or manual) voice navigation procedures.

The main technical indicators

• System manages users with permission menu scheme with multi protections such as word of command and password.
• System can check its own configuration, working status of data terminal, network performance, operational information and other contents.
• System has self-maintenance and alarm functions. It can give real time monitor of hard disk space, memory consumptions and CPU occupancy. It also monitors database logs, dynamic library space and status of table.
• The system has good access controlling functions, including controlled access to user interface of system, interfaces between machines, important commands and databases. It gives detailed logs of all the accesses.
• Even KH-PRBT suffers from systematic fault, upgraded software of GSM switching equipment will make sure users can connect to ringback tones without being affected under the circumstance.
• The design of the system and architecture of system is flexible and can adapt to various running environment. It takes use of the currently most popular Client/Server architecture and is highly open and expandable. According to the requirements of TMN, the system can be integrated into future communication management network and can be updated and expanded if necessary.
• The system supports multiple solutions of group network, including TDM mode and IT softswitch mode network.
• Design of software of system meets requirements of increased management function, development of management of network and other requirements of GSM.
• With the promise of advanced technology, adopt the most mature technology for development and make best efforts to synchronize with hardware development.
• Application software adopts user interface of complete chinese version and modular design method to classify modules of systems and standardize interfaces between modules.
• System MTBF > 4 years
• System Acquisition Recovery time <= 12 hours
• Design life of system > 20 years
• Any successive reactions time < 100 milliseconds