A Study Of New Kinds Of Value-added Services' Implementation In Fixed Network

This paper is to study new kinds of value-added services'implementation in the fixed network(PSTN/ISDN), mainly about the new service trigger method of using SDC(Subscriber Data Center).At First, the features of the fixed network and value-added services are generally introduced. There are 2 types of"old"value-added services: supplementary services(eg:call forward) and IN services(eg:800) in the fixed network.The valued-added services'implement procedure consists of two steps: service trigger and service providing. For supplementary services, service trigger is performed by"query of subscriber data at local exchange"; For IN services, it's done by AC(Access Code).The new kinds of value-added services, including CRBT,PPS,UPT and NP, are different from the"old"services. They are assigned to normal subscribers and very popular in recent years. Since the fixed network is designed to provide voice service originally, it's less powerful to provide value-added services than the mobile network(GSM/CDMA).If a new service assigned to normal subscribers will be introduced to fixed network,the mainly problem need to be solved is how to perform service trigger. Both service trigger methods listed before are not suitable to new type of services. To solve this problem completely, one wholely new method is purposed: add centralized subscriber service information database system into the fixed network; get service information from this system during call setup to perform service trigger. This database system is call as SDC.This method consists of two key factors: one is the design of SDC(Standalone SDC or Internal SDC?),another is selection of trigger point(at which exchange the service trigger is performed, local or tandem exchange?). According to the combination of these two factors, 5 concrete methods are summarized: PSR-SSDC, local-SSDC, tandem-SSDC, tandem-ISDC and tandem-STPSDC. They are analysed in detail and compared in different aspects.In order to insure the method of using SDC is executable and affordable, a set of rules must be prepared. This paper gives 5 kinds of rules:safty rule,trigger sequence rule,avoiding loop-trigger rule and service consistency rule, etc. These rules are explained in this paper.Since introducing SDC into the fixed network is a big change for the current network, the influence of this method need to be evaluated. Some important indicators, including prolong delay of call setup, load of No.7 signalling link, traffic of trigger point, are calculated in theory and the actual case is presented.SDC is the core facility in the method of perform service trigger for new kinds of services. This paper gives the description about SDC's technical requirement, architecture and interface. The main part of SDC is the database system which contains subscriber service information This database must be designed to satisfy 3 requirements: large quantity, fast and average response, easy to expand and update. Several ways of database's design are discussed in this paper. The"tree-structure"is proposed and has been verified on site.Although SDC is developed for the fixed network, it will continue to play important role during the process of network's evolution and service's development. SDC will works in fixed/3G combined network, and comes to be HSS of IMS which is key component of NGN.Finally,the problems of new kinds of services's implementation in fixed network except service trigger are discussed, including technical ones and non-technical ones. In general, the other technical problems are easier to be sloved than service trigger, non-technical problems (such as market promotion's strategy) need to be considered and sloved by market and sales person.