Cost Effective Calling Mechanism for Roaming Users

Abstract

The cost of initiating a call when roaming in a foreign PLMN network is considerably high. As a remedy for this, VoIP services can be used, but both calling and called parties have to have internet connectivity with suitable QoS at both ends. This research paper is directed towards implementation of a cost effective solution for international roaming, where only the calling party (roaming in foreign country) requires internet connectivity and the called party (in home country) does not need internet connectivity. This roaming architecture is assisted by the Public Switched Telephone Network (PSTN) of a local fixed operator. The service network consists of Customer Network (CN) and Provider Network (PN). CN consists of a Customer Premises Equipment (CPE), VoIP Gateway (GW), Internet connectivity (preferably ADSL line) and PSTN line. The PN consists mainly of a Roaming Connectivity Server (RCS) and Call Accounting Server (CAS). These specifications are only used in-order to simulate the conceptual network which is further described. Network infrastructure described in this paper can be subjected to change, according to the customer base, network security, and other parameters. In the customer end, accessibility is increased by using several applications and configurations. This network service can be deployed without interfering the other operator revenue generation and still be cost effective from customer point of view.