Temporary call-back telephone number service

Conventional temporary telephone number (TTN) service provides a secondary telephone number to a service subscriber. The subscribers can protect privacy by sharing their TTNs without revealing their private numbers. However, TTN service is rarely provided because it requires a large amount of temporary telephone numbers. In this paper, we present a restricted form of TTN service - temporary call-back telephone number (TCN) service - to reduce the amount of telephone numbers needed. A TCN is assigned only for the communications between a subscriber and the correspondent parties specified by the subscriber. Other users, except for the specified correspondent parties, cannot reach the subscriber through the assigned TCN. A TCN assignment can be specified by a telephone number mapping record that consists of a subscriber's number, a TCN, and a correspondent party's number. A TCN can be assigned to more than one subscriber, as long as the subscribers' specified correspondent parties are different. Analytic models using Markov chains have been developed to show that the TCN service significantly reduces the amount of temporary numbers required. The TCN service can be implemented using the Intelligent Network (IN) service architecture as a value-added service. TCN Subscribers can initiate calls to and receive calls from the specified correspondent parties without revealing their private telephone numbers. However, the TCN service is not a replacement of the conventional TTN service because only the specified correspondent parties can reach the subscriber by the assigned TCN.