Performance of hot billing mobile prepaid service. - Ming-Feng Chang; Yi-Bing Lin; Wei-Zu Yang (Comput. Networks, 2001)

Performance of mobile prepaid and priority call services. - Ming-Feng Chang; Wei-Zu Yang (IEEE Commun. Lett., 2002)

Performance of service-node-based mobile prepaid service. - Ming-Feng Chang; Wei-Zu Yang; Yi-Bing Lin (IEEE Trans. Veh. Technol., 2002)

The implementation of prepaid services over the SIP-based VoIP network. - Liang-Chang Yu; Tai-Liang Chen; Wei-Zu Yang (ITRE, 2005)

The Design of Multimedia Web-based Phone and Billing System with Freeware over the VoIP Network. - Wei-Zu Yang; Liang-Chang Yu; Po-Chou Chen; Tai-Liang Chen (SUTC (1), 2006)

Performance Modeling of Integrated Mobile Prepaid Services. - Wei-Zu Yang; Fang-Sun Lu; Ming-Feng Chang (IEEE Trans. Veh. Technol., 2007)