National Taiwan University Dept Elect EngnLin, PhonePhoneLinLin, Yi-BingYi-BingLinGan, Chai-HienChai-HienGanJeng, Jeu-YihJeu-YihJeng2006-11-142018-07-062006-11-142018-07-062006-01http://ntur.lib.ntu.edu.tw//handle/246246/200611150121416Prepaid phone service requires a user to make payment before calling. In 2.5G or the 3G networks, a user may be engaged in multiple voice and/or data prepaid sessions at the same time. For such services, it is important to distribute appropriate amounts of prepaid credit units to simultaneously executed sessions of a user. By considering the universal mobile telecommunication system (UMTS) as an example, this paper studies the prepaid credit allocation for the prepaid sessions. To simulataneously accommodate more prepaid sessions for a user, we propose a credit reclaim mechanism called prepaid credit reclaim (PCR). Analysis and simulation experiments are conducted to investigate the performance of our mechanism. Our study indicates that PCR can significantly improve the performance of the prepaid mechanism.application/pdf597750 bytesapplication/pdfzh-TWCredit allocationcredit reclaimprepaid servicesuniversal mobile telecommunication system (UMTS)journal article10.1109/TVT.2005.858190http://ntur.lib.ntu.edu.tw/bitstream/246246/200611150121416/-1/03.pdf