TY - SER AU - Peirce, Michael AU - O'Mahony, Donal TI - Flexible real-time payment methods for mobile communications KW - AUTHENTICATION KW - AUTOMATIC CONTROL KW - CD RECORDING KW - CONTROL SYSTEMS KW - EDUCATIONAL INSTITUTIONS KW - LAND MOBILE RADIO CELLULAR SYSTEMS KW - MOBILE COMMUNICATION KW - SWITCHES KW - SWITCHING SYSTEMS KW - TELEPHONY N1 - The method of billing users for mobile telephony is based on systems developed over time for fixed networks. We survey the technology involved, and argue that these systems will become increasingly inadequate for large populations of mobile users where frequent roaming is involved. We present two micropayment schemes which permit a caller to inject a payment stream into the network which allows multiple network operators and value-added service providers to be paid in real time ER -