Table of Contents:

Definition and Overview

1. Network Architecture

2. Positive-Balance Call Origination

3. Positive-Balance Call Termination

4. Mid-Call Zero Talk Time at Home

5. Zero Talk Time at Home

Self-Test

Glossary

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The prepaid subscriber initiates a call within the home area. When the S_MSC detects the origination attempt, it sends an origination request invoke message (ORREQ) to its remote service unit (RSU). The RSU determines that the mobile identification number (MIN) is a prepaid account and queries the market server for talk time available to this account. The market server calculates the available talk time and forwards it to the RSU.

The RSU sends an origination request return result message (orreq) to the S_MSC to indicate that call processing can continue. The S_MSC attempts to connect the call. When the S_MSC detects an answer, it sends an origination answer message (OANSWER) to the RSU. The RSU begins timing the call, and the call is connected.

The subscriber ends the call. The S_MSC sends an origination disconnect invoke message (ODISCONNECT) to the RSU. The RSU stops timing the call and sends the call duration to the market server. The market server prices the call and decrements the subscriber's account. The RSU sends an origination disconnect return result message (odisconnect) to the S_MSC, and the S_MSC releases the call.

Figure 2: Positive-Balance Call Origination