vices mapped to a pricing schema. The customer is offered various plans by the service provider from which the customer selects a plan to be mapped to the account. The account is billed based on the selected plan. 4. Call detail record (CDR): This record is generated by the exchange switch with details of the call between source and destination. CDRs have valuable information about the call that can be used for billing. 5. Recurring charge: The charge the customer has to pay periodically for a prod- uct or service offered by the service provider. 6. Billing cycle: It is the periodic cycle during which the customer is billed for the subscribed service. That is, a billing cycle can be calculated as the time interval between two bill generations. 7. Accounting cycle: In order to generate a bill, a set of accounting activities needs to be performed. The cycle for which the activities to identify charges against an account are calculated. Accounting does not involve bill genera- tion and accounting is only about tallying the customer account. Some of the billing types are: Wireline billing: The billing of utilization in a wireline network. The call records are generated at the switch or elements handling billing in the core network. Wireless billing: The billing of utilization in a wireless network. Similar to wireline networks, billing records are collected to compute the utilization. Convergent billing: In convergent billing all service charges associated with a user or user group is integrated onto a single invoice. This will give a unified view of all the services provided to that customer. Services in a convergent bill can account for voice, data, IPTV (Internet Protocol Television), internet, Fundamentals of EMS, NMS and OSS/BSS Video-On-Demand (VOD), and many more services that a customer is using from the service provider. IP billing: The billing for IP-based services like VoIP (Voice over Internet Protocol). In IP billing it is usually the content that determines the bill amount rather than the distance betwe