MITTAL INSTITUTE OF TECHNOLOGY & SCIENCE, PILANI

Cellular Billing System: Architecture, Functionality, and Software Packages

  1. Introduction

A Cellular Billing System is a mission-critical component of any mobile telecommunications service provider. It ensures accurate charging, invoicing, and revenue collection for mobile services such as voice, data, SMS, roaming, and value-added services. These systems must process millions of call detail records (CDRs), handle various pricing plans, support regulatory compliance, and ensure real-time charging to prevent fraud or revenue loss.

  1. Components of a Cellular Billing System

A comprehensive cellular billing system typically consists of the following components:

  1. Mediation System
  • Collects raw usage data from network elements such as MSCs (Mobile Switching Centers), SGSNs (Serving GPRS Support Nodes), and VoIP gateways.
  • Normalizes and filters the data to produce standardized Call Detail Records (CDRs).
  1. Rating Engine
  • Applies the appropriate pricing model to CDRs or EDRs (Event Detail Records).
  • Handles complex tariff plans including peak/off-peak pricing, discounts, loyalty points, and promotional offers.
  1. Billing Engine
  • Aggregates rated events to produce a final bill.
  • Manages billing cycles (prepaid/postpaid), taxation, usage summaries, and customer balances.
  1. Customer Relationship Management (CRM)
  • Provides interfaces for customer care representatives.
  • Allows management of accounts, complaints, subscriptions, billing inquiries, and payments.
  1. Payment Gateway Integration
  • Interfaces with banks, wallets, or other financial platforms to process payments.
  • Supports prepaid recharge, postpaid bill payment, and auto-debit functionalities.
  1. Roaming and Interconnect Billing
  • Supports TAP (Transferred Account Procedure) records for international roaming.
  • Manages settlements with interconnecting telecom partners.
  1. Fraud Management and Revenue Assurance
  • Uses analytics and anomaly detection algorithms to flag suspicious activities.
  • Ensures that revenue is not lost due to leakage, misbilling, or fraud.
  1. Reporting and Analytics
  • Generates KPIs, churn analysis, ARPU (Average Revenue Per User), and revenue forecasts.
  • Helps in marketing, customer segmentation, and product planning.
  1. Billing Modes
  • Prepaid Billing: Real-time charging, often integrated with IN (Intelligent Network) platforms.
  • Postpaid Billing: Event-based billing, with credit limits and end-of-cycle invoicing.
  • Hybrid Models: Allow users to maintain both prepaid and postpaid accounts (e.g., prepaid data with postpaid voice).
  1. Software Packages Used in Cellular Billing

The cellular billing system market includes both proprietary and open-source platforms. Major software packages include:

  1. Commercial Solutions

Software

Vendor

Description

Amdocs CES

Amdocs

End-to-end digital billing, charging, CRM, and revenue management solution. Highly scalable, used by large telecoms.

Ericsson BSCS iX

Ericsson

Modular billing and customer care system with real-time charging and policy control.

Oracle Communications Billing and Revenue Management (BRM)

Oracle

Cloud-ready convergent billing system used for prepaid, postpaid, and digital services.

NetCracker Billing

NEC/NetCracker

Supports converged BSS/OSS operations including billing, charging, and CRM.

SAP Convergent Charging & Convergent Mediation

SAP

Telco-specific billing, especially when integrated with SAP CRM and ERP modules.

Huawei CBS (Convergent Billing System)

Huawei

Popular in Asia and Africa, includes charging, billing, and partner settlement modules.
  1. Open Source and Customizable Tools

Software

Description

JBilling

Open-source enterprise billing system (Java-based) with extensible modules for telcos.

KBilling

Suitable for smaller operators or MVNOs (Mobile Virtual Network Operators).

Freeside

Web-based open-source billing system supporting VOIP, dialup, and wireless services.

OpenCell

Open-source convergent billing platform designed for telecoms and ISPs.
  1. Integration and Technologies Used
  • Databases: Oracle, MySQL, PostgreSQL, MongoDB
  • Programming Languages: Java, C++, Python, Erlang (real-time systems)
  • Middleware: Apache Kafka (for event streaming), RabbitMQ
  • Web Services: REST APIs, SOAP for integration with third-party apps and mobile apps
  • Protocols: Diameter (for real-time charging), RADIUS, TAP3 (for roaming)
  1. Real-Time vs. Batch Processing
  • Real-Time Billing is crucial for prepaid users to prevent revenue leakage.
  • Batch Billing is suitable for generating postpaid invoices and handling legacy systems.
  1. Reliability and Redundancy
  • High Availability (HA) architectures with redundant servers, load balancing, and database replication are employed.
  • Disaster Recovery (DR) setups with automatic failover and regular backups.
  • Service Level Agreements (SLAs) ensure minimal downtime and high transaction throughput.
  1. Future Trends in Cellular Billing
  • 5G and Network Slicing Billing: Charging based on QoS parameters, ultra-low latency use cases, and dynamic resource allocation.
  • AI/ML in Billing Analytics: Predictive pricing, churn prediction, and personalized offers.
  • Cloud-Native Billing: Migration to microservices, containerized platforms using Kubernetes and Docker.
  • Blockchain for Roaming Settlements: Transparent, fast, and tamper-proof inter-carrier settlements.
  • Digital Wallet Integration: Seamless billing via Apple Pay, Google Pay, and other mobile money systems.
  1. Conclusion

The cellular billing system is the financial backbone of any telecom operator. Its complexity has grown with the evolution of mobile networks from 2G to 5G, and the rise of converged services. Modern billing systems must be agile, scalable, and integrated with customer-facing and regulatory platforms. Software packages such as Amdocs CES, Ericsson BSCS, Oracle BRM, and newer cloud-native solutions form the basis of today’s telecom revenue management systems.

 

Professor Rakesh Mittal

Computer Science

Director

Mittal Institute of Technology & Science, Pilani, India and Clearwater, Florida, USA