A Beginners Guide To Telecom BSS/OSS for Mobile Networks

Understand the generic telecom bss service flow from product catalog to charging and billing, covering prepaid and postpaid options, price configurations, and sharing with crm, order management, and billing systems.

Explore telecom CRM within BSS/OSS, detailing multi-channel customer interactions and how CRM software registers customers, processes orders, handles queries, and generates insights.

Register a customer to capture personal information, national ID, and contact details in the CRM, verify identity, create a CRM account with a service identity, and record billing details.

The order management block verifies orders, checks capacity with inventory and workforce management, and triggers provisioning and activation of the voice service over 3G, then handles billing and crm notification.

Understand online charging in real time for prepaid services and offline charging for postpaid services, including monthly billing cycles and charging across mobile networks.

Trace the evolution of mobile communication from 1G analog systems to 5G, covering 2G GSM, 3G UMTS with broadband data, 4G all-IP LTE, and 5G speeds.

Identify the three main components of a mobile network: the mobile station, the radio access network, and the core network; the mobile station houses the SIM and IMSI.

Discover how the backhaul transport network links the radio access network to the core network using microwave links, electrical cables, or optical fiber, with Dwdm enabling high data rates.

Explore charging and billing in 2G GSM networks, including offline and online charging architectures, through a concise overview of GSM architecture and the essential components for billing.

Trace the gsm architecture from base transceiver system to the bsc and msc, and understand how hlr and authentication center handle subscriber data and authentication.

Explain how the authentication procedure verifies a subscriber's identity using the authentication center's key and a random number, producing a response that is verified by the Vlr and Hlr.

Trace the postpaid call flow from mobile station to the PSTN, including dialing, authentication, routing through BSC/MSC to the gateway, dial tone, ring back, and charging.

Record a call detail record (CDR) in the MSC for charging the call, including caller and callee numbers, start and end times, duration, and a unique MSC identifier.

The offline charging system bills subscribers after the monthly cycle, using mediation to convert diverse records into a common ascii format for processing.

Read CD-R, verify the called party number and time, apply the reference price plan with peak, off-peak, local, and international rates, then multiply duration by the rate to compute cost.

Describe how rated cards feed billing block to generate invoices by summing 30 days of calls, applying discounts, taxes, and credits, formatting as pdf, html, or print.

Explore prepaid charging architecture in GSM networks, including SSP (co-located with MSC), SCP with service logic, rating engine with balances, and SMP with voucher management system.

Follow the prepaid call flow in mobile networks, from MSC authentication and SSP to SCP rating, balance reservation, tariff per minute, and call termination if funds run out.

Learn how 2g data services use gpu and edge technologies in gsm networks, and how sgsn and gsn allocate ip addresses to enable mobile data.

Explore how crs are generated in sgsn and ggsn, with time-based charging in the sgsn and volume-based charging in the ggsn, linked to postpaid and prepaid charging systems.

Explore 3G UMTS architecture, where the core network remains like 2G, radio access shifts to RNC and Node B, and VoIP and video streaming shape quality of service and charging.

Learn how policy and charging control (PCC) enables precise per data service quality of service and differentiated charging for online and offline charging in 4G LTE and 5G networks.

Explore the policy and charging control within the PCC architecture, focusing on the subscriber profile repository, a logical database of all subscribers that stores allowed services, QoS, and charging rules.

Formulate the PCF-driven QoS policy and charging rules for VoIP and other IP flows in the PCC architecture, using inputs from the SPR and the application function.

Explore the 4g lte architecture with pcc for qos and charging, comparing 3g evolution, and explain eps bearers as ip flow pipes with qos, latency and priority.

Describe postpaid data access in 4g lte, from enodeb data requests and authentication via hss with sbr and spr, to pcf-driven QoS, charging rules, and EPS bearer setup.

The charging trigger function generates charging events and forwards them to the offline charging system, where the charging data function creates raw cards for mediation by gateway and billing system.

Learn CDR rerating, recalculating charges for CRS when rates are misapplied or dated back. The re-rating engine reads CRS, checks data usage and numbers, applies tariff, and updates subscriber bills.

Show how reject rating reprocesses CD-Rs in telecom billing by removing errors such as call rates, inactive subscribers, or duplicates, then rating and moving them to the rated CD-R database.

Explore the prepaid data call flow in 4G LTE, from data session setup to EPS bearer establishment and PCF guided QoS and charging via the OCS.

Explore the online charging system, from the charging trigger functions ICF and PCF to credit control, prepaid authorization, and credit reservation, including charging events stored in a database for billing.

Explore how monetary and non-monetary credit units power telecom billing, with minutes, data, and SMS, and how plans deduct from non-monetary units before spending the monetary balance.

Explore the account balance management function (ABMF), which manages containers of credit units (voice call minutes, SMS, MBS, money) and defines the deduction sequence for consuming these credits.

Explore the rating function in online charging systems, converting monetary units to credit units and calculating charges per voice time, per unit, or per service event, including free minutes.

Explore the online charging function's two sub-types: session based for real-time voice and data charging, and event based charging for SMS, content purchases, and on-demand video.

Online charging scenarios include immediate event charging for SMS, event charging with reservation for MMS, and session charging with unit reservation for voice or data calls.

Explore immediate event charging in mobile networks, from the charging trigger function and ECF to online charging, event-based charging, account balance management, and rating control for SMS credits.

Learn how event charging with unit reservation works for an mms, detailing how the charging trigger, online charging function, rating control, and account interactions reserve and deduct units.

Explore session charging with unit reservation for voice calls, as the charging trigger and online charging function reserve units, apply rating, and adjust balances with usage and refunds.

Explore 5g architecture and charging, including pdu sessions, qos flows, and the roles of smf, pcf, and udm in policy and subscriber profiles.

Unifies online and offline charging in 5g within a single converged charging function. Replaces 4g components and links to the billing domain and the gpf.

Explain the initial 5G charging call flow from PDU session establishment through AMF authentication, PCF QoS policy, UPF charging events, and the online vs offline charging interaction.

Explore how 5g offline charging uses event-based charging for sms and mms; the upf triggers the charging function, which creates and updates a cdr via charging data requests and responses.

Describe session based charging in 5g offline charging, where the UPF and the charging function create and update a CR during a voice call using charging data requests and triggers.

Explore 5G online charging, covering immediate event charging and unit-reservation schemes. UPF determines units; charging function deducts via account and rating controls, creates a CDR, and delivers SMS.

Learn how event charging with unit reservation works for MMS. Reserve units via the charging function, as the UPF coordinates delivery, and deduct them after delivery.

Explore session charging with unit reservation in 5g charging. The upf reserves units, updates the cdr, deducts units via charging data requests, and credits unconsumed units back at call end.

Explain how interconnect enables calls and SMS between CSPs via interconnect agreements, service scope, and pricing, and how a trunk line (T1/T2) physically carries calls.

Identify interconnect partners, including originating and termination partners with interconnect agreements, and explain transit partners that enable traffic exchange between non-directly connected CSPs, with transit fees charged.

Explore interconnect billing between CSPs, where the originating partner pays the terminating partner, how trunk labels and CRS identify calls, and how invoices and reconciliation invoices drive settlement.

Explains roaming between operators, where a subscriber from CSP one uses CSP two's network under a roaming agreement, identified by IMSI with MCC, MNC, and MSIN fields.

Understand how roaming occurs between home and visited networks, including IMSI identification, authentication via HLR keys, and data transfer to the visited VLR, with roamer terms for 2G–5G.

Explore how postpaid roaming calls are routed by querying the HLR for the subscriber's location and delivering calls to the home or visited network.

Understand roaming billing: how KDR and CRS are generated in the visited network, how in-roamers' CRS are tariffed, and how tab files enable settlement between home CSPs and visited networks.

Near real time roaming data exchange enables visited networks to send tab files every few hours, allowing home networks to detect postpaid credit limit breaches and reduce fraud quickly.

Explore how a clearinghouse acts as a central hub to exchange tap files, interconvert formats, settle roaming dues, and resolve disputes.

Explore how prepaid voice call routing differs from postpaid, with balance checks between home and visited networks, roaming charges, and call setup via HLR checks.

Examine how data calls are routed in prepaid roaming, with the visited network coordinating with the home network for real-time charging and QoS enforcement via the home GSN.

Explore how itu-t m.3010 defines the telecommunications management network and structures telecom management into four layers: element management, network management, service management, and business management to support end-to-end service delivery.

Explore TMN layers, where element management systems collect performance data and alarms, support maintenance, and connect to the network management system that optimizes resources, QoS, services, billing, and insights.

Explore FCAPS—fault, configuration, accounting, performance, and security management—as defined by ITU-T M.3400, and learn how faults are identified, auto-configuration occurs, usage billed, performance optimized, and assets secured.

Explore the TMN model in mobile networks through its layered structure, with the network element layer housing the radio access network, transport network, core network, and application servers.

Explain how EMS one manages radio access network elements for logging, backup, key performance indicators, and configuration, while EMS two, three, and four handle transport, core, and application server elements.

Element management systems consolidate data and reports and forward them to the network management system, which provides a view of network inventory and the status of physical and logical components.

Operate and monitor the network infrastructure and services from a centralized network operations center, staffed 24/7 to detect faults, resolve outages, and support customers with FCAPS reports.

Extends tmn by mapping telecom processes to the Tom model's management layers, linking planning, provisioning, inventory, and maintenance to network, service, and customer care processes.

eTOM extends the TOM framework into a complete business model, detailing supplier and partner management, enterprise life cycle management, and governance, standardized by the TM Forum.

Discover eTOM level zero, defining the main domain areas of a communication service provider, including strategy, infrastructure and product, operations, and enterprise management, and how operations directly support customers.

Explore level one horizontal eTOM groupings, including marketing and offer management, service development and management, resource development and management, and supply chain development and management, viewed through the CIO lens.

Explore level one vertical process groupings to gain an end-to-end view of processes across billing, assurance, fulfillment, and operations support and readiness.

Explore enterprise management through strategic planning, risk management, knowledge and research management, and asset and financial management to support the company's goals and external stakeholder relationships.

Examine how eTOM level 2 business processes emerge from level one intersections, including blocks like selling, order handling, service configuration and activation, resource provisioning, and supplier partner requisition management.

Break down the eTOM level 3 problem handling block into four level-three blocks: isolate problem and initiate resolution, problem reporting, track and manage, and close, with identifiers.

Map level four blocks to level three tasks, showing how to coordinate with customers during resolution, escalate issues, engage external suppliers, and cancel or end problems per Telecommunication Management Forum.