Acctopus NetMaut OCS (Online Charging System) manages available quota in terms of data volume, time or units (e.g. number of SMS). It serves the OCS requirements for more than 32 million subscribers, having 15 million concurrent sessions on a single environment.
As an OCS, it features the major functionalities of
- an Account Manager
- a Session Manager
- a Balance Manager
- a Charging Manager
- a Campaign Manager
- a Reservation Manager
as well as a flexible Rating Engine to calculate the tariff options booked by the subscriber.
Functionalities of NetMaut OCS
The Account Manager maintains the structure of dynamic subscription data with monetary equivalence.
An account can have one or more users associated with it and may have balances/counters of currency or a unit type.
The Account Manager keeps a configurable transaction history in the OCS account data structure.
In principle, the Account Manager
- checks the account balance,
- supports account balance updates (credit/debit),
- supports account balance reservations,
- gets/sets counters to the Admin GUI and the API and
- gets/sets expiry date of the (pre-paid) account.
The Session Manager maintains the chargeable or free of charge sessions.
In most cases a session is a data communication and might be of type data session (e.g. 4G or GSM) or of type duration e.g. of a movie, streamed to the end user. A session also might be a voice call, if not counted as data session.
Sessions always carry parameters to identify (at least) the user, the device, the location, the communication originator, the consumer, and many more, depending on the type of session.
During and after the session these parameters are used for rating, charging and for CDR creation.
The Session Manager keeps a history of the sessions for troubleshooting and reporting for a configurable period of time.
The Charging Manager provides real-time charging and authorization of resource usage. It supports session based charging as well as event based charging, both immediate and with unit reservation, where the reservation task is maintained by the Reservation Manager.
To support these tasks, the Charging Manager collects information related to a chargeable event, which has been formatted, transferred and evaluated in order to make it possible to determine the usage the subscribers account balance may be debited (online charging) or for which the charged party may be billed (offline charging).
Every chargeable event is evaluated for type of service, location of usage, time of day and checked against the subscriptions, the user has on her account or against products, the user has to be charged for as single charge or as start of a recurring charge. To do so, the Charging Manager gets its information from the Rating Engine.
The Campaign Manager helps to kick off marketing campaigns for a certain group of subscribers. It is the most efficient way to start special discounts or free of charge units for volume or time units or for setting up a higher QoS for a certain period of time, if supported by the PCRF or if accompanied with NetMaut PCRF.
Campaigns might be set up within minutes, without involving configuration of several other systems. The operator can manage all types of large-scale, multi-wave and cross-channel campaigns, execute and measure them.
The Balance Manager cooperates with the Account Manager, but takes care of the subscriber account balances (subscriptions), instead of the subscriber and users.
Account balances include units/currency or subscriber counters, e.g. SMS/MMS/volume/time used per time unit (day/week/month/year).
The Reservation Manager gets involved during sessions or at events, which require unit reservation.
Unit reservation is the standard way to prevent fraud scenarios, where e.g. a prepaid subscriber places a phone call after her monetary units are depleted.
Interfaces and Protocols
The OCS includes the interfaces required for the full MVNO integration and supports voice, data and SMS charging.
The Diameter Gy interface sits between the PCEF (e.g. on a PGW) and the OCS. It is used for online charging of data sessions. Diameter Gy is a subset of the Ro interface.
The Diameter Ro interface sits between the AS and the OCS for charging of IMS & LTE sessions.
The Diameter Sy interface sits between the OCS and the PCRF. Via this interface, the PCRF might subscribe policy counter values from the OCS, related to subscribers who have active data sessions at a PGW which is controlled by the PCRF, using Diameter Gx.
All Diameter applications might either have their peer on the far end entity or might be connected to a DRA in between the far end entity and the NetMaut OCS.
CAP, the CAMEL Application Part protocol, is used when the subscriber is roaming between networks, allowing the home network to monitor and control calls made by the subscriber. CAMEL provides services such as prepaid roaming services and authenticates the services in accordance to the account balance of the subscribers account settings, which might come from an available unit or available free of charge.
NetMaut OCS has a powerful function which lets MVNO’s services platform interrogate or book services even using HTTP/ LDAP, which are not primarily designed or foreseen for this application, but help to speed up evolution of product design at the MVNO.
Short Message Peer-to-Peer (SMPP) is used to send status information to the subscriber (e.g. balance notifications) as well as to receive balance upgrades, sent by the subscriber to the MVNO’s charging system, which take these upgrades and - if successfully applied – creates CDRs to the billing system.
For charging of SMS’ the SMSC might support Diameter Ro or can be interfaced using HTTP/ SOAP.
Integration of the NetMaut OCS
The OCS controls the data usage of the subscribers through the internal "Flow Based Service Data Credit Control Function" to the PCEF (Policy Charging and Enforcement Function) in the gateway (GGSN/PGW).
During the session the OCS uses Diameter Reauthentication Requests (RAR) to control the volume and time quotas.
The quotas that are managed by the OCS are sent to the gateway in parts or completely for internal management. Each time a volume limit or a preset time has been reached, the gateway sends a status message about the data usage (Credit Control Request) to the OCS. Based on this status the OCS takes its next decisions.
The OCS communicates with the subscriber and session databases to get the relevant information for the calculation of the available quotas.
The PCRF can communicate with the OCS via a Diameter Sy interface to request quota status changes (Spending Limit Reports), in order to change the PCC rules respectively.