Derived from the TM Forum’s (http://www.tmforum.org/) Application Framework (TAM), TCA has the flexibility to allow operators to pick and mix components from both billing vendors and network suppliers, utilising standards-based interfaces such as Diameter to fulfil the integration. It also supports phased deployment and upgrades, with real benefits being delivered at each stage on the path to total convergence.

With TCA, Cerillion is helping operators to achieve business improvement at all layers of the TAM, covering sales and marketing, product management, customer management, service management and resource management:

• Market/Sales Level Convergence
  

  Convergence at the Market/Sales level can be achieved relatively easily from an external viewpoint. It is possible to promote broadly the same set of products and services to both prepaid and postpaid markets without actually converging the BSS and OSS.

  However this requires complete replication of products, tariffs, discounts and rating rules between both system stacks, which can significantly slow down time-to-market as configuration and testing effort will be duplicated. It will also restrict flexibility of the product and services that can be offered by limiting to the “lowest common denominator” – i.e. the weaker system – so only features or tariff models that are supported on both systems can be offered to the market.

• Product Level Convergence
  Convergence at the Product level can deliver great benefits in terms of how products and services can be packaged for the market. However it is also perhaps the hardest to achieve in isolation, as it will require the underlying offline and online rating engines to be decoupled from how products and tariffs are defined.
  
  There is also a dependency on customer management functions including order management and bill processing which must access the same product catalogue information.
• Customer Level Convergence
  Convergence at the Customer level is one where significant benefits can be achieved. Moving customer care and self-care onto a unified platform for both prepaid and postpaid segments enables a common level of service to be delivered to all customers, irrespective of how they choose to pay for their services. The obvious beneficiary of this is the traditional prepaid customer base, which can be offered prepaid usage statements and access to the full range of Call Centre services.
  
  However it is also at this level that new combined prepaid and postpaid propositions can be offered. The concept of “family accounts”, where parents are postpaid and children are prepaid, can be easily supported with this level of convergence. Family accounts can then be offered discounts and incentives based on the total usage of all family members, and parents can apply regular top-ups (e.g. pocket money) to the child prepaid accounts, for example.
• Service Level Convergence
  

  Convergence at the Service Level means bringing together the offline and online rating engines and providing a single balance management platform that can support all types of services and their attributed operator and customer-defined balance policies.

  This provides perhaps the biggest technical challenge in convergence, but also offers the most significant benefits to the traditional “postpaid” customers. Policy management enables all customers to manage their own service-level “spending controls” according to their desired budget within the rules defined by their service provider. Online authorisation and advice of charge offers fully transparent pricing, meaning customers know what they are spending as they consume their services, without the risk of overspend or so-called “bill shock”.

  Service Level convergence also creates a new opportunity to offer hybrid services that sometimes behave according to postpaid rules and sometimes in prepaid mode. For example, a voice service could be defined as “postpaid” charged to a business account during office hours and “prepaid” from a personal wallet out of office hours.

• Resource Level Convergence
  Convergence at the Resource Level brings together the mediation and session control functions into a convergent layer. When addressing an IMS compliant network, these functions are clearly defined by the ETSI/3GPP online and offline charging specifications, however in hybrid legacy / NGN environments the layer remains much more complex. The key benefits to be achieved by converging this layer are in improved time-to-market and revenue assurance.