A Prepaid Rating System must be able to tackle the following 6 challenges:

1. Exceptional throughput. Because of the call/session control, the number of events a system manages in a prepaid scenario can be easily 10 times greater than the number of events the same system would manage for the same services in a postpaid scenario. Poor throughput is the first obstacle to ARPU increasing in prepaid services.
2. Exceptional low latency. Call/session set up and call/session control have to be performed in milliseconds. The lack of real time rating is the first cause of revenue loss in prepaid environment.
   
3. Real authorization flexibility. A prepaid system has to be able to authorize call/session set up and call/session ongoing activities by taking into account several parameters like pricing variables (e.g. time, bytes, hit, content) and charging rules (e.g. charge during the call/session, reserve everything and charge at the call/session complete only). Typically these parameters vary according to service types and tariff plans. Inability to manage several authorization rules hinders the possibility to manage services, launch new offers, create marketing schemes and makes fraud easy.
   
4. Concurrent sessions' management. Today customers can have several concurrent sessions active at the same time. For example, one can make two different telephone calls at the same time whilst downloading his/her mails. Having an effective concurrent sessions' management means the ability to manage, on each single session, several complex features such as reservation, advice of charge and discounts. Moreover, most of the innovative services are inherently transactional based.
   
5. Reverse rating. Reverse rating is the ability to invert a rating formula. Unfortunately, most of the common rating rules are not simple to invert. In prepaid scenarios, reverse rating is often required as part of the call/session set up, therefore prepaid rating engines have to be able to effectively create reverse rating rules.
   
6. Value chain support. New services, such as MMS, content, download and so forth, are inherently open to create marketing schemes based on complex value chains. Also traditional services such as voice calls are now being offered as based on multi party rating (e.g. mobile calls made by a prepaid customer can be paid by the customer's company during working hours). New prepaid rating systems are now asked to manage such a complexity without introducing any lag time in pricing events.

WARP4 provides a set of powerful tools to face all the above challenges.

1. Power. WARP4 provides unprecedented throughput even on small servers. For example, on a single CPU Linux server having a database of 1,000,000 subscribers database WARP4 can rate, with near zero latency, up to 20,000,000 events/hour (working as Balance Manager) or 200,000,000 events/hour (providing Advice of Charge) in real world scenario.
2. Speed. Latency time: 5 milliseconds.
3. Authorization managed via GUI. WARP4 provides a GUI enabling fast definition, for each commercial package and for each service included in the package, of the related authorization model and service quota.
   



4. Sessions. Up to 100,000 transaction based concurrent sessions without any performance drawback.
   
5. Reverse rating definition via GUI. Reverse rating creation is as simple as you can draw it! In WARP4 for each rating rule you define, it is possible to associate a reverse rating by simply clicking on the GUI and drawing it!
   



6. Value chain support via GUI. Unlike the vast majority of the other rating systems, which provide only two pre-configured revenue sharing policies (fixed fee and percentage) and/or only two value chain levels, WARP4 enables its user to freely define both revenue sharing policies and the number of value chain levels. Moreover, thanks to its unprecedented power and speed, WARP4 is able to compute the entire value chain in milliseconds.