Revenue assurance and fraud management is the software that finds money an operator should have billed but did not, and catches people who use the network without paying for it. Money lost through billing mistakes is called revenue leakage. Money lost to cheating is called telecom fraud. Operators often handle both in one team, because both show up as a gap between what the network carried and what was paid for.
Leakage usually comes from systems that do not agree with each other. A call is recorded by the network, but the record is lost before it reaches billing. A customer's plan is changed in one system and not in another. A discount meant for one month stays on for a year. Each mistake is small, but an operator handles crores of records a day.
Revenue assurance software finds these gaps by reconciliation, which means matching two sets of records that should be equal. Here is a typical case. On one day, the network records 40,00,000 postpaid data sessions in one state. The billing system has rated only 39,96,800 of them. The software lists the 3,200 missing sessions. It traces them to one network server whose records were being rejected because of a wrong date format. The team fixes the format and sends the records again, and the 3,200 sessions are billed. The software runs the same kind of check on roaming records from foreign operators.
Fraud management looks for patterns of behaviour. Consider SIM box fraud. Someone places a box holding 64 local SIM cards in a rented room. International calls are sent to the box over the internet, and the box connects each one to an Indian phone as if it were a local mobile call. The operator receives the low price of a local call instead of the higher price for an incoming international call. In India, such a setup is an illegal telephone exchange. The fraud software spots the 64 SIMs, because each one makes hundreds of calls a day, never receives a call and never moves from one tower. The software blocks the SIMs and passes the details to the operator's security team, which informs the police.
Other patterns include SIMs bought with forged identity documents, and sudden heavy use abroad on a stolen SIM. Deep packet inspection (DPI) helps by reporting traffic that does not match a customer's plan. Text messages have their own filter, the SMS firewall, which blocks spam and fraudulent business messages before they reach phones.
Revenue assurance sits in the business half of telecom OSS and BSS. It does not charge anyone itself. It checks the work of the systems that do.