Use Case - Hybrid Customers
Prepared (Subject resp) / No.
Ajeet S Patil
Approved (Document resp) / Checked / Date / Rev / Reference
2014-03-08 / PA1
Use Case - Hybrid Customers
Abstract:
This document attempts to enlist the risks associated with subscriber profile of Hybrid subscribers which varies throughout the subscriber lifecycle. Hybrid subscribers can be broadly described or classified as under the below categories
1. Budget Control Scenario
Budget Control comes into effect when a normal postpaid subscriber is unable to pay his monthly dues, hence is “suspended” (inactive till monthly bills are paid up). However, to retain the subscriber, CSP provides an option to continue to use the services by making a top-up (recharge) like a prepaid subscriber and make use of typical services (voice, SMS etc) till the topped up balance is exhausted.
CSP provides a facility to those postpaid subscribers who are unable to pay the monthly bills to be able to continue to use the services by topping up their account by need based recharges (top-ups). The following use cases highlight the risks when subscriber voluntarily moves to a mode called “Budget Control”.
2. The definition of Hybrid subscriber also encompasses scenarios where depending on time of day and weekday or weekends, the calls will be billed from the respective account. Eg
1) From 9AM to 5 PM the calls will be billed for Company account
2) For rest of the time the calls will be charged from subscriber's personal DA.
So apart from classical movement of subscriber when he runs out of balance, this is another scenario where hybrid subscriber comes into play.
3. The subscriber will maintain a postpaid account with a specific credit limit. The postpaid service is basically just like any ordinary postpaid service, with a new twist on the service. The billing service automatically cuts off the outgoing telephone service when the credit limit is reached unlike the usual delay in the cutting off of the service when the postpaid credit limit is reached. To resume full incoming and outgoing call service, the subscriber simply performs a prepaid reload. The service now becomes a prepaid service and the subscriber can use the telephone service as long as there are prepaid credits available in the prepaid account or until the next billing cycle of the postpaid account is reset.
4. Other possible scenario that happens in consideration of ‘Hybrid Subscribers’ is that of having distinct profiles when accessing different services such as voice, sms or data. All voice usage and SMS services are accounted towards Postpaid account, while data usage is debited in real time from Prepaid account.
The risks enlisted below are those associated in and around the movement to Budget control.
These risks cover the following Business Scenarios
- Use Case 1 – Cross Charging and Collection
- Use Case 2 – Faulty Transitions
- Use Case 3 – Roaming Scenarios
- Use Case 4 – Traffic scenarios for Hybrid subscribers. (Example Voice = Postpaid, whilst Data=prepaid + variants)
Use Case 1 / Cross Charging
Details / Step charging is applicable for typical postpaid subscriber whereby pulse is 60 sec/pulse followed by 20 sec pulse and subscriber is charged for specific durations where he has used the airtime. So, an 80 sec call is split into 1st pulse measuring 60 sec and 2nd pulse of duration 20 sec. The appropriate rates for those 60 sec and 20 sec pulses are applied. The charges/rates for 20 sec pulse are lesser; at1/3rd of 60 sec pulse.
While the prepaid charging for prepaid customers is based on 60 sec pulse. So an 80 sec call, will be charged as two 60 sec pulse calls.
Once such postpaid subscriber switches over to Hybrid subscriber mode (Budget Control) the charging pattern should be that of Prepaid subscriber which is on basis of every 60 sec. However on account of flaws in proper tagging once a subscriber switches over, the Prepaid subscriber continues to be charged as per Step charging and gets benefits associated with typical Postpaid subscriber, whereas in reality he should have been charged for the full minute (pulse of 60 sec).
All the transitioned subscribers (hybrid subscribers) have account number of 2000, whereas the postpaid subscriber is tagged to dedicated account number different from 2000. Based on this account number the billing system picks the pulse, the rate and hence charges at rates applicable to postpaid. In this scenario, the tagging to hybrid acct number of 2000 did not happen, hence, charging continues with rates/pulse as applicable to typical Postpaid subscriber.
Similar case under Hybrid Subscriber scenario 2:
Cross Charging can also occur in such a scenario where subscriber’s personal calls (apart from 9am to 5 pm) are accounted/invoiced to company. For his personal calls made, a prepaid indicator flag is set to indicate that calls are to be charged from dedicated account. The above cross charging scenario can also happen to above company + personal account scenario in event the indicator is not set. And all these calls are charged as normal postpaid calls
Challenges / The transition of subscriber from postpaid mode to hybrid mode is not technically translated or communicated at Billing and Charging systems. The triggers that should get activated are located at Collections side where the proper tagging to Hybrid mode needs to be done. This is defined at Account level.
So basically this change of account number (to 2000) did not happen or inaccurately happened.
Further, there is also a possibility that such incorrect tagging could occur at other products/services that are defined, for example even when a subscriber temporarily moves to suspended mode and comes out of it after making due payments, the product tagging may still be incorrect.
Hence, all points at Collection need to be properly validated. As it can affect all the scenarios wherein subscriber moves across different states.
Other possible impacts
a. The continuation of the old tagging can impact charging of normal postpaid subscribers also. All the existing subscribers tagging also have an impact.
b. All the cases where movement of subscribers with a change in account id is involved: When certain subscribers move from negative balance to positive balance; when subscribers move from suspended to active state. So this occurrence is not specifically limited to hybrid scenarios as such.
Recommendation / A regular check on all such transactions at table level in both systems – Charging and Billing needs to be carried out. Further the tagging and non-tagging of relevant account number needs to be delved deep to arrest the incorrect tagging.
Use Case 2 / Benefits of Faulty Transition
Details / Upon enabling of Hybrid mode, subscriber is a typical Prepaid subscriber. However, subscriber is also able to continue to avail of benefits of packages that were earlier entitled to him as a Postpaid subscriber (eg SMS, rate plans etc). The change-over from Postpaid mode to Prepaid mode is not fully implemented technically; hence hybrid subscriber is able to avail of services that he is not entitled to hence leading to Revenue Loss.
Challenges / This happens on account of improper up-date and inconsistencies in status across Charging and Billing systems (BSS). Presence of main accounts and dedicated accounts has to be further explored to understand the changes happening during status changes.
Though the systems that reflect are limited to Billing/Charging, however, the impact is humungous in terms of revenue loss as revenue collection is adversely effected.
Recommendation / A basic reconciliation of services and statuses across systems needs to be performed for Hybrid subscribers. The impact of transition of main account and dedicated accounts needs to be studied in detail to inhibit the defects.
Use Case 3 / Roaming Access
Details / The subscriber on Hybrid mode is on International Roaming. While on International Roaming, Host country interrogates Home country. Home country sends service barring request to Host country. However, Host country fails to recognize the barring request and hybrid subscriber (original postpaid subscriber currently on prepaid mode) continues to use the services that are entitled to postpaid subscribers only.
Challenges / This is a failure for authentication at International Gateway/VLR access level.
This scenario is not limited to just Hybrid subscribers’ accounts, but also with other subscriber or Billing accounts (non-Hybrid subscribers) as well. This has the potential for high risk case whereby host country CSP can invoice home country for its subscribers roaming usage. While at same Home country CSP cannot retrieve the expenses from its subscribers, as the contract specifies that hybrid subscribers cannot roam.
This is one of key revenue leakage situations as International Roaming is involved.
Recommendation / The communication protocol for services and authentication needs to be re-visited and strictly enforced as per contractually agreed terms. Again a regular check on all such Hybrid subscribers on International Roaming needs to be performed at-least fortnightly.
Use Case 4 / Traffic Scenarios or Services Subscription Scenarios
Details / Under Scenario 2 (different profiles for specific usage), upon successful switch over to Prepaid state for data usage, subscribers were still able to make use of voice and sms services without getting charged/billed for that usage. Simultaneously, subscriber makes a payment towards his Postpaid usage. Voice and SMS services were limited to profile where subscriber is in postpaid mode. Subscriber is entitled to certain usage in certain profiles. Though subscriber moved to different profile, he continued to avail of services that are not part of the other profile.
Subscriber makes a payment towards his postpaid usage. The payment made reflects in Charging system as accounted for Postpaid and Charging system considers this subscriber as a postpaid subscriber. Whereas at Billing system, since the Postpaid indicator flag is disabled, Billing system considers the CDRs associated with such subscriber as Prepaid and ignores them (does not rate/charge them nor account it). It does not check against the subscriber profile for the services entitled or services that are subscribed.
Expanding the above usage further, the additional cases in which operations is exposed to higher risk are those in which prepaid mode is considered as a safe/less risk prone however, if Charging system rejects Prepaid CDRs and Billing system also ignores them, thereby exposing all prepaid traffic (data traffic) as going unbilled.
Challenges / The issue arises primarily on account of profiles maintained in Charging and Billing systems, which are subject to changes as explained in scenario above.
Recommendation / The signaling associated with payments that tags subscriber to either Prepaid or Postpaid should be expanded to be included in the CDRs generated so that a secondary check is performed during rating/billing on flags included in CDRs, and not just based on subscriber profiles maintained on Charging and Billing systems.