Threshold Limits

Each balance has a threshold limit that is determined internally by the MATRIXX Charging Application as subscribers use balances. The threshold limit helps determine the amount in a balance that can be used, which can be different than the actual balance amount available, taking credit limits into consideration.

The threshold limit is particularly helpful when a subscriber is sharing a group balance and has an available amount that is larger than the available group balance amount. In such cases, the subscriber's available amount is limited to the group amount. This value is the threshold limit. For all balance types, the threshold limit must always be greater than or equal to 0, but the value itself is determined based on the balance type and by using a credit floor. For prepaid periodic balances, the credit floor is the sum of all grants to the current balance entry. For prepaid simple balances, the credit floor is the sum of the current balance amount and the most recent grant. For virtual prepaid balances, the credit limit is the absolute value of the credit floor. For example, if a balance is granted 300 minutes, the credit floor is -300 and the threshold limit is set at 300.

Threshold Limits describes how the threshold limit is determined for aggregated and non-aggregated balances.
Table 1. Threshold Limits
Type Non-Aggregated Aggregated
Prepaid The threshold limit is the absolute value of the credit floor, which is determined by the balance type:
  • Simple Balances — The sum of the current balance amount and the most recent grant. The credit floor is reset on each grant or top-up to the balance. For example, if the balance was $5 and there is a $10 top-up, the new floor is $15.
  • Periodic and On-Demand Balances — The floor of each period is the sum of all grants or top-ups into the balance during that period.
Note: For percentage threshold notifications, the notification is sent when the balance is at a percentage of the threshold limit (absolute value of credit floor).

For example, assume a subscriber has a threshold limit of 1000 Mb and a threshold notification is configured at 50%. If the subscriber does a balance top-up of 500 Mb, a notification is triggered when the balance is at 50% of the new threshold limit (1000 + 500) or 750 Mb.

The threshold limit is the minimum of all threshold limits in the aggregation chain from the point of query to the root of the group. For example, if a subscriber has no credit limit but the group has a credit limit of +1000, the subscribers threshold limit is +1000.

The following example describes the threshold limits for a prepaid aggregation chain. Virtual balances are postpaid in this example.

Assume the following balance credit limits (CL):
  • Sub1_Bal — Virtual = 750 CL
  • GrpMid_Bal — PREPAID GL = -500 CL
  • CreditFloor GrpTop_Bal — Virtual = INF CL
When querying the balances, the threshold limits (TL) are:
  • Sub1_Bal = 500 TL
  • GrpMid_Bal = 500 TL
  • GrpTop_Bal = INFINITE TL
Postpaid The threshold limit is the credit limit. For example, if the starting balance is 0 and the credit limit is +300, the threshold limit is +300. The threshold limit is the minimum of all threshold limits in the aggregation chain from the point of query to the root of the group.

The following example describes the threshold limits for a postpaid aggregation chain. Virtual balances are postpaid in this example.

Assume the following:
  • Sub1_Bal — Virtual = INF CL
  • GrpMid_Bal — POSTPAID GL = 500 CL
  • GrpTop_Bal — Virtual = 750 CL
When querying the balances, the threshold limits are:
  • Sub1_Bal TL = 500
  • GrpMid_Bal TL = 500
  • GrpTop_Bal TL = 750

When the MtxBalanceThresholdEvent is enabled, the ThresholdLimit field value in the EDR is the current threshold limit value on the balance.

For information about querying balances using the SubMan APIs, see MATRIXX Subscriber Management API.