The Mining Data Mart - Data Mining Techniques in CRM: Inside Customer Segmentation - page 169

the account. Therefore, another data dimension, concerning only the prepaid
customers, that should be tracked is the top-ups. The minimum information
that should be monitored on a monthly basis includes the frequency (number)
and value (credit amount added) by top-up type. Additionally, an organization
might also follow the top-up recency (time since last top-up) and the trend of
average times between top-ups, although the latter would require a detailed
recording of each top-up.

Incoming Usage

The incoming usage table (''M_Inc_Usage''), Table 4.20, applies the logic of
monthly aggregations presented above to the incoming traffic data. Incoming
usage behavior is tracked over time with monthly aggregations that summarize the

Table 4.20 The incoming usage table.

Field name Field type Field description

Year_Month Int The number that indicates the year and month of data

MSISDN Int The MSISDN (the telephone number that received the

calls)

Service_Code Int Theservicecodethatdescribesthetypeofcall(voice,

SMS, etc.)

Network_Code Int The network code from where the calls originated (source)

Roaming_Flag Bit A flag indicating if the calls were received in a foreign

country

Peak_Flag Bit A flag indicating if the calls started during peak hours

Working_Flag Bit A flag indicating if the calls started during working

days

Number_of_Calls Int Number of calls

Duration_of_Calls Real Duration of calls (in seconds, for voice calls)

Volume_of_Data Real Volume of data transferred (where applicable, for instance

Internet calls)

Roaming_Amount Real The amount that was rated to the calls due to incoming

roaming

Intercon_Amount Real The incoming amount charged to third parties for calls made

to the specific MSISDN

Year_Month, MSISDN, Service_Code, Network_Code, Roaming_Flag, Peak_Flag, and Working_Flag are the
primary keys (PKs) of this table.