Page 116 - Intelligent Communication Systems

CHAPTER 9 / DESIGN METHODOLOGY FOR TELECOMMUNICATION SERVICES 97
9.6 CONFLICT OF CHARGE POLICY

When more than one service applies to a terminal, a conflict of charge policy may
occur. Examples of such conflicts follow.
Case 1: toll-free phone service. In Figure 9.16 terminal B is charged when a
toll-free phone call is issued to terminal B.
Case 2: Call forwarding variable service. In Figure 9.17, call forwarding
service is defined at terminal B and B is busy. When terminal A calls termi-
nal B, the call is forwarded to terminal C. Then the call between terminal A
and B is charged to terminal A, and the forwarded call between terminal B
and terminal C is charged to terminal B. When toll-free phone service and
call forwarding variable service are defined at terminal B, then whether
a call between A and B is charged to A or B is not clearly decided. In this
case the charge policy has to be rewritten to resolve the conflict.
In general the specification for the charge policy is described as follows:

IF C THEN T, R

FIGURE 9.16 Toll-free phone charge.

FIGURE 9.17 Call forwarding charge.