3 Charge Advice Information
22.0243GPPDescription of Charge Advice Information (CAI)Release 17TS
The MS is supplied with the necessary Charge Advice Information (CAI) at the charging point on a per call basis, in a signalling message over the radio interface.
The MS uses the CAI elements to compute the AOC value for the relevant call. Thus the signalling CAI not only provides charging information, but indicates the charging point and hence initiates the timing of the chargeable duration.
The information sent to the MS from the MSC consists of seven elements as follows:
Table 1: Information elements
|
Element |
Dimensions |
Description |
MIN |
MAX |
RES |
|
e1 |
u/i |
Units per interval |
0 |
819.1 |
0.1 |
|
e2 |
t/i |
Seconds/time interval |
0 |
819.1 |
0.1 |
|
e3 |
‑ |
Scaling Factor |
0 |
81.91 |
0.01 |
|
e4 |
u |
Unit increment |
0 |
819.1 |
0.1 |
|
e5 |
u/d |
Units per data interval |
0 |
819.1 |
0.1 |
|
e6 |
seg/d |
Segments/data interval |
0 |
8191 |
1 |
|
e7 |
t/i |
Initial secs/t interval |
0 |
819.1 |
0.1 |
where:
u = units; t = time; i = interval; seg = segments; d = data interval.
The CAI Message need only contain those elements required for the particular situation. If elements are missing from the initial CAI message of a call, they shall be treated as zero.
Element e1 ‑
This element defines the number of units incremented per interval. It is set in terms of LPLMN units/interval to a resolution as defined in the table above under RES.
Element e2 ‑
This element defines the time interval for unitization, and is specified in seconds, to a resolution as defined in the table above under RES.
Element e3 ‑
This element defines the scaling factor to convert from LPLMN units to HPLMN units. It is a dimensionless multiplier given to a resolution as defined in the table above under RES.
Element e4 ‑
This element defines the number of units to be incremented on receipt of the message containing the CAI elements. It is specified in units of the LPLMN to a resolution as defined in the table above under RES.
Element e5 ‑
This element defines the number of units incremented per data interval. It is set in terms of LPLMN units/interval, to a resolution as defined in the table above under RES.
Element e6 ‑
This element defines the data usage interval for unitization, and is specified in segments (SEG), to a resolution as defined in the table above under RES., for Dedicated Access to the PSPDN (whether directly or via Dedicated PAD). It does not apply to circuit switched access to modems or PADs, (except Dedicated PAD’s) or MS to MS calls.
Element e7 ‑
This element defines the initial time interval for unitization, and is specified in seconds, to a resolution as defined in the table above under RES.