A band is used to charge a user different amounts depending upon how much of a particular resource they have actually used. A band can be defined technically as a range of usage (usage band) for which certain charges per unit apply. The unit in which the ‘usage’ is measured could be be something like ‘Mb downloaded’, ‘hours connected’, or ‘number of calls made’.
For example, a band might state that the user gets charged $0.15 for every Mb downloaded below 200 Mb during the billing period. Another band might state that the user gets charged $0.12 for every Mb downloaded below 1000 Mb during the billing period. A final band might state that, unless otherwise specified, all other usage is charged at $0.10.
If a plan had these three bands attached, the end result would be that the user will be charged $0.15 per Mb for the first 200Mb downloaded, then $0.12 per Mb for the next 800 Mb and then $0.10 for each Mb thereafter.
Bands can also be used to charge for flag fall – a single charge at the start of a session. This is mainly useful for wireless applications such as Internet cafés, and can also be useful for Voice Billing plans.
Plans may also optionally have Location Variants attached to them. These location variants may each have different plan bands and location associated with them. These, in effect, allow the definition of alternative charge schema (plan bands) to be set to apply to clients on the corresponding plan when those clients connect from different locations. This is useful for wireless roaming implementations.