This chapter aims at describing the history and practice of Internet and telecommunications charging, their mathematical foundations, and the research activity and propositions in this domain.

History and evolution of access pricing models

Internet access has historically been and often still is charged through a flat-rate pricing scheme, meaning that users pay a subscription fee to their provider, and then can use the service as much as they want at no additional cost. It corresponds to an “all-you-can-eat” buffet. We can remark, and are going to develop here, that flat-rate pricing exists in many other contexts, but also that it has not been and still is not always the case in telecommunications, and that there is a trend to move from a flat rate to a more general usage-based scheme, meaning here that the price you will pay will depend on your consumption pattern. For an extensive description of flat-rate versus usage-based pricing, we advise the reader to refer to [241].

To discuss a bit more the evolution and comparison of pricing schemes, we can first remark that flat-rate pricing is commonly admitted in other areas. It is typically the case for television (cable TV, but not only), for which there is a subscription fee, and the user can watch as many shows as he wants. In telephony, flat-rate pricing has always been the traditional charging scheme for local calls in the USA, even before the emergence of voice-over-IP.