ABSTRACT
The size of investments required for setting up and running digital television transmissions as well as the bewildering increase in transmission rights of attractive contents (sports, recent movies) are such that the vast majority of digital TV programs are not free-to-air in countries where they have a significant penetration (the United States, United Kingdom, France, Italy, Spain). Even if the DVB consortium, like the GSM in the field of mobile telephony, played the role of a powerful unifier in Europe, it could not impose a common conditional access system or a unique user interface specification.
We saw in Chapter 5 that there were numerous conditional access systems using the DVB-CSA scrambling algorithm. These systems differ from one another due to the protocols used to manage and transmit access rights and keys,mainly by software embedded in the set-top box and the subscriber’s smart card. Besides the conditional access system, the most important part of the software for ensuring complete interoperability between different operators of digital TV bouquets (beyond the simple passive reception of TV programs compliant with the DVB standard) is what is generally referred to as “middleware” or sometimes “interactivity engine” or, less often, just API (application programming interface). In fact, the term “middleware” is rather vague and does not mean anything more than that it is situated somewhere between the hardware and (application)
