Method of Determining an Unusual Behaviour of an Electronic Apparatus, and Electronic Apparatus Able to Implement Such a Method

1. A method of determining user profiles of an electronic apparatus, said electronic apparatus to carry out an operation requiring the use of an item of information regarding an internal reference clock of said electronic apparatus, the method comprising: comparing the internal reference clock information item with a span of temporal coherence of the electronic apparatus, said span of temporal coherence being determined on the basis of various temporal information items associated with different information sources and stored within the electronic apparatus; in the case of inconsistency between the internal reference clock information item and the coherence span, storing an information item relating to a use of said electronic apparatus, wherein said storing of the information item relating to the use of the electronic apparatus comprises conditioning said storing on the observation of at least one of the following conditions in a limited time interval related to the carrying out of the operation requiring the use of the internal reference clock; a number of information sources, from which the temporal information items are acquired, accessible by the electronic apparatus, has varied; an operation of connecting and/or disconnecting a cable connected to the electronic apparatus has been observed; an operation of purchasing an audio and/or video content has been carried out through the intermediary of the electronic apparatus.

2. The method according to claim 1 , further comprising: in order to determine the span of temporal coherence, acquiring from a first information source a first temporal information item able to be used as internal clock of said electronic apparatus; acquiring from at least one following information source at least one following temporal information item, each following temporal information item being able to be used as internal clock of said electronic apparatus; storing in a memory of the electronic apparatus the first temporal information item and each following temporal information item, all of the stored temporal information items constituting a time base of the electronic apparatus; selecting among the different stored temporal information items an internal reference clock of the electronic apparatus.

3. The method according to claim 2 , wherein selecting the internal reference clock is carried out by associating a hierarchy level with each stored temporal information item, the internal reference clock being constituted of the stored temporal information item associated with the highest hierarchy level.

4. The method according to claim 3 , wherein the hierarchy level is assigned, for each stored temporal information item, as a function of the information sources from where the considered temporal information item comes.

5. The method according to claim 3 , wherein association rules of the levels of hierarchy are stored in a memory of the electronic apparatus prior to the acquisition of the temporal information items.

6. The method according to claim 2 , further comprising replacing a stored temporal information item by a more recent temporal information item coming from the same information source as said stored temporal information item.

7. Electronic apparatus able to implement the method according to claim 1 .

8. Digital television decoder able to implement the method according to claim 1 .