A method of performing clock synchronization between two apparatuses includes storing, in a first apparatus, information representing synchronization accuracy required by at least one function of the apparatus； carrying out, by the first apparatus, a service discovery procedure with a second apparatus, and receiving clock information from the second apparatus during the service discovery procedure； determining, by the first apparatus on the basis of the received clock information and said stored information, whether or not synchronization accuracy is sufficient for the at least one function； and upon determining that the synchronization accuracy is sufficient for the at least one function, synchronizing a clock of the first apparatus with a clock of the second apparatus.
