Communication system and method for operating such a system

The present invention relates to communication system comprising first and second communication devices ( 11,12 ) each capable of communicating with a telecommunications network ( 10 ), and both being connectable to each other by a data link ( 17 ) for information transfer and to a method for operating the same. The first communication device ( 11 ) contains individual information, and the second communication device ( 12 ) comprises a special memory area ( 21 ) for storing individual information acquired from the first communication device ( 11 ). To enable an improved and facilitated usage of the system comparator means ( 22 ) for comparing the individual information contained in the first communication device ( 11 ) with that stored in the special memory area ( 21 ) of the second communication ( 12 ) device are provided. Therefore, only changes of the individual information of the first communication device ( 11 ) are stored in the second communication device ( 12 ) after comparing the individual information from the first communication device ( 11 ) stored in the second communication device ( 12 ) with the individual information in the first communication device ( 11 ) when the first communication device ( 11 ) is connected again to the second communication device ( 12 ).