A radio base station comprising - a first radio module (21, 23) for radio communication with first radio communication devices (11, 16) assigned thereto, and - a second radio module for radio communication with second radio communication devices (2 - 10) assigned thereto, wherein the two radio modules (21, 22, 23) have a coupling with each other, - the second radio module with the aid of the coupling is configured to influence the radio activity of the first radio module (21, 23), and - the first radio module (21, 23) is designed to be influenced in terms of its radio activity, - wherein the second radio module is configured to communicate with electronic price indication signs as the second radio communication devices (2 - 10) assigned thereto, and - wherein during the communication of the second radio module with the electronic price indication signs (2 - 10) a time slot communication method is used in which in a repeating sequence a number of time slots (Z1 - ZN) of identical time slot duration per time slot cycle are available for communication, wherein each time slot (Z1 - ZN) is characterised by a distinct time slot symbol (ZS1 - ZSN), and wherein the second radio module always at the start of every time slot duration sends a synchronisation data signal having the respective time slot symbol (ZS1 - ZSN) so that the price indication sign assigned to the respective time slot (Z1 - ZN) can, during a receiving duration, during which the assigned price indication sign has left its sleep state and is in the ready to receive active state, receive the time slot signal (ZS1 - ZSN) to determine its synchronous state, - wherein the radio activity of the first radio module (21, 23) is always influenced by way of the coupling in such a way that during a mute time span, during which the synchronisation data signal appears, the first radio module (21, 23) is muted, wherein the mute time span overlaps the receiving time duration with a lead time and a lag time. - a first radio module (21, 23) for radio communication with first radio communication devices (11, 16) assigned thereto, and - a second radio module for radio communication with second radio communication devices (2 - 10) assigned thereto, wherein the two radio modules (21, 22, 23) have a coupling with each other, - the second radio module with the aid of the coupling is configured to influence the radio activity of the first radio module (21, 23), and - the first radio module (21, 23) is designed to be influenced in terms of its radio activity, - wherein the second radio module is configured to communicate with electronic price indication signs as the second radio communication devices (2 - 10) assigned thereto, and - wherein during the communication of the second radio module with the electronic price indication signs (2 - 10) a time slot communication method is used in which in a repeating sequence a number of time slots (Z1 - ZN) of identical time slot duration per time slot cycle are available for communication, wherein each time slot (Z1 - ZN) is characterised by a distinct time slot symbol (ZS1 - ZSN), and wherein the second radio module always at the start of every time slot duration sends a synchronisation data signal having the respective time slot symbol (ZS1 - ZSN) so that the price indication sign assigned to the respective time slot (Z1 - ZN) can, during a receiving duration, during which the assigned price indication sign has left its sleep state and is in the ready to receive active state, receive the time slot signal (ZS1 - ZSN) to determine its synchronous state, - wherein the radio activity of the first radio module (21, 23) is always influenced by way of the coupling in such a way that during a mute time span, during which the synchronisation data signal appears, the first radio module (21, 23) is muted, wherein the mute time span overlaps the receiving time duration with a lead time and a lag time.