System for selectively transmitting messages to passers-by

摘要

Messages are selectively transmitted from a transmitting means to at least one mobile means when inside a first area, the mobile means roaming around a second area which includes the first area. A control signal is sent from the transmitting or the receiving means for pick-up by the other whenever the receiving means substantially enters the first area. In response to the pick-up signal, the information message is transmitted from the transmitting means into the first area. The receiving means is enabled to receive this message. Reception of the information message at the receiving means is detected and in response to this the control signal continues to be sent. The information message continues to be transmitted into the first area while the control signal is picked up and the link between the transmitting and receiving means is terminated when the control signal stops being received. The system is particularly suitable for use in a supermarket in which the mobile receivers are mounted on the shopping carts. Other uses include public galleries and museums where the receiver is carried by a visitor.