Abstract: An alert device includes electronic circuitry and at least a first antenna. The circuitry is designed for sending out a first signal, for wireless communication with at least a first hand held communication device, and at least a second signal for wireless communication with at least a second hand held communication device. The second signal differs from the first signal, preferably in at least one of transmitting energy, transmitting frequency, coding and pulse length. The device includes a switch for switching between: a first mode in which only the first signal is transmitted and a second mode wherein the first and second signal are transmitted; or a first mode wherein only the first signal is transmitted and a second mode wherein only the second signal is transmitted.

Abstract: An alert device includes electronic circuitry and at least a first antenna. The circuitry is designed for sending out a first signal, for wireless communication with at least a first hand held communication device, and at least a second signal for wireless communication with at least a second hand held communication device. The second signal differs from the first signal, preferably in at least one of transmitting energy, transmitting frequency, coding and pulse length. The device includes a switch for switching between: a first mode in which only the first signal is transmitted and a second mode wherein the first and second signal are transmitted; or a first mode wherein only the first signal is transmitted and a second mode wherein only the second signal is transmitted.

Abstract: Alert device comprising electronic circuitry and at least a first antenna, wherein the circuitry is designed for sending out a first signal, for wireless communication with at least a first hand held communication device, and at least a second signal for wireless communication with at least a second hand held communication device, wherein the second signal differs from the first signal, preferably in at least one of transmitting energy, transmitting frequency, coding and pulse length, wherein the device comprises a switch for switching between: —a first mode in which only the first signal is transmitted and a second mode wherein the first and second signal are transmitted; or —a first mode wherein only the first signal is transmitted and a second mode wherein only the second signal is transmitted.

Abstract: Alert device comprising electronic circuitry and at least a first antenna, wherein the circuitry is designed for sending out a first signal, for wireless communication with at least a first hand held communication device, and at least a second signal for wireless communication with at least a second hand held communication device, wherein the second signal differs from the first signal, preferably in at least one of transmitting energy, transmitting frequency, coding and pulse length, wherein the device comprises a switch for switching between:—a first mode in which only the first signal is transmitted and a second mode wherein the first and second signal are transmitted; or—a first mode wherein only the first signal is transmitted and a second mode wherein only the second signal is transmitted.