A transmitting external defibrillator, for use with a receiving external defibrillator distinct from the transmitting external defibrillator, the receiving external defibrillator including a first housing, a first energy storage module in the first housing for storing a first electrical charge, a first defibrillation port for guiding via electrodes the first electrical charge to a person, and a first wireless communication module, for transmitting resuscitation event data to the receiving external defibrillator, the transmitting external defibrillator comprising: a second housing; a second energy storage module in an interior of the second housing that stored a second electrical charge; a second defibrillation port adapted to be coupled to electrodes, and via which the second electrical charge was guided to the person; a memory in the interior of the second housing adapted to store event data about when the second electrical charge was guided to the person; a bump sensor in the interior of the second housing, for generating motion information of the second housing; a bump detector in the interior of the second housing configured to determine whether the second housing has been subjected to a local bump event based on the generated motion information, the local bump event including a physical contact between the transmitting and receiving external defibrillators; a second wireless communication module in the interior of the second housing; and a processor in the interior of the second housing configured to, responsive to a determination that a local bump event has occurred, cause the second communication module to establish a wireless communication link with the first communication module, in which the second communication module is further adapted to transmit a data signal that encodes the resuscitation event data over the communication link, in which establishing the communication link includes establishing a bump confirmation that the local bump event also involved the receiving external defibrillator, and the data signal encoding the resuscitation event data is transmitted only if the local bump confirmation is established, and in which establishing the communication link further includes causing the second communication module to transmit an availability signal, and the availability signal is output with a preset time delay after a time of the local bump event. a second housing; a second energy storage module in an interior of the second housing that stored a second electrical charge; a second defibrillation port adapted to be coupled to electrodes, and via which the second electrical charge was guided to the person; a memory in the interior of the second housing adapted to store event data about when the second electrical charge was guided to the person; a bump sensor in the interior of the second housing, for generating motion information of the second housing; a bump detector in the interior of the second housing configured to determine whether the second housing has been subjected to a local bump event based on the generated motion information, the local bump event including a physical contact between the transmitting and receiving external defibrillators; a second wireless communication module in the interior of the second housing; and a processor in the interior of the second housing configured to, responsive to a determination that a local bump event has occurred, cause the second communication module to establish a wireless communication link with the first communication module, in which the second communication module is further adapted to transmit a data signal that encodes the resuscitation event data over the communication link, in which establishing the communication link includes establishing a bump confirmation that the local bump event also involved the receiving external defibrillator, and the data signal encoding the resuscitation event data is transmitted only if the local bump confirmation is established, and in which establishing the communication link further includes causing the second communication module to transmit an availability signal, and the availability signal is output with a preset time delay after a time of the local bump event.