One or more computing devices, systems, and/or methods for determining a time-length of an action are provided. For example, a first event may be detected. Responsive to detecting the first event, a first inquiry may be transmitted in a first direction, using a first device. The first inquiry may be received by a second device. Responsive to receiving the first inquiry, a first reply data packet, comprising an identification number associated with the second device, may be transmitted, using the second device, to the first device. A second event may be detected. Responsive to detecting the second event, a second inquiry may be transmitted in a second direction, using a third device. The second inquiry may be received by the second device. Responsive to receiving the second inquiry, a second reply data packet, comprising the identification number, may be transmitted, using the second device, to the third device.