Abstract: A system may comprise a plurality of subsystems, each including an encoder, a transmitter configured to transmit ultrasonic signals, a receiver configured to receive ultrasonic signals, and a local memory. Each subsystem may be configured to: encrypt data relating to first subsystem status of the subsystem; encode, using the encoder, the encrypted data relating to the first subsystem status to an ultrasonic signal; transmit, using the transmitter, the ultrasonic signal relating to the first subsystem status to other subsystems of the plurality of subsystems; receive, using the receiver, one or more signals from each of the other subsystems of the plurality of subsystems, the one or more signals relating to other subsystem statuses of the other of the plurality of subsystems; store, in the local memory, the received one or more signals; and transfer, to a server, data regarding the first subsystem status and the other subsystem statuses.