A navigation device includes a communication subsystem and a navigation subsystem. The communication subsystem communicates with a remote navigation database via a gateway using variable-size data payloads. Each variable-size data payload is accompanied by a content-identifier and a size-identifier. The navigation subsystem determines a current position of the navigation device and encodes the current position of the navigation device as one or more position payloads that are sent from the communication subsystem to the remote navigation database via the gateway. Each position payload is sent with an accompanying content-identifier and size-identifier.