The disclosed embodiments are directed to methods and apparatuses for providing efficient and enhanced protection of data stored in a nonvolatile memory system. If an LTE-A system transmits a reference signal per subframe to support eight transmitting antennas, a problem occurs in that overhead is great. The method further includes receiving information from a 10 second secondary site disk at the local site, and determining if the information received from the second secondary site disk includes updated heartbeat information. The liquid droplet discharge device is adapted to discharge a liquid from the multiple nozzles to form the liquid into liquid droplets. One shaft extends forwardly of the engine to a front transmission on the front axle and the second extends rearwardly to a rear transmission on the rear axle. The hook members may be oriented toward one another, in the same direction or opposite one another.