There is disclosed a reusable shipping pallet formed from plastic parts and a method of assembling the same. A door is rotatably attached to the front wall. When auxiliary services are selected, the cellular operation may cause interference with the auxiliary services. The root node can be coupled to the event bus and to centralized correlation logic programmed to identify a high correspondence between events from a particular event source among the nodes and a particular set of correlation rules in that correlation engine. Upon the occurrence of a failure in the primary circuit interruption means, a secondary circuit breaker, or in some embodiments, a redundant primary circuit breaker release mechanism, serves to remove power from a protected outlet or output conductors. The stopped state determination may be based on RTT measurements alone, or on RTT measurements in combination with other positioning and movement measurements.