Patent ID: 8418813

Claim:
A network for a safety system in a transportation system, wherein the transportation system includes a shaft and a car arranged in the shaft, wherein the shaft is relatively narrow, elongated and an enclosed space, and wherein the shaft is fixed in place and the car is moveable within the shaft, and the car substantially fills a cross section of the shaft: a set of wall nodes arranged in the shaft, wherein each wall node is fixed in place, and wherein the set of wall nodes includes a first wall node at a first end of the shaft, and a second wall node at a second end of the shaft, and other wall nodes in between as relay nodes, wherein each wall node includes at least one wireless transceiver connected to one or more antennas and each wall node is a source or sink of safety message; a set of car nodes arranged on the car, wherein each car node includes at least two wireless transceiver connected to one or more antennas, wherein each transceiver includes a transmitter and a receiver, wherein each car node can be the source or sink of the safety messages, wherein the first transceiver uses a first frequency and the second transceiver uses a second frequency to communicate each safety messages in duplicate; and a wired backbone connecting the set of wall nodes to a controller of the safety system of the transportation system.