Abstract: Methods and apparatus for selecting from among multiple available path for transporting messages between a train application in a head-of-train area (HOT) and a train application in an end-of-train area (EOT), the multiple paths including at least one direct path and, optionally, one or more indirect paths, each path including at least one wireless segment. A communications manager selects a path using a predetermined method that considers, optionally, how many attempts there have been to transmit an application message and one or more predetermined key performance indicators.

Abstract: A wireless train control network is adapted for forwarding data between a remote radio in an EOT unit and remote radio at the head of train using the base stations of the wireless train control network. A base station's current table of base station radios and remote radios that it hears or has a connection is distributed to neighboring base stations by a routing information exchange application. Tables are sent to and received from the application using a messaging service of the wireless train control network. A base station builds from the tables of neighboring base stations a route to a remote radio to which it is not connected, and forwards wireless data packets received for it by transmitting it to another base station radio.

Abstract: Methods and apparatus for selecting from among multiple available path for transporting messages between a train application in a head-of-train area (HOT) and a train application in an end-of-train area (EOT), the multiple paths including at least one direct path and, optionally, one or more indirect paths, each path including at least one wireless segment. A communications manager selects a path using a predetermined method that considers, optionally, how many attempts there have been to transmit an application message and one or more predetermined key performance indicators.

Abstract: An end-of-train (EOT) unit that comprises an enclosure housing its monitoring, control, and communication equipment and systems, an arm that positions and supports at least one auxiliary wheel on a rail of a track to rotate electrical generator coupled to the auxiliary wheel while the train is moving.

Abstract: A radio for determining the occupancy of a variable width channel for secondary use, the variable width channel with a bandwidth equal to an integer multiple of the bandwidth of a plurality of narrowband channels in an RF frequency band. The radio decides whether the variable width channel in the RF band is occupied by whether classifying each of the narrowband channels corresponding to the variable width channel and each of a plurality of sub-bands with bandwidths of narrowband channels but center frequencies shifted by one-half of the bandwidth of the narrowband channel and overlap with the bandwidth of the variable width channel as containing signal or noise based on measured energy levels.

Abstract: An interface device for interfacing a set of wayside systems with a radio transmitter includes a plurality of input ports each having at least one input for receiving a signal representing a state of a corresponding wayside system and first and second parallel data paths coupled to the plurality of input ports. Each data path includes input protection circuitry coupled to the inputs of the input ports for preventing short-circuit and open-circuit conditions from triggering a false input state, a multiplexer for selecting between the input port; and a processor for scanning the input ports with the multiplexer to determine the state of current signals appearing at the inputs. In response to determining the state of the current signals appearing at the inputs, the processor generates a message communicating a current state of the wayside systems for delivery to the radio transmitter.

Abstract: A method for exchanging information within a radio communications system includes establishing communications between radio systems utilizing a carrier sense multiple access mode during a period of lower traffic load on the radio communications system and establishing communications between the radio systems utilizing a time division multiple access mode during a period of higher traffic load on the radio communications system.

Abstract: A communications system includes a plurality of operational nodes and a plurality of data distribution systems. A data distribution system operating in an active mode manages exchanges of data between the operational nodes and further operable to periodically transmit go passive messages commanding at least one other of the data distribution systems to operate in a passive mode. A data distribution system operating in the passive mode waits for receipt of one of the go passive messages, continues to operate in the passive mode after receiving one of the go passive messages within a predetermined time out period, and transitions to the active mode after the time out period has expired without receipt of one of the go passive messages.