Method and mechanism for reduction of within-train reported data
First Claim
1. A method of tracking assets comprising the steps of:
- affixing a tracking unit to each asset to be tracked;
establishing a mobile local area network of tracked assets between a plurality of tracking units in close proximity, each of said tracking units constituting a node of the mobile local area network;
establishing a master tracking unit among tracking units in the mobile local area network, all other tracking units in the mobile local area network being slave tracking units; and
approximately locating each one of the slave tracking units in the mobile local area network with respect to the master tracking unit bytransmitting a tone signal from the master tracking unit to each one of the slave units,tracking a returned tone signal from each one of the slave units respectively, andmeasuring a distance between the master tracking unit and each one of the slave units, respectively, as a phase difference in transmitted and returned tone signals, respectively.
1 Assignment
0 Petitions
Accused Products
Abstract
A tracking system for railcars is configured as a dynamic local area network having a master tracking unit and a plurality of slave tracking units, each tracking unit being affixed to a separate railcar. To improve reliability of communications between railcars, the distance from a master unit to a slave unit is estimated by comparing phase of a transmitted signal with that of the transmitted signal returned by another tracking unit in the network. Optionally, a determination is made as to whether the slave unit is "ahead" of or "behind" the master unit. Communication path loss between the master and slave units due to frequency selective fading may also be determined. A spectrum survey determines quality of the channel as to its capacity for passing data from the slave unit to the master unit.
37 Citations
7 Claims
-
1. A method of tracking assets comprising the steps of:
-
affixing a tracking unit to each asset to be tracked; establishing a mobile local area network of tracked assets between a plurality of tracking units in close proximity, each of said tracking units constituting a node of the mobile local area network; establishing a master tracking unit among tracking units in the mobile local area network, all other tracking units in the mobile local area network being slave tracking units; and approximately locating each one of the slave tracking units in the mobile local area network with respect to the master tracking unit by transmitting a tone signal from the master tracking unit to each one of the slave units, tracking a returned tone signal from each one of the slave units respectively, and measuring a distance between the master tracking unit and each one of the slave units, respectively, as a phase difference in transmitted and returned tone signals, respectively. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
Specification