Moving object communication control system

Abstract

A communication system between mobile and wayside stations wherein the mobile stations are traveling on a track which is divided into sections by means of an open-type transmission line paralleling the track. A frequency selection and conversion device for each section of transmission line or track is connected to the transmission line to define the length of each section. A series of lower frequency carriers transmitted on the line are allotted respectively to each specific section of transmission line. These low-frequency carriers travel with a low loss along the transmission line and they are selected and converted by their respective frequency selection and converter device to a common high-frequency carrier signal for leaky transmission to a mobile station on the corresponding track section. These signals are used for train control and other communication signals may be transmitted on the same transmission line by a high-frequency carrier signal which is common to all sections, such that the common signal will leak from the transmission line for reception by a mobile station no matter its location on the track.

We claim: 
     
       1. A communication system between mobile and a wayside stations, said mobile stations traveling on a track divided in sections by means of an open-type transmission line paralleling the track, a frequency selection and conversion device for each section along said open-type transmission line and connected thereto at the proper position to define the length of each section, means to transmit a series of first lower frequency carriers on said open-type transmission line at a low loss from said wayside station, said carriers allotted respectively to each specific section of said open-type transmission line, said selection and conversion devices operable to select and convert their respective first lower frequency carrier to a first higher frequency carrier for leaky transmission from said transmission line to a mobile station on the corresponding track section, an antenna for each mobile station for receiving and transmitting signals to said open-type transmission line. 
     
     
       2. The communication system of claim 1 wherein the frequency of said first higher frequency carrier is common to all sections of said open-type transmission line. .[.3. The communication system of claim 1 characterized by means to transmit at least one high-frequency carrier which is common to all of said sections from said wayside station or said mobile stations 
     
     
        on said open-type transmission line..]. 4. The communication system of claim .[.3.]. .Iadd.1 .Iaddend.characterized in that selected of said mobile stations are .Iadd.substituted by .Iaddend.stationary ground stations coupled through their corresponding of said frequency selection 
     
     
        and conversion devices directly to said transmission line. 5. The communication system of claim 1 .[.characterized by means on selected of said.]. .Iadd.wherein a .Iaddend.mobile .[.stations to transmit.]. .Iadd.station traveling along a track section transmits .Iaddend.at least one second higher frequency carrier .[.common to all of said sections.]. from its .[.respective.]. antenna to said transmission line.[.,.]. .Iadd.and .Iaddend.said conversion device for the corresponding track section of said open-type transmission line .[.being.]. .Iadd.is .Iaddend.operable to convert said carrier of second higher frequency to .[.a.]. .Iadd.the .Iaddend.second lower frequency .Iadd.allotted to said corresponding section on which said mobile station travels .Iaddend.for 
     
     
        transmission along said line at a low loss to said wayside station. 6. The communication system of claim .[.1.]. .Iadd.5 .Iaddend.characterized in that selected of said mobile stations are .Iadd.substituted by .Iaddend.stationary ground stations coupled through their corresponding of said frequency selection and conversion devices directly to said 
     
     
        transmission line. 7. The communication system of claim 1 wherein said 
     
     
        open-type transmission line is an open-type coaxial transmission line. 8. The communication system of claim 7 wherein said coaxial line has an outer conductor sheath with a longitudinal series of alternately slanted slots having a spacing pitch P, said lower frequency .[.carries.]. .Iadd.carriers .Iaddend.all having a frequency regulated by the condition ##EQU8## and said higher frequency carriers all having a frequency regulated by the condition ##EQU9##