WO1991014247A1

WO1991014247A1 - Mass-transit communication system

Info

Publication number: WO1991014247A1
Application number: PCT/FI1991/000075
Authority: WO
Inventors: Lauri Virtaperko; Ari Kukkonen; Jari Leino
Original assignee: Lauri Virtaperko; Ari Kukkonen; Jari Leino
Priority date: 1990-03-15
Filing date: 1991-03-15
Publication date: 1991-09-19
Also published as: AU7482191A; WO1991014247A9

Abstract

A mass-transit communication and display system is provided for communication update information to vehicles, such as buses, along their routes. The system has a plurality of update communication stations along the vehicle route for transmitting update information, received from a central control center, to vehicles as the vehicles pass the stations. Receivers in the vehicles receive the information and display the information on displays in the vehicles. The information can be advertising particular to that portion of the bus route, or updated news, weather or traffic information. The system also comprises stopping place or location indicating transmitters which trigger the vehicle to display advertising particular to the immediate location of the vehicle, in response to codes received from the transmitters which identify the location of the vehicle.

Description

MASS-TRANSIT COMHϋHΣCATION SYSTEM

Background of the Invention

The present invention relates to a mass-transit communication system and more particularly to such a system for controlling and updating information announced to passengers in mass-transit vehicles along vehicle routes.

In public vehicles, as for example buses moving in urban areas, is it often desirable that passengers from time to time receive information while the vehicle is en route. One existing system for relaying information to passengers about bus location, for example, incorporates a display sign within the bus which displays the location of the next stop that the bus will make. The system uses stopping place transmitters (sometimes called encoder transmitters or beacons) which are located on utility poles or the like along the bus route. The stopping place transmitters transmit stopping place codes to the display unit within the bus. The display unit within the bus receives the stopping place codes and compares the codes with a pre-stored list of codes in a memory. If the transmitted stopping place code matches one of the pre-stored list of codes in memory, that location is displayed on the display sign to alert the passengers of the next stop. The stopping place transmitters have a transmission range on the order of several blocks so that a bus will be within the range of the stopping place transmitter only when it is about to make that particular stop.

Other systems have been proposed, wherein general information or announcements such as short news blips. weather or sports information, entertaining bits of trivia, information on bus scheduling, and general advertising may be displayed to the passengers in the bus. However, in one such system the display program is set for a cycle of say seven minutes and is repeated continually over the entire bus route. If a passenger on the bus is making a rather long trip, his attention is quickly lost due to the repetition of the information. Moreover, the information, while even if it is updated daily at a bus depot overnight for example, may be fresh and interesting in the beginning of the day, but will lose its ability to interest passengers and may even be inaccurate by the end of the day. Examples of such information are weather forecasts, information on traffic reports or news events of the day.

It would therefore be desirable to provide a system wherein information being displayed on bus or other vehicle signs could be updated periodically to provide updated information on current news, local traffic information, updated sports scores or weather forecasts, as well as any detours that the bus may have to make off of the scheduled route because of traffic or any other unusual conditions.

It would also be desirable to provide a system wherein messages such as advertising may be displayed which is keyed to a particular portion of the vehicle route.

F TΠ ^TT of t Invention

In accordance with the present invention, a mass-transit communication system is provided for use in a vehicle which travels along at least one route and for announcing advertising information to passengers on said vehicle. The system comprises memory means in said vehicle for storing advertising information to be announced to passengers in said vehicle, a plurality of.location indicating stations located generally along said vehicle route for transmitting location indicating signals, and receiver means in said vehicle for receiving location signals from said location indicating transmitters only when within predefined communication range. Message announcement means are provided within the vehicle for announcing selected advertising information to passengers on said vehicle in dependence on the location signal received, whereby local advertising information may be displayed which is keyed to the particular geographical location of the vehicle along its route.

Also in accordance with the present invention, a mass- transit communication system is provided for communicating information to least one vehicle which travels along at least one route and announcing said information to passengers on said vehicle. The system comprises a plurality of update communication stations located generally along the vehicle route, central control means for transmitting update information to said update communication stations, with said update communication stations having means for transmitting update information to vehicles, located within a defined communication range generally proximate to respective update communication stations. Receiver means are located in each vehicle for receiving update information from the update communication station when the vehicle is within the defined range. Message announcement means are located within each vehicle for announcing update information to passengers traveling in the vehicle. The message announcement means preferably comprises means for displaying the update information.

Although the invention has particular applicability to vehicle mass transit systems, particularly bus transit systems, the system according to the present invention can be used any place where the audience needs periodic update information, particularly where the audience congregates for a mean time on the order of 5 to 30 minutes, for example. The system according to the invention will be further described herein as it relates to a bus mass-transit system, but it is to be understood that other such applications include trains or similar public transportation systems such as tramways, subways, subway stations, airports and even amusement parks.

Of particular interest to municipalities which typically run their own transportation systems, the present invention provides means for generating advertising revenue to offset and even exceed the cost of implementing such a system. In particular, advertising can be sold which would be displayed in the normal display cycle of 5 to 30 minutes along the entire bus route period. More particularly, advertising can be keyed to particular geographical areas and will reach the very target audience where the advertising will have its greatest impact, namely those persons riding along the segment of the bus route to and from work for example, which are already on the route. By targeting advertising to particular geographical areas to reach persons on the bus who travel to those geographical areas-, greater advertising revenue can be generated because an advertiser ould likely pay more for say 5 total minutes of advertising which targets a particular geographical area than 5 minutes worth of advertising spread over the entire bus route covering a much larger and thus much less effective means of reaching his audience of interest. Assuming a particular bus route passes through ten different geographical areas, advertising can be targeted to the ten separate areas and each advertising spot of say 10 or 15 seconds within the 5 to 30 minute display cycle can be sold for each of the ten geographical areas the bus passes through. An advertiser can also contract for one or more routes for only a particular time of the day.

The invention also provides means for updating information supplied to the vehicle along the route. Therefore, timely news bulletins can be relayed to passengers within minutes of a news event, updated weather reports can be displayed, and traffic information can be displayed, such as expected delays in minutes or the necessity that the bus take an alternate route due to excessive traffic or emergency conditions.

Other objects and advantages of the present invention will become more readily apparent to those skilled in the art in view of the follow detailed description, accompanying claims and attached drawings.

Brief Description of the Drawings

Figure 1 shows various components of the mass-transit communication system according to the present invention;

Figure 2 shows a depot transmitter, stopping place or location transmitter, and update transmitter, with the depot and update transmitter connected by a telephone line network to a controlling computer;

Figure 3 shows the message blocks in radio transmitting information;

Figure 4 is a block diagram showing the individual elements in the display unit, update transmitter and stopping place transmitter;

Figure 5 is another diagram showing the depot area, stopping place code transmitter and update loading transmitter with the respective near field transmitting ranges of the latter two transmitters being schematically shown;

Figure 6 is an electrical block diagram of a data controller for a vehicle; and

Figure 7 is an electrical block diagram of a display controller for a vehicle, which is connected to the data controller of Figure 6. Detailed Description of the Preferred Embodiment

In accordance with the present invention, a mass-transit communication system is provided for use in a vehicle which travels along at least one route and for announcing advertising information to passengers on said vehicle. The system comprises memory means in said vehicle for storing advertising information to be announced to passengers in said vehicle, a plurality of location indicating stations located generally along said vehicle route for transmitting location indicating signals, and receiver means in said vehicle for receiving location signals from said location indicating transmitters only when within a predefined communication range. Message announcement means are provided within the vehicle for announcing selected advertising information to passengers on said vehicle in dependence on the location signal received, whereby local advertising information may be displayed which is keyed to the particular geographical location of the vehicle along its route.

Also in accordance with the present invention a mass-transit communication system is provided for communicating information to a least one vehicle which travels along at least one route and for announcing said information to passengers on said vehicle. The system comprises a plurality of update communication stations located generally along the vehicle route, central control means for transmitting update information to said update communication stations, wherein said update communication stations have means for transmitting update information to vehicles located within a defined communication range generally proximate to said respective update communication stations. Receiver means are provided in each vehicle for receiving update information from the update communication station when the vehicle is within the defined range, and message announcement means within the vehicle are provided for announcing update information to passengers traveling on the vehicle. The message announcement means preferably comprises means for displaying the update information.

The system preferably includes memory means on the vehicle for storing vehicle stop information and update information. Memory means are preferably provided on the vehicle for storing general and advertising information, with display control means being provided for displaying the general and advertising information in predetermined timed cycles; wherein the display control means, depending on the type of update information, may interrupt the sequence of the general and advertising information to display the update information upon receipt. The update information may comprise information on advertising for merchants located proximate to the update communication station, or timely news bulletins, sports scores or weather reports, or information on local traffic conditions proximate to the update communication station or further along the vehicle route. The update information may comprise information on rerouting the vehicle from its normal route.

The system also preferably comprises stopping place transmitting means, for a least some of the stops along the route for the vehicle, for transmitting information identifying the particular stop location on the vehicle route, and wherein the vehicle has memory means for storing vehicle stop information identifying all of the scheduled stops of the vehicle along the route, and further wherein the vehicle further comprises display control means for comparing the vehicle stop information received from the stopping place transmitting means and for displaying the vehicle stop location if the vehicle stop information received is among the vehicle stop information stored..

The central control means preferably comprises means for transmitting general and advertising information to the vehicle when the vehicle is depoted at a central station or depot, which may be overnight if the vehicle is a bus, subway or the like. The system according to the present invention is preferably used for a transportation system having a plurality of such vehicles and a plurality of vehicle routes and wherein memory means in each vehicle stores vehicle route and stop information on all of the routes. Alternatively, memory means in each vehicle stores route and stop information only for one route for' that vehicle. In the former case the vehicle has means for enabling selection of one of the routes to which it is assigned for that day or that shift. The latter alternative will provide the capability for each vehicle to be assigned to any route of all of the routes over the transit system, with the particular route being preferably selected by the vehicle operator at the beginning of the vehicle workshift, by operating a keyboard connected to the display control means.

In order to minimize any loss in information being transmitted between the various components, the information is preferably transmitted in data blocks so that a single burst disturbance will only impact a single block. The central controls means preferably transmits update information to the update communication stations over a telephone network. The vehicles may be buses, or other mass-transit vehicles such as subways, tramways, and like vehicles either in a metropolitan urban area, suburban area, or in tourist villages or amusement parks. Turning now to Figure 1, a mass-transit communication system 10 according to the invention comprises a central control computer 12 attached to a reference display 14 and modem 16 for connection to a telephone. The control computer 10 may be any personal computer. The reference display 14 enables the user of the control computer to see the whole cycle of information displayed as it would be on vehicle. The modem 16 enables the operator of the central computer to send information sequences to the various transmitters as will be described.

Figure 1 also shows a depot transmitter 20 connected to a modem 22 and antenna 24. The controlling computer modem 16 - can thus communicate information over telephone lines to the depot transmitter 20. The depot transmitter 20 can transmit information from its antenna 24 to an antenna 26 of a vehicle display unit 28 when the vehicle is parked overnight in the depot, for example. The depot may have several antennas especially if the depot is large, so that all vehicles can receive information without the need for each antenna to output strong signals which go beyond the range of the depot. Thus, the vehicle display has associated memory as will described below which can store information on bus routes and stops, news, weather, sports and other information which can be updated daily or weekly, or whenever a bus is within the range of a depot or central transmitter. Instead of the vehicle display unit receiving information by a radio transmitter as just described the vehicle display unit may instead comprise a display unit 32 which is connected to a modem 34 which may receive information from the control computer 12 over a telephone line which may be either cellular or connected in a hard¬ wired fashion for security or other reasons, to modem 16 of the central computer or modem 22 of the depot loading transmitter 20. In either case the vehicle display unit 28 or vehicle display unit 32 has means for receiving information transmitted by update transmitter shown representatively by reference number 36 in Figure 1.

Turning now Figure 2, the three basic types of transmitters according to the present invention are shown schematically. Figure 2 shows a depot loading transmitter 20 as described above in conjunction with Figure 1. An update transmitter 36 is also shown, as is a stopping place or location transmitter 40.

The depot transmitter 20 and the update transmitter 36 are connected via their respective modems 22, 42, to respective receivers over a telephone network 50 to a control computer 12 through modem 16. This telephone network system enables the depot transmitter 20 and the update transmitter 36 to receive, periodically, or on demand, information transmitted thereto by the control computer 12. The update transmitters may be located at the end point of a vehicle route or at a mid point, turnaround or crew changeover point.

In contrast, the stopping place transmitters 40, (sometimes called "location indicating transmitters" herein) one each of which is located at the assigned stops along the vehicle or bus route, is preprogrammed with a transmission code which uniquely identifies the location of that transmitter along the bus route. Such a stopping place transmitter may be equipped with one or more encoders which transmit FM signals to provide DTMF (dual tone multi-frequency) signals whereby each stopping place transmitter sends its own code consisting of a combination of two separate frequencies. The transmission is normally done with intervals of 1.5 to 2 seconds and the duration of the transmission may be on the order of 100-200 milliseconds. The transmitters 40 are battery powered and their effect can be adjusted. In normal use the transmitters may be mounted on telephone, light or other utility poles or structures in the vicinity of the vehicle stop. The stopping place transmitters 40 have a limited or near field range which may be on the order of 50-100 meters, with their range being such that preferably no two stopping place transmitters 40 have their ranges overlap along a particular bus route.

The update transmitter 36 may be arranged to transmit the entirety of its information on the order of several seconds to a receiver in a moving vehicle. The display units in the vehicles typically display alphanumeric digits, therefore the update transmitter 36 need only submit codes representative of the alphanumeric digits such as ASCII code. This ASCII code can be stored in memory associated with the vehicle display unit. The information for the different update transmitters 36 is divided by the central control computer 12 so that the receiving vehicle is able to receive the entirety of the information along its route, picking up information as it goes along. Certain of the information that the vehicle display units display along the entire route can be unchanged (such as general news, bus transit announcements, trivia to entertain passengers) with updating information (such as local advertising, news bulletins, sports scores and weather reports) replacing various like types of information in the information display cycle. The information displayed can be transfer point information and service changes to be effective in the future.

The display cycle period of a vehicle display unit could typically be on the order of 5 to 30 minutes, with the specific period length selected to be dependent on the mean time that a passenger is on a vehicle. For a relatively short bus ride in an urban area which may average about ten minutes, the display cycle period could be on the order of five to seven minutes, to enable the average bus rider to see all of the messages in the display cycle. On the other hand, for relatively longer bus routes where the average rider is on the bus for 30 minutes, the display cycle period may be on the order of 20 to 25 minutes.

Referring now to Figure 3, the transmitted messages are shown divided into blocks. Such an arrangement minimizes the loss of a significant or any amount of information due to burst disturbances on radio channels if such information transfer was made over radio channels. By dividing this information into blocks, only one block would be lost in case of a burst disturbance. The arrangement may also be used for security purposes when units are directly connected to a telephone network.

Figure 4 shows the various components of the vehicle display unit, update transmitter 36 and stopping place transmitter 40. The stopping place transmitter 40 comprises an antenna 60, a radio modem 62, and a stop information formatter 64. These components, serve to transmit stopping place codes to the display unit of the vehicle. The update transmitter 36 comprises an antenna 70, a radio modem 72, a message formatter 74, an information memory 76, a receiver 78 and a telephone modem 80 which are arranged to receive mixed and blocked information from the computer 12, and to accept information, store it and transmit the mixed blocked information to the display unit within its limited or near field transmitting range as described above.

The vehicle display unit 28 comprises a display message board 30 which may be formed of an LED grid of say 16 vertical by 96 horizontal LED's arranged in a size of 96 by 576 millimeters, for example. Of course other size display boards may be provided, and other types of displays may be provided, such as light bulbs, electroluminescent, liquid crystal, electromechanical and multicolored displays. The display 30 is connected to a display scanner 82, which in turn is connected to an information selector 84 which selects active sequences and loads the sequences to the display memory. The information selector 84 is connected to an information memory 86 which in turn is connected to a receiver 88 which solves, (decodes) and accepts information provided to it from radio modem 90 and from antenna 92.

Turning now to Figure 5, the relative near field range transmitting capabilities of the stopping place code transmitter 40 and the update loading transmitter 36 are shown schematically by way of dotted lines~ The range of such transmitters, as was described above may be on the order of several blocks or 50-100 meters, which range should be sufficient to enable adequate code or data transmission from the transmitter to the vehicle, while being small enough so not to overlap other transmitters along the route. The range of the depot loading transmitter 20 should likewise be sufficient to reach all of the vehicles in the depot, while also being small enough to minimize interference with other communication systems. Of course, more than one depot loading transmitter may be provided, or a single depot loading transmitter may be provided with several antennas, to reach all of the vehicles in the depot without making the transmission range too large.

Further in accordance with the present invention, the message announcement means may comprise an audio sound generating means such as a voice synthesizer. The message announcement means can thus comprise means for generating audio messages alone or in combination with video messages. However, announcements based only on sound are not as desirable as visual announcements because of the disturbing traffic noise.

Preferably, stop location information is displayed on the display for a certain period of time, for example 7 seconds. The time may be controlled by a clock function circuit and a microcomputer in the vehicle display. It is also possible to control the disappearance of the information on the display sign with either the fading away of the code signal from the bus stop transmitter or the opening of the doors of the vehicle. However, because sometimes the doors of the bus are not opened at a bus stop the termination of the stop display on the vehicle display board should preferably be combined with either the fading away of the coding signal or with a time control.

Figure 6 is an electrical block diagram of a data controller 100 which forms part of the vehicle display unit 32 of Figure 1. The data controller is connected to a modem 34 through serial interface 102. The serial interface is connected to an electrical bus 104 which is in turn connected to information memory 106, real time clock 108, program memory 110 and micro-controller 112. The micro¬ controller 112 is also connected to a serial interface 114 which in turn is connected to a display controller. The program memory 110 stores a control program, for the data controller, and the information memory stores information on vehicle routes, stops along the routes, advertising information, news, weather and sports information, and other information as described above. The data controller controls the advertising to be displayed in dependence upon the particular location of the vehicle, as indicated by the code received from the stopping place or location indicating transmitters 40. Figure 7 is an electrical block diagram of a display controller 120 which forms part of the vehicle display unit 32 of Figure 1. The display controller 120 is connected to the serial interface 114 of data controller 100 through its serial interface 122. The serial interface is connected to micro-controller 124, which is used for controlling the message announcement device or display device. The micro¬ controller is connected, by means of an electrical bus 126, to program memory 128, data memory 130 and serial interface 132, the latter of which is connected to a display device 134 of Figure 1.

Further in accordance with the present invention, each vehicle in the system can be assigned its own unique identifying code, and messages can be encoded so that they are received, decoded and displayed only on one or more vehicles of interest.

In accordance with the preferred embodiment described, where the present invention is used in a bus transit system, there could typically be 100 buses in the system, with each bus equipped with a receiver, display and associated components as described above. The system could have 60 stopping place transmitters, spread over various routes of say 15 transmitters per route. For one depot, three radio transmitters would be provided, with the central control computer located at the depot. There would also be four update communication stations located along the routes or at turnaround, mid point, shift change locations and/or route start or end locations. The central control computer may be an IBM PC computer.

For such a bus system where there are fifteen stopping place transmitters per route, the display means in the bus would display advertising or other information particular to the areas that the bus is traveling through in dependence upon the particular stopping place code received from the transmitter, which indicates the location of the bus. If the system according to the invention were used in a subway or train system for example, the system could use relatively more or exclusively update transmitters and few or no stopping place transmitters . Of course, the number and location of the stopping place transmitters and the update transmitters will depend on the particular application, and bus or other vehicle systems may be set up to have update transmitters exclusively and no stopping place transmitters. Similarly, subway or train systems could be set up to have stopping place transmitters and no update transmitters.

The particular functions of the circuit elements described herein are not described in detail, since such functions are readily apparent to those skilled in the art, once the principles according to the present invention are disclosed as above.

The transmitters may be infrared, ultrasound, or amplitude modulated (AM) transmitters, instead of the above described FM transmitters. The receivers of course would be compatible therewith. Further, it is possible to connect the above described system to an existing radio telephone in the vehicle so that a central traffic control center continuously is aware of the location of each vehicle based upon the received signals from the coded bus stop transmitters. Even though the distance between two vehicle stops can be relatively long, because the memory in the vehicle display unit is stored with other kinds of information such as advertising news and,sports and weather, the passengers in the vehicle are entertained and actually look forward to commuting on a transportation system incorporating the present invention.

While a preferred embodiment of the present invention has been shown and described, it should be apparent to those skilled in the art that numerous variations and modifications may be made without departing from the true spirit and scope of the novel concept of the invention. The present invention is intended to include such modifications and the scope of the invention is limited only by way of the following claims.

Claims

What is Claimed, is;

1. A mass- transit annunciation system use for use in a vehicle which travels along at least one route and for announcing advertising information to passengers on said vehicle, comprising:

memory means in said vehicle for storing advertising information to be announced to passengers in said vehicle;

a plurality of location indicating stations, located generally along said vehicle route, for transmitting location indicating signals;

receiver means in said vehicle for receiving location signals from said location indicating transmitters only when within a predetermined communication range; and

message announcement means within said vehicle for announcing selected advertising information to passengers on said vehicle in dependence on the location signal received, whereby local advertising information may be displayed which is keyed to the particular geographical location of the vehicle along its route.

2. The system according to claim 1, wherein said message announcement means comprises means for displaying said advertising information.

3. The system according to claim 3, wherein said memory means also stores vehicle stop information.

4. The system according to claim 1, further comprising central control means for transmitting advertising information to said vehicle.

5. The system according to claim 4, wherein the central control means transmits the advertising information within a limited range, and wherein the receiver means receives said advertising information and wherein the memory means stores the advertising information.

6. The system according to claim 1, wherein the message announcement means announces selected advertising information for business establishments located proximate to the location of location indicating station.

7. The system according to claim 4, further comprising update transmitting means, for transmitting update information to said receiver means in said vehicle.

8. The system according to claim 7, wherein the central control means transmits advertising information on a periodic basis less frequent than daily, and wherein the update transmitting means transmits information more frequently than daily.

9. The system according to claim 1, wherein memory means, ^ receiver means and message announcement means are provided for a plurality of vehicles, and wherein the memory means in each vehicle stores vehicle route and stop information for a plurality of routes.

10. The system according to claim 9, further comprising means in each of said vehicles for enabling selection of one of the routes for announcing the stops thereof.

11. The system according to claim 1, wherein the memory means stores information on news, weather and sports and wherein said message announcement means announces information on news, weather sports and advertising in predetermined timed cycles.

12. The system according to claim 1, wherein the vehicles are buses.

13. A mass-transit communication system for communicating information to at least one vehicle which travels along at least one route and for announcing said information to passengers on said vehicle, comprising:

a plurality of update communication ^' stations located generally along said vehicle route;

central control means for transmitting update information to said update communication stations;

said update communication stations having means for transmitting update information to vehicles located within a defined communication range generally proximate to said respective update communication stations;

receiver means in said vehicle for receiving update information from said update communication station when said vehicle is within the defined range;

message announcement means within said vehicle for announcing update information to passengers on said vehicle.

14. The system according to claim 13, wherein the message announcement means comprises means for displaying said update information.

15. The system according to claim 13, further comprising memory means on said vehicle for storing vehicle stop information and update information.

16. The system according to claim 13, further comprising memory means on said vehicle for storing general and advertising information, and announcement control means for announcing said general and advertising information in predetermined timed cycles, and wherein the announcement control means interrupts the sequence of the general and advertising information to display the update information upon receipt.

17. The system according to claim 13, wherein update information comprises information on advertising for merchants located proximate to the update communication station.

18. The system according to claim 13, wherein update information comprises information on timely news bulletins, sports or weather reports.

19. The system according to claim 13, wherein update information comprises information on local traffic conditions proximate to the update communication station or further along the vehicle route.

20. The. system according to claim 13, wherein update information comprises information on rerouting the vehicle from its normal route.

21. The system according to claim 13, further comprising stopping place transmitting means, for at least some of the stops along said route for said vehicle, for transmitting information identifying the particular stop location on said vehicle route, and wherein said vehicle has memory means for storing vehicle stop information identifying all of the scheduled stops of said vehicle along route, and where said vehicle further comprises announcement control means for comparing the vehicle stop information received from said stopping place transmitting means and for displaying the vehicle stop location if the vehicle stop information received is among the vehicle stop information stored.

22. The system according to claim 16, wherein said central control means comprises means for transmitting general and advertising information to said vehicle when said vehicle is located at a central station.

23. The system according to claim 13, wherein receiver means and message communication means are each provided for a plurality of vehicles, and wherein each vehicle has means for storing vehicle route and stop information for a plurality of routes.

24. The system according to claim 23, further comprising means for enabling selection of one of the routes for announcing the stops thereof.

25. The system according to claim 13, wherein the update communication stations transmit update information in data blocks, to minimize any loss in information being received due to burst disturbances.

26. The system according to claim 13, wherein the central control means transmits update information to said update communication stations over a telephone network.

27. The system according to claim 13, wherein the vehicles are trains.