AU603247B2

AU603247B2 - Data transmission arrangement

Info

Publication number: AU603247B2
Application number: AU20687/88A
Authority: AU
Inventors: Eric Tuohy
Original assignee: ASSMANN AUSTRALIA Pty Ltd
Current assignee: ASSMANN AUSTRALIA PTY Ltd
Priority date: 1987-08-14
Filing date: 1988-08-12
Publication date: 1990-11-08
Anticipated expiration: 2008-08-12
Also published as: AU2068788A

Description

COMMONWEALTH OF AUSTRALIA Patents Act 1952-1969 COMPLETE SPECIFICATION Form

(ORIGINAL)

FOR OFFICE USE: 603247 Class Int. Class Application Number Lodged oQ Complete Application No.

S Specification Lodged Published Priority: o 0o .,Related art: 0 o 0 0 0 o0 1 a ~~rn.

a 0 0 0 Name of Applicant: 0 00 o Address of Applicant: 0 6o Actual Inventor: 0 a o TO BE COMPLETED BY APPLICANT ASSMANN AUSTRALIA PTY. LTD.

16 SULTRAM PLACE, ADELAIDE, STATE OF SOUTH AUSTRALIA, COMMONWEALTH OF AUSTRALIA ERIC TUOHY 0 "Address for Service: COLLISON CO., Patent Attorneys, 117 King William Street, Adelaide, South Australia, 5000.

Complete Specification for the invention entitled: "DATA TRANSMISSION ARRANGEMENT" The following statement is a full description of this invention, including the best method of performing it known to us: M T1b EIPE5.c1ZP PATENT, TRADE MARKS DESIGNS SUE-OFFICE 12 AUG 88 SOUTH AUSTRALIA

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L L4 la This invention relates to a data transmission arrangement and in particular to a method of information transmission.

The problems to which this invention are generally directed relate to the difficulty of providing on a continuous basis repeated information in message form where such information is to be provided over a long period of time and if desirable at minimum cost.

In a supermarket for instance it may be desirable to provide a repeated message of perhaps one or two minute duration describing specials or bargains available in such a supermarket. Prior art devices suitable for such an information service have significant problems. In the past endless tape recordings have been used but these have the problem that such devices wear out and whereas the target life proposal such as the one to which the present invention is directed may be continuous repetition over many months of perhaps a two or three minute message, mechanical devices such as continuous tape recordings may not be expected to last more than a few days without a breakdown.

In a further proposed system it may be desirable to provide information 4",,'about a locality into which a motor vehicle is driving by means of a continuously transmitted broadcast of a message which may be only of 25 two or three minutes duration, but once again with the problem of mechanical wear on an endless tape system, such an arrangement could not be expected to be relatively maintenance free.

4 4 This present invention is specifically directed therefore to a method of providing a continuous message and a system for providing such a cori.nuous message.

It will be understood that herein solid state memory refers to solid state semi-conductor memory.

lb The present invention therefore is directed to an informati system for a particular locality including a radio frequency acting at a power to encompass the locality, solid state se memory means to to store information in the form of a me messages to be provided in the locality, the message or r being a digitized form or forms of a corresponding audio audio messages, clock means to repetitively select the inf the memory means and means to convert the information an audio modulated signal for transmission by the radio f transmitted to the locality, wherein the solid state semi-co on provision transmitter *mi-conductor ssage or nessages nessage or formation from retrieved to requency nductor

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memory S Sr

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4I 4 S I 3 S S ;1 I. 2 means is an erasable programmable read only memory and wherein the memory means includes a selection of information and control means are provided to select one of the pieces of information for transmission.

In a preferred embodiment the memory means may be selected from a read only memory, a programmable read only memory, a erasable programmable read only memory, a dynamic random access memory or a non-volatile random access memory or any other suitable addressable solid state memory.

a I In a preferred embodiment such a memory means may include at least two messages, one of which may be retrieved and means to select one message or another.

The means to select a message may include a further clock arrangement such as different times of day, different messages may be transmitted. Alternatively the means to select a message may include means to receive an instruction transmitted from a remote location and means to select an appropriate message depending on the instruction. The means to select one message from another Smay comprise a telephone, radio or induction loop system link from a remote location.

In an alternative form the may invention may be said to reside in an information provision system for a particular locality including a radio frequency transmitter acting a power to encompass the locality, solid state memory means, to store information in the form of a message to be provided into the locality, clock means to repetitively select the information from the memory means and means to convert the information retrieved to an audio modulated signal for transmission by the radio frequency transmitter into the locality.

Such a memory means may be an erasable programmable memory or alternatively may be dynamic or non-volatile random access memory and the system may include means for the remote addition, amendment of deletion of information from the memory means.

The memory means may include a selection of information and control means may be provided to select any one of the pieces of information.

___Jj 3 The invention may also be said to reside in a method of providing continuously repeated information for transmission in a specific locality comprising the steps of storing the information in a solid state semiconductor memory means, accessing the stored information at intervals selected by a clock means, selecting one message from a group of messages stored on the memory means, the messages being digitized forms of corresponding audio messages, converting the stored information into a form for transmission by a radio transmission and transmitting the information.

It will be seen that by this invention there is provided a method and means of storing a message and continuously transmitting the message over a long period of time without mechanical failure because in effect there may be no moving parts in the arrangement because the critical portion, the storage of the information, is by means of a solid state memory which is not subject to the same problems of wear and mechanical failure that mechanical memory means may have. As is indicated above, the actual memory means may include two or three stored messages, for instance one message may be in the English language and the other message in another language, so that upon a motor vehicle entering the message transmission locality, an appropriate message may be received by transmitting an instruction signal from the motor vehicle to switch the appropriate message on.

Therefore the means of effecting a change from one memory group to a second memory group can include remote detection devices and in a particular case there may be provided a transmitter held by an operator, the transmitter including means to modulate the transmission in such a way as to provide an identifiable code and detection means within the location to detect such a transmitted 4 signal and means to respond to such a signal to effect within the transmitter a change from the first memory group to an alternative memory group.

The advantage of such an arrangement is that if a bus full of tourists is approaching a town and it is preferred that the message be given in a language other than English, for instance, the bus operator can simply operate a small inductive loop tube transmitter device which will then revert the transmission to the second memory group which could for instance transmit the message from the town in Taiwanese or some other language. Alternatively as discussed above the message may be changed automatically by clock means at a particular time of day to describe different features that may be available in the town at different times.

The feature of this arrangement is that two separate memory groups may be able to be selected on only a single transmitter so that this removes the difficulty of having to allocate separate general broadcast frequency bands which are extremely limited. Alternatively the transmitter may be connected to a telephone line by means of a modulator/demodulater such that upon an entry code being offered access to the memory can be made for switching messages.

In a preferred form such telephone access may also enable reprogramming of the memory group when such a memory group is of a dynamic random access memory type. Such access to the memory storage area may of course be restricted by some form of coding arrangement so that access is blocked to others than those permitted to achieve such access and thereby reprogramme the messages stored in the system.

Alternatively to the telephone line connection the received signal can be offered ;by any remote transfer technique such as a radio frequency signal provided that once again there can be an interpretable pass word access and to some extent remote control and then of functions within the transmitter including play back from the a message recorded so as to check the message and provisional clearance code to confirm that the replacement message is available for access ior transmission purposes.

It will be realized that such a device will have great value in respect of continuous warning messages providing weather messages and even a warning to motorists when a particular road hazard might occur. In a preferred arrangement a message would be made available to warn motorists to turn their radios to a particular frequency and a road crew could then have a message on the transmission arrangement advising all oncoming motorists of a problem such as a detour or care to be taken. T'he instruction to warn motorists to transfer their radio transmitters to a particular frequency may be by means of a road-side sign.

This then generally describes the invention the subject of the present application but to assist with understanding of the invention reference will now be made to the accompanying drawings which show preferred embodiments of the invention.

In the drawings: Fig. 1 shows a single channel arrangement of a radio transmitter according to the present invention, Fig. 2 shows an alternative embodiment in which two memory sources having alternative messages are provided, and Fig. 3 shows an embodiment including a dynamic random access memory which may be reprogrammed and selected.

Now looking more closely at the drawings and in particular Fig. 1, it will be seen that this shows in general a radio transmitter arrangement including a memory means to provide a message to be transmitted by the radio transmitter means.

The memory means in this embodiment is an EPROM 1 an erasable programmable read only memory, which stores the message in digital form and which provides by means of a data bus 2 a parallel signal to parallel to serial converter 3 which transfers the signal into a serial signal to be transferred to the radio transmitter. The memory means 1 also is monitored by means of an end of text decoder 4 which when it receives an end of text signal from the memory means 1 transmits a reset signal to the clock counter 5 which resets the memory

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means 1 and cc mmences transmission of the signal through data bus 2 again.

The signal from the parallel-to-serial converter is transmitted by means of a controller and prescaler 6, decoder and filter 7 and low pass filter 8 to the radio frequency portion of the circuit. The filter 7 is adapted to correct for the Sin x/x response of the decoder and in one embodiment is adapted to reject frequencies above approximately 3400 hertz. The low pass filter 8 is then included to remove the commutation effects of the first filter 7. A monitor amplifier 9 and loudspeaker 10 take off is provided at this stage to provide for monitoring of the audio signal.

There is then provided a radio transmission frequency synthesizer and modulator 11 so that a synthesized radio frequency signal at a known frequency can be modulated by means of the data signal and it is then amplified in power amplifier 12 and transmitted through a harmonic filter 13 to aerial 14.

In preference the RF power amplifier is operated in class and the harmonic filter then prevents serious radiation harmonics which can be other wise transmitted and therefore cause interference from the so called class "C" amplifier.

This then describes a preferred embodiment insofar that it comprises a transmitter operating at low output power such that it can be offered on an appropriate broadcasting band within a small geographical 4r p 7 area and such that a message stored on the solid state memory means can be provided on a repetitive basis over a long period of time.

For changing the message where this is encoded within the erasable programmable read only memory (EPROM) this may be done by changing the EPROM to an alternative EPROM or erasing the EPROM using conventional techniques and reprogramming the EPROM.

To provide a message on the memory means of approximately two minutes duration would require approximately one megabyte of memory.

An alternative embodiment of radio transmitter arrangement according to the present invention is shown in Fig. 2. In this Fig. two audio sources substantially similar to that shown in Fig. 1 are provided. A first audio source 20 may use an EPROM 21 to store a first message while a second audio source 22 may use a further EPROM 23 to store a second message. A changeover controller 24 may be activated by means of a local changeover switch 25 by remote control from a telephone line 26, by means of a remotely received radio signal 27, or a time clock 28 to change over the message being transmitted from the first audio source 20 to the second audio source 22 or back again as required. Audio signals on lines 29 or 30 are mixed in a mixer pre-amplifier 31 and filtered through a low pass filter 32 before going to a similar radio frequency modulator transmitter 34 as shown in the first embodiment. Once again a monitor 35 and loudspeaker 36 are provided to monitor the signal being transmitted.

It is possible however to use memory means other than erasable programmable read only memory and Fig. 3 shows an alternative embodiment with some additional features.

In Fig. 3 there is used a dynamic random access memory 40 to store a number of messages which can be reprogrammed as required. A microprocessor controller 41 controls the unit and when a suitable signal is provided from the random access memory a signal may be sent to a radio transmitter 42 and out through aerial 43. Once again a monitor 44 and loud speaker 45 are provided to monitor the output signal.

The microprocessor controller 41 used to select the memory locations in the dynamic random access memory for selection of one signal or another may be have local control 46 or remote powered hard wired control 47 or remote control by telephone or radio 48.

Clock means may be provided to continuously transmit a repetitive message.

Because the dynamic random access memory can be changed in situ there is provided an arrangement also for reprogramming with alternative messages. A remote message input and output monitor 49 includes an output amplifier which enable remote monitoring of a signal being selected and an input amplifier 51 allows input signals to control the microprocessor controller and also for the input of new messages which are decoded through the coding/decoding and filter arrangement 52 and by means of the microprocessor controller stored in the random access memory 40. Alternatively local microphone 53 may provide an input signal through preamplifier 54 which is again coded and transmitted through the microprocessor controller to the dynamic random access memory The random access memory 40 may be a sufficient size to store a number of messages and the microprocessor controller by control from remote or local control may select a suitable message for transmission through the radio transmitter.

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9 The arrangement of Fig. 3 may be such that during transmission of a first message from the dynamic random access memory a further message may be in the process of being encoded and stored on the random access memory.

This then generally describes the invention the subject of the present application but is stressed that the invention is particularly directed towards a solid state memory means for storing a signal to be transmitted and means to select a signal and to transmit that signal as required on a repetitive basis.

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Claims

1. An information provision system for a particular locality including a radio frequency transmitter acting at a power to encompass the locality, solid state semi-conductor memory means to store information in the form of a message or messages to be provided in the locality, the message or messages being a digitized form or forms of a corresponding audio message or audio messages, clock means to repetitively select the information from the memory means and means to convert the information retrieved to an audio modulated signal for transmission by the radio frequency transmitted to the locality, wherein the solid state semi-conductor memory means is an erasable programmable read only memory and wherein the memory means includes a selection of information and control means are provided to select one of the pieces of information for transmission.

2. An information provision system as in Claim 1 wherein the memory means is a dynamic random access memory and the system includes means for the remote addition amendment or deletion of information from the memory means.

3. A method of providing continuously repeated information for transmission in a specific locality comprising the steps of storing the information in a solid state semi-conductor memory means, accessing the stored information at intervals selected by a clock means, selecting one message from a group of messages stored on the memory means, the messages being digitized forms of corresponding audio messages, converting the stored information into a form for transmission by a radio transmission and transmitting the information. 1

4. A radio transmitter including solid state semi-conductor memory means to store a message to be transmitted, the message being a digitized form of a corresponding audio message, clock means to initiate a regular repetitive retrieval of the message from the memory means and an audio modulation means to convert the retrieved message into a radio frequency transmittable signal wherein the memory means is selected from one of a read only memory, a programmable read only memory, an erasable programmable read only memory, a non-volatile random access memory, a dynamic random access memory, or other addressably solid state memory and wherein the memory means includes at least two messages any one of which may be retrieved and means to select one message or another.

A radio transmitter as in Claim 4 wherein the means to select a message includes a further clock arrangement such that at different times of day different messages may be transmitted.

6. A radio transmitter as in Claim 4 wherein the means to select the message includes means to receive an instruction transmitted from a remote location and means to select an appropriate message depending upon the instruction.

7. A radio transmitter as in Claim 4 wherein the means to select one message from another comprises a telephone link from a remote location.

8. A radio transmitter as hereinbefore described with reference to the accompanying drawings. DATED this 3rd day of August 1990 ASSMANN AUSTRALIA PTY. LTD. By their Patent Attorneys COLLISON CO.