GB2295062A

GB2295062A - Recording the call sign of a radio station for play back when tuned

Info

Publication number: GB2295062A
Application number: GB9422466A
Authority: GB
Inventors: Peter Shelswell; David Meares; Michael Charles Martin
Original assignee: British Broadcasting Corp
Current assignee: British Broadcasting Corp
Priority date: 1994-11-08
Filing date: 1994-11-08
Publication date: 1996-05-15
Anticipated expiration: 2014-11-08
Also published as: JPH08265199A; DE19541493A1; GB2295062B; GB9422466D0

Abstract

An RDS, DAB etc receiver in which the received data signal instructs the receiver to record an audible call sign of a station so that when in future the station is tuned the call sign may be heard. <IMAGE>

Description

METHOD OF TUNING TO A DESIRED BROADCAST STATION When tuning into a broadcast radio or television station, it is often difficult to know which channel has been selected.

It is easy to mis-tune a radio receiver because there are so many radio stations that a small error in tuning can lead to the wrong station being selected.

Unless the listener knows that the sound he hears matches the programme he expects to hear, it is difficult to be sure which station has been selected. In many cases, the first time that this is noticed is when the station announces its identity.

Sometimes the listener may be fortunate and tune in at a time when the station is transmitting its identification signal. By International agreement, all radio stations are expected to transmit such an identification signal on a regular basis. This does not happen sufficiently often, however, to be a reliable way of tuning in to the channel.

This problem has been solved in many instances by transmitting data with the broadcast signal to identify the station selected. For example, both the Radio Data System (RDS)described in the European Telecommunications Standard No. ETS 300 401 published by ETSI and Digital Audio Broadcasting (DAB) systems described in CENELEC Standard No. EN 50067 published by the European Committee for Electro-Technical Standards, include some signalling capacity to help identify the station. There are other methods of transmitting data with broadcast signals which accomplish a similar objective. These systems all operate on the basis that the receiver will identify the transmitted data and convert it to text which can then be displayed on a visual display on the receiver itself.

This solution is good for normal listeners.

However, people who have difficulties in seeing, or who are unable to look at the display because of their other activities (such as driving a vehicle), cannot use this type of system with ease to identify selected radio stations. Similarly, the blind may have difficulty in selecting television channels.

In accordance with the invention there is provided a receiver for broadcast signals comprising means for receiving and reproducing in audible form a audio signal transmitted on a selected one of a plurality of channels; means for receiving a data signal; and control means operable in response to the received data signal to provide an audible identification of the one of said plurality of channels selected by a user on selection thereof.

In this proposal, the visible display is replaced or augmented by an audible indication of the selected station. This allows the listeners to choose precisely the station they wish to hear.

Some receivers already use voice synthesisers to convert traffic information transmitted as simple digital codes into a form suitable for human understanding. This approach could also be used for station identification. However, the quality of the sound is, with current technology, not very good and will not provide the same artistic impression as the radio station's normal identification which is part of the main audible broadcast.

A novel, and preferred approach is to use a recording of the station's own identification signal to indicate the chosen station.

In this system, we propose that whenever the broadcast station transmits an audible identification as part of its programme, this fact is signalled in the data stream in an unambiguous manner.

When the identification is being transmitted, the receiver responds by detecting the data signal, and recording the station identification on a suitable recording medium.

Then, whenever the listener needs to know which station has been selected, the appropriate recording of the station identification can be replayed so that the listener knows which station he has currently selected, without having to read the information on a display.

Using this system, the tuning of a radio or television is made easier. It is proposed, as outlined above, to record the audible identification signals of the stations that the listener may select. Whenever the listener selects a station (tunes in), the recording of that audible identification is replayed.

This confirms to the listener which station has been selected1 audibly, and without need to look at a visual display. This makes life easier for everyone, but especially for those who have impaired vision, or those who cannot look at a screen such as drivers of vehicles.

By this means, people of limited sight, car drivers, and others who are not in a position to see a visible display, can all tune to a broadcast radio or television station with full knowledge of the name of that station.

An embodiment of the invention will now be described in detail, by way of example, with reference to the drawings, in which: Figure 1 is a block diagram illustrating the formation of a transmission signal for use in the method of the invention; and Figure 2 is a block diagram showing a receiver for use in the method of the invention.

The system of the invention requires that the broadcast radio or television station, in addition to its normal sound programme, also transmits a signalling channel. There are many such signalling channels in use or proposed for adoption with broadcast channels.

Examples are: the RDS channel used with Frequency Modulation radio in Europe.

the various signalling channels associated with the DAB system.

the data channel used in the Amplitude Modulated Data System (AMDS).

In this data channel, in addition to other information which may also be transmitted, two separate features are signalled.

Firstly it is necessary to transmit an unambiguous signal which identifies the station. This station identification code should be transmitted in the data channel at very frequent intervals. A suitable timing would be at least once a second, but preferably more frequently. In RDS for example, this information is already transmitted as the Programme Identification (PI) code, and in DAB signals, this code is transmitted by the Service Identifier (SId) feature.

Secondly, whenever the station identification is being broadcast by the station on its sound channel, it is necessary to ensure that the data channel carries an unambiguous signal to communicate this fact to the receiver. There are a number of options available in the RDS and DAB systems. DAB features such as the Programme Type, Announcement Switching and the Programme number could all be adapted to provide this function. There are related features in RDS which could similarly be used.

Figure 1 shows a signal source or transmitter 10 including means 12 for generating the audio component of the signal to be transmitted, and a data channel 14 on which is transmitted data to indicate the identity of the station and the times at which the station is transmitting its identification audibly on the audio component of the signal. The data signal transmitted on the data channel 14 thus has two parts generated separately. A first data component is the signal identifying the station which is generated at 16 by conventional circuitry used, for example, in RDS systems to provide an indication of station identity. To this is added a second data component generated at circuit 18 which provides an indication as to when an audible identification signal is included in the audio component. These two data signals are combined for transmission over the data channel 14. The data channel signal is then combined at 20 with the audio component to give a signal with the appropriate transmission format for use in the RDS system.

Figure 2 indicates how a receiver 30 is configured to provide the proposed functionality.

The receiver shown at 30 comprises the normal components of a broadcast receiver, but with three additional features. As well as making a sound channel 32 available (in digital or analogue format), there is provided a digital bus 34 which carries data from the data channel signal which is transmitted with the audio component of the transmission signal, and a control signal which indicates when the listener has attempted to select a programme by operating the controls of the receiver 30.

The digital bus 34 carries data to a processor and memory circuit 36 which identifies the data signal corresponding to the identification of the station and controls a recorder 38 and to a second processor circuit 46.

The incoming data signal to processor and memory circuit 36, indicating the identity of the station, is compared with a list of stations which have already been processed, contained in a memory internal to circuit 36. This memory also indicates the position of the recording of the audio identification signal in the recorder 38. Circuit 36 can exchange information about the addresses of material in the recorder through a data bus 40, which may comprise two unidirectional buses, or one bi-directional bus.

A control circuit 42 confirms that the audio identification signal is being broadcast.

A second control circuit 44 identifies when the listener has attempted to select a programme by operating the controls of the receiver and or when processor circuit 36 has identified that the audio identification signal is being broadcast. When the audio identification signal is being broadcast, control circuit 44 enables the recorder 38 to record the audio identification signal. If the listener has attempted to select a programme and the audio identification is not being broadcast, then control circuit 44 switches the recorder 38 to replay the appropriate audio identification signal and signals an audio switch 48 to relay the recording to the audio output stages. Communications to the switch 48 from control circuit 44 are via a signalling bus 50.

Recorder 38 includes a recording medium capable of recording extracts from the audio output of the receiver 30 and replaying them to the audio output stages through the switch 48. The medium is controlled to record, replay or be passive by control circuit 44 through control bus 52. The position of the recording being recorded or replayed is exchanged with processor and memory circuit 36 through data bus 40. The recording can be analogue or digital, depending on the nature of the incoming signal.

The switch 48 is an audio switch which selects either the normal audio programme or the output from the recorder 38 to the normal audio output stages 54 of the receiver.

In the receiver, it is necessary for both the audio signal and the data to be received using such technology as may be appropriate for the particular broadcast channel in question.

In addition, there must be a means of recording the audio signal. The capacity of this recording means must be sufficient to record the audible station identification signals of all the signals likely to be received by the receiver. Although this could be a conventional magnetic tape system, the preferred embodiment is a digital memory using a non-volatile store.

A volatile memory supported with a backup battery would be another option. If the original transmission uses digital techniques, the signal recorded can be the original transmission. If the transmitted signal is an analogue system, then it is necessary to convert the analogue signal to digital prior to recording.

If the cost of the memory is of concern, it is possible to bit-rate reduce the sound before recording using one of the known bit-rate reduction methods.

If the recording medium has limited capacity, it may not be possible to record all the audible station identification signals available. One way of dealing with this is to include an additional memory which records the pattern of use of the receiver by the listener. Whenever new capacity is needed and the recording medium is full or near to full, then recording capacity can be released by deleting the least necessary station identification.

Whether this is the station identification of the station which is least listened to, or the station accessed least recently are two non-exclusive options.

In addition to the components mentioned before, it is also necessary to include a means of controlling the system. This controller receives the incoming data signals. It must decode and detect the data signal which identifies the station. It must also decode and detect the data signal which indicates the times that the station's identification signal is being broadcast.

Whenever the programme signal corresponding to the station identification is being broadcast, the controller must record the station identification.

If the data channel also includes a cross reference to other broadcasts, then it is also possible that the station identification from those broadcasts can be detected and recorded too.

There will be several such station identifications recorded, so it is also necessary to know where they are recorded in the recording medium, whether it be, for example, magnetic tape, magnetic disc or digital memory. For this the preferred implementation is a digital non-volatile memory, or a memory backed up by a long life battery.

When the listener first switches the receiver on, when the listener selects another station, or at any other time when the listener needs to know the which station has been selected,the control circuit must access the signalling data, decode the station identification code, and then retrieve and replay on the receiver's headphones, loudspeaker or loudspeakers the recording of the station's identification signal.

By this means, the listener has confirmation that the correct station has been selected.

It is possible that the station might broadcast its identification at the same time as the listener tries to tune in. At that time, there could be a conflict in the receiver between recording the identification and replaying one recorded earlier. The preferred action is for the receiver to play the live broadcast of the audible identification signal.

The description of the operation of this system assumes that all the input to the receiver is via a broadcast link. This could cause some difficulty when the receiver is used for the very first time. It is entirely feasible to programme the system during manufacture to provide these facilities from new.

In addition, if a broadcaster does not transmit the necessary signalling, or if the listener prefers other means of identifying a radio station, or if it is thought preferable, it is possible for the listener to choose the audible station identification signal to be recorded, either from the normal programme material or by recording of an additional signal. This can be controlled by a separate user-operated control switch or button, not referred to in the figures.

Claims

CLAIMS:

1 A broadcast receiver comprising means for receiving and reproducing in audible form a audio signal transmitted on a selected one of a plurality of channels; means for receiving a data signal; and control means operable in response to the received data signal to provide an audible identification of the one of said plurality of channels selected by a user on selection thereof.

2. A receiver according to claim 1 comprising means for recording a channel identification signal; the control means being operable to replay the recorded channel identification signal to provide the said audible identification of the selected channel.

3. A receiver according to claim 2 in which the channel identification signal recorded by said means for recording is a channel identification signal forming a part of the audio signal transmitted over the said audio channel.

4. A receiver according to claim 1 in which the channel identification signal comprises a synthesised representation of an audible channel identification signal which forms a part of the audio signal transmitted over the said audio channel.

5. A receiver according to any of claims 2,3 or 4, in which the means for recording includes memory for storing in digital form the audible channel identification signal.

6. A receiver according to any of claims 2,3 or 4, in which the means for recording includes a magnetic recording medium for recording a portion of the transmitted audio signal comprising the transmitted audible channel identification signal.

7. A receiver according to any preceding claim including means for interrogating a data channel over which the data signal is transmitted for data indicating when the audio channel is carrying an audio signal representing the audible channel identification signal; and for effecting recordal of the audible channel identification signal in dependence on the result of said interrogation.

8. A method of operating a broadcast receiver comprising receiving and reproducing in audible form a audio signal transmitted on a selected one of a plurality of channels; receiving a data signal; and operating control means in response to the received data signal to provide an audible identification of the one of said plurality of channels selected by a user on selection thereof.

9. A method according to claim 8 comprising recording a channel identification signal; and operating the control means to replay the recorded channel identification signal to provide the said audible identification of the selected channel.

10. A method according to claim 9 in which the channel identification signal recorded by said means for recording is a channel identification signal forming a part of the audio signal transmitted over the said audio channel.

11. A method according to claim 8 which incudes synthesising a representation of an audible channel identification signal which forms a part of the audio signal transmitted over the said audio channel for use as a channel identification signal.

12. A method according to any of claims 9,10 or 11, in which the channel identification signal is stored in memory in digital form.

13. A method according to any of claims 9, 10 or 11, in which a portion of the transmitted audio signal comprising the transmitted audible channel identification signal is recorded on a magnetic recording medium.

14. A method according to any of claims 8 to 13 including interrogating a data channel over which the data signal is transmitted for data indicating when the audio channel is carrying an audio signal representing the audible channel identification signal; and effecting recordal of the audible channel identification signal in dependence on the result of said interrogation.

15. A broadcast receiver substantially as hereinbefore described with reference to Figure 2 of the drawings.

16. A method of operating a broadcast receiver substantially as hereinbefore described with reference to the drawings.