A METHOD OF SELECTIVELY TRANSMITTING INFORMATION

Abstract: A method of selectively transmitting information via a radio transmitter, wherein a subscriber has a radio receiver (1) which includes a decoder (2) that functions to decode a received radio signal and convert the signal to a video signal which is applied to the antenna input (4) of a television set (3). The invention is characterized by transmitting one or more services in the form of information, wherein each service transmitted includes a code for the service concerned, wherein in order for the subscriber to be able to receive a service, there is sent a signal which includes an identification code for a given specific receiver (2) and a service code for each of the services that can be received, and wherein the decoder (3) is caused to store the service code and the decoder (3) is caused to decode solely that information which is applicable to a stored service code.

Description: A METHOD OF SELECTIVELY TRANSMITTING INFORMATION The present invention relates to a method for selectively transmitting information. More specifically, the invention relates to a method of transmitting with the aid of radio, wireless, transmission means different types of information to a large number of subscribers that have equipment which is capable of receiving information on their respective television sets, and there¬ with enable a given subscriber to subscribe solely to a given amount of the information transmitted. The transmitted information may be of any nature whatsoever, for instance news, advertisements, stock exchange informa¬ tion, weather forecasts, etc. A subscriber will have to this end a radio receiver in the form of a decoder which decodes a received radio signal and converts the signal to a video signal which is applied to the antenna input of a television set. One problem in this regard is that a subscriber would be able to receive all of the information transmitted unless the decoder is provided with a lockout device which enables solely information to which the subscriber has subscribed to be received. This problem could be solved, for instance, by issuing the subscriber with a card, such as a smart card, which is inserted by the subscriber into and read by the decoder, where the information read from the card discloses the nature of the information to which the subscriber has subscribed. The decoder would therewith be adapted to receive solely such information. A system of this kind resembles the system in which subscriptions are paid for certain satellite television channels. However, a system of this kind incurs costs for the reader in the decoder, costs for the smart card and program handling costs, and costs entailed by mailing a large number of smart cards. Furthermore, it would be necessary to issue a sub¬ scriber with a new smart card when the subscriber wishes to change his/her subscription in one respect or another. The present invention eliminates these drawbacks and provides a very simple method in this regard. The present invention thus relates to a method of selectively transmitting information via radio transmitters, wherein a subscriber has a radio receiver which includes a decoder that is able to decode a received radio signal and convert this signal to a video signal which is applied to the antenna input of a television set, and wherein the method is charac¬ terized by transmitting one or more services in the form of information where each transmitted service includes a code for the service concerned; transmitting a signal which includes an identi ication code for a given specific receiver and a service code for each of the services that can be received, such that the subscriber is able to receive a subscribed service; and by causing the decoder to store said service code and causing the decoder to decode solely the information that is applicable to a stored service code. The invention will now be described in more detail partly with reference to an exemplifying embodiment thereof and partly with reference to the accompanying drawing, in which Figure 1 illustrates schematically an arrangement with which the inventive method is applied. The inventive method for selectively transmitting informa¬ tion relates to the transmission of signals via a radio transmitter. Each subscriber which is to receive information has a radio receiver l which includes a decoder 2 that is capable of decoding a received radio signal and converting this signal to a video signal. The video signal is applied to the antenna input 4 of a television set 3. The radio receiver is connected to a receiving antenna 5. The radio receiver is conveniently constructed to form a single unit with the decoder, as indicated in broken lines in Figure 1. The radio receiver may also be designed so that the antenna cable 6 which extends from a typical television antenna 7 will enter the radio receiver, and such that solely a cable 8 extends from the radio receiver to the television set. In this regard, the radio receiver may be designed to deliver the video signal to the television set through the cable 8 only when the radio receiver is switched on, and to deliver the antenna signal in the cable 6 through the cable 8 when the radio receiver is switched off. When the radio receiver is switched on and receives a radio signal pertaining to information to which the subscriber has subscribed, the video signal is sent to the television set and said information is shown on the television screen. This information may have the form of text and/or pictures (graphics) . The decoder 2 includes a computer in which decoding software is installed. The computer also includes a memory in which received information can be stored. All information received will preferably be stored in the memory, so that the sub¬ scriber can subsequently choose the information he/she wishes to see. Information selection can appropriately be implement¬ ed with the aid of a subscriber-operated remote control device 9 whose signals are received by the decoder. In this regard, different types of information may have a three digit code number which is transmitted by the subscriber to the decoder with the aid of the remote control device, i.e. a system of the same kind as that used in commercially avail¬ able text TV systems. It is also conceivable to select information with the aid of buttons on the decoder, or by using the standard remote control device belonging to the television set to send to the television control signals that relate to the information desired. In this latter case, a control cable must be fitted between the television set and the decoder so that the control signals received by the television set can be sent to the decoder. It is also conceivable that not all of the received informa¬ tion will be stored in the computer, but can be shown directly on the television screen as the information is received. This may apply to changes in exchange rates for in- stance. According to the invention, one or more information services are transmitted, where each service transmitted includes and is tied to a code for the service concerned. In order for the subscriber to be able to receive a service, there is trans¬ mitted a signal which includes an identification code for a given specific receiver and a service code for each of the services that can be received. The decoder is caused to store the service code. The decoder is also caused to decode solely the information that belongs to a stored service code. Thus, each receiver has a specific identification code stored in the computer. Upon receipt of a signal which includes an identification code, the identification code of the received signal is compared with the stored code. When the compared codes agree with one another, the computer memory is opened for insertion of one or more service codes corresponding to the service or services to which the subscriber has sub¬ scribed. Thus, transmission of such a signal directed to a specific receiver will only take place when one or more service subscriptions are to be maintained or changed. In the transmission of given information, the service code that corresponds to the information concerned is transmitted prior to the actual information itself. Information is sent simultaneously to a large number of receivers. An identifica¬ tion code which is common to all receivers or a given group of receivers can then be sent instead of a specific identifi¬ cation code, this common identification code being compared with a computer-stored code which allows the service code carried by the signal to be received. Thus, the service code is received upon receipt of a signal which does not include a specific identification code. In this case, the received service code is compared with the service codes earlier stored in the computer, so as to establish whether or not the subscriber has subscribed to the service concerned. The information is decoded when it is established that the subscriber has subscribed to said service and will not be decoded when the opposite is the case. The hardware and software required to practice the inventive method can be readily compiled and put into effect by one skilled in this art, and will not therefore be described in detail here. It is mentioned in the aforegoing that an identification code which is common to a given group of receivers can be trans¬ mitted instead of a specific identification code. According to one preferred embodiment of the invention, a code which relates to a given geographical area or region is sent in conjunction with the transmission of a service code. This enables certain types of information, such as locally pertinent information, for instance local weather reports, to be directed to subscribers within the local region. According to one preferred embodiment of the invention, the geographical regional code includes the postal number or post code of the region concerned or a part of said number or code. By part of the postal number, or post code, is meant for instance a five-digit number relating to a given region or area, whereas the first three digits are common to the region and a number of regions bordering thereon. For instance, a code 18100 may refer to all regions whose postal numbers begin with 181. Thus, a transmitted signal may first include an identifica- tion code of a specific or general nature, followed by a service code which is, in turn, followed by a code relating to a given geographical region or area, and finally with the actual information. Preferably, an RIC signal (Radio Identification Code) which opens the receiver to receive the following part of the signal and which includes a time signal is preferably sent prior to the identification code. This will thus provide the decoder with information concerning the current date and time. This information is used to control the time during which a given subscription shall apply. The decoder is thus caused to receive a time signal. Accord¬ ing to on embodiment, information is sent to the decoder relating to the time period during which the subscription to the service concerned in conjunction with transmitting said identification code and said service code. This subscription period or term is stored in the computer memory. When the subscription period has expired, the decoder will be caused to no longer decode information for which the subscription has expired. This can be achieved conveniently by erasing the service code concerned from the computer memory. According to an alternative embodiment, the identifiςation code and service code are sent periodically at given time intervals, wherein the decoder is caused to decode solely received information relating to said service code over a period of time that corresponds to said time interval. The time interval may be five minutes, for instance. Thus, in the case of this embodiment relevant subscribers are updated every five minutes. Naturally, the time interval may be of longer duration, for instance one calendar day. The present invention thus enables different types of information to be transmitted nationwide over an existing mini-call network, for instance. Despite nationwide transmis¬ sion, each individual receiver can be programmed, in the aforedescribed manner by transmitting on the network, to decode a certain part of the information by transmitting its identification code and information relating to a service code or codes. In addition, the receipt of information in a given geographical region or area can be controlled by transmitting said code to this end. Although the invention has been described with reference to a number of embodiments thereof, it will be obvious that modifications and changes can be made. For instance, not all information need be transmitted nationwide. Furthermore, more codes than those given above may be sent for other purposes. For instance, there may be transmitted a password which must agree with a password installed in the subscriber computer in order for the receiver to decode received information included in the subscription. The invention is therefore not limited to the aforedescribed and illustrated embodiments thereof, since variations and modifications can be made within the scope of the following Claims.

Claims: CLAIMS 1. A method of selectively transmitting information via a radio transmitter, wherein a subscriber has a radio receiver (1) which includes a decoder (2) that functions to decode a received radio signal and convert said signal to a video signal which is applied to the antenna input (4) of a television set (3) , characterized by transmitting one or more services in the form of information, wherein each service transmitted includes a code for the service concerned, wherein in order for the subscriber to be able to receive a service, there is sent a signal which includes an identifica¬ tion code for a given specific receiver (2) and a service code for each of the services that can be received, and wherein the decoder (3) is caused to store said service code and the decoder (3) is caused to decode solely that informa¬ tion which is applicable to a stored service code. 2. A method according to Claim 1, characterized by causing the decoder (3) to receive a time signal; and by sending to the decoder (3) in conjunction with said identification code and said service code information relating to a time period during which the subscription to the service concerned shall apply. 3. A method according to Claim 1, characterized by causing the decoder (3) to receive a time signal; sending said identification code and said service code periodically at a given time interval; and causing the decoder (3) to decode solely received information relating to said service code over a time period that corresponds to said time interval. 4. A method according to Claim 1, 2 or 3, characterized by sending a code relating to a given geographical region or area in conjunction with the transmission of said service code. 5. A method according to Claim 1, 2 , 3 or 4, characterized by transmitting a code which relates to a predetermined geographical region or area, wherein said code is preferably comprised of the postal number or post code of the region or area concerned, or a part of said postal number or post code.

Inventors: SJOEBLOM KURT, SJOEBLOM, KURT
Applicants: CETRONIC AB, SJOEBLOM KURT, SJOEBLOM, KURT
Application year: 1996
Main classification: H04N7
IPC codes: H04H40, H04H60, H04N1, H04N7