NO321683B1 - Procedure and arrangement for wireless data transfer between computers using a DAB system - Google Patents

Abstract

A method of wirelessly transmitting data between a computer and one or more other computers by means of the DAB system or an equivalent system for wirelessly transmitting digital data, wherein the transmitting computer is connected to a DAB transmitter and wherein the receiving computer or computers are connected with a respective DAB receiver. The invention is characterized in that information output in succession from the transmitting computer (1) is temporarily stored in a memory (8) in a first matching circuit (7) between the transmitting computer (1) and the DAB transmitter (3), that the information is discharged substantially continuously from the memory (8). ) to the DAB transmitter (3) under the control of an output oscillator (9) in the matching circuit, that the transmitted information is received by means of a DAB receiver (4) and fed into a memory (12) in a second matching circuit (11) under the control of an input oscillator (13) in the second matching circuit. (11), in that the two oscillators (9, 13) operate at the same frequency or substantially the same frequency, and that the receiver computer (2). caused to retrieve information intermittently from the memory (12) in the second fitting circuit (11). The invention also relates to an arrangement for carrying out the method.

Description

The present invention relates to a method and an arrangement for wireless data transmission. More specifically, the invention relates to the transmission of data by means of digital broadcast transmissions.

The present invention primarily relates to a method and an arrangement for transferring data from a computer to one or more other computers by means of a radio transmitter and one or more receivers, to enable data to be transferred in applications that use equipment manufactured in compliance with the international standard DAB (Digital Audio Broadcast).

The DAB standard is described in prETS 300 401 radio Broadcasting Systems; digital audio broadcasting (DAB) to mobile, portable and fixed receivers, February 1997. The invention is not limited to this standard, but may nevertheless be used with digital radio transmissions in accordance with other standards.

Frequencies are currently allocated to terrestrial DAB transmissions across Europe. The frequency ranges that are mainly used are TV channels in the VHF band III. Each DAB channel can transmit a total of 2,304 Mbit/s, which corresponds to, for example, five to six high-quality stereo programmes.

The modulation and signal processing technique chosen in accordance with the DAB standard is COFDM (Coded Orthogonal Frequency Division Multiplex), which enables all transmitters in a region-wide network to transmit the same signals on the same frequency without creating interference problems due to co-channel interference .

According to this standard, the entire bit stream in the DAB signal is transmitted in frames that have a typical duration of 96 ms. Each frame combines data from three channels, namely from the main service channel MSC, from the fast information channel FIC and from the synchronization channel.

The main service channel MSC can contain both service information, ISO/MPEG audio signals and general data transfers in packet mode or stream mode. A so-called multiplex controller determines how the various information components are to be combined. This control information is sent separately in the fast information channel FIC. The mutual sharing between the information components can be controlled dynamically in accordance with the requirements. The information channel FIC also reveals how data in the main service channel should be interpreted at any point in time.

The entire main service channel MSC can in principle be used for data transmissions, given a net bit rate of 1.2 to 1.5 Mbit/s.

The DAB standard is primarily intended to enable the transmission of six to seven high-quality stereo radio programs in each DAB channel at around 2 Mhz, although the distribution of the content of a DAB channel, called an "ensemble", can be dynamically allocated and be used for purposes other than the transmission of digitized and compressed audio channels. The standard also allows for the transmission of data in larger or smaller parts of a DAB channel, either with a limited transmission requirement in the form of packet-switched data amounts in a simpler case, or for the highest data rate of up to 2 Mbit/s when the entire "ensemble " is available for data transfer in a stream mode.

The publication US 5,132,989 describes an arrangement for the wireless transmission of data between a computer and one or more other computers by means of a wireless digital data transmission system, where the sending computer is connected to a wireless transmitter and the receiving computer is connected to a wireless receiver, and where a first matching circuit is arranged between the sending computer and the transmitter, and a second matching circuit is arranged between the receiver and the receiving computer.

Publication US 4,591,973 describes an input/output system for digital computers, the system comprising circuitry adapted to store information delivered in bursts from a host computer for intermediate storage in a memory, and adapted to output information from the memory for transfer to external input-Aitgangs modules substantially continuously under the control of a microprocessor in the adaptation circuit and circuits which, upon reception, are adapted to input information received from the external input/output modules substantially continuously into the memory and under the control of the microprocessor, and where the host computer is adapted to fetch the information in bursts from the memory in the circuits.

According to the foregoing, the DAB system should be able to transfer digital data from one computer to one or more other computers, at a speed of up to 1.5 Mbit/s.

However, a serious problem in this regard is that a computer is not designed to receive a more or less continuous DAB data stream, because a computer that usually includes a standardized PCI bus is designed to perform PCI bus transactions in the form of sheds.

The present invention solves this problem and enables data transmission between computers using the DAB system.

Currently, many computers are connected by cable networks or telecommunication networks for the exchange of information between different computers. When a number of computers are to receive certain information from one computer, this latter computer must be connected to each of the other computers in an orderly sequence. This is both time-consuming and expensive.

The cost of transmitting ether-borne information using the present origin can be drastically reduced, while many receivers can be reached simultaneously.

An example of an application can be found in the transfer of price information from a grocery wholesaler to all businesses, shops, etc., belonging to the wholesaler. The application of ether-bound information transmission will enable the sending of all price information to all businesses at once and simultaneously and also very quickly. Another obvious application is found in the distribution of news and advertisements, i.e. mainly in a newspaper.

Another important advantage should be obtainable if a receiver does not have to be stationary, but can be mobile. An example in this regard can be found in emergency services and police services, to particular advantage. Information relating to a rescue service, emergency service or a police service can be sent to mobile units, i.e. to rescue vehicles and police cars. Such a transfer will facilitate the coordination of personnel etc., in rescue operations and police operations of a significant size, by all parties concerned receiving updated information at the same time.

However, the present invention is not limited to any specific application, but can be used in any context where information is to be transferred between computers.

The present invention provides a method for the wireless transmission of data between computers using the DAB system or a similar system for digital wireless data transmission, characterized by the features that appear in the accompanying independent patent claim 1.

Further advantageous features of the invention's method for the wireless transmission of data between computers using the DAB system appear from the accompanying non-independent patent claims 2 to 4 inclusive.

The present invention provides an arrangement for the wireless transmission of data between computers using the DAB system or a similar system for digital wireless transmission of data characterized by the features that appear in the accompanying independent patent claim S. Further advantageous features of the present invention's arrangement for wireless transmission of data between computers using the DAB system or equivalent system for digital wireless transmission of data, appears from the accompanying non-independent patent claims 6 to S.

The present invention thus uses a method for the wireless transmission of data between a computer and one or more other computers using the DAB system or a similar system for the digital, wireless transmission of data where the transmission computer is connected to a D AB transmitter, where the receiving computer or computers are connected to a respective DAB receiver and where the method is characterized by the fact that information that is output in bursts from the transmitting computer is temporarily stored in a memory in a first adaptation circuit between the transmitting computer and the DAB transmitter, that the information is fed from the memory to the DAB transmitter substantially continuously under control of an output oscillator in the matching circuit, that the transmitted information is received by the DAB receiver and fed to a memory in a second matching circuit under control of an input oscillator in the second matching circuit, that the two oscillators operate on the same or substantially the same e frequency and that the receiving computer is caused to retrieve information in bursts from the memory store in the second matching circuit.

The present invention will now be described in more detail with reference to embodiment examples thereof and also with reference to the accompanying drawings, where Figure 1 is a block schematic illustration of a transmitter side and a receiver side.

The figure shows an arrangement for the wireless transmission of data between a computer 1 and one or more other computers 2 using the DAB system or a similar system for the wireless transmission of digital data. Such a corresponding system could be a system for digital TV transmissions. The transmitting computer is connected to a known DAB transmitter 3 which has a transmitting antenna 5. The receiving computer or computers 2 are connected to a respective known DAB receiver 4 which has a receiving antenna 6.

Arrangement according to the invention includes a first adaptation circuit 7 between the transmitting computer 1 and the DAB transmitter 3. The adaptation circuit 7 is adapted for the intermediate storage of information which is output in bursts from the transmitting computer 1 in a memory 8 belonging to the adaptation circuit. The memory can be a RAM memory or a FIFO memory. The matching circuit is also adapted to take information from the memory 8 and to feed this information to the DAB transmitter 3 generally continuously under the control of an output oscillator 9 in the matching circuit 7. The oscillator 9 controls the output of information from the memory 8 to the DAB transmitter 3, via a output circuit 10 of some known type.

A second adaptation circuit 11 is provided between respective DAB receivers 4 and receiver computers 2. This second adaptation circuit 11 is adapted to feed information received by the DAB receiver 4 into a memory store 12 in the second adaptation circuit under the control of an input oscillator 13 in the second adaptation circuit. The oscillator 13 controls the input of information from the DAB receiver 4 to the memory 12, via an input circuit 14 of a suitable known type. The memory 12 can be a RAM memory or a FIFO memory.

The two oscillators 9, 13 are adapted to operate at the mutually same frequency, or substantially at the same frequency, in accordance with the DAB standard.

The receiving computer 2 is adapted to retrieve information in bursts from the memory 12 in the second adaptation circuit.

In a preferred embodiment, the oscillator 13 in the second matching circuit 11 is adapted to be synchronized with the oscillator 9 in the first matching circuit by locking the frequency in the second oscillator 13 to a reference included in the received signal. This can be achieved by including in the second adaptation circuit 11 a microprocessor 15 which acts to detect the signal received by the DAB receiver and to decode a predetermined part of the received signal which constitutes the reference and thereby activate the oscillator 13.

In a preferred embodiment, the microprocessor 15 is adapted to determine from a FIC (fast information channel) in the DAB system those parts of the received signal which contain data. The microprocessor is also adapted to store received data in the memory 12 of the adaptation circuit.

In one embodiment, the microprocessor 15 includes software that causes the received information to be structured and stored in the memory 12 in a form that enables an ordinary PC 2 to retrieve the information from the memory 12. Alternatively, the software can be installed in the personal computer PC.

In a highly preferred embodiment, the microprocessor 15 in the second adaptation circuit 11 is adapted to identify information relating to the receiving computer 2 and which includes identification of address information and possibly also authorization.

It is thus possible to address one or more of all the computers connected to a DAB receiver 4.

This enables, for example, a kiosk wholesaler or trader who sends information relating to prices for goods found in shops or businesses across the relevant country to send price information to businesses in different parts of the country when the prices of goods vary in different parts of the country at mutually different times.

The ability to demonstrate authorization is achieved by programming the microprocessor so that it will only feed received information into memory 12 when the information received includes an authorization code. This authorization can, for example, be given by supplying a subscriber who has a DAB receiver with a smart card which is read by a card reader 16 connected to the microprocessor 15 and which contains the authorization code. The microprocessor is, in this respect, adapted to compare an authorization code received using the DAB receiver with the authorization code entered using the smart card. This embodiment can, for example, be used when the information being transmitted includes different types of news. Only subscribers who have paid for their subscription and thereby obtained a smart card that includes a valid authorization code can receive the transmitted information.

This is how the information to be transferred is buffered in the memory of the first adaptation circuit. The information to be transmitted is sent via the DAB system in a more or less continuous form, while information is delivered in bursts from the transmitting computer 1, as previously mentioned. In this way, the information is output to the DAB transmitter from the memory 8 mainly continuously and under the control of the output oscillator 9. Transmitted information is thus received by the DAB receiver in a mainly continuous form, and fed into the memory in the second adaptation circuit 11 under the control of the input oscillator 13 The receiving computer is then caused to retrieve the information in bursts from memory in the second matching circuit.

The present invention thus enables information to be transmitted via the DAB system, or a similar system for wireless transmission of data, at high speed and in a more or less continuous form between standard computers, such as typical personal computers, PCs, which are not designed to output and input data essentially continuously, but instead are designed to output and input information in bursts.

In this way, the present invention solves the problem mentioned in the introduction.

The matching circuits 7,11 have been described above. These circuits can be physically separate units or can include an electronic card that can be mounted in a PC or other computer. The invention naturally does not only concern personal computers and can be applied to all types of computers. The matching circuit can of course be constructed in many different ways to achieve the function described above. It will be obvious to one skilled in the art that the structural design of the matching circuits may vary. The present invention is thus not limited to the embodiments described above, because variations and modifications can be made within the scope of the following claims.

Claims (8)

1. Method for the wireless transmission of data between a computer and one or more other computers using the DAB system or a similar system for the wireless transmission of digital data, where the sending computer is connected to a DAB transmitter and where the receiving computer or computers are connected to a respective DAB receiver, characterized in that information that is output in bursts from the transmitting computer (1) is buffered in an output memory (8) in a first adaptation circuit (7) between the transmitting computer (1) and the DAB transmitter (3), that the information is mainly continuously output from the output memory (8) to the DAB receiver (3) under the control of an output oscillator (9) in the adaptation circuit, that transmitted information is received by means of a DAB receiver (4) and fed into an output memory (12) in a second adaptation circuit (11) under the control of an input oscillator (13) in the second adaptation circuit (11), in which the input memory ( 12) the received information is buffered by the fact that the two oscillators (9,13) work at mutually the same frequency or essentially the same frequency, and that the receiving computer (2) is caused to retrieve information in bursts from the input memory (12) in the other the adaptation circuit (11). 2. Method as stated in claim 1, characterized in that the input oscillator (13) in the second adaptation circuit (11) is caused to be synchronized with the output oscillator (9) in the first adaptation circuit (7) by locking the frequency of the input oscillator (13) to a reference including in the received signal. 3. Method as stated in claim 1 or 2, characterized in that the second adaptation circuit (11) includes a microprocessor (15), which microprocessor is caused to determine from a fast information channel (FIC) in the DAB system the parts of the received signal that contain data and causing the storage of received data in the input memory (12) in the second adaptation circuit (11). 4. Method as stated in claim 3, characterized by effecting identification by means of the microprocessor (15) in the second adaptation circuit (11) of information relating to a recipient computer (2) and which includes identification of address information and possibly also authorization. 5. Arrangement for the wireless transmission of data between a computer and one or more other computers using the DAB system or an equivalent system for the wireless digital transmission of data, where the sending computer is connected to a DAB transmitter and where the receiving computer or - the the receiving computers are connected to a respective DAB receiver, characterized by a first adaptation circuit (7) between the transmitting computer (1) and the DAB transmitter (3), which circuit is arranged to temporarily store information delivered in bursts to the transmitting computer (1 ) in an output memory (8) belonging to the first adaptation circuit (7), that the adaptation circuit (7) is arranged to output the information from the output memory (8) to the DAB transmitter (3) mainly continuously and under the control of an output oscillator (9) in the adaptation circuit (7), a second adaptation circuit (11) between the respective DAB receiver (4) and the receiving computer (2), which second adaptation circuit (11) is arranged to input information received by means of the DAB receiver (4) into an input memory (12) in the second adaptation circuit (11) under the control of an input oscillator (13) in the second adaptation circuit (11), which input memory is arranged to temporarily store the received information, that the two oscillators (9, 13) are arranged to work at the same or substantially the same frequency, and that the receiving computer (2) is arranged to retrieve information in bursts from the input memory (12) in the second adaptation circuit (11). 6. Arrangement as stated in claim 5, characterized in that the input oscillator (13) in the second adaptation circuit (11) is arranged to be synchronized with the output oscillator (9) in the first adaptation circuit (7) by locking the frequency of the input oscillator (13) to a reference including in the received signal. 7. Arrangement as stated in claim S or 6, characterized in that the second adaptation circuit (11) includes a microprocessor (15), which microprocessor is arranged to determine from a fast information channel (FIC) in the DAB system the parts of the received signal that contain data, and is arranged to store received data in the input memory (12) in the second adaptation circuit (11). 8. Arrangement as stated in claim 7, characterized in that the microprocessor (15) in the second adaptation circuit (11) is arranged to identify information relating to the recipient computer (2) and includes identification of address information and any authorization.