NL9400548A - Broadband transmission system - Google Patents

Abstract

Modular system for the transmission of broadband signals, using the available standard equipment, specifically for wireless transmission of narrowband signals, such as mobile telephones, carphones and the like. In principle, any required transmission bandwidth can be implemented. A broadband signal which is to be transmitted is split up at the transmitting end into a number of narrowband signals with a bandwidth for which a mobile telephone is suitable. Each of these narrowband signals is transmitted by means of a number of parallel-operating mobile telephones. At the receiving end, the narrowband signals are (separately) received and combined into a replica of the broadband signal. The system can also be used in non wireless narrowband equipment such as conventional line connections. <IMAGE>

Description

Broadband transmission system

A. BACKGROUND OF THE INVENTION

The invention relates to a system for the transmission of broadband signals, in particular the wireless transmission thereof. Broadband signal transmission and processing is increasingly penetrating the day-to-day operations of larger and smaller companies. By means of broadband transmission, electronic documents and images can be exchanged between parties quickly and efficiently. In addition to texts and static images, it is also becoming possible to include even moving images ("video clips") in (multimedia) documents. Along with this trend towards multimedia, there is a trend towards mobility, which is reflected in the unstoppable popularity of cordless telephones, such as car and cellular phones. The transmission of broadband signals via such cordless telephones (but also via mobile radios, etc.) is currently not possible in practice and is not encouraged, partly due to the high rise of cordless telephones and the limited availability of carrier frequencies. In future, the pressure on transmission bandwidths of mobile communication means will increase.

B. SUMMARY OF THE INVENTION

The present invention seeks to establish a link between the need for larger bandwidths on the one hand and the need for mobile signal transmission on the other. The invention thereby provides a modular solution, in which use can be made of available standard equipment for, in particular, wireless transmission, mobile telephones, car telephones, etc., whereby, in principle, any desired transmission bandwidth can be realized by applying the present invention.

According to the invention, a broadband signal to be transmitted is split on a number of narrowband signals with a bandwidth for which a mobile telephone is suitable and each of these narrowband signals is transmitted by means of a number of parallel mobile telephones. On the receive side, the narrowband signals are received (separated) and then combined into a replica of the broadband signal.

The invention is based on the applicant's insight that, although it is often argued that certain transmission channels have a limited transmission capacity - bandwidth, bit rate - this cannot be denied per se, but that it is possible to multiply the transmission capacity by parallelizing transmission channels . Parallelisation of channels with a limited capacity per se offers an in principle unlimited capacity multiplication, which in practice may of course meet certain limits of applicability.

The invention can, of course, as specified in the claims below, be more generically specified than, as above, related to the field of mobile communication, although the invention offers an attractive system especially there. The invention is thus not limited to the transmission of the narrowband signals via wireless channels, but also extends to other media such as wireline channels, for example conventional telephone channels, but also, for example, standard 2Mb / s channels. In this way it is possible, for example, to transfer broadband signals via a number of standard telephone or other connections. TV journalism and the like are seen as an area of application for the present invention, for example, in which people often want to be able to quickly send video images and such from locations that are not provided with broadband facilities and which cannot be provided with them quickly. This can nevertheless be carried out in the manner proposed by the invention, namely by means of, for example, a "battery" of conventional car telephones that can be taken to such a location, together with a portable PC. In the manner indicated by the invention, for example, satellite channels can also be parallelized, so that transmission with very large bandwidth is possible via channels which are normally available.

C. IMPLEMENTATION EXAMPLES

Figure 1 shows an exemplary embodiment of a system according to the invention, in which video images must be transmitted from a location 1 to a studio 2. At location 1 there is a TV camera 3, the images of which must be transferred. The images are stored in a controller 4, which includes a memory means and means for converting a digital broadband signal into a plurality of digital narrowband signals, each of which is transferred separately. The operation of that controller 4 will be explained in more detail below with reference to Figure 2. The narrowband signals are transmitted via modems 5, each having, for example, a bit rate of 9600 bits / sec. transferred to as many car telephones 6 (if use is made of GSM equipment, the modems are not required »but the (digital) signals can be offered directly to the telephones 6). If a video recording of a few minutes is assumed, which (after compression) has a size of 10 Mbytes (80 Mbits), and if only one car phone would be used, then it would take a while to transfer such a video clip. from 80000 / 9.6 / 60 = approx. 139 minutes required. Since according to the invention such an amount of data can now be transferred via a number of parallel car telephones, the transfer time can be considerably reduced. If the 80Mbits file is sent through five car phones, it only takes 1/5 * 139 · approx. 28 minutes; if even faster transmission is desired, this can be achieved by adding more car telephones: with 10 car telephones, only 14 minutes are required, which is very acceptable in TV journalism. It should be borne in mind that it is not necessary, as hitherto, to set up a special broadband connection, for example using a mobile radio or satellite transmitter. Due to the modularity of the system, it can be easily arranged in a very short time. In the same way, still-picture images, digitized photos and high-quality sound can be transferred, using a smaller or larger number of car telephones depending on the desired transfer speed and quality. Moreover, it is clear that wherever car phones are spoken of, other available media can be used instead; however, the use of mobile phones currently seems very attractive, given the advantageous performance / price ratio over other means which can be achieved in the manner indicated above.

On the receiving side 2, the narrowband signals are transmitted by receivers 7 to modems 8, converted into a controller 9 and further processed as a broadband signal in a device 10.

Figure 2 shows a video camera 11 (incl. Video recorder), the (broadband) output of which after digitization is presented to a memory device 12, for example a hard disk of an FC. The members 13 and 14 can also be part of the same FC, possibly extended with one or two insert cards, controlled by loaded application software through which the functions of the members 12, 13 and 14 are performed; the PC thus actually forms the control member 4 shown in figure 1. A file thus placed from video camera 11 on the hard disk 12 (of, for example, approximately 10 Mbytes) is read, under the control of the application software, and the data stream thus generated is the member 13 is converted into five data streams which are routed by the member 14, provided with five RS232 ports, to the modems 5, which transmit the five data streams, each with a transmission speed of 9600 bits / sec, via the mobile telephones 6 to the reception side transfer. The conversion of one bit stream to five bit streams by means 13 can be effected by converting the read bit stream into frames, hereinafter referred to as data cells, each consisting of a header and a data part. By alternately giving the header labels 1 ... 5, the cells are alternately routed through output 14 to output channel numbers 1 ... 5; this is shown schematically in figure 3. The element 13 receives the bit stream read from the hard disk 12 - in the figure each block represents an octet (byte) - and always makes, for example, ten octets one data cell with a header in which a channel number 1 ... 5 is placed. In addition, a sequence number is placed in the header in the series of, for example, 0 - 255; the byte reserved for this is shown in hatch. In this way, a stream of data cells is created, which is then supplied to the device 14 which reads the channel number of the incoming data cell from the header and subsequently routes the data cell to an output 1 ... 5 corresponding to that channel number. The channel number byte can then be deleted. Each output is connected to a modem 5 via an RS232 port. In this way, the data stream is divided into data cells which are alternately presented to the different modems. Each data cell has a —per 256 cells — unique sequence number that is used on the receive side to create a replica of the original data stream. On the receiving side (see FIG. 1), the data cells transmitted by the five transmitting mobile telephones 6 are received by a receiving system, for the understanding here represented by five receivers 7, and passed on to the modems 8. In the controller 9, the received data cells are their order numbers in order, after which the sequence number bytes are cleared, leaving a replica of the original bitstream. This can be saved and further processed. Fig. 4 shows this schematically: member 24, part of the controller 9, receives the separate cell flows 1 ... 5 from the five modems 8 and converts (recombines) them into one cell flow. Each cell is preceded by its sequence number. In organ 23, also part of organ 9, the data cells are arranged in the correct order according to their sequence numbers, after which the sequence numbers are deleted and at the output of organ 23 a replica of the original broadband data stream is created which can be stored on a hard disk 22, also part of controller 9.

Figure 5 shows an embodiment in which a second, similar member 15 is placed parallel to the member 14, also with five RS232 ports. In this case, organ 13 must produce data cells with channel numbers 1 ... 10 and those data cells are presented to both organ 14 and organ 15, with organ 14 routing all data cells with channel numbers 1 ... 5 and organ 15 routing all data cells with the channel numbers 6 ... 10. A corresponding 10-channel receiver must be on the receiving side.

It is noted that members 12 and 13 may be part of a standard PC system, while member 14 (and member 15) must be connected to the PC either as an additional plug-in card or as a standalone unit, since a standard PC will normally be one or more has two RS232 ports. This remark also applies to the corresponding organs 22, 23 and 24 on the receiving side.

Figure 6 shows once again the mobile system shown in Figure 1 on location 1, provided with five mobile telephones 6. In practice, these telephones will connect to one of the many fixed base stations for mobile telephony, one of which is shown 25. Such base stations 25 are connected to a public telephone network (PSTN), either a conventional telephone network or an ISDN network. In location 2, the system located there is connected via the modems 8 to the FSIN. The mobile telephones 6 - controlled by the controller 4 and the modems 5 - select the subscriber numbers of the terminals with which the modems 8 are connected to the telephone network. Thus, for the transmission of the broadband signal, use is made of (in this case) five connections, i.e. normal, available transmission channels, each of which only has a limited bandwidth, but which have been made suitable for parallel transmission, as described above. transmitting signals of greater bandwidth.

Finally, for the sake of completeness, it is also noted that on the transmission side it is not necessarily necessary to use separate telephone sets 6, but that these can of course be integrated into one unit via which several connections can be set up in parallel. The other organs could also be integrated.

D. References

No

Claims (4)

System for the transmission of a broadband signal, characterized in that on the transmission side the broadband signal is presented to first conversion means which convert the broadband signal into a number of narrowband signals, each suitable for transmission via an available transmission channel, each of which narrowband signals are supplied to such a available transmission channel and are thereby transmitted to the reception side, and on the reception side the transmitted narrowband signals are presented to second conversion means which convert those narrowband signals into a replica of the broadband signal presented on the transmission side. System according to claim 1, characterized in that said available transmission channels are wireless transmission channels. System according to claim 2, characterized in that the broadband signal, after conversion by said first conversion means into a number of narrowband signals, is presented to a number of mobile transmitters. System according to claim 3, characterized in that said mobile transmitters form part of mobile telephones.