WO2005062611A1

WO2005062611A1 - Data transmission method and data transmission device

Info

Publication number: WO2005062611A1
Application number: PCT/PL2004/000108
Authority: WO
Inventors: Maciej Muzalewski; Jaroslaw Kupis
Original assignee: Vector Sp Z O.O.
Priority date: 2003-12-22
Filing date: 2004-12-20
Publication date: 2005-07-07
Also published as: PL364202A1

Abstract

The data transmission method consists in data signal being transmitted by means of CATV system. Data signal is located in the band above the cable TV bandwidth in the form of a modulated signal. Next, the data signal is combined with cable TV signal and sent via CATV line to the recipient. Data transmission device contains a unit (2) that converts data signal for each subscriber (3). The source of input data is the Ethernet switch output (1). The converting unit (2) output is connected to the module (4) that combines data signal with the signal from CATV signal splitter (5). Compound signal is fed to coaxial cable (6) that leads to the subscriber (3). The Ethernet data switch (1) serves n number of independent data channels, of which two extreme channels (7,8) have been presented in the picture.

Description

Data -transmission method and data transmission device.

Subject of Invention. The subject of invention is a dual-direction data transmission method through CATV cable networks. The notion of data transmission is understood here as both the provision of access to a data line, including the Internet, to the end user, and data transmission, including the Internet, within the whole CATV distribution network. The invention solves the problem of CATV network users accessing a data line of significant throughput. The subject of invention also includes a data transmission device, especially in CATV cable networks.

State of the art. There are systems supplying TV signal to the recipient by means of cable TV network system, denoted under the CATV abbreviation. These networks are installed in newly raised buildings during their construction, or else the cables are laid in existing buildings exclusively for the purpose. More and more, existing, i.e. CATV or telephone, cable networks are used for data transmission. A known state of the art solution uses cable TV network to connect buildings to the external data network. Data transfer through the CATV network requires digital signals to be converted to analogue signals whose standard and band is accepted in the CATV networks. A commonly known data transfer system uses data transmission compatible with DOCSIS, EURO-DOCSIS standards, or their variations. This solution transmits data signal in the CATV network, where the delivery data stream and the reverse data stream are located in different frequency bands . TV signals can be transmitted simultaneously with Ethernet signals, as it is relatively simple to separate them due to their different frequency bands. One of the widespread solutions applies special filters to shape part of the CATV band, and uses thus created special channel to locate the Ethernet signal in it. The subscriber's device uses thus prepared compound signal to separate the CATV and Ethernet signal. There are a number of known transmission solutions and devices that allow transmission of Ethernet and CATV signals together. There is also known a wireless data transmission standard defined as the IEEE 802. llx standard, where x stands for subsequent variations that use e.g. frequency band of 2.4 GHz. This system is a wireless system used in construction of local computer networks that enables the data throughput of 54 Mb/s in the IEEE 802. llg. version. Data transmission here uses a set of transmitting and receiving antennas plus data encoding mechanisms that . guarantee the safety of communication. Also other data signal transmission systems are known. A common solution of this type transmits signal data above the cable TV band, ranging between 860 MHz and 1 GHz. Two separate channels are used here for data transmission in both directions, which allows a throughput of up to 100 Mb/s. For this purpose the network has to be supplemented with additional facilities. The solution described in the invention application no. PL 346123 transmits data signal together with phone signal in one cable network. According to this popular solution, the signal device contains the compound signal terminal designed for reception and transmission of compound signal, while the signal contains a telephone and an Ethernet sub-signal. Furthermore, the device contains a telephone sub-signal reception and transmission terminal, and an Ethernet sub- signal reception and transmission terminal. This widely known device is characterised by the filtering module it contains, which serves to combine the outgoing sub-signals into an outgoing compound signal to be transmitted from the compound signal terminal, and by the filtering modules serving to decompose the incoming compound signal into an incoming telephone sub-signal and an incoming Ethernet sub-signal, to be sent from the telephone sub-signal terminal and the Ethernet sub-signal terminal accordingly. The filtering modules in question contain at least one passive filter. The filter is a high-pass or a low-pass filter. To improve its operation the device contains a symmetriser placed at the Ethernet sub-signal terminal or/and at the telephone sub- signal terminal. According to the same known solution, the way to combine the Ethernet and telephone signals in the telecommunication network consists in the reception of the outgoing telephone and Ethernet sub-signals, which are then combined into a compound outgoing signal by means of at least one filter, and subsequently transmitted as a compound outgoing signal. Next, the compound incoming signal is received and decomposed into a telephone sub-signal and an Ethernet sub-signal by means of at least one filter, afterwards the incoming telephone sub-signal is transmitted to the subscriber through the first sub-signal terminal, whereas the incoming Ethernet sub-signal is sent to the subscriber through the second sub-signal terminal. The filter in question is a passive filter. In the popular solution in question the outgoing telephone sub-signal is balanced by means of a symmetriser, before the sub-signals are combined. Similarly, the incoming telephone signal is balanced after the compound incoming signal has been decomposed. Likewise, the Ethernet signal is balanced by means of a symmetriser, after the compound incoming signal has been decomposed and before the outgoing Ethernet sub-signals are combined. This common solution also provides for the data distribution method, where computer-oriented data signal is combined with the CATV signal into a compound signal, the compound signal is sent to the recipient by means of CATV cable, next, the compound signal is decomposed into data signal and TV signal, and then data signal is fed to the computer, while TV signal is led to the TV set. Computer outgoing data is sent along the same route as the compound signal, though in the opposite direction. In a cascade configuration, after the data signal and CATV signal have been supplied to the computer and TV set, they are again combined to be transmitted to the next recipient. In this known solution all data is sent to all the recipients, and it is in the computer where the data for a given recipient is selected, or all data is switched before the signals are combined, so that every computer receives only the data that has been designated for it or for a given computer cascade it is linked to. The incoming data signal is combined with CATV signal by means of filters and is supplied through CATV lines. Incoming data signal and TV signal are demodulated in a CATV modem before the signals are combined. At least data signalling is two directional here. This method combines base-band data signal with CATV sub-signal or with telephone sub-signal. The same known solution has provided a device combining and/or decomposing CATV and data signals, which contains CATV signal reception terminal as the first terminal, data signal input/output terminal as the second, and CATV compound signal input/output terminal as the third, high-pass filter at the first input terminal, low-pass filter at the second input/output terminal, along with a combination unit linked to the high-pass filter, low-pass filter and the third input/output terminal. The device contains an impedance conversion unit, located between the second input/output terminal and the low-pass filter. The device in question has been adapted for dual direction traffic and contains additional filtering module that combines and decomposes the sub-signals .

The purpose of the invention

The aim of the invention is to develop a new high-speed data transmission method and device, through application of the existing CATV system solutions.

Nature of invention

According to the invention the dual direction data transmission method consists in the data signal being transmitted by means of CATV system, where data signal is located above the cable TV band as a modulated signal, and subsequently the signal is combined with CATV signal, and such compound signal is sent through a CATV line to the transceiver, after which the compound signal is decomposed at the recipient's into CATV signal and data signal. The method's characteristic attribute is that the data signal, before it is combined with CATV signal, is translated into data signal in the IEEE 802.11 standard, and next the translated data signal is combined with CATV signal to form a compound signal that is transmitted by the system of CATV lines to the transceiver. The data signal at the recipient's is fed to the wireless digital communication card, where this wireless digital communication card is used for conversion of the used IEEE 802.11 data format into the data format used by the target device. The compound signal, before it is fed into the wireless digital communication card, is decomposed at the recipient's by means of filtering modules. Data signal is fed through cables. In another beneficial application of the subject of invention, the data signal can be supplied through wireless connection. The data signal is fed to an antenna terminal of the wireless digital communication card. The beneficial solution as set by the invention, feeds the compound signal through one selected channel, compatible with the IEE 802.11 standard, to the receiver, while for every receiver separate coaxial cable is used. In the solution offered by the invention, the compound signal can be fed through selected channels, compatible with the IEE 802.11 standard, to the receiver by means of a common coaxial cable. According to the invention, the data transmission device, which contains a unit converting the data signal into a wireless data transmission signal, for each subscriber, is characterised by the fact that the output of the system converting data signal into a wireless transmission signal is cable-connected to the module that combines data signal with CATV signal, in order to supply such compound signal to the coaxial cable connected to the transceiver. According to the invention the output of one coaxial cable in the device is linked with n number of input modules in the n number of locations of transceivers. Another beneficial solution is that according to the invention, the device contains n number of data converting systems for n number of subscribers, whose inputs. are connected with n number of data switch outputs. Another beneficial solution connects n number of coaxial cable outputs with n number of input modules in the locations of n number of transceivers. The recipient's input module contains at least one module separating data signal from CATV signal, where the output of the module is connected with the input of the transceiver. This _.filtering module can be a high-pass filter. This does not render the use of band-pass filter as a filtering module impossible. The filtering module can also be the subscriber' s TV SAT socket .

Beneficial effects of the invention.

The solution offered by the invention enables simultaneous transmission of data along with signals characteristic of CATV network, i.e. TV signals and data transmission signals currently used in the CATV service. The upper limit frequency of Ethernet 10 Mbit/s does not exceed 30 MHz, whereas of Ethernet 100 Mbit/s - 60 MHz. This zone of CATV band is commonly used for transmission of reverse channel (signal from the subscriber to the head-end) used in data transmission by means of cable modems. Popular solutions make it necessary to give up the hitherto function of this frequency zone. The invented solution involves no necessity to eliminate the initial fraction of the CATV band, in particular the described reverse channel band.

Examples of the realization. To illustrate the subject of invention examples of its realization have been presented in the drawing, where individual figures represent the following: fig. 1 - data signal transmission device in the form of a block diagram displaying the spectrum of component signals and the compound signal, fig. 2 - layout of subscriber's socket with a cable-connection to the receivers, fig. 3 - layout of subscriber's socket with a wireless connection to the receivers.

The dual direction data transmission method consists in the data signal being transmitted by means of CATV system. The data signal is located in the band above the CATV band in the form of a modulated signal. CATV band is accommodated within the band brackets of 5 MHz to 862 MHz. The described finished product example locates the data signal in ISM 2.4 GHz band. Next, this data signal is added up with the cable TV signal, and that compound signal is sent through cable TV line to the transceiver. The transceiver could be for example a wireless data transmission network card compatible with the IEEE 802. llx standard, where x, in the case of this product example, stands for version b of the standard. Such compound signal is decomposed at the recipient's into cable TV signal and data signal. In the case of this product example the recipient is the cable TV subscriber. In the case of another product example the recipient can be the re-transmission central module in the cable TV network. Data signal, before it is combined with the cable TV signal, is translated into an IEEE 802.11b standard data signal, defined as Wi-Fi standard, and next the translated data is added up with the cable TV signal. Other product examples allow different standards: IEEE 802.11a, g, h, or i. This does not exclude the use of the subject of invention in other products together with future versions of the IEEE 802.11 standard, or other wireless data transmission standards. The compound signal is transferred through a system of cable TV lines to the transceiver, which has been defined above. At the recipient's data signal is fed into the wireless digital communication card 12. The wireless digital communication card device serves to convert the used data format to e.g. IEEE 802.11b or another data format used in the target device, e.g. a format compatible with USB 1.1. Compound signal, before it is fed to the wireless digital communication card 12, is separated at the receiver's by means of separating filtering units 10, e.g. in the TV SAT socket 9 at the subscriber's 3. The socket is equipped with its own filters. Data signal is fed from the SAT output 11 of the subscriber' s socket 9 through a wire connection to the antenna input of the wireless Wi-Fi data transmission card 12, which has been demonstrated in fig. 2. In another product example of the subject of invention, data signal can be fed from subscriber's socket 9 through wireless connection via a system of antennas 13, which has been demonstrated in the attached fig, 3. Compound signal is fed through one selected channel 7,8 compatible with IEEE 802.11b standard, to the subscriber's 3 receiver, while for every subscriber's receiver a separate coaxial cable 6 is used. In another exemplary solution employing the invention, compound signal can be fed through selected channels 7,8, compatible with IEEE 802.11b standard to the receiver by means of common coaxial cable 6.

As shown in the enclosed fig. 1., data transmission device contains a unit 2 converting data signal to Wi-Fi standard signal, for each subscriber 3. The source of input data is the output of Ethernet switch 1. The output of the unit 2 converting data signal to Wi-Fi standard signal is wire connected to the module 4 combining data signal with the signal from cable TV signal splitter 5., in order to feed the compound signal to the coaxial cable 6 leading to the subscriber 3. The combining module 4 can be e.g. made up by a set of high-pass filter and low-pass filter. In the product example presented in the enclosed fig. 1., the Ethernet switch 1 serves 12 independent data channels, of which two extreme channels 7,8 have been shown in the picture. In this exemplary solution twelve coaxial cable outputs 6 are linked to twelve Wi-Fi cards in the locations of twelve subscribers 3. The subscriber's 3 socket 9 i.e. a standard TV SAT socket, may for example contain a system of filters that has been demonstrated in fig. 2. The separating module 10 could e.g. be made up by a system of high-pass filter 14 and low-pass filter 15. TV SAT output 11 of this filtering system is wire- connected with the output of Wi-Fi card 12. Wi-Fi card output 12 is in this product example connected by means of USB 1.1 interface with the input of the subscriber's computer 3. In another example of the realization, demonstrated in the enclosed fig. 3, TV SAT output 11 of subscriber's socket 9 has wireless connection with the input of Wi-Fi card 12 through the use of a system of receiving and transmitting antennas 13.

Claims

Patent claims.

1. Data transmission method in dual direction that consists in the data signal being transmitted by means of CATV system, while the data signal is placed in the band above the cable TV bandwidth in the form of a modulated signal, and next, the signal is combined with cable TV signal, and such compound signal is sent via CATV line to the transceiver, where subsequently the compound signal is decomposed at the recipient's into cable TV signal and data signal, characterized in that the data signal, before it is combined with CATV signal, is translated into an IEEE 802.11 standard data signal, and subsequently the translated data signal is combined with cable TV signal, and subsequently the compound signal is fed through a system of CATV lines to the transceiver.

2. Method, according to claim 1, wherein the signal data is fed at the recipient's to a wireless digital communication card, while the wireless digital communication card is a device serving to convert the used IEEE 802.11 data format to another data format used in the target device.

3. Method, according to claim 2, wherein the compound signal, before it is fed to the wireless digital communication card, is decomposed at the recipient's by means of filtering modules.

4. Method, according to claim 2, wherein the data signal is fed through cables .

5. Method, according to claim 2, wherein the data signal is transmitted through wireless connection.

6. Method, according to claim 2, wherein the data signal is fed to antenna terminal of the wireless digital communication card.

7. Method, according to claim 1, wherein the compound signal is fed through one selected channel, compatible with the IEEE 802.11 standard, to the receiver, while for every receiver a separate coaxial cable is used.

8. Method, according to claim 1, wherein the compound signal is fed through selected channels, compatible with IEEE 802.11, to the receiver by means of a common coaxial cable.

9. Data transmission device, which contains a unit converting data signal to wireless data transmission standard- for each subscriber, characterized in that the output of the unit (2) converting data signal to wireless transmission standard has wireless connection to the module (4) combining data^~s±gnaA~wit-h -CATV- s-ign-a-l,- which se-rvesAo feed the compound signal to the coaxial cable (6) leading to the transceiver.

10. Device, according to claim 9, wherein the output of one coaxial cable (6) is connected with n number of input modules in the locations of n number of transceivers.

11. Device, according to claim 9, wherein that it contains n number of units (2) converting data signal for n number of subscribers (3) , whose inputs are linked to n number of data switch outputs (1) .

12. Device, according to claim 9, wherein that n. number of coaxial cable (6) outputs are connected with n number of input modules in the locations of n number of transceivers.

13. Device, according to claim 9, wherein the recipient's input module contains at least one unit (10) whose role is to separate data signal from CATV signal, where the output of the unit (10) separating the combined signals acts as the input of the transceiver.

14. Device, according to claim 13, wherein the separating unit (10) contains a high-pass filter (14) .

15. Device, according to claim 13, wherein the separating unit (10) contains a band-pass filter.

16. Device, according to claim 13, wherein the role of ^• separating unit (10) is assumed by the subscriber's SAT TV socket (11) .