RU2594008C2 - Information resource frequency-time division system - Google Patents

Abstract

FIELD: communication.

SUBSTANCE: invention relates to equipment of satellite communication and can be used to provide telephone communications, data transmission in communications-satellite networks using “star” topology, for acquisition and processing of large amount of information from remote sources. For this purpose, the system consisting of one node communications-satellite network and N terminal communications-satellite networks, as well as a satellite vehicle transponder, node communications-satellite network transmission path and receive path of each terminal communications-satellite network include a computer for implementation of system operating modes and a computer with routing software.

EFFECT: technical result consists in receiving and processing large amounts of information from remote sources by a collection point.

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Description

The system of time-frequency separation of the information resource is designed to provide telephone communications, data transmission in satellite communication networks using the star topology [1], in the interest of collecting and processing a large amount of information from remote sources.

The field of application and the primary field of use of the invention are satellite communication systems that provide the possibility of simultaneous access to the repeater of a space station (RTR KA) of several ground stations.

There are distributed processing systems in which it is required to provide data collection from remote sources at a data collection point (PSI) over channels with high (1-2 Mbit / s) bandwidth [2]. From PSI, which includes a satellite communications node station (USSS), to sources, i.e. satellite communication terminal stations (OSSS) receive control commands that are of a one-time nature and do not require a high exchange rate (not more than 64 kbit / s). The information received from all OSSS is processed on the PSI using an electronic computer (computer) and is issued to the communication node of a higher control center (VPU). Generalized information transmitted from PSI to VPU, as a rule, also does not require a high-speed channel (up to 64 kbit / s). At the same time, in all these areas, the availability of an operational-command communication channel (up to 64 kbit / s) should be provided. The flow diagram is shown in FIG. one.

Currently, in the Unified Satellite Communication System ESSC-2 [3], there are several basic ways of multiple access (MD) [2].

The principle of operation of multi-station access with time division of an information resource (TDMA) [2] is as follows: each user is given a certain time interval (frame) during which he transmits and receives data. To transmit data from the USSS to the RTR spacecraft, one group frequency is used. Data transmission from the RTR spacecraft to the OSSS is carried out at a different group frequency. Each station receives its data in the allotted time interval for it. At the same time, time is synchronized at all stations. The advantages of this method are the use of one frequency group, as well as a small number of transmit and receive paths to the USSS and OSSS. Disadvantages are high requirements for channel synchronization or centralized time distribution. All information processing can be carried out using equipment on the RTR spacecraft.

TDMA in this form is not used in ESCC-2 due to the uneven flow of data from the SSSS, since the time intervals for data transmission are not always filled, as well as due to insufficient noise immunity, but the principles of this solution are applied when using multiple access with time-frequency division (FDMA).

When using multi-station access with frequency division of an information resource (FDMA) [2], each subscriber is allocated separate interconnected pairs of frequencies for transmitting and receiving data, i.e. for each OSSS there is a binding of one pair of frequencies associated with the OSSS, for example, f ₁ - to transmit, f ₂ - to receive.

The number of USSS and OSSS depends on the network topology. For the star topology, one OSSS and several OSSSs are used. The structure of the CSSS and all the CSSS contain computers for the implementation of the operating modes of the systems.

In FIG. Figure 2 presents an example of a scheme for organizing communication with FDMA for one USSS and two OSSS with an indication of the frequencies of data exchange. Information is transmitted from the USSS through the RTR SC to OCCC ₁ and OSSS ₂ using interconnected pairs of frequencies f ₁ and f ₂ :

f ₁ - for data transmission from USSS to RTR spacecraft;

f ₂ - for data transmission from RTR SC to OSSS ₁ , OSSS ₂ .

To transfer information from OSSS ₁ , OSSS ₂ through the RTR of the spacecraft to the USSS, other interconnected pairs of frequencies are used (f ₃ , f ₅ and f ₄ , f ₆ ):

f ₃ , f ₄ - for data transmission from OSSS ₁ , OSSS ₂ to the RTR SC, respectively;

f ₅ , f ₆ - for data transmission from the RTR of the spacecraft to the USSS (from OSSS ₁ , OSSS ₂ ).

When transmitting information from OSSS ₁ and OSSS ₂ , the processing of the received data on the RTR of the spacecraft and their subsequent transmission to the USSS, and then to the VPU, not shown in FIG. 2. During the operation of FDMA, the separation of pairs of receivers and transmitters by frequency occurs. Each pair has its own spectrum for the entire time of the connection.

The advantages of this MD method are the independence of frequency channels that do not require synchronization or centralized time distribution. The disadvantage is the high consumption of the frequency resource, and therefore, the presence of a large number of receiving paths on the USSS equal to the number of communication directions.

Multiple access with time-frequency division of an information resource (FDMA) [2] uses both of the above methods simultaneously. When transmitting data from the SSSS to the RTR KA, frequency division is used, and for the reception of each OSSS from the RTR KA, time division is used, i.e. one group of frequencies. All information processing occurs on the RTR spacecraft.

An example of communication with FDMA for one CSSN and two CMNSs is shown in FIG. 3, where the frequencies for data transmission are indicated:

f ₁ - from USSS to RTR spacecraft;

f ₃ , f ₄ - with OSSS ₁ , OSSS ₂ on the RTR SC, respectively;

f ₇ - from RTR SC to USSS, OSSS ₁ , OSSS ₂ .

Using this method allows to reduce the number of receiving paths on the CSS. The disadvantage is the need to use complex and expensive on-board equipment for RTR spacecraft for information processing.

Existing MD systems in satellite communications networks make it possible to receive a large amount of data on the USSS, as indicated above, but with certain limitations. So, in networks with FDMA (2048 kbit / s for transmission - 2048 kbit / s for reception) [5], there will be a significant “overrun” of traffic in the opposite direction, because the entire channel is not needed for reception, but only 64 kbit / s, and in networks with FDMA (64 kbit / s for transmission - 256 kbit / s for reception) [5] the required traffic at the technical features of the RTR spacecraft operating modes is currently not can be provided because there is no way to use the entire channel at the reception. In addition, the USSS when working in the FDMA mode requires the same number of receiving paths and communication directions.

The closest analogue (prototype) of the present invention is a FDMA system with asymmetric communication channels using the star topology shown in FIG. 2.

The use of an asymmetric satellite communication channel [4] in the present invention makes it possible to obtain more information at the reception and use only the minimum necessary speed for outgoing transmission.

The technical result of the invention is the ability to receive and process a collection point of large amounts of information from remote sources, as well as reducing the cost of the system due to the fact that the processing of digital streams is performed by a special computer with routing software (software) to the USSS and OSSS instead of complex and expensive equipment RTR KA. Computer data with routing software allows combining information for all OSSS into one group stream on USSS, and also select only the necessary information from the general group stream of each OSSS.

The specified technical result is achieved by the fact that in the prototype system consisting of one USSS and N OSSS, for example OSSS ₁ and OSSS ₂ , as well as RTR KA, and the output of the OSSS is connected to the second input of the RTR KA, the first and fourth outputs of which are connected to the inputs OCCC ₁ and OSSS ₂ , and their outputs - with the first and third inputs of the RTR KA, the second and third outputs of which are connected to the first and second inputs of the OSSS, and the USSS and each OSSS contain computers for implementing the operating modes of the system, special computers are introduced with Routing software as part of the transmission path CAS and reception paths each OSSS.

In FIG. 4 presents a diagram of the invention with a designation of data transmission frequencies:

1 - RTR KA;

2 - OSSS ₁ ;

3 - USSS;

4 - OSSS ₂ ;

f ₁ - from USSS to RTR spacecraft;

f ₂ - from RTR SC to OSSS ₁ , OSSS ₂ ;

f ₃ - from OSSS ₁ to the spacecraft RTR;

f ₄ - from OSSS ₂ to the spacecraft RTR;

f ₅ - from RTR spacecraft to USSS (from OSSS ₁ );

f ₆ - from the RTR SC to the USSS (from OSSS ₂ ).

As can be seen from FIG. 4, the system of time-frequency separation of the information resource consists of RTR KA 1, the first and fourth outputs of which are connected to the inputs of the OSSS ₁ 2 and OSSS ₂ 4. The outputs of the OSSS ₁ 2 and OSSS ₂ 4 are connected to the first and third inputs of the RTR KA 1 the second input is connected to the output of USSS 3, and the second and third outputs are connected to the first and second inputs of USSS 3. The OSSS ₁ 2 and OSSS ₂ 4, as well as USSS contain computers necessary for implementing the system operating modes, not shown in FIG. 4. In addition, the transmitting and receiving paths of the USSS and each OSSS respectively contain special computers with routing software.

In the transmitting channel USSS 3 using a special computer with routing software, information for all OSSS is combined into a single group stream and at a frequency f ₁ is transmitted from the output of the USSS 3 to the second input of the RTR KA 1. At the frequency f _{2 the} data from the first and fourth outputs of the RTR KA 1 are transmitted to the OSSS ₁ 2 and OSSS ₂ 4. The necessary information is allocated using special computers with routing software located in the receiving paths of each OSSS. Then the information is processed and simultaneously at frequencies f ₃ and f ₄ with OCCC ₁ 2 and OSSS ₂ 4 respectively transmitted to the first and third inputs of the RTR KA 1 with high speed (1-2 Mbit / s). From the second and third outputs of the RTR KA 1 at frequencies f ₅ and f ₆ (from OSSS ₁ 2 and OSSS ₂ 4), information is transmitted to the first and second inputs of USSS 3, on the receiving paths of which it is processed using a computer and then transmitted to the VPU, not shown in FIG. four.

In this case the transmission rate at the frequency f ₁ output from USSS 3 to the second input RTR spacecraft 1 is the reception rate at the frequency f ₃ from the output OSSS ₁ 2 to the first input RTR SC 1, but the transmission rate at a frequency f ₅ from the second output RTR SC 1 at the first input of USSS 3 it is not equal to the reception speed at a frequency f ₂ from the first and fourth outputs of the RTR KA 1 to the input of the OSSS ₁ 2 or OSSS ₂ 4. For each OSSS, a separate frequency of data transmission to the USSS 3 with RTR KA 1 is required, as during operation systems with FDMA.

The advantages of the invention are:

- the ability to obtain large amounts of information from remote sources through asymmetric satellite communication channels;

- a combination of the advantages of systems with FDMA and TDMA, namely simplicity and economical use of the frequency resource, without the use of processing equipment on board the RTR spacecraft;

- the use of standard previously issued satellite communications systems, such as R-439-MS and R-439-US, as OSSS and USSS, with minimal modifications.

Currently, routers of the UHP-1000 type [5] have been developed, which make it possible to implement the requirements of information exchange of remote sources in Full Mesh TDMA mode with dynamic resource redistribution between stations. Nevertheless, the proposed invention, as a transitional solution from systems with FDMA and TDMA to Full Mesh TDMA [5], allows you to use previously issued OSSS without significant revision, only by adding an additional computer with routing software to the computer, which is quite simple and does not require a large amount of work.

The system of frequency-time separation of the information resource has been tested and is currently in operation.

Thus, the introduction to the known system consisting of one USSS and N OSSS, for example two, as well as RTR KA, and the output of the USSS is connected to the second input of the RTR KA, the first and fourth outputs of which are connected to the inputs of OCCC ₁ and OSSS ₂ , and their outputs - with the first and third inputs of the RTR spacecraft, the second and third outputs of which are connected to the first and second inputs of the USSS, and the USSS and each OSSS contain computers for implementing the operating modes of the system, additional computers with routing software as part of the transmitting and receiving paths of the USSS and each OSSS, respectively about, allowing for the asymmetric exchange of large amounts of information with remote sources, as well as reduce the cost of the system as a whole.

Literature

1. Computer networks. Principles, technologies, protocols. - Peter, 2013. V. Olifer, N. Olifer.

2. Digital communication. Theoretical Foundations and Practical Application Sklyar Bernard, no. 2 Spanish Williams Publishing House 2003.

3.Http: //krtz.rf/esss.tml [February 12, 2014].

4. http://ixbt.com/comm/sat-inet.shtml [February 12, 2014].

5. http://russianarmy.mybb.ru [February 12, 2014].

Claims (1)

A system of time-frequency separation of an information resource containing one nodal (OSSS) and N terminal (OSSS) satellite communication stations, for example two: OSSS ₁ and OSSS ₂ , as well as a spacecraft repeater (RTR KA), and the OSSS output is connected to the second input RTR KA, the first and fourth outputs of which are connected to the inputs of OCCC ₁ and OSSS ₂ , and their outputs - to the first and third inputs of the RTR KA, the second and third outputs of which are connected to the first and second inputs of the OSSS, and as part of the OSSS and each OSSS electronic computers to implement system operation modes; moreover, in asymmetric satellite communication channels, a frequency-division multiple access system is used, characterized in that additional computers with routing software are introduced into the transceiver path of the UCCN and the transceiver paths of each OSSS, allowing information to be combined for all the OSSS into one group stream to the USSS, extracting only the necessary information from the general group flow of each OSSS, as well as transmitting information to the communication center of a higher control point I'm on a low speed channel; In addition, in asymmetric satellite communication channels, a combination of time and frequency division multiple access systems is used.

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