KR19980058115A - Central Station Redundancy Control Algorithm for Radio Call Data Satellite Transmission System - Google Patents

Abstract

The present invention relates to a central station redundancy control algorithm of a radio call data satellite transmission system. The present invention provides a centralized earth station in a data communication using satellites to prepare for simultaneous failure of signal attenuation and duplication equipment for rainfall and snowfall. The method uses the uplink power controller to compensate for signal attenuation due to rainfall and snowfall. However, since the uplink power is limited, the central earth station is duplicated in parallel with the uplink power up method. In the case of simultaneous failure of redundant pairs of transmitters, the switchover to a spare central station can continue to transmit via satellite without interrupting service.

Description

Central Station Redundancy Control Algorithm for Radio Call Data Satellite Transmission System

1 is a functional block diagram of a central station redundancy configuration for explaining a central station redundancy control algorithm of a radio call data satellite transmission system according to the present invention;

The present invention relates to a radio call data satellite transmission system, and in particular, to implement the central station duplication of the radio call data satellite transmission system to prepare for an emergency situation in which signal attenuation due to rainfall and snowfall and a failure of a transmission part occur. The situation is related to the central station redundancy control algorithm (AlgorUhm) of the radio call data satellite transmission system that enables the transfer of data to the satellite without interruption of service.

In other words, the central station duplication of the radio call data satellite transmission system is implemented, and if a serious problem occurs in the satellite station's satellite transmission equipment or the signal attenuation due to rainfall and snowfall is higher than the standard value, it is impossible to transmit data. As a control algorithm for switching to a central station, the present invention is used in a radio call data satellite transmission system, and is a system that can be operated and used for data transmission and reception equipment using satellites.

In general, methods for compensating for the excess attenuation of the propagation magnetic flux density due to rainfall include a high power system method of increasing the signal firing power by the attenuation value by adjusting the transmitter output, the antenna, and the like, and other paths that are not affected by the excess attenuation path. There is a path diversity method for switching to a path, or a frequency diversity method for switching to a frequency with less influence of rainfall. The overdamping compensation method should be selected in consideration of economics and reliability when designing the system, because the economic aspect considering only the reliability of the system may be deteriorated.

Accordingly, a method of using the path diversity method for the satellite communication link has been proposed, which has a very limited rainfall cell (Cel1) that causes large attenuation, and the rainfall cell does not occur in close proximity to other cells at the same time. I assume it does. Therefore, there is less probability of attenuation occurring simultaneously in both paths. This assumption was tested using radiolocation noise emission measurements to determine rainfall attenuation on independent paths.

These experiments confirmed that path diversity is an effective technique for improving system reliability during rainfall confinement. The frequency diversity method is based on frequencies that are not affected by rainfall attenuation. And 10 GHz or less channels are allocated, so that in the case of rainfall, high priority traffic is converted to a frequency at which the effect of rainfall attenuation is low. Thus, channel capacity is reduced to maintain reliability for that portion of the traffic. This means that all high-priority traffic is allocated at low frequencies and low-priority channels are allocated at least 10 GHz.

In addition, angular diversity is a satellite located in orbits away from one earth station and has different paths between earth stations and satellites.

Therefore, if the rainfall cell is generated on the path which is a certain distance from the earth station, the same effect as the path diversity can be obtained, but when the rain cell is generated near the earth station, the improvement effect is very weak. This method works best when multipath configuration is possible using multiple satellites.

However, the existing satellite data transmission system uses a method of transmitting the signal attenuation caused by rainfall and snowfall by increasing the power of the transmission equipment, and preparing for the failure of the equipment by using the transmission equipment as a redundant structure, There was a limit, and even if the transmission equipment was duplicated, the possibility of failure of the transmission equipments A and B could not be excluded.

Accordingly, the present invention has been made in view of the above-described circumstances, and as a countermeasure against the above-mentioned problems, the present central station should be replaced when the signal is severely attenuated or a fatal damage of the transmission equipment occurs at the central station transmitting the current data. NMS (Nenvork) that monitors and controls the central central station by switching to the central station to enable transmission from the central station and using the 128 Kbps dedicated line as a back-up line for transmitting data. 9600bps dedicated line is used between NMS monitoring Network Management Unit) and the reserve central station, and the dedicated line between the central NMS and the reserve NMS is a control line that transfers between the central central station and the reserve central station. To be used as the receiving line, and the transfer from the central central station to the reserve central station takes place. The following three algorithms, HPA Transmitters A and B, which detect the signal attenuation due to rainfall and snowfall in the central NMS and automatically switch to the reserve central station, transmit radio waves to the satellites of the central station. Algorithm for switching to a spare central station in case of simultaneous failure or failure of modems A and B, a device that modulates data with BPSK (BPSK), and REF A and B, which provide a 10 MHz reference clock for the modal at the same time By providing a, the purpose is to solve the existing problems.

The central station redundancy control algorithm of the radio call data satellite transmission system according to the present invention for realizing the above object is mainly focused on the central station mainly used for implementing the central station redundancy, and the central station which inputs and outputs a predetermined satellite and a signal. The network management unit for controlling and monitoring the central central station and the network management unit for controlling and monitoring the central central station include the network management unit for controlling and monitoring the central central station.

That is, according to the present invention having the above-described configuration, the central earth station in the data communication using the satellite can be duplicated to prepare for the simultaneous failure of the signal attenuation and duplication equipment for rainfall, snowfall, and the existing method is rainfall, snowfall Although the signal attenuation caused by the uplink power controller is compensated for the signal attenuation due to the uplink power controller, the uplink power is limited. Therefore, the duplication of the transmission equipment that duplicates the central earth station is performed in parallel with the uplink power up method. In the case of a simultaneous failure of the pair, it is possible to switch to a spare central station and continue to transmit via satellite without interrupting service.

Hereinafter, embodiments according to the present invention will be described.

First, in order to implement the central station redundancy, the central station and the preliminary central station mainly used should be located at remote locations. For example, if the central central station is located in Seoul, the preliminary central station should be far away from Daejeon or Seoul, so that the effects of rainfall and snowfall are different from Seoul to increase the central station's effect. The high speed dedicated line is used to transfer data between the central station and the reserve central station, and a separate dedicated line is used for control commands related to the transfer.

In the present invention, as shown in FIG. 1, the central station redundancy includes a network management unit (NMS) that controls and monitors the central central station centered on the central central station that always inputs and outputs predetermined satellites and signals. If the signal received from the satellite is attenuated by the elements of rainfall or snowfall, or if the transmission equipment in the satellite earth station fails, it is necessary to replace it, for example, at a point such as Daejeon or Gwangju, which is farther away if the central central station is located in Seoul. If a preliminary central station is permanently found and a cause of an abnormality of the central central station is found, it is identified through a 128 Kbps high-speed data transmission line connected thereto.

In addition, like the network management unit for controlling and monitoring the central central station, the preliminary central station has a network management unit (NMS) for controlling and monitoring the central central station so that when the switchover is made to the reserve central station due to an abnormality of the central central station, the reserve central station is controlled and monitored. There is a dedicated line for control command of 9600bps between the network management unit for controlling the central central station and the network management unit for controlling the preliminary central station. A signal relating to the state is input and output.

2 is an operation flowchart for describing a central station redundancy control algorithm of a radio call data satellite transmission system according to an embodiment of the present invention.

Initially, when the NMS (Boot Management Unit) boots, the processor inside the NMS reads the database and determines whether it is a central NMS or a spare NMS and operates in the corresponding mode (ST 1). In the case of Master (ST 2 stage), it is selected whether the transfer to the spare central station is auto (automatic) or manual (manual) (ST 3 stage), and in case of automatic (ST 4 stage) the state of the central center station (ST step 5).

Then, if the state of the central central station is normal (ST 6 stage), the status of the UPC (Uplink Power Contro1ler) is determined (ST 7 stage), and the status of this UPC or downlink (downlink) link is checked for errors. Back (ST 8 steps) Read the Beacon signal level (S _M ) (ST 9 steps) and refer to the test table to find the S _MdB value (ST 10 steps), followed by the beacon signal (S _CdB ) on a clear day. (Step ST 11), the difference with the beacon signal level (D _LM ) on a clear day (ST 12 step) is multiplied by the variable value to obtain the uplink loss (U _LM ) of the central station (ST step 13). ).

Also, as shown in (c), if the U _LM value is greater than 10 and less than 13 (ST 14 steps), the absolute value of the difference with the uplink signal attenuation value (U _LS ) read from the spare NMS is smaller than 2. If the absolute value is less than 2 (ST 15 step) after the comparison, the central modem transmits. If it is greater than 2, the size of U _LM and U _LS is compared. If U _LM is not large, the central modem transmits and if U _LS is small. (ST 16 step) The spare modem switches over to transmit.

Also, if the U _LM value is not greater than 10 and less than 13, then the difference between the U _LM and U _LS values is less than 1; if less than 1 (ST 17), the central modem transmits; If If the _LM is large compared to the magnitude of U U U _LM and _LS central modem and make the transmission, U _LS is less and the transfer so as to transmit the pre-modem.

In addition, when the state of the central central station is manual instead of automatic in step ST 4, the central central station and the spare central station are switched when there is a transfer command (ST 18), and from the central central station to the spare central station (ST 19). Or transfer from the reserve central station to the central station (ST 20).

In addition, if the central central station is not normal in step ST6, the transfer to the reserve central station is performed. Based on the abnormal state of the central central station, the NMS determines the state of the reserve central station (step ST21). In normal state (ST 22), the carrier of the spare central station modem is turned on (ST 23), and the line of the spare central station is turned on (ST 24) and muted by the modem carrier of the central station. (Mute) (ST 25 stage), and the central central station is thus switched off (ST 26 stage) to the reserve central station.

In addition, in step ST8, the gain value U _LM of the UPC attenuator ATT in which the UPC or the downlink state is not an error is read (step ST27). If the _ULM value is not larger than I0, If the modem transmits and the U _LM value is greater than 10 (ST 28), the loss of the uplink attenuator of the reserve central station (U _LS ) is read (ST 29) and the above steps from ST 14 to ST 17 are repeated.

In addition, when the result determined by the NMS in step ST 2 is not a central central station, if the manual operation is performed first, steps ST 18 to ST 20 are repeatedly executed, and in the case of automatic, the NMS is in the state of the spare central station. (ST 30) If the preliminary central station is not normal and is transmitting from the preliminary central station, the transfer to the central center station is carried out. First, the state of the central center station is determined (ST 32). Step ST 33) is turned on by the modem carrier of the central station (ST 34), and the line of the central station is turned on by the carrier signal of the modem (ST 35), and based on the line on of the central center station Therefore, the preliminary central station modem outputs a carrier signal and mutes the signal (ST 36). Accordingly, the preliminary central station modem turns off the line (ST 37).

In addition, in step ST 31, if the preliminary central station is normal, the state of the UPC (Uplink Power Controller) is determined (ST 38), and the state of the UPC or downlink (downlink) is checked for an error, Back (ST 39 Step) Read the Beacon Signal Level (S _M ) (ST 40 Step) and _obtain the S _MdB value by referring to the test table (ST 41 Step), followed by the beacon signal (S _CdB ) (Step ST 42), the difference between the beacon signal level on a sunny day (D _LM ) is calculated (ST 43) and multiplied by the variable to obtain the uplink loss (U _LM ) of the spare central station (ST 44). ).

If there is no UPC or downlink error in step ST 39, the gain value U _LM of the attenuator ATT of the UPC is read (step 47), and the loss of the uplink attenuator of the reserve center station (U _LS ) is read. (Step ST 46), the above steps are repeated from step ST 14 to step ST 16.

On the other hand, the present invention is not limited to the above embodiments and can be variously modified within the scope without departing from the technical spirit of the present invention.

As described above, according to the present invention, in the data communication using satellite, the central earth station can be duplicated to prepare for attenuation of rain, snow for signal attenuation, and simultaneous failure of the duplication equipment, and the conventional method attenuates signal due to rainfall and snow. Although a method of compensating for signal attenuation by using an uplink power controller is used, there is a limit to increasing uplink power, so that a redundant pair of transmission equipment that duplicates a central earth station in parallel with a method of increasing uplink power may fail. In this case, it is possible to realize the central station redundancy control algorithm of the radio call data satellite transmission system, which can switch to a spare central station and continue to transmit via satellite without interruption of service.

Claims (2)

In order to realize central station redundancy, a network management unit for controlling and monitoring the central central station mainly for a central station mainly used, a central central station for inputting / outputting predetermined satellites and signals, and a network management unit for controlling and monitoring the central central station; Similarly, the redundant central station also includes a network management unit for controlling and monitoring the central station redundancy control device of the radio call data satellite transmission system. When the network manager boots up, the processor inside the NMS reads the database to operate the mode, the second step of determining whether the determined mode is the center, and whether the transfer to the spare central station is automatic. A third step of selecting a fanzine, a fourth step corresponding to automatic, a fifth step of grasping the state of the central central station in the case of automatic, and a sixth step of determining whether the state of the central central station is normal And a seventh step of checking the status of the UPC, an eighth step of checking whether the UPC or downlink status is an error, an eighth step of the case of an incorrect status, a ninth step of reading the beacon signal level, A tenth step of obtaining an S _MdB value by reference, an eleventh step in which a beacon signal is input on a clear day, a twelfth step of obtaining a difference between a beacon signal level in a clear day, and multiplying the variable value to a center Compare the thirteenth step of obtaining the uplink loss of the central station, the fourteenth step if the U _ILM value is greater than 10 and less than 13, and the absolute value of the difference between the uplink signal attenuation value read from the spare NMS is less than two. and the step 15, if the absolute value is less than 2, then, if the center modem, and to transmit, to greater than 2 compares the magnitudes of U _LM and U _LS is U _LM large central modem is transmitting and claim to be transmitted if the U _LS less step 17, which, if large, step 16, and a U _LS value of less than 10 is not in a range between 13 comparing U _LM and U _LS value and the absolute value of the difference is smaller than 1, and the transmission is less than 1, the central central station If the status of is not manual but automatic, the eighteenth step of switching the central and spare central stations when the transfer command is given, the nineteenth step of transmitting from the central central station to the spare central station, or the transition from the reserve central station to the central central station. In step 20, and if the central central station is not normal in the sixth step, the transfer to the reserve central station is carried out. Based on the abnormal state of the central central station, the NMS detects the state of the reserve central station; A twenty-second step of transmitting if the spare central station is in a normal state; a twenty-third step of turning on a carrier of the spare central station modem; a twenty-fourth step of turning on the line of the spare central station; The twenty-fifth step of muting by the modem carrier, the 26th step where the central central station is switched off and the transfer to the preliminary central station is performed, and also in the step 8, UPC or downlink If the link status is not an error, the 27th step of reading the gain value (U _LM ) of the UPC attenuator ATT), and if the U _LM value is not greater than 10, the modem of the central station transmits and the U _LM value is greater than 10. 28th stage to transmit A step 29 of reading the loss of the uplink attenuator (U _LS ) of the preliminary central station, and if the result determined by the NMS in step ST 2 is a preliminary central station instead of a central central station, the first step is ST 18. Step 20 is repeated from step 20. If it is automatic, step 30 is performed by the NMS to determine the status of the spare central station. If the spare central station is not normal and transmitting from the spare central station, transfer to the central central station is performed. First step (32) of determining the state of the central central station; and step (33) of transmitting if the central central station is in a normal state; and step 34 of turning on by the modem carrier of the central central station; A third step in which the line of the central central station is turned on, and the preliminary central station modem outputs a carrier signal and mutes on the basis of the line on of the central central station. Step 6, and accordingly, the preliminary central station performs the 37th step in which the line is turned off), and in step ST 31, when the preliminary central station is normal, the 38th step of identifying the state of the UPC (Uplink Power Contro1ler); Or checking whether the downlink downlink condition is an error, and if the faulty status is found, step 39, reading the beacon signal level S _M , and referring to a test table, the S _MdB value. A forty-first step of obtaining a signal, followed by a forty-second step of receiving a beacon signal (S _CdB ) on a clear day, and a forty-third step of obtaining a difference (D _LM ) between a beacon signal level on a clear day, and a variable value Multiplying to obtain the uplink loss (U _LM ) of the spare central station; and in step ST 39, if there is no error of the UPC or the downlink, reading the gain value (U _LM ) of the attenuator (ATT) of the UPC. Step 47 and read the loss of the uplink attenuator (U _LS ) of the spare central station. A central station redundancy control algorithm method for a radio call data satellite transmission system, comprising the step 46.