JPH07273706A - Satellite line switching system - Google Patents
Satellite line switching systemInfo
- Publication number
- JPH07273706A JPH07273706A JP5759794A JP5759794A JPH07273706A JP H07273706 A JPH07273706 A JP H07273706A JP 5759794 A JP5759794 A JP 5759794A JP 5759794 A JP5759794 A JP 5759794A JP H07273706 A JPH07273706 A JP H07273706A
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- JP
- Japan
- Prior art keywords
- level
- threshold value
- satellite
- switching
- reception
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Links
- 230000005540 biological transmission Effects 0.000 claims abstract description 27
- 238000012937 correction Methods 0.000 claims description 14
- 230000007423 decrease Effects 0.000 claims description 12
- 238000000034 method Methods 0.000 claims description 6
- 230000002159 abnormal effect Effects 0.000 claims 1
- 230000007613 environmental effect Effects 0.000 description 5
- 230000000737 periodic effect Effects 0.000 description 5
- 238000001514 detection method Methods 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000002238 attenuated effect Effects 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 230000005856 abnormality Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 230000007257 malfunction Effects 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は衛星回線の受信レベル低
下を検出して地上回線に切替える衛星回線切替方式に関
し、特に人工衛星を利用する同報システムにおける受信
レベル変動値補正機能付き衛星回線切替方式に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a satellite line switching system for detecting a decrease in the receiving level of a satellite line and switching to a terrestrial line, and particularly to a satellite line switching with a receiving level fluctuation value correcting function in a broadcasting system using artificial satellites. Regarding the scheme.
【０００２】[0002]
【従来の技術】人工衛星を利用する同報システムにおけ
る受信局では気象条件の変化例えば降雨があると、これ
によって衛星から送信された電波は減衰され、受信レベ
ルが低下し、良好な画像や音声、あるいはデータを得る
事ができないことが発生する。この対策として各受信局
の受信レベルを検出し、この検出値が予め定めたしきい
値より低下した場合は同報用の衛星回線とは別に具備し
た伝送線路（例えば地上回線を利用したバックアップ回
線）に切り替える事で良好な画像や音声あるいはデータ
を得る方法が利用されていた。2. Description of the Related Art When a receiving station in a broadcasting system using an artificial satellite changes weather conditions, such as rain, the radio waves transmitted from the satellite are attenuated by this, and the reception level is lowered, so that a good image or sound is received. Or, it happens that data cannot be obtained. As a countermeasure against this, the reception level of each receiving station is detected, and if this detected value falls below a predetermined threshold, a transmission line (for example, a backup line using a terrestrial line) provided separately from the satellite line for broadcasting is provided. ) Was used to obtain good images, voice or data.
【０００３】図２は、従来の衛星回線切替方式の構成を
示したものである。本図において、画像，音声等のデー
タを送信する送信機能を有する送信用地球局１は衛星２
を介して複数（ｎ：２以上の整数）の受信局３０−１〜
３０−ｎに同報送信している。各受信局３０−１〜３０
−ｎは、全て同一の構成をしており、例えば受信局３０
−１については、受信アンテナ５により受信された受信
信号は低雑音増幅器（ＬＮＡ）６により増幅された後、
ケーブル７を通って復調器（ＤＥＭ）８に入力される。
ＤＥＭ８は、受信信号を復調して得られる復調信号９を
制御装置５０に出力すると共に、受信レベルを検出し、
その検出出力を受信レベル情報１０として制御装置５０
に出力する。制御装置５０は制御部４０によりＤＥＭ８
より得られた受信レベル情報１０が所定の値以上であれ
ば正常と判断し、切替器１３を切替えて、切替器１３の
出力信号２１に復調信号９が得られるようにする。ま
た、受信レベル情報１０が所定の値以下となった場合
は、異常と判断し切替器１３を切り替えて送信局１から
地上回線２０を通して送られるデータを受信できるよう
にし、出力信号２１を得る。FIG. 2 shows the configuration of a conventional satellite line switching system. In the figure, a transmitting earth station 1 having a transmitting function for transmitting data such as image and voice is a satellite 2
Via a plurality of (n: integer of 2 or more) receiving stations 30-1 to
Broadcast to 30-n. Each receiving station 30-1 to 30
-N all have the same configuration, for example, the receiving station 30
For -1, after the received signal received by the receiving antenna 5 is amplified by the low noise amplifier (LNA) 6,
It is input to the demodulator (DEM) 8 through the cable 7.
The DEM 8 outputs the demodulated signal 9 obtained by demodulating the received signal to the control device 50, detects the received level,
The detection output is used as the reception level information 10 in the control device 50.
Output to. The controller 50 controls the DEM 8 by the controller 40.
If the obtained reception level information 10 is greater than or equal to a predetermined value, it is determined to be normal, the switch 13 is switched, and the demodulated signal 9 is obtained as the output signal 21 of the switch 13. When the reception level information 10 becomes equal to or lower than a predetermined value, it is determined that there is an abnormality, and the switch 13 is switched to enable the data transmitted from the transmission station 1 through the ground line 20 to be received, and the output signal 21 is obtained.
【０００４】[0004]
【発明が解決しようとする課題】しかし、上述した従来
の方法では単に受信レベルを基準にして衛星回線と地上
回線との切り替えを行う為、受信レベルと受信信号の品
質との相関が低くなった場合に、受信レベルはしきい値
以下だが受信信号が十分な品質であるにも関わらず衛星
回線かわ地上回線に切り替えたり、逆に受信レベルはし
きい値以下ではないが受信信号の品質が劣化し良好な画
像や音声、あるいはデータが得られていないにも関わら
ず別の伝送線路への切り替えを行わなかったりする場合
がある。具体的には、主に周囲の環境条件によって図２
に示す低雑音増幅装置６の利得や雑音量、ケーブル７の
減衰量及びその他の外来雑音量が変動し、必ずしも受信
レベルと受信信号の品質との間に確固たる相関関係が成
立しない。つまり同じ受信レベルで受信していも受信信
号の品質は周囲の環境条件等により良い場合もあれば悪
い場合もある。この為従来の技術では衛星回線からバッ
クアップ用の伝送線路への切り替えを行うために単に受
信レベルを検出するだけではできず、十分な受信電界マ
ージンのあるる回線設計を構築した上、十分に余裕のあ
るレベルで切り替えを行う必要があった。また、回線品
質が劣化し十分な画像や音声、あるいはデータが得られ
ていない状態になってもなお受信レベルがしきい値まで
低下していない為別の伝送線路への切り替えを行わなか
ったりする問題があった。However, in the above-mentioned conventional method, since the satellite line and the terrestrial line are simply switched on the basis of the reception level, the correlation between the reception level and the quality of the received signal becomes low. In this case, the reception level is below the threshold, but the quality of the reception signal is deteriorated even though the reception signal is not below the threshold although the reception signal is of sufficient quality and the satellite line or ground line is switched. However, there is a case where switching to another transmission line is not performed even though good image, sound, or data is not obtained. Specifically, Fig. 2 mainly depends on the surrounding environmental conditions.
The gain and noise amount of the low noise amplifying device 6, the attenuation amount of the cable 7 and other external noise amounts shown in (4) vary, and a firm correlation is not always established between the reception level and the quality of the received signal. That is, even if the signals are received at the same reception level, the quality of the received signal may be good or bad depending on the surrounding environmental conditions. For this reason, in the conventional technology, it is not possible to simply detect the reception level in order to switch from the satellite line to the backup transmission line.In addition to constructing a line design with a sufficient reception electric field margin, there is a sufficient margin. It was necessary to switch at a certain level. Also, even if the line quality deteriorates and sufficient image, voice, or data is not obtained, the reception level has not dropped to the threshold value, so switching to another transmission line may not be performed. There was a problem.
【０００５】さらに、この対策として、本切替条件を受
信レベルではなく例えば復調データのＢＥＲ（符号誤り
率）の良否による方法も取られていたが、データ速度が
遅い場合には、ＢＥＲの検出時間が長くなり瞬時の切替
ができない問題を有していた。Further, as a countermeasure against this, there has been adopted a method in which this switching condition is based on whether the BER (code error rate) of demodulated data is good or not instead of the reception level. However, when the data speed is slow, the BER detection time is detected. However, there is a problem in that it is not possible to switch instantly due to the long period.
【０００６】例えばデータ伝速３８４ｋｂｐｓの伝送路
では符号誤り率＝１０-6を検出するには少なくとも３秒
以上かかる。符号誤り率＝１０-6となる前に切替を行う
為には符号誤り率＝１０-6よりも良い状態、例えば符号
誤り率＝１０-7で切替を行なわなければならずこの符号
誤り率＝１０-7を検出する為には少なくとも３０秒以上
必要とする。なぜなら、例えば１ｂｉｔの誤りを検出し
た時に、それが符号誤り率＝１０-8の確率で発生したも
のか又は符号誤り率＝１０-7の確率で発生したものかを
判別する為には次の誤りｂｉｔ又はさらに次に発生する
誤りｂｉｔを検出するまで待つ必要が有る為である。For example, it takes at least 3 seconds or more to detect the code error rate = 10 −6 on a transmission line with a data transmission speed of 384 kbps. BER = 10 -6 to become before good to perform switching than the bit error rate = 10-6 to a state, for example bit error rate = 10-7 must perform switching in the code error rate = It takes at least 30 seconds or more to detect 10 −7 . This is because, for example, when an error of 1 bit is detected, it is possible to determine whether it occurs with a probability of code error rate = 10 −8 or a probability of code error rate = 10 −7 as follows. This is because it is necessary to wait until an error bit or an error bit that occurs next is detected.
【０００７】以上の様に、符号誤り率はその値が受信信
号の品質そのものではあるが、衛星回線を別の伝送回線
へ切り替える判断基準とするには問題となっていた。As described above, the value of the code error rate is the quality itself of the received signal, but it has been a problem to use it as a criterion for switching the satellite line to another transmission line.
【０００８】また別の手法として、受信信号の雑音量を
測定する方法もあるが、雑音測定用の狭帯域フィルター
が必要となりまた安定な検出出力を得るには高価な構成
となる問題を有していた。Another method is to measure the noise amount of the received signal, but it has a problem that a narrow band filter for noise measurement is required and an expensive structure is required to obtain a stable detection output. Was there.
【０００９】したがって、本発明の目的は、検出した受
信レベルに対し周囲の環境条件による各変動値の補正を
行うと共に実際の回線品質の情報を考慮して、降雨等の
気象条件の変化に対し、良好な画像や音声、あるいはデ
ータが得られなくなる前に確実に別の伝送線路への切り
替えを行うと共に、簡単な構成で切り替えができる衛星
回線切替方式を提供する事を目的とする。Therefore, an object of the present invention is to correct each variation value according to the surrounding environmental conditions for the detected reception level and to consider the information of the actual line quality to cope with changes in weather conditions such as rainfall. It is an object of the present invention to provide a satellite line switching system capable of surely switching to another transmission line before a good image, voice, or data cannot be obtained, and switching with a simple configuration.
【００１０】[0010]
【課題を解決するための手段】上述した問題点を解決す
る為、本発明による衛星回線切替方式では受信レベルの
変化をその変動パターンを基に実際に受信信号の品質に
影響を及ぼす変化と品質には影響しない変動分とに分離
し、別途検出した符号誤り率との対比を行い記憶してお
くことで、実際に降雨等により受信レベルが低下した場
合は受信レベルの低下量に対する衛星回線の品質を変動
値に関係なく定量的に把握し、単に受信レベルの低下に
基づき別の伝送線路に切り替えを行うのではなく、実質
的に衛星回線の品質の劣化に基づき別の伝送線路に切り
替えを行う事で上記目的を達成している。In order to solve the above-mentioned problems, in the satellite line switching system according to the present invention, the change and the quality of the reception level are actually affected by the change pattern of the reception level based on the fluctuation pattern. If the reception level actually drops due to rainfall, etc. Quantitatively grasp the quality regardless of the fluctuation value and switch to another transmission line based on the deterioration of the quality of the satellite line instead of simply switching to another transmission line based on the deterioration of the reception level. By doing so, the above-mentioned purpose is achieved.
【００１１】[0011]
【実施例】次に、本発明について図面を参照して説明す
る。図１は、本発明の一実施例を示すシステム系統図で
ある。本図において送信用地球局１から送信され、人工
衛星２により折り返された電波をそれぞれ異なる地域に
設置された複数（ｎ：２以上の整数）の受信局３−１〜
３−ｎで受信する同報システムにおいて、受信アンテナ
５で受信した信号は低雑音増幅装置６及びケーブル７を
経て復調装置８に入力される。この時例えば人工衛星２
から受信局３−１への電波伝搬路上に降雨があると人工
衛星２からの電波は減衰され、受信局３−１の受信レベ
ルが低下するが、復調装置８ではこの受信レベルを検出
し受信レベル情報１０を制御装置１７のレベル補正部１
４に出力する。レベル補正部１４は、受信レベル情報１
０の変動パターンから受信信号の品質に影響を及ぼす主
要因である衛星回線上の降雨によるレベル変動値αを下
記の手法により算出し、これが予め設定したしきい値ａ
を越えた時、切り替え制御部１６において衛星回線が信
号の伝送に十分な品質を確保できないと判断し、スイッ
チ１３で別の伝送線路２０に切り替える。すなわち、衛
星通信における受信信号のレベル変動は、短時間で変動
するもとの（α）と、長時間に変動するもの（β）に分
類される。長時間に変動するレベル変動β（受信信号の
品質にほとんど影響を与えないレベル変動）は低雑音増
幅器６の利得やケーブル７の損失が周囲温度等の環境条
件の変化により変動することにより発生する。機器等が
正常であればこの変化は緩慢でありかつ周期的である
為、短時間のレベル変動α（実際に受信信号の品質に影
響を及ぼす降雨等に起因する急峻で周期性の無いレベル
変動）とは明らかにレベル変動の内容が異なっている。
そこで、本発明は、受信信号の品質に影響を与えないレ
ベル変動βを常時観測し、降雨等により急峻で周期性の
無いレベル低下が発生した場合に前記のレベル変動分を
差し引くことで、受信信号に影響を与えるレベル変動分
αのみを回線切替条件としている。即ち、制御装置１７
は、受信レベル情報１０のしきい値を以下のとおり補正
する。先ず受信信号のレベルをＬとすると次式で表せ
る。 Ｌ＝Ｌnom −α−β …… ここで、Ｌnom ：晴天時の受信信号のレベルの長期的な
平均値（固定） α：降雨等に起因する変動であり、受信信号の品質劣化
に直接影響を受ける、急峻で周期性の無いレベル変動値 β：周囲温度環境条件に起因する、変動であり受信信号
の品質に殆ど影響を与えない緩慢で周期的なレベル変動
値 図２の従来の方式の切り替え条件は次の式に基づく。 Ｌ＜Ｌnom −ａ …… ａ：しきい値 式に式を代入すると、 Ｌ＝Ｌnom −α−β＜Ｌnom −ａ α＋β＞ａ …… 以上の様に式には、βが含まれているため、βの影響
で切替誤動作を発生していた。一方、本発明の図１の制
御装置１７内のレベル補正部１４は、ある時点での晴天
時における受信レベルを所定の時間Ｔだけ計測し、その
値をＬａｖｅとし記憶する。このＬａｖｅはαの成分を
含まないので式より Ｌａｖｅ≒Ｌnom −β …… となる。さらに、その後、所定の時間Ｔだけ受信レベル
を計測し、所定レベルΔＬ（例えば１ｄＢ）以上のレベ
ル低下が観測されなければ、この時間Ｔに発生したレベ
ル変動には急峻なレベル変動であるαの成分は含まれ
ず、緩慢なレベル変動であるβの成分のみとなる。この
操作を繰り返すことにより、晴天時における平均受信レ
ベルＬａｖｅを最新の値に更新する。また、ある計測時
間Ｔにおいて、ΔＬ以上のレベル低下が観測された場合
は、急峻なレベル変動が発生したとして、Ｌａｖｅの値
を更新せず、前の値を保持する。以上の様にして求めら
れたＬａｖｅにはβが含まれていないため受信レベルＬ
は Ｌ＝Ｌnom −α−β≒Ｌａｖｅ−ａ …… となる。本発明では切り替え条件をＬａｖｅを用いて、 Ｌ＜Ｌａｖｅ−ａ …… としている。この式に式を代入すると Ｌ＝Ｌａｖｅ−α＜Ｌａｖｅ−ａ …… となり、本発明ではＬａｖｅを用いて切り替え条件を設
定することによりβに依存することが無いこととなる。DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a system diagram showing an embodiment of the present invention. In the figure, a plurality of (n: an integer of 2 or more) receiving stations 3-1 to 3-1 are installed in different regions, respectively, the radio waves transmitted from the transmitting earth station 1 and returned by the artificial satellite 2.
In the broadcast system for receiving at 3-n, the signal received by the receiving antenna 5 is input to the demodulating device 8 via the low noise amplifying device 6 and the cable 7. At this time, for example, artificial satellite 2
From the satellite to the receiving station 3-1 when there is rainfall on the propagation path, the radio waves from the artificial satellite 2 are attenuated and the receiving level of the receiving station 3-1 is lowered. However, the demodulator 8 detects this receiving level and receives it. The level information 10 is transferred to the level correction unit 1 of the control device 17.
Output to 4. The level correction unit 14 receives the reception level information 1
From the fluctuation pattern of 0, the level fluctuation value α due to rainfall on the satellite line, which is the main factor affecting the quality of the received signal, is calculated by the following method, and this is set to the preset threshold value a.
When it exceeds, the switching control unit 16 determines that the satellite line cannot secure sufficient quality for signal transmission, and the switch 13 switches to another transmission line 20. That is, the level fluctuation of the received signal in the satellite communication is classified into the original (α) that fluctuates in a short time and the one (β) that fluctuates in a long time. The level fluctuation β (level fluctuation that hardly affects the quality of the received signal), which fluctuates for a long time, occurs when the gain of the low noise amplifier 6 and the loss of the cable 7 fluctuate due to changes in environmental conditions such as ambient temperature. . If the equipment is normal, this change is slow and periodic, so a short-term level fluctuation α (a steep, non-periodic level fluctuation due to rainfall etc. that actually affects the quality of the received signal) ) And the contents of the level fluctuation are obviously different.
Therefore, the present invention constantly observes the level fluctuation β that does not affect the quality of the received signal, and subtracts the level fluctuation amount when a steep and non-periodic level drop occurs due to rainfall or the like. Only the level variation α affecting the signal is set as the line switching condition. That is, the control device 17
Corrects the threshold value of the reception level information 10 as follows. First, when the level of the received signal is L, it can be expressed by the following equation. L = L nom −α−β where L nom is the long-term average value of the level of the received signal in fine weather (fixed) α is the fluctuation caused by rainfall or the like and directly affects the deterioration of the quality of the received signal. A steep, non-periodic level fluctuation value β that is affected: Slow and periodic level fluctuation value that is a fluctuation due to ambient temperature environmental conditions and has little effect on the quality of the received signal. Conventional method of FIG. The switching condition of is based on the following formula. L <L nom −a ・ ・ ・ a: Substituting the equation into the threshold value equation, L = L nom −α−β <L nom −a α + β> a …… As described above, β is included in the equation. Therefore, the switching malfunction occurs due to the influence of β. On the other hand, the level correction unit 14 in the control device 17 of FIG. 1 of the present invention measures the reception level at a certain time in fine weather for a predetermined time T, and stores the value as Love. Since this Love does not include the component of α, from the equation, Love≈L nom −β. Furthermore, after that, the reception level is measured for a predetermined time T, and if no level decrease of a predetermined level ΔL (for example, 1 dB) or more is observed, the level fluctuation occurring at this time T is a sharp level fluctuation α. No component is included, and only the β component, which is a gradual level change, is included. By repeating this operation, the average reception level Love in fine weather is updated to the latest value. Further, when a level decrease of ΔL or more is observed at a certain measurement time T, it is determined that a steep level change has occurred, and the value of Love is not updated and the previous value is held. Since the Love obtained as described above does not include β, the reception level L
Is L = L nom −α−β≈Lave−a. In the present invention, Lave is used as the switching condition, and L <Lave-a. By substituting the equation into this equation, L = Lave-α <Lave-a is established, and in the present invention, by setting the switching condition using Love, β does not depend on β.
【００１２】さらに本発明の、復調装置８は、符号誤り
率を検出し符号誤り率情報１１としてしきい値補正部１
５に出力する。しきい値補正部１５は、この符号誤り率
情報１１が予め設定した回線品質の限界値となる符号誤
り率εより劣化した時も上記と同様に別の伝送線路２０
への切り替え信号を切り替え制御部１６へ出力し、切り
替えを行う。また、上記の受信レベルによる切り替えの
為のしきい値ａの補正をこの信号品質と等価な符号誤り
率に基づきしきい値補正部１５で行い、補正されたしき
い値ａを切り替え制御１６に供給することで常に受信レ
ベルと回線品質の相関性を把握し、より確実な切り替え
動作を実現する。Further, the demodulator 8 of the present invention detects the code error rate and outputs the code error rate information 11 as the threshold value correction unit 1.
Output to 5. When the code error rate information 11 deteriorates below the code error rate ε which is the preset limit value of the line quality, the threshold value correction unit 15 separates another transmission line 20 as described above.
A switching signal for switching to is output to the switching control unit 16 to perform switching. Further, the threshold value a for switching according to the above reception level is corrected by the threshold value correction unit 15 based on the code error rate equivalent to this signal quality, and the corrected threshold value a is sent to the switching control 16. By supplying the signal, the correlation between the reception level and the line quality is always grasped, and more reliable switching operation is realized.
【００１３】本発明の符号誤り率に基づくしきい値ａの
補正の手法に関して以下に詳細を記載する。The details of the method of correcting the threshold value a based on the code error rate of the present invention will be described below.
【００１４】最初に、復調装置８で得られた符号誤り率
の限界値ε（例えば１０-6）を設定し、回線切替の判定
条件としている。すなわち、前述の受信レベルの低下に
よる判定条件を優先し、受信レベルの低下がしきい値ａ
以上の場合には、符号誤り率が限界値εより良好であっ
たとしても切り替える。一方、干渉波が増加した場合等
では受信レベルの低下がしきい値ａ以下であったとして
も、受信信号の品質が劣化し受信信号の符号誤り率がし
きい値（１０-6）をこえる場合が有る。この時の受信信
号レベルの低下をａ′とすると、本発明ではしきい値ａ
をａ′に変更してしきい値の変更を行うと共に切替を行
う。又、前述の受信信号のレベル低下がしきい値ａ以上
で符号誤り率が限界値εより良好の場合にその後、さら
に受信レベルが低下し、受信信号レベルの低下がａ″
（ａ″＞α）となった場合、ａ″を新しいしきい値ａに
更新しその後は新しいしきい値ａで切替を行う。First, a limit value ε (for example, 10 -6 ) of the code error rate obtained by the demodulator 8 is set and used as a condition for determining line switching. That is, the judgment condition due to the decrease in the reception level is given priority, and the decrease in the reception level is the threshold value a.
In the above case, switching is performed even if the code error rate is better than the limit value ε. On the other hand, when the number of interference waves increases, even if the decrease in the reception level is equal to or less than the threshold value a, the quality of the reception signal deteriorates and the code error rate of the reception signal exceeds the threshold value (10 −6 ). There are cases. Assuming that the received signal level drop at this time is a ', the threshold value a in the present invention.
To a 'to change the threshold value and switch. Further, when the level of the received signal decreases above the threshold value a and the code error rate is better than the limit value ε, the received level further decreases and the received signal level decreases by a ″.
When (a ″> α), a ″ is updated to a new threshold value a, and then switching is performed with the new threshold value a.
【００１５】また、本発明の制御装置１７の切り替え制
御部１６は、しきい値ｂ（しきい値ｂ＜しきい値ａ）を
記憶してあり、受信レベルの低下がこのしきい値ｂを越
えた時点で別の伝送線路２０を接続するための発呼要求
を送信局１に対して送出し、受信レベルの低下がしきい
値ａを越える前に別の伝送線路２０を確保する。これに
より、受信レベルの低下がしきい値ａを越える時には、
回線の瞬断を起こす事無く衛星回線から別の伝送線路２
０への切り替えを行う事ができる。Further, the switching control unit 16 of the control device 17 of the present invention stores a threshold value b (threshold value b <threshold value a), and the lowering of the reception level is caused by this threshold value b. When it exceeds, a call request for connecting another transmission line 20 is sent to the transmitting station 1, and another transmission line 20 is secured before the decrease in the reception level exceeds the threshold value a. As a result, when the decrease in the reception level exceeds the threshold value a,
Separate transmission line 2 from the satellite line without causing a momentary disconnection of the line
You can switch to 0.
【００１６】なお、本発明の制御装置１７は自動切り替
え動作と同様に受信信号レベルを監視し、衛星回線が復
旧した場合に自動的に別の伝送線路２０から衛星回線へ
の復旧切り替え動作を行う。Incidentally, the control device 17 of the present invention monitors the received signal level similarly to the automatic switching operation, and when the satellite line is restored, the control device 17 automatically performs the restoration switching operation from another transmission line 20 to the satellite line. .
【００１７】[0017]
【発明の効果】以上説明したように、本発明による衛星
回線切替方式は、単に受信レベルに基づき切り替えを行
うのではなく切り替えに不要な情報を排除しかつ実際の
回線品質に基づく補正を自動で行うことで、必要が無い
にも関わらず別の伝送線路に切り替える事を防止しかつ
必要な場合は確実に別の線路に切り替える事が可能であ
り、かつ別の伝送線路を使用する延べ時間を最小限にす
ることで経済的で信頼性の高いシステムを実現できる。As described above, the satellite channel switching system according to the present invention does not simply switch based on the reception level, but eliminates information unnecessary for switching and automatically corrects based on the actual channel quality. By doing so, it is possible to prevent switching to another transmission line even if it is not necessary and to switch to another line surely when necessary, and to increase the total time to use another transmission line. An economical and reliable system can be realized by minimizing it.
【図１】本発明の衛星回線切替方式の一実施例のシステ
ム系統図である。FIG. 1 is a system system diagram of an embodiment of a satellite line switching system of the present invention.
【図２】従来の衛星回線切替方式のシステム系統図であ
る。FIG. 2 is a system diagram of a conventional satellite line switching system.
１ 送信局 ２ 人工衛星 ３−１〜３−ｎ 受信局 ５ 受信アンテナ ６ 低雑音増幅装置 ７ ケーブル ８ 復調装置 ９ 受信信号 １０ 受信レベル情報 １１ 符号誤り率情報 １２ 障害情報 １３ スイッチ １４ レベル補正部 １５ しきい値補正部 １６ 切り替え制御部 １７ 制御装置 １８ 発呼要求信号 １９ 自動発呼装置 ２０ 伝送線路 ２１ 外来雑音 1 transmitting station 2 artificial satellites 3-1 to 3-n receiving station 5 receiving antenna 6 low noise amplifying device 7 cable 8 demodulating device 9 received signal 10 received level information 11 code error rate information 12 fault information 13 switch 14 level correction unit 15 Threshold correction unit 16 Switching control unit 17 Control device 18 Call request signal 19 Automatic call device 20 Transmission line 21 External noise
Claims (5)
送信された信号を衛星を介して分配される複数の受信局
と、前記送信信号を前記受信局へ接続する地上回線とを
有し、衛星回線の異常時の場合に前記地上回線へ自動的
に切り替える衛星回線切替方式において、前記受信局の
復調装置で検出された受信レベル情報を入力し、衛星区
間におけるレベレ変動と前記受信局における受信装置の
レベル変動を識別し、衛星区間におけるレベル変動のみ
を検出し、所定の第１のしきい値との比較を行なうレベ
ル補正部と、前記復調装置で検出された符号誤り率情報
を入力し、前記第１のしきい値を補正するしきい値補正
部と、前記レベル補正部としきい値補正部からの出力信
号を入力し前記復調装置の復調出力と前記地上回線から
の送信信号とを切り替える切り替え制御部と、前記切り
替え制御部の制御信号により前記復調装置の出力と前記
地上回線のどちらを切り替えるスイッチとを具備するこ
とを特徴とする衛星回線切替方式。1. A transmission earth station, a plurality of reception stations for distributing signals transmitted from the transmission earth station via satellites, and a ground line connecting the transmission signals to the reception station. However, in the satellite line switching method that automatically switches to the terrestrial line when the satellite line is abnormal, the reception level information detected by the demodulator of the receiving station is input, and the level fluctuation in the satellite section and the receiving station are input. The level correction unit for identifying the level fluctuation of the receiving device in the above, detecting only the level fluctuation in the satellite section, and comparing with the predetermined first threshold, and the code error rate information detected by the demodulating device. A threshold value correction unit for inputting and correcting the first threshold value, an output signal from the level correction unit and the threshold value correction unit are input, and a demodulation output of the demodulator and a transmission signal from the ground line. Cut off A satellite line switching system comprising: a switching control unit for switching and a switch for switching between an output of the demodulation device and the ground line according to a control signal of the switching control unit.
調装置の受信レベル情報において、所定のレベル以上の
低下がない場合に、所定の時間ごとに更新し平均受信レ
ベルを検出して前記衛星区間におけるレベル変動のみを
検出することを特徴とする衛星回線切替方式。2. The level correction unit according to claim 1, wherein the reception level information of the demodulator is updated every predetermined time and detects the average reception level when the reception level information does not decrease more than a predetermined level. A satellite line switching method characterized by detecting only level fluctuations in the satellite section.
受信レベル変動が前記第１のしきい値よりも少なく前記
符号誤り率情報が所定の値より劣化している場合又は、
前記受信レベル変動が前記第１のしきい値より大きく、
前記符号誤り率が所定の値より良好の場合に、前記受信
レベル変動値を前記第１のしきい値に更新することを特
徴とする衛星回線切替方式。3. The threshold value correction unit according to claim 1, wherein the reception level fluctuation is less than the first threshold value and the code error rate information is deteriorated below a predetermined value, or
The reception level variation is greater than the first threshold,
A satellite line switching system characterized in that when the code error rate is better than a predetermined value, the reception level fluctuation value is updated to the first threshold value.
受信レベル情報を入力し、前記第１のしきい値よりも小
さな第２のしきい値より低下した場合に、前記地上回線
にて前記送信局に対して発呼要求信号を送信することを
特徴とする衛星回線切替方式。4. The switching control unit according to claim 1, wherein the reception level information is input, and when the reception level information is lower than a second threshold value which is smaller than the first threshold value, the switching control section uses the ground line. A satellite line switching system characterized by transmitting a call request signal to the transmitting station.
上回線と前記スイッチとの間に自動発呼装置を具備し、
前記切り替え制御部からの制御信号によって、自動発呼
することにより発生することを特徴とする衛星回線切替
方式。5. The call request signal according to claim 4, further comprising an automatic call device between the land line and the switch,
A satellite line switching system, which is generated by automatically making a call in response to a control signal from the switching control unit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6057597A JP2818540B2 (en) | 1994-03-28 | 1994-03-28 | Satellite line switching method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6057597A JP2818540B2 (en) | 1994-03-28 | 1994-03-28 | Satellite line switching method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07273706A true JPH07273706A (en) | 1995-10-20 |
| JP2818540B2 JP2818540B2 (en) | 1998-10-30 |
Family
ID=13060269
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6057597A Expired - Fee Related JP2818540B2 (en) | 1994-03-28 | 1994-03-28 | Satellite line switching method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2818540B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003069514A (en) * | 2001-08-24 | 2003-03-07 | Nhk Engineering Services Inc | Data broadcasting system, data receiving terminal and data receiving program |
| CN114142917A (en) * | 2022-01-14 | 2022-03-04 | 中国人民解放军61096部队 | Satellite channel selection method and device |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01183229A (en) * | 1988-01-18 | 1989-07-21 | Fujitsu Ltd | Supervisory and controlling system |
-
1994
- 1994-03-28 JP JP6057597A patent/JP2818540B2/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01183229A (en) * | 1988-01-18 | 1989-07-21 | Fujitsu Ltd | Supervisory and controlling system |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003069514A (en) * | 2001-08-24 | 2003-03-07 | Nhk Engineering Services Inc | Data broadcasting system, data receiving terminal and data receiving program |
| CN114142917A (en) * | 2022-01-14 | 2022-03-04 | 中国人民解放军61096部队 | Satellite channel selection method and device |
| CN114142917B (en) * | 2022-01-14 | 2024-03-19 | 中国人民解放军61096部队 | Satellite channel selection method and device |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2818540B2 (en) | 1998-10-30 |
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