JP2818540B2 - Satellite line switching method - Google Patents
Satellite line switching methodInfo
- Publication number
- JP2818540B2 JP2818540B2 JP6057597A JP5759794A JP2818540B2 JP 2818540 B2 JP2818540 B2 JP 2818540B2 JP 6057597 A JP6057597 A JP 6057597A JP 5759794 A JP5759794 A JP 5759794A JP 2818540 B2 JP2818540 B2 JP 2818540B2
- Authority
- JP
- Japan
- Prior art keywords
- satellite
- level
- threshold value
- reception level
- line
- 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.)
- Expired - Fee Related
Links
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 reception level of a satellite line and switching to a terrestrial line, and more particularly to a satellite line switch with a reception level fluctuation value correction function in a broadcast system using an artificial satellite. About the method.
【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 At a receiving station in a broadcast system using an artificial satellite, when a weather condition changes, for example, when rainfall occurs, a radio wave transmitted from the satellite is attenuated, a reception level is reduced, and a good image and sound are obtained. Or data cannot be obtained. As a countermeasure, the reception level of each receiving station is detected, and if the detected value falls below a predetermined threshold, a transmission line provided separately from a broadcasting satellite line (for example, a backup line using a terrestrial line) ), A method of obtaining a good image, sound, or data by switching to the above method has been used.
【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 channel switching system. In FIG. 1, a transmitting earth station 1 having a transmitting function of transmitting data such as images and sounds is a satellite 2
(N: an integer of 2 or more) receiving stations 30-1 to 30-1
30-n. Each receiving station 30-1 to 30
−n have the same configuration, and for example, the receiving station 30
For -1, the received signal received by the receiving antenna 5 is amplified by a low noise amplifier (LNA) 6,
The signal is input to a demodulator (DEM) 8 through a cable 7.
The DEM 8 outputs a demodulated signal 9 obtained by demodulating the received signal to the control device 50, detects the received level,
The control device 50 uses the detected output as reception level information 10.
Output to The control device 50 controls the DEM 8
If the obtained reception level information 10 is equal to or more than a predetermined value, it is determined that the signal is normal, and the switch 13 is switched so that 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 less than a predetermined value, it is determined that an abnormality has occurred, and the switch 13 is switched so that data transmitted from the transmitting station 1 through the terrestrial line 20 can be received, and an 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-described conventional method, since the switching between the satellite line and the terrestrial line is performed simply based on the reception level, the correlation between the reception level and the quality of the received signal is low. If the reception level is below the threshold but the received signal is of sufficient quality, switch to a satellite or terrestrial line, or conversely the reception level is not below the threshold but the quality of the received signal is degraded In some cases, switching to another transmission line is not performed even though good images and sounds or data are not obtained. More specifically, FIG.
The gain and noise amount of the low-noise amplifying device 6, the attenuation amount of the cable 7, and the amount of other extraneous noise shown in (1) vary, and a firm correlation is not always established between the reception level and the quality of the reception signal. In other words, even if the signal is received at the same reception level, the quality of the received signal may be better or worse depending on the surrounding environmental conditions and the like. For this reason, in the prior art, switching from the satellite line to the backup transmission line cannot be performed merely by detecting the reception level, and a line design having a sufficient reception electric field margin is constructed and a sufficient margin is provided. Had to be switched at a certain level. Further, even if the line quality is deteriorated and sufficient images, voices, or data are not obtained, the switching to another transmission line is not performed because the reception level has not yet decreased to the threshold value. 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, a method has been adopted in which this switching condition is determined not by the reception level but by, for example, the quality of a BER (code error rate) of demodulated data. , And there is a problem that instantaneous switching is not possible.
【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 to detect a code error rate = 10 −6 on a transmission line having 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 to detect 10 -7 . This is because, for example, when a 1-bit error is detected, to determine whether the error has occurred with a probability of a code error rate = 10 −8 or a probability of a code error rate = 10 −7 , This is because it is necessary to wait until an error bit or a next error bit 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, although the value of the code error rate is the quality of the received signal itself, 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。As another method, there is a method of measuring a noise amount of a received signal. However, a narrow band filter for noise measurement is required, and an expensive configuration is required to obtain a stable detection output. I was
【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。[0009] Therefore, an object of the present invention is to correct each fluctuation value of the detected reception level due to the surrounding environmental conditions and to take into account the actual line quality information to prevent a change in weather conditions such as rainfall. It is another object of the present invention to provide a satellite line switching system capable of reliably switching to another transmission line before good images, voices, 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 channel switching system according to the present invention, the change in the reception level is determined based on the change pattern and the change which actually affects the quality of the received signal. Is separated into fluctuations that do not affect the data, and stored by comparing with the separately detected bit error rate. If the reception level actually decreases due to rainfall, etc. Quantitatively grasp the quality irrespective of the fluctuation value, and instead of simply switching to another transmission line based on a decrease in reception level, switch to another transmission line substantially based on deterioration of the quality of the satellite line By doing so, the above purpose has been 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。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, radio waves transmitted from the transmitting earth station 1 and returned by the artificial satellite 2 are transmitted to a plurality of (n: an integer of 2 or more) receiving stations 3-1 to 3-1 installed in different areas.
In the broadcast system receiving 3-n, a signal received by the receiving antenna 5 is input to the demodulation device 8 via the low-noise amplification device 6 and the cable 7. At this time, for example, satellite 2
If there is rain on the radio wave propagation path from the satellite to the receiving station 3-1, the radio wave from the artificial satellite 2 is attenuated and the receiving level of the receiving station 3-1 decreases, but the demodulation device 8 detects this receiving level and receives it. The level information 10 is stored in the level corrector 1 of the controller 17.
4 is output. The level correction unit 14 receives the reception level information 1
The level fluctuation value α due to rainfall on the satellite line, which is a main factor affecting the quality of the received signal, is calculated from the fluctuation pattern of 0 by the following method, and this is calculated as a predetermined threshold a
Is exceeded, the switching control unit 16 determines that the satellite line cannot secure sufficient quality for signal transmission, and switches to another transmission line 20 with the switch 13. That is, the level fluctuation of the received signal in the satellite communication is classified into (α) which fluctuates in a short time and (β) which fluctuates in a long time. The level fluctuation β that fluctuates for a long time (a level fluctuation that hardly affects the quality of a received signal) 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-time level change α (a steep, non-periodic level change caused by rainfall that actually affects the quality of the received signal) ) Is clearly different from the level change.
Therefore, the present invention always monitors the level fluctuation β that does not affect the quality of the received signal, and when a steep, non-periodic level drop occurs due to rainfall or the like, subtracts the level fluctuation to obtain Only the level variation α that affects the signal is used as the line switching condition. That is, the control device 17
Corrects the threshold 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 a long-term average value of the level of the received signal in fine weather (fixed) α is a variation caused by rainfall and the like, and directly affects the quality of the received signal. Affected, steep, non-periodic level fluctuation value β: Fluctuation caused by ambient temperature environmental conditions, which is a slow and periodic level fluctuation value that hardly affects the quality of the received signal. Conventional method shown in FIG. Are based on the following equation. L <L nom −a... A: Threshold value When the equation is substituted into the equation, L = L nom −α−β <L nom −a α + β> a... As described above, β is included in the equation. Therefore, a switching malfunction has occurred 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 “Lave”. Since this “Lave” does not include the component of α, from the equation, “Lave ≒ L nom −β” is obtained. Further, thereafter, the reception level is measured only for a predetermined time T, and if a level decrease of not less than a predetermined level ΔL (for example, 1 dB) is not observed, the level change occurring at this time T is a steep level change α. No component is included, and only a component of β, which is a slow level change. By repeating this operation, the average reception level “Lave” in fine weather is updated to the latest value. If 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 previous value is held without updating the value of “Lave”. The received level L does not include β in the Lave obtained as described above.
Is L = L nom −α−β ≒ Lave−a. In the present invention, the switching condition is set to Lave, and L <Lave-a... By substituting the equation into this equation, L = Lave−α <Lave−a... In the present invention, by setting the switching condition using “Lave”, there is no dependence 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 demodulation device 8 of the present invention detects the bit error rate and outputs it as the bit error rate information 11 to the threshold correction unit 1.
5 is output. When the bit error rate information 11 is degraded from the bit error rate ε, which is a preset limit value of the channel quality, the threshold value correcting unit 15 outputs another transmission line 20 in the same manner as described above.
The switching signal is output to the switching control unit 16 to perform switching. The threshold value a for switching based on the reception level is corrected by the threshold value correction unit 15 based on the bit error rate equivalent to the signal quality. By supplying the signal, the correlation between the reception level and the line quality is always grasped, and a 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 method of correcting the threshold value a based on the bit error rate of the present invention will be described in detail 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 bit error rate obtained by the demodulation device 8 is set, and is used as a determination condition for line switching. That is, the determination condition based on the decrease in the reception level is prioritized, and the decrease in the reception level is determined by the threshold a.
In the above case, switching is performed even if the bit error rate is better than the limit value ε. On the other hand, when the interference wave increases, the quality of the received signal is degraded and the code error rate of the received signal exceeds the threshold value (10 -6 ) even if the reception level decreases below the threshold value a. There are cases. If the decrease in the received signal level at this time is a ', the threshold a
Is changed to a 'to change the threshold value and switch. Further, when the above-mentioned decrease in the level of the received signal is equal to or greater than the threshold value a and the code error rate is better than the limit value ε, the receive level further decreases, and the decrease in the receive signal level becomes a ″.
When (a ″> α), a ″ is updated to a new threshold value a, and thereafter 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。The switching control section 16 of the control device 17 of the present invention stores a threshold value b (threshold value b <threshold value a). At that point, 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. Thereby, when the decrease of the reception level exceeds the threshold value a,
Another transmission line 2 from the satellite line without causing a line break
Switching to zero can be performed.
【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。The control device 17 of the present invention monitors the received signal level in the same manner as the automatic switching operation, and automatically performs the restoration switching operation from another transmission line 20 to the satellite line when the satellite line is restored. .
【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 line switching method according to the present invention eliminates information unnecessary for switching and performs automatic correction based on actual line quality instead of simply performing switching based on the reception level. By doing so, it is possible to prevent switching to another transmission line even if it is not necessary, and it is possible to reliably switch to another line if necessary, and to reduce 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 diagram of a satellite line switching system according to an embodiment 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 DESCRIPTION OF SYMBOLS 1 Transmitting station 2 Artificial satellite 3-1-3-n Receiving station 5 Receiving antenna 6 Low noise amplifier 7 Cable 8 Demodulator 9 Received signal 10 Reception level information 11 Code error rate information 12 Failure 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
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平１−183229（ＪＰ，Ａ) 特開 昭63−179629（ＪＰ，Ａ) 特開 平４−33425（ＪＰ，Ａ) 特開 平４−240926（ＪＰ，Ａ) (58)調査した分野(Int.Cl.6，ＤＢ名) H04B 7/14 - 7/22 H04B 1/74──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-183229 (JP, A) JP-A-63-179629 (JP, A) JP-A-4-33425 (JP, A) 240926 (JP, A) (58) Field surveyed (Int. Cl. 6 , DB name) H04B 7/14-7/22 H04B 1/74
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
間におけるレベル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、前記衛星区間におけるレベル変動と所定の第
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か
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 transmitting earth station, a plurality of receiving stations for distributing a signal transmitted from the transmitting earth station via a satellite, and a terrestrial line connecting the transmitting signal to the receiving station. and, in a satellite line switching method in case when the satellite line abnormality to automatically switch to the land line, enter the reception level information detected by the demodulator of the receiving station, level change and the reception at the satellite segment A level correction unit for identifying a level fluctuation of a receiving device in a station, detecting only a level fluctuation in a satellite section, and comparing the level fluctuation in the satellite section with a predetermined first threshold value; The detected bit error rate information is input, and the first
A threshold value correction unit for correcting the threshold value of, and a switching control unit that receives an output signal from the level correction unit and the threshold value correction unit and switches between a demodulation output of the demodulation device and a transmission signal from the terrestrial line. If, satellite line switching system, characterized by comprising a switch for switching the <br/> either output and the ground line of the demodulation device by the 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 demodulation device is updated every predetermined time and detects an average reception level when the reception level information does not decrease by a predetermined level or more. A satellite line switching system characterized by detecting only a level change in a 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、
前記符号誤り率情報が所定の値より良好の場合に、前記
受信レベル変動を前記第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 smaller than the first threshold value and the code error rate information is degraded from a predetermined value, or
The reception level fluctuation is larger than the first threshold value,
A satellite channel switching method, wherein when the bit error rate information is better than a predetermined value, the reception level fluctuation 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 smaller than the first threshold value, the switching control unit uses the reception level information. A satellite line switching system for 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, wherein the call request signal comprises an automatic calling device between the land line and the switch,
A satellite line switching system which is generated by automatically calling according 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 JPH07273706A (en) | 1995-10-20 |
| JP2818540B2 true 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) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4504601B2 (en) * | 2001-08-24 | 2010-07-14 | 財団法人エヌエイチケイエンジニアリングサービス | Data receiving terminal and data receiving program |
| CN114142917B (en) * | 2022-01-14 | 2024-03-19 | 中国人民解放军61096部队 | Satellite channel selection method and device |
Family Cites Families (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
Also Published As
| Publication number | Publication date |
|---|---|
| JPH07273706A (en) | 1995-10-20 |
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