DE1766616A1 - Messaging system - Google Patents

Description

Patent attorneys Dipl.-Ing. F. Weickmann, Dr. Ing.A.Weickmann

D1PL.-ING. H. Weickmann, Dipl.-Phys. Dr. K-Fincke Dipl.-Ing. RA ₁ WeICKMANN, Dipl.-Ghem. B. Huber

8 MUNICH 27, DEN

MOHLSTRASSE 22, CALL NUMBER 48 3921/22

rPÜH TKuEHiüilS AbB TELEGHAtH PUBLIC CORPORATION, 1,1-chorne üchisaiwaicho ₅ Ghiyod.a-ku, Toxcyo, Japan

l <news transmitted (? un £ ss ystem '

L) Ie Έι · ϊ ± ηΦιηβ refers to .ein-Funkverbindun ^ ssysbem, with the; In particular, a large number of earth radio stations can enter into radio communication with one another via an intermediate transmitter located far above the troposphere and formed by a fjatelliben.

2098U / 0333

It is generally known that a SnF-IIRecuence band has a large capacity for ^ rd-Funitv connections ;. In such a case, the transmission quality drops, but considerably as a result of fading effects, when the carrier frequency is? is several gigahertz. Such fading effects occur -j-. Also due to a signal attenuation by blessing, falling or by sleet precipitation (which in the following is also counted as a fall), if the 'i! Rä: -; joy i · ¹ over Ί0 Chζ amounts to.

Third, if there is a strong loss, the i5ii-jf & n.vsleictuiir of the Mv'isch transmitting device sinks down to bull. Thereby v. ·: '. :: · o. a disconnection is inevitable. In one: a multitude of systems that all use the same propagation intrav; ege "ongoing communication and communication systems, a connection disruption normally only occurs in one system. Therefore, one procedure is often initiated. ™ turns, t- ^: ö ^ril äß Q- © ^{111 a} i ©, respective connection directly from: c failure of a Lwischensenäeeinrichtun. After a '/ erbinaungsinterruptunp; to an intermediate transmission device;., Sines riilf s syst eras is switched , which results in a shortening of the connection interruption:; -.

Since the attenuation in an Srd-Machrich-cen connection is through a Re ^ en is not infinitely large, the connection interruption can be eliminated by reducing the transmission power increased and the distance between the relay stations decreased

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cetzt wire. » However, this results in a significantly inefficient message delivery system. Therefore läX; t nan,. ^: ; possibly ^{It is} possible to compromise the connection to a certain extent when designing the system. If there is strong re;, then a connection interruption occurs; in the entire system using the frequency band concerned. iii Such a connection interruption lasts longer than when a fading phenomenon occurs where the respective connection is switched to a system that uses the same or a different frequency band and runs in a different direction and which is only weakly steamed by a fall.

to switch to later. In such a case · a Avoid connection interruptions by using the '-' respective Change of the economic utilization of the individual Zv / iscliensendesöationen ' degraded.

is; 'also' known - that in the ta'BiT band a large number from running between JJrdfumjstationen via a satellite- ^. en i''unr.connections can be accommodated. Will, however ο used in; ji'jy band, in which the latency is low,

BAD OFlIQSKi

20981 470333

only a very limited traffic capacity is available, so that mutual interference with the earth IP radio transmission system is avoided.

Therefore, an effective use of an SHP frequency range or millimeter wave range, in which the attenuation by a rainfall is strong, thus with regard to an economic one Realization of a large capacity satellite communication system is indispensable.

If the transmission power emitted by a satellite is increased, its price and weight increase. It also increases the financial outlay required to place the satellite in a particular orbit. That's why a reduction in the effect of the rain dampening with the help of an economical device does not bring just one Advantage in terms of reducing the transmission power to be generated in a satellite, but it will In addition, the electrical transmission power required in the respective earth radio station is also reduced. Through this the facilities to be provided in the earth stations become more economical, and besides, there is a risk of Reduced interference with other transmission systems. The entire system is therefore extremely economical as well as considerable advantages in messaging.

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The invention is now based on the object of creating a system which allows a relatively large number of communications links to be routed in an economical manner via an intermediate transmission station, such as a satellite. The new message transmission system to be created should have a high transmission quality and be characterized by low susceptibility to interference in connection with other message transmission systems. M.

The invention is explained in more detail below with reference to drawings. ■ · ·

Fig. 1 illustrates schematically communication links existing between a plurality of earth radio stations via a satellite or an intermediate transmission station. Fig. 2 shows in a diagram the relationship existing between the amount of precipitation R and the cumulative probability P in an earth radio station, where particularly clearly ^ as, - ■■■ - ■ 'f | is, / in the manner according to the invention, the effects caused by the respective amount of precipitation can be reduced.

Fig. ^ Illustrates a subdivision in a diagram of a frequency band to be used.

4 illustrates an embodiment of a space diversity device, which can be used in an earth station to reduce rain attenuation.

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According to FIG. 1, earth radio stations A 1 to A 1 are to enter into communication with one another via an intermediate transmission station formed, for example, by a satellite. A 'carrier frequency band £' to F _{2 should be} used; the attenuation of the radio signals caused by Hegen fall should increase progressively from J <\ to.

At the points where the earth radio stations A ^, A ₂ , A ^ ... AjT are located, the amounts of precipitation (per unit of time) Rm., Hm ₂ , Rm ^ ... Rm should occur. Because the frequency band F _{1 to F 2 is} in such a frequency range that it is common to maintain the desired communication transmission quality at the earth stations with the maximum amounts of precipitation Rm ,,, Rm ₂ , Rm ^ ... Rm Making readjustments results in a considerable increase in the cost of the intermediate transmission stations in the satellite and in the earth radio stations, whereby the economy of the entire power transmission system is considerably impaired.

In the following it is assumed that there is no correlation between the amounts of precipitation at the individual locations prevails, at which the individual earth stations A ^, A are located; the statistical distribution of rainfalls at the points concerned should be the same everywhere, and that which occurs The maximum amount of precipitation should be given on the basis of an amount of precipitation R per unit of time

2098U / 0333 bad original

Earth radio stations A, *, Ap .... A ^ according to 3? Ig. 2 Em. The cumulative probability associated with the maximum amount of precipitation Em is assumed to be Pm. The cumulative probability Pp per earth radio station that simultaneously with two earth radio stations from a number K "of earth radio stations A ,,,
Ap .... AjY rainfall with a sum probability
lü? m occur, results from '

2! IcPm N (NI)

1/2 ■ §

(D

'Herein-k is a constant.

then Pp ^ Pm (3)

In the same way, the cumulative probability is P ^ per earth radio station in the event that three

■ i

Earth radio stations rainfalls with a cumulative probability- ^ ity of IPm occur,

V3

I XlI Pm L

P-

■ {-

(H-2)

If % i is Pm,

then P-. ^ P ₉ (6)

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In the same way, «, P _c ... can be calculated. If equations (5) and (6) are fulfilled, ie if the amounts of precipitation corresponding to the sum probabilities Pp, -c-'y, ··· are equal to Rp, R-- ..., then

R ₂ 4 Rm (y)

and, _, // -.j c ν

The values -for R ₁ ,,, Ar ... can be determined in the same way.

The transmission system according to the invention takes advantage of the property that the amount of precipitation Rm, R ~, R-. ..., as indicated in equations (7) and (8), progressively decreased. Therefore, the frequency band F ^ to Fp used in the system according to the invention is divided into a plurality of frequency bands I to η, as i? 'Ic. ^ clarified. The intermediate transmission stations operating on frequencies lying in the frequency bands I, II, 111 ... ... have satisfactory properties.

The üänipi'un ;; caused by rainfall in frequency band 1 ;; is essentially so low that you influl: sotiar in that Case that the properties of the directions in Bezur "aui-Rm are intended with a view to increasing the size Antennensysteniß, on a titling of the end of the ice

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an increase in the noise margin in the receiver and interference with other systems is low. In the jj'reauenzbänder ΙΓ, III .... the extent of the attenuation caused by rainfall progressively increases; however, the values It ^, R- ..... decrease very quickly. Overall, the properties differ the establishment is not so affected by the case that the Entg is only geared towards good weather. Anged

the face of such development is expected facilities message transmission easier not only in the SEF-bands but also in the i ^v iillimeterwellen-Bäiidern mit'Hilfe and small x.achri ent enüb he tr Agung whose operation requires only a very low electrical power required is (both in the earth stations and in the intermediate broadcasting stations).

In the message transmission system according to the invention, which uses the various intermediate transmission devices for the ent- ^w

Using speaking frequency bands with the properties listed above, the following operating processes can occur (in that the frequency band ~ a \ to i '^ is divided into three sub-bands):

a) If there is no rain at any earth radio station or if the amount of precipitation is below H ₇ and if one or more of the earth radio stations occur at the same time, the occupancy status of the earth radio stations in question will continue to be maintained and the intended frequency band facilities will continue to be used.

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b) If rain occurs at an iSrdefunkstation, so that

H-. έ, R <. Rp is, in this radio station, any suitable carrier wave in frequency band I or II is preferably used as the transmit and receive carrier wave.

c) Kick at the same time; at two earth radio stations α and A,

c \ D

Regenerate so that E ~ CR <£ R ₀ and R- £ - id, <. R, is, so

'5> Ά. c. 'j D cL '

is preferably either one at both earth radio stations ■ Appropriate carrier waves in frequency band I or II are used.

d) occurs at a first earth radio station A Re-ven so that R _{0 is} C R, and occurs at a second earth station

CL C

Α-, rain on, so that R-- <£. R- ^. Is Rp, then at aer "Srdefunkstation A any suitable 'Jrägererv.-elle im Frequency band I used, while the earth radio cation A ^ preferably any other suitable carrier Frequency band I and II is used.

The frequency bands used in the individual earth radio stations are thus interrelated in the present system with the occurrence of rain at the individual earth radio stations. The intermediate station of the satellite used also works in frequency bands I to 111.

With regard to the example above, aieo means that in any case, i.e. under the conditions according to a), b), c) and d), the intermediate transmitter in the satellite is constantly is in working condition.

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To liberü-anx '; to the -, respective - state of an earth at ion-corresponding carrier waves become R, the received power and the disturbance _____ distance is monitored; Control and liEischaltunp are done by each occurring x'etcelv / ert a discriminator value is derived. Here provided monitoring circuit can be in the frequency band F. to F., or in a separate frequency band '. The Jbervachuiirrsverfahren applied can either be a centralized one or a decentralized process.

j emv the individual radio stations have different traffic conditions: en and the wish exists, all 'existing Achievement connections as far as possible; to age, it is necessary that the radio,

station λ the total traffic performance and the radio station A- ^c _: die.: ■■ ci

in case d) / ^ has the largest transport performance. Have the radio stations A>, A ₀ ... A- in the order: decreasing traffic performance ■ associated bandwidths of W ^, -V / p ,. "W" .-. ..., as thin as can be seen in FIG. 5, when implementing the carrier frequency bands, the frequency bands I, II, ... are correspondingly wider than W-, W ,, ..... In such a case, in every earth radio station if h is the number of intermediate transmission stations that are required to take over the entire traffic capacity of the station, the number Q of high-frequency transmitting and receiving devices with regard to the frequency bandwidths W ^, W ^ .... is determined by Q> H.

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"As can be seen from the above explanation In the system according to the invention, j is the influence of the rainfall damping on the communications reduced between the individual earth radio stations, furthermore there is only one channel for the respective intermediate broadcasting station electrical power required, and beyond that are the The size and price of the required facilities small and thus also the financial outlay for fulfilling the condition Q)> M.

The cumulative probability t'c of a disconnection is the same in such a case

The values for Rm, k, 1 ... can thus be selected accordingly by designing devices for the frequency bands I, II, III and taking into account the minimization of l ^{J c.}

If the message signal attenuation caused by lying down is large, the traffic performance can in some cases be '!' Deliberately reduced. In such a case, which certainly does not require any special reference, the bandwidths Vi 1, My, and Wp within the three frequency bands 1, II and IE, as in the above example, are chosen so that they are smaller than the values given above 'v.' / whose bandwidth W, of the .frequonseB ill can be made larger.

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In the foregoing, the EaIl has been considered that a Intermediate transmission station S according to IPig. 1 is present and that Use of frequency band F. to Fp is permitted.

The system according to the invention can also be used without further ado in the event that separate frequency bands are used / hen%, the intermediate end station S of a plurality of individual stations S ^, Sp. ".. is, which can be applied in separate Frequenzbänderriarbeiten that en'indungsgemäße system 'readily. If between den.Regenfällen to aen individual radio stations a correlation, so the calculations according to equations (1), (4) ... become more complicated; the effects on the present system are reduced and are less than what appears from equations (1) and (3), but it is nevertheless M. there is still a considerable improvement. In the event that the statistical distributions of the Hegen falls at the individual earth radio stations differ from one another, grounds the calculations more complicated, but the effects are not diminished.

There is no need to state how and in many frequency bands the frequency range to be used F ^, to .I ^

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divide is ;; Here, namely, the transmission quality h and the change in traffic performance R, the transmission output, the signal-to-noise ratio of the individual radio stations, as indicated by equation (9) at;: e ';, and also the monitoring system are also taken into account to draw, with the help of which the ultrasonic frequency bands or 'i! rä;: erxrequenzen of the intermediate Senäestation under 3u £ -; runc.el9 ~ un ·: of the preceding sizes are switched over.

In order to reduce the message signal attenuation caused by the event of the invention in the system according to the invention, a space diversion can be used at the same time, as indicated in FIG. 4. Fi: - ;. ^L , - t only schematically one for the sake of simplicity

Radio station A. · from the p; eKiäi < iPig. 1 reserved U

Stations A ^. ... A--. This radio station A .. is assigned an additional station A. ¹ , which has the same function v. ^r ie cie station A .. (and of which a large number can be provided). The station A. is at a distance L_ with

ν ύ

of station A. ¹ operated in parallel. The distance L- is so J -J

It is said that the correlation of a rainfall at both stations (which are connected to each other via a suitable earth connection) is sufficiently small that during the period during which a high amount of precipitation occurs at radio station A ... Communication link to the radio station A. · ¹ can be switched. The rainfall correlation

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group (consisting of "single stations A_., A · ¹ , A-" ...)

d J U ■

! "./ laugh at the places where the earth radio stations A-

■ '■' ■■ <J

and. A, 'is like that. low that the rainy weather J - ■

in the area of the radio station -A- 'during this period is sufficiently low. Eggs and the cohesive effects will be discussed in more detail below.

vie im-, but. e.g .. a rainfall corresponding to a lnieder-Rm at the point c <of any radio station

occurs, then due to the effect of the space diversity applied in this radio station group, the amount of precipitation of this radio station group in the design of the system is to ^{be reduced to the i / ert Rm 1} , which is lower than the fourth Rm. This means that the r; Message connections will continue to be managed via the swiss transmission station designed for a corresponding transmission quality * in the case of the R'm precipitation rate. : m

'If at the same time at any other location unter.den radio stations ß a radio station group containing places rain occurs, can run at this point on this radio station group Ve3? Bonds -weiterhin- to-r · follow the existing there room Diversities above that between the end station are led ', which the compound snoria for the rudder stroke amount Rß' , which is lower than H- _j5 can suffice. The calculations can be done in

BATH C

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carried out correspondingly for the third and fourth, rain leading position of the radio station group will.

If the economic impact of the reduction in the electrical transmission power, as a result of the fact that Em ^ Hm ¹ and Rp ^> Rß ^x , the result of the readjustment of an additional station for the respective radio station and that of an earth connection line between the respective earth radio station and The financial outlay required by their additional station is more than compensated for by using the method according to the invention in the frequency bands according to E ¹ Ig. 5 possible to achieve the advantages that can be achieved with the aid of the invention. In the case that a frequency band in which a weak rainfall attenuation occurs as the frequency band I or II according to according to the presence can not be used an earth-message W transmission system or the like. Fig. 5, or in the case That the traffic performance is to be increased by using higher frequency bands is also achieved by the invention a considerable effect.

As above in connection with an inventive Satellite message transmission system explained, the message signal attenuation caused by Kep; enfall so st ar κ reduced that over a wide nn.! '' re

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range, a message transmission with high Quality can be achieved without any Interference with other communications systems appear. The message transmission can; over a Intermediate transmission station take place, for their operation only one low electrical power is required and that of is small in size. In addition, a very high traffic performance and an economical mode of operation be achieved. The invention therefore has in terms of aer messaging has a very large applicability.

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Claims (2)

- 1 & - ■ —-U1 'ww "1766816 B a t e η t a η s ρ r ii c h e 1. ri message transmission system for the transmission of Communication signals between a variety of earth radio stations via a satellite, characterized in that for the transmission of the message signals Frequency bands are used in which the message signals are attenuated to different degrees by precipitation takes place, and that of the respectively in i-: achx-ichten- ^ connection with each other standing radio stations the one Station at which the bodice chi ags damping ö.er i-message signals related to those at the other station ensuing precipitation attenuation of the message signals is stronger, is preferably operated in a frequency band in which a weaker precipitation damping per se the news signal occurs while the one Station at which the precipitation dampening of the Message signals related to those at the other station ensuing precipitation attenuation of the message signals is weaker, is preferably operated in a frequency band in which a stronger precipitation attenuation the message signals occurs, so that the satellite with its intermediate broadcasting station within all frequency bands to be used works. BATH ORIGINAL 2098U / 0333 -.19- 2. message transmission system according to claim 1, characterized ■■ marked, that every earth radio station (e.g. A-) . together with an additional station (Ay ') in the room diversity Operation is operated. 209 8 U / 0333