Information transmission system.

The invention relates to a system for transmission of information by electrical means with a high safety, in particular radio relay system in which multiple transmission channels are provided, as well as monitoring and switching devices, which cause an equivalent circuit in disturbances in a transmission channel. Such a system is known for example from DE-C-2 152 721st

In such transmission systems, it is provided that a certain number of transmission channels in each case one or more spare channels are assigned to the exchange. Such spare channels require additional bandwidth, which is not desirable because of the increasing band shortage in microwave bands. Instead, the hot spare from radio fields should now take place with an electronically tunable hot spare.

The invention has for its object to provide a solution to such a transmission system that allows the replacement shift particularly reliably and with little effort on microwave link lines and switches. Furthermore, should it be possible uninterrupted by hand switch.

This object is according to the invention by an in-service state to a control. device related spare transmitter (hot spare), who triggered by the control device switching elements (n + 1) in the baseband to the individual transmission channels is selectively connectable and in case of failure after setting the frequency of the transmitter of the faulty transmission channel on the transmitter output to the channel branching filter of the relevant transmission channel is turned on and the disturbed transmitter is separated from this filter, and further characterized by a correspondingly controlled spare receiver (hot spare) at the receiving end with an analogous switching arrangement according to the channel switches filters ..

Advantageous refinements and developments of the subject of the application are indicated in the dependent claims.

The invention will be explained in more detail with reference to embodiments shown in the drawing.

Show it<ul><li>FIG. 1, the transmission system comprising transmitting means and receiving means in the block diagram,</li><li>Figs. 2 and 3 partial representations of the transmit side of the switching devices and</li><li>FIG. 4 a partial view of the transmission-side devices for by-hand switch.</li></ul>

FIG. 1 shows the N + 1 hot standby with tunable transmitters and receivers in the block diagram. Here, on the sending side, the individual switching device with the N + 1-replacement associated transmission channels to the individual direction lines RL1, RL2 ... of being at the transmitting antenna SA closed transmission channel switch is turned on. The individual transmission channels each include a modulator Mo 1, Mo2 ..., a transmitter S1, S2 ..., a switch U1, U2 ... and a channel branching filter KF1, KF2 ... which in the example with the respective direction line RL1, RL2 ... connected. Further, a hot spare a transmitter S_H sustained branch provided, to which a connected to the N + 1-Mo equivalent circuit device modulator is connected upstream and which is connected to the center tap of a distribution switch V1. The individual terminals of the distribution switch V1 are connected to the transmission channels lying in the switch U1, U2 .... The switches U1, U2 ..., the distribution switch V1 and the hot spare transmitter S_H are controlled by the control signals of a control device St Ste. The control is with the individual transmitters S1, S2 ... emitted control signals St indicative of the need for a spare transmitter. In the transmitter of a transmission channel failure then this transmission channel is via the control unit StE off and switched the hot standby transmitter to vote on the corresponding frequency on the transmission channel. Transmitting and receiving side are interconnected via a radio field FF. When shown transmission system for space diversity operation an antenna GA for the basic signal and a second antenna DA are provided for the diversity signal receiving end. Accordingly, each transmission channel of the receiving side is equipped with the facilities for the basic signal and the diversity signal. The reception branches, where the received signals are supplied via the direction lines RL1, RL2 ... or RL11, RL22 ..., each containing one channel branching filter KF1, KF2 ... or kF11, KF22 ..., a switch U11, U21. .. or U12, U22 ..., a receiver E1, E2 ... for the fundamental signal and a diversity receiver E1_D, E2_D..., A combiner Ko1, Ko 2 ... over which the receiver for the basic signal and the diversity signal are respectively output side to each other and the combiners downstream demodulator De, which are connected to the N + 1-Ersatzschaltein- direction , The branch for the hot spare receiver consists of a receiver E_H for the basic signal and a receiver ER_D for the diversity signal, the output side are connected via a combiner Ko, where a demodulator De is connected downstream, and each of which a distribution switch V2 and V3 is connected upstream of the individual connections to the lying in the transmission channels switch U11, U21 .. . or U12, U22 ... are performed. A control unit controls the receiving end StE the HeiBersatzsystem to the correct RF frequency and further the individual switches in the transmission channels. The input signal M of the control unit StE example includes the message via a transmitter failure of the transmission side. At the receiving end, the hot spare circuit is delayed somewhat until a message from the transmitting side is present.

Fig. 2 shows a partial view of the switching devices of the transmitting side which are present on the receiving side in an analog formation. There are for each transmission channel two mechanical switches S1, S2; S11, S12 ... provided, of which the one is arranged in the conduction path S11 of the transmission channels one and the other S1 S2, S12 respectively associated with this and with its middle contact to the output of HeiBersatzsenders S_H connected is. These switches (Fig. 1 see.) May be of the control device StE driven. In Fig. 2 shows the case that the transmission channel K2 is switched spare. The signal of the hot spare transmitter S_H thus reaches via the switch S2 in the open for the transmission channel K1 position to the switch S12 of the second transmission channel, which is located in the provisions for the replacement operating position, and the switch S11, which interrupts the passageway of this transmission channel, the channel branching filter KF2 this transmission channel ,

Fig. 3 shows a partial view of the example of the transmitting side a further embodiment of the switching devices that are used in the same way, for the receiving side. Compared to the embodiment of FIG. 2 in this case, the mechanical switches are replaced by low-loss electronic switch. They consist of circulators, which are each assigned in pairs to a transmission channel. One of the circulators Z1, Z11 is turned on in the conduction path of the transmission channels, the associated second circulator this Z2, Z12 is respectively on the hot standby transmitter SH connected. By reversing the polarity of the magnetic field rotation direction of the circulators is reversed. This reversal of polarity is controlled by the control signals St of the control unit, (see. FIG. 1) and causes shut down in case of failure of the disturbed transmitter and the hot standby transmitter is switched on the previous setting of the frequency corresponding to the disturbed transmission channel.

The advantage of this switch is that they are resistant to mechanical switches without contact, particularly low loss and reliable, soft To circuit is possible. Opposite PIN switches, for example, they have very small transmission losses. Furthermore, in them is given advantageously also the possibility of an uninterruptible by hand switch.

An embodiment of a hand-over for the transmitting side. is shown in Fig. 4 in a partial view. This switching off the microwave switching is an RF-phase synchronization between the transmitter and to spare ersetzendem stations, as well as an uninterrupted, smooth adjustment of the microwave switch. The receiving side needs only the slidably passing over microwave switch and, as the transmission side, des.unterbrechungsfreien Bb changeover switch. The transmission side phase-locked switching is easily achieved in that the quartz signals f_q1, f_q2... The RF carrier supplies all ersatzzuschaltenden stations S1, S2 ... for Eeißersatzsender S_H be conducted. Before Mikrowellenumschaltvorgang the hot spare support supply is phase-synchronized to the appropriate, through the switch V selected crystal frequency. In addition, all modulators including the hot spare modulator fed by an intermediate frequency carrier oscillator.

The phase occurs fine synchronization to synchronize the transmitter if it is necessary, with a microwave phase detector φ the microwave switch consisting of the circulators Z1, Z2; Z11, Z12 ..., each of which couplers are K1 and K2, K11 or K12 ... upstream, the decoupled signal is supplied to the Phasendetktor φ. The microwave switch controls the output signals (control signals) φ1, φ2 the phase detectors φ a between the distribution switch V and the hot spare transmitter S_H switched phase shifter ♂ hot spare support supply. Because of the crystal frequency multiplication factor in the hot spare support supply the quartz phase must be turned only by a few degrees in order to synchronize both transmitter phase-locked in the RF layer. After completion of the synchronization, the shock-free RF channel switching to the switches Z1, Z2 takes place; Z11, Z12 .... The limited decoupling of the switch ensures that during the switching the transmission amplitude never falls over, for example 20 dB, which is compensated at the receiving side by the fade control. The switching speed is controlled by the magnetic field generation of the circulators.