JP2901459B2 - Wireless transmission reserve method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a standby system for wireless transmission, and more particularly to a standby system for wireless multi-carrier transmission having a redundant transmission line as a network.

[0002]

2. Description of the Related Art FIG. 3 is a block diagram showing a conventional wireless transmission reserve system in the case of a two-multicarrier transmission system.

[0003] In FIG. 3, a transmitting unit transmits a transmission signal TS.
A network switch 1 for switching the signal to one of a wireless transmission path and a redundant transmission path 12 for output, a digital signal separation circuit 13 for a multicarrier transmission system for separating the output into two signal streams, It includes a hitless switch 14 that branches the output to a wireless working transmitter 15 and a wireless backup transmitter 16. On the other hand, the receiving unit includes a wireless working receiver 17, a wireless standby receiver 18, and a hitless switch 19 for switching the output of these receivers and outputting to the digital signal multiplexing circuit 20. The network switch 2 switches and outputs the outputs of the redundant transmission line 12 and the digital signal multiplexing circuit 20.

[0004] As described above, in the conventional system, 100% reserve is provided for one working line in the wireless section regardless of the presence or absence of the redundant transmission line 12 of the network. Further, the transmitter and the receiver have independent configurations for the working line and the protection line, respectively, and have become a completely redundant system as a wireless device. Taking the method shown in FIG. 3 as an example, FIG.
Protection line radio transmission wave 21 and working line radio transmission wave 2
2, as shown in the multi-carrier radio frequency arrangement by
The same transmission capacity as that of one working line, and the same transmission capacity of 2
By providing a multi-carrier transmission line to a protection line, a protection method has been adopted in which a transmission signal of one working line is directly transferred to the protection line. Furthermore, in consideration of equipment failures, the equipments had a complete reserve. As a result of this configuration,
In the example of FIG. 3, transmission is performed using twice the radio frequency, which is one of the causes of deteriorating the frequency use efficiency, and, at the same time, having an independent spare, the equipment of the radio equipment becomes excessively large. I was

[0005]

In the case of the conventional protection system, the capacity of one working line is required for a protection line that is invalid for signal transmission, which has been a problem in promoting effective use of frequency. One of the reasons why such a backup method is required is that the wireless transmission path is independent, that is, when a device failure occurs in a wireless section, the recovery is performed using a wireless-specific backup line. For this reason, the working spare of the wireless device must be independent, which hinders simplification of the equipment.

Another reason that the wireless transmission system requires a spare line is to relieve a line failure due to selectivity fading or the like peculiar to the wireless transmission line, and this is an important technique in terms of improving wireless transmission quality. I have. However, in this case, it is sufficient to have a spare that can rescue only the transmission wave that is the obstacle.

[0007] In view of the above problems, an object of the present invention is to provide a radio transmission standby system capable of improving the frequency efficiency by lowering the transmission capacity ratio of a standby channel.

Another object of the present invention is to provide a radio transmission protection system in which a radio transmitter and a receiver can be shared by a working line and a protection line.

[0009] The radio transmission standby system according to the present invention employs N (N is 2
In the multi-carrier wireless transmission path, the transmission unit switches the transmission signal to one of the wireless transmission path and the redundant transmission path and outputs the signal, and the first network switching switch Switch output to N
A demultiplexing circuit for demultiplexing the signal into a signal sequence, and branching any one of the outputs of the demultiplexing circuit to a protection line to shift selective fading.
A transmission switch having a switching speed capable of sufficiently following the movement , and a transmitter for modulating and transmitting the N-line working line signal sequence and the 1-line protection line signal output from the transmission switching device. Is a receiver that receives and demodulates N working line signal trains and one protection line signal, and outputs the N working line signal sequences, which are the outputs of the receivers, to the protection line branch output of the transmission switch. Is selected as a protection line signal.
Switching speed that can sufficiently follow the movement of selective fading
A switching unit that switches between the wireless transmission line and the redundant transmission line, and a multiplexing circuit that returns the N signal lines to the transmission signal of the transmission unit. The working line is to divide the transmission signal by N and transmit by N multi-carriers, and the protection line is to perform one carrier transmission with an equivalent transmission capacity to one carrier of the working line, and one carrier of the working line is used. If a transmission line fault by the selective fading or equipment failure of the radio transmission path, and repaired by the spare channel, the selection
When a disturbed carrier moves due to the movement of sex fading
In this case, the faulty carrier is relieved by the protection line, and if the working line becomes a transmission line failure of two or more multicarriers due to a device failure, the first network switch and the second network switch are performed. A switch is switched to the redundant transmission line, and the transmission signal is relieved by the redundant transmission line.

[0010]

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of one embodiment of the present invention, and FIG. 2 shows a multicarrier radio frequency arrangement of the present embodiment.

In FIG. 1, on the transmitting side, a transmission signal TS
Is switched by the network switch 1 to either the redundant transmission line 3 constructed by an optical fiber transmission line or the like or the wireless transmission line, and the network switch 2 on the receiving side selects both routes. . Although the network switches 1 and 2 employ a hitless switch to perform maintenance of the network without any hit, the hit switches are not particularly required in a system where no hit is required. .

The wireless transmission path is composed of a working line for 2-multicarrier transmission and a protection line for 1-carrier transmission of a communication system having a transmission capacity equivalent to one carrier of the working line and maintaining the same transmission quality. In this embodiment, both carriers of the working line and the protection line are 16QAM having the same modulation speed.
By setting the same wireless transmission output level in the modulation method,
The wireless transmitter 6 and the wireless receiver 7 simplify the equipment by common processing such as active spare common amplification.

The switching between the working line and the protection line is performed by the hitless switch 5 at the wireless transmitting end and the hitless switch 8 at the wireless receiving end. That is, when selective fading occurs in the radio propagation path and one carrier of the working line becomes a fault, the fault is remedied by switching the faulty carrier to the protection line. Further, when a failed carrier moves due to fading movement, the carrier is switched to a protection line. Further, the wireless switching system including the hitless switches 5 and 8 has a switching speed that can sufficiently follow the selective fading movement occurring in the wireless propagation path, and can improve wireless transmission quality. it can.

On the other hand, if the working line of the wireless transmission path becomes a transmission path failure in both of the two multi-paths due to equipment failure or the like, the network transmission switches 1 and 2 are used to switch from the wireless transmission path to the redundant transmission path 3, It is relieved by the redundant transmission line 3 of the network.

As described above, according to the present invention, first, the failure is remedied on the spare line in the wireless transmission path, and if the remedy is not possible, the failure is relieved on the redundant transmission line 3 so that the spare line transmission capacity is reduced. Can be reduced, and the radio frequency utilization efficiency when using a radio transmission path can be increased.

It is sufficient that the redundant transmission line 3 exists as a network, and the redundant transmission line 3 is not necessarily paired with the wireless transmission line (1 + 1).
(Preliminary configuration).

In this embodiment, the working line has two multi-carriers, but if the number of carriers is further increased, the frequency use efficiency and the device sharing rate are further improved. In this embodiment, the number of working lines is one. However, if the number of working lines is increased to two or more, the frequency use efficiency and the sharing rate of devices can be further improved.

[0019]

As described above, according to the present invention, by making the number of protection line carriers in a radio transmission line smaller than the number of carriers in one working line, the transmission capacity ratio of the protection line to the working line is reduced, and the frequency utilization efficiency is reduced. Has the effect of improving In addition, since the transmitter and the receiver are commonly used for the working spare, the simplification of the device is achieved, and a high economical effect is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIG. 2 is a radio frequency layout diagram of the present invention.

FIG. 3 is a block diagram of an example of a conventional system.

FIG. 4 is a diagram showing a conventional radio frequency arrangement.

[Explanation of symbols]

 1, network switch 3, 3, redundant transmission line 4, 13, digital signal separation circuit 5, 8, 14, 19 uninterruptible switching device 6, wireless transmitter 7, wireless receiver 9, 20, digital signal multiplexing circuit 10, Reference Signs List 21 wireless transmission wave for protection line 11, 22 wireless transmission wave for working line 15 wireless working transmitter 16 wireless protection transmitter 17 wireless working receiver 18 wireless protection receiver

Continuation of front page (56) References JP-A-4-196830 (JP, A) JP-A-62-189823 (JP, A) JP-A-2-149135 (JP, A) JP-A-5-259939 (JP, A) JP-A-5-259940 (JP, A) JP-A-61-105128 (JP, A) JP-A-4-284728 (JP, A) JP-A-5-48582 (JP, A) 1-228328 (JP, A) Japanese Patent Laid-Open No. 5-90995 (JP, A) Japan Institute of Invention and Innovation Technical Publication No. 91-6529 (58) Fields investigated (Int. Cl. ⁶ , DB name) H04B 1 / 74 H04L 1/22

Claims (1)

(57) [Claims] In a N (N is an integer of 2 or more) multi-carrier wireless transmission path, a transmission unit switches a transmission signal to one of a wireless transmission path and a redundant transmission path and outputs the signal. A switch, a separation circuit for separating the output of the first network switching switch into N columns of signal trains, and branching any one of the outputs of the separation circuit to a protection line for selective fading
A transmission switch having a switching speed capable of sufficiently following the movement of the transmission line, and a transmitter for modulating and transmitting the N-line working line signal sequence and the 1-line protection line signal output from the transmission switching device. The receiver receives and demodulates N columns of the working channel signal sequence and one column of the protection channel signal, and outputs N as the receiver output.
Select one of the same working line signal sequence as the protection line branch output in the transmission switcher as the protection line signal .
A reception switching device that switches at a switching speed that can sufficiently follow the movement of fading, a multiplexing circuit that returns an N-column signal sequence to a transmission signal of the transmission unit, the wireless transmission line and the redundant transmission line A working network, which divides a transmission signal by N and transmits by N multi-carriers, and a protection line is one carrier having an equivalent transmission capacity to one carrier of the working line. is intended for transmitting, if the first carrier of the developing for line becomes a transmission line fault by the selective fading or equipment failure of the radio transmission path, and repaired by the spare channel, the movement of the selective fading
If the faulty carrier moves, the faulty carrier is
When the working line becomes a transmission line failure of two or more multi-carriers due to equipment failure, the first network switch and the second network switch are connected to the redundant transmission line. Wherein the transmission signal is rescued by the redundant transmission line.