JP4717277B2 - Relay device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a relay apparatus such as a base station that relays between a lower station and an upper station, which is used in a system constituting a tree-like hierarchical digital link network.
[0002]
[Prior art]
An example of a system constituting a tree-like hierarchical digital link network is shown in FIG. As shown in the figure, in this system, the highest-level control station 12, a relay station 13 such as a base station, and a terminal station 14 such as a mobile phone are connected in a tree shape by a digital link line. Note that the tree shape here is a hierarchical network having the highest control station 14 as the apex as shown in FIG. 1, and when attention is given to a certain relay station, there is one upper station. On the other hand, there are n lower stations (n ≧ 1), and the network can branch only to the lower route.
[0003]
FIG. 7 is a block diagram showing a configuration of relay station 13 which is a conventional relay device. As shown in the figure, a conventional relay device (relay station 13) includes a lower line interface unit 1, a radio line interface unit 2, a communication data bus 3, a control unit 4, an upper line interface unit 5, And a prefetch priority selection unit 6. The lower line interface unit 1 and the radio line interface unit 2 are respectively connected to the control unit 4, the upper line interface unit 5, and the prefetch priority selection unit 6 by a communication data bus 3.
[0004]
The lower line interface unit 1 is a line interface unit that communicates with a digital dedicated line or a micro line for relaying from a lower station to an upper station, and communicates with other relay stations that are lower stations. is there. The wireless line interface unit 2 performs wireless communication with the terminal station 14 in the communicable area. The upper line interface unit 5 is a wired line interface unit for relaying from the lower station to the upper station, and communicates with another relay station or the control station 12 that is the upper station.
[0005]
Further, the prefetch priority selection unit 6 receives a signal of a route with an arbitrary or predetermined priority from a plurality of signals sent from the lower line interface unit 1 or the wireless line interface unit 2 via the communication data bus 3. Are selected and transmitted to the upper line interface unit 5. The control unit 4 controls the prefetch priority selection unit 6 or the entire relay station 3.
[0006]
Next, the operation of the relay station 13 will be briefly described. Signals transmitted from a plurality of lower stations are received by the lower line interface 1 or the radio line interface unit 2 and sent to the prefetch priority selection unit 6 via the communication data bus 3. The prefetch priority selection unit 6 selects one signal from a plurality of lower stations and transmits it to the upper line interface unit 5, and the upper line interface unit 5 transmits a signal to the upper station.
[0007]
[Problems to be solved by the invention]
However, in the conventional relay apparatus (relay station 13), when a failure occurs in the upper line connected to the upper station, the signal received from the lower station stops in the apparatus, so that the signal is relayed to the upper station. Will not be able to. When communication with the highest control station 12 becomes impossible, the uplink signal cannot be folded back and branched to the lower stations, and there is a problem that communication is interrupted as a system. Further, even when a failure occurs in the prefetch priority selection unit 6 or the upper line interface unit 5, it is impossible to continue communication with all lower routes directly connected to the relay apparatus having the prefetch priority selection unit 6. There was a problem that it was.
[0008]
The present invention has been made in view of the above-described conventional problems, and is capable of continuing communication while minimizing the influence on the system even if a failure occurs in the host line or device. The object is to provide a device.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, a relay device according to the present invention is a relay device that constitutes a tree-like hierarchical link network, and transmits a plurality of uplink signals transmitted from a lower station to an upper line. First prefetch priority selection means for selecting one signal to be transmitted, signal return means for returning an upstream signal selected by the first prefetch priority selection means to the lower side when the upper line fails , and the upper line Line failure detection means for detecting whether or not is in a failure state, and second preemptive priority selection means for selecting one signal to be transmitted to the lower line from a plurality of uplink signals returned by the means in the relay apparatus , wherein the first preemption priority selection means provided in the upper interface means for connecting the upper station through the upper line, the second preemption priority selection means against the lower station through the lower circuit Provided in the lower interface means for said host interface means and the lower interface unit are connected to each other by a communication data bus. Therefore, even when a failure occurs in the upper line, the uplink signal from the lower station is returned by the signal return means, so that communication with the lower station can be continued. As a result, the influence on the system can be minimized.
[0013]
Further, in the relay apparatus according to the present invention, when the upper interface means fails, all the upstream signals transmitted from the lower stations are turned back on the communication data bus, and the second preemptive priority selection means included in the lower interface means The signal selected in is transmitted to the lower line. Therefore, even when a failure occurs in the upper interface means, communication with the lower station can be continued, and the influence on the system can be minimized.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The relay apparatus according to the present invention is a base station or the like that relays between a lower station and an upper station, which is used in a system that constitutes a tree-like hierarchical digital link network. First, FIG. 1 shows an example of a system constituting a tree-like hierarchical digital link network. As shown in the figure, in the system, the highest-level control station 12, a relay station 100 such as a base station, and a terminal station 14 such as a mobile phone are connected in a tree shape by a digital link line. Note that the tree shape here is a hierarchical network having the highest control station 14 as the apex as shown in FIG. 1, and when attention is given to a certain relay station, there is one upper station. On the other hand, there are n lower stations (n ≧ 1), and the network can branch only to the lower route.
[0015]
Hereinafter, an embodiment of a relay device according to the present invention will be described in detail with reference to the drawings.
FIG. 2 is a block diagram illustrating a configuration of the relay station 100 which is a relay apparatus according to an embodiment of the present invention. As shown in the figure, the relay apparatus (relay station 100) of the present embodiment includes a lower line interface unit 101 and a radio line interface unit 103 corresponding to lower interface means in the claims, a communication data bus 105, A control unit 107 and an upper line interface unit 109 corresponding to the upper interface means are provided. Each of the lower line interface unit 101 and the wireless line interface unit 103 is connected to the control unit 107 and the upper line interface unit 109 via the communication data bus 105.
[0016]
Hereinafter, each component which the relay apparatus of this embodiment has is demonstrated.
First, the lower line interface unit 101 is a line interface unit that communicates with a digital dedicated line or a micro line for relaying from a lower station to an upper station, and communicates with other relay stations that are lower stations. Is. The wireless line interface unit 103 performs wireless communication with the terminal station 14 in the communicable area. The relay apparatus shown in FIG. 2 has two lower line interface units 101 and one wireless line interface unit 103. However, any one of the interface units may be provided, and the number is one. It may be more than one.
[0017]
Further, the lower line interface unit 101 and the wireless line interface unit 103 of the present embodiment include a prefetch priority selection unit 111a corresponding to the second prefetch priority selection unit in the claims. The prefetch priority selection unit 111a selects one signal to be returned to the lower line from a plurality of uplink signals returned when a failure occurs in the upper line or the upper line interface unit 109.
[0018]
The upper line interface unit 109 is a wired line interface unit for relaying from the lower station to the upper station, and communicates with another relay station or the control station 12 that is the upper station. The upper line interface unit 109 of the present embodiment corresponds to the prefetch priority selection unit 111b corresponding to the first prefetch priority selection unit in the claims, the line failure detection unit 113 corresponding to the line failure detection unit, and the signal loopback unit. A signal turn-back portion 115 is provided.
[0019]
The prefetch priority selection unit 111b selects one of the signals of an arbitrary or predetermined route from a plurality of signals sent from the lower line interface unit 101 or the wireless line interface unit 103 via the communication data bus 105. To do. Further, the line failure detection unit 113 detects a failure in the upper line. Further, when a failure occurs in the upper line and the signal return unit 115 cannot transmit the uplink signal, the signal return unit 115 transmits the uplink signal to the lower line interface unit 101 and the wireless line interface unit 103 via the communication data bus 105. It wraps around.
[0020]
Further, the control unit 107 controls the lower line interface unit 101, the radio line interface unit 103, and the upper line interface unit 109. Specifically, the control unit 107 inquires the line failure detection unit 113 about the state of the upper line, When a failure occurs in the upper line, the signal return unit 115 is instructed to execute signal return processing, or when a failure occurs in the upper line interface unit 109, the preempting of the lower line interface unit 101 and the wireless line interface unit 103 The priority selection unit 111b is instructed to execute the prefetch priority selection process.
[0021]
A typical difference of the relay device (relay station 100) of the present embodiment having the above-described components from the conventional (relay station 13) is that the signal return unit 7 can return the signal, and the prefetch priority selection unit is The lower line interface unit 101, the radio line interface unit 103, and the upper line interface unit 109 are provided.
[0022]
Next, the operation of the relay apparatus (relay station 100) of the present embodiment will be described with reference to FIGS. 3 is a sequence chart showing the operation of the relay device during normal operation, FIG. 4 is a sequence chart showing the operation of the relay device when the upper line failure occurs, and FIG. 5 is the relay when the upper line interface unit fails. It is a sequence chart which shows operation | movement of an apparatus.
[0023]
First, the operation of the relay apparatus during normal operation will be described with reference to FIG. The control unit 107 inquires of the line failure detection unit 113 of the upper line interface unit 109 about the state and receives a notification indicating that it is in a normal state, thereby determining that the upper line and upper line interface unit 109 are normally operated. To do. At this time, the uplink signal transmitted from the lower station and received by the lower line interface unit 101 or the radio line interface unit 103 is transmitted to the prefetch priority selection unit 111 b of the upper line interface unit 109 via the communication data bus 105. . The uplink signal selected by the prefetch priority selection unit 111b is sent to the upper line as it is toward the upper station via the signal loopback unit 115.
[0024]
Next, with reference to FIG. 4, the operation of the relay apparatus when an upper line failure occurs will be described. The operation is the same as that in the normal operation described above until a failure occurs in the upper line, but when a failure occurs in the upper line, the line failure detection unit 113 of the upper line interface unit 109 detects this. At this time, when a status inquiry is made from the control unit 107, the upper line interface unit 109 sends a notification indicating the failure state to the control unit 107. Receiving this notification, the control unit 107 instructs the signal return unit 115 of the upper line interface unit 109 to return the uplink signal. Therefore, the signal return unit 115 returns the uplink signal sent from the prefetch priority selection unit 111 b to the lower line interface unit 101 or the wireless line interface unit 103 via the communication data bus 105. The uplink signal returned to each interface unit 101, 103 is then transmitted to the lower station. When the upper line is restored, the operation returns to the normal operation, and the uplink signal is transmitted to the upper line again.
[0025]
Next, the operation of the relay apparatus when the upper line interface unit 109 fails will be described with reference to FIG. Until the failure occurs in the upper line interface unit 109, the operation is the same as that in the normal operation described above. However, when the failure occurs in the upper line interface unit 109 as shown in FIG. The failure state of the higher-level line interface unit 109 is notified whether the notification is not received even if the inquiry is made. At this time, all uplink signals transmitted from the lower line interface unit 101 or the wireless line interface unit 103 are returned to the lower line interface unit 101 and the wireless line interface unit 103 via the communication data bus 105. In addition, the control unit 107 instructs the prefetch priority selection unit 111a of the lower line interface unit 101 and the wireless line interface unit 103 to perform prefetch priority selection processing. Therefore, the signal selected by the prefetch priority selection unit 111a from the signals returned to the interface units 101 and 103 is transmitted to the lower station. When the upper line interface unit 109 is restored, the operation returns to the normal operation, and the uplink signal is transmitted to the upper line again.
[0026]
As described above, according to the relay apparatus of the present embodiment, the upstream line interface unit 109 is provided with the signal loopback unit 115 and the prefetch priority selection unit 111b, so that the upstream signal is in the lower order even if a failure occurs in the upstream line. Since it is returned to the station, communication with the lower station can be continued. Furthermore, by providing the preemptive priority selection unit 111a in the lower line interface unit 101 and the radio line interface unit 103, an uplink signal is returned to the lower station even if a failure occurs in the upper line interface unit 109. Communication can be continued. As a result, even if a failure occurs in the upper line or the upper line interface unit 109, the influence on the system including the relay device of the present embodiment can be minimized.
[0027]
【The invention's effect】
As described above, according to the relay apparatus of the present invention, even when a failure occurs in the upper line, the uplink signal from the lower station is looped back by the signal loop-back means, so that communication with the lower station can be continued. . Further, even when a failure occurs in the upper interface means, the uplink signal is looped back through the communication data bus, so that communication with the lower station can be continued. As a result, the influence on the system provided with the relay device can be minimized.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an example of a system constituting a tree-like hierarchical digital link network. FIG. 2 is a block diagram showing a configuration of a relay apparatus according to an embodiment of the present invention. Sequence chart showing operation of relay device [FIG. 4] Sequence chart showing operation of relay device when upper line failure occurs [FIG. 5] Sequence chart showing operation of relay device at upper line interface unit failure [FIG. 6] Upper line FIG. 7 is a block diagram showing a configuration of a relay device according to an embodiment in which a failure has occurred in an interface unit. FIG. 7 is a block diagram showing a configuration of a conventional relay device.
12 Control station 100 Relay station 14 Terminal station 101 Lower line interface unit 103 Wireless line interface unit 105 Communication data bus 107 Control unit 109 Upper line interface units 111a and 111b Preemption priority selection unit 113 Line failure detection unit 115 Signal return unit

Claims (2)

A relay device constituting a tree-like floor link network,
First preemptive priority selection means for selecting one signal to be transmitted to the upper line from a plurality of uplink signals transmitted from the lower station;
A signal loopback means for looping up the upstream signal selected by the first preemptive priority selection means to the lower side in the event of a failure of the upper line;
Line failure detection means for detecting whether the upper line is in a failure state;
Second preemptive priority selection means for selecting one signal to be transmitted to the lower line from a plurality of uplink signals returned by the relay apparatus means ,
The first preemptive priority selection means is provided in an upper interface means for connecting to an upper station via the upper line,
The second preemptive priority selecting means is provided in a lower interface means for connecting to a lower station via the lower line,
The relay apparatus, wherein the upper interface means and the lower interface means are connected to each other by a communication data bus . When the upper interface means fails, all the upstream signals transmitted from the lower stations are looped back on the communication data bus, and the signal selected by the second preemptive priority selecting means included in the lower interface means is transmitted to the lower line. The relay apparatus according to claim 1, wherein:

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