JP4776637B2 - Communications system - Google Patents

Description

  The present invention relates to a communication system using a wired line and a wireless line.

  In the conventional communication system, the base station of each of the radio base station and the distributed radio base station has one carrier, that is, one wave simplex for assigning the same frequency to both downlink / uplink voice channels with the portable radio device. An SCPC (Single Channel Per Carrier) wireless link is employed. Simplex is a communication system that performs transmission in only one direction, and SCPC is a communication system that allocates one carrier wave per audio channel. Each base station communicates with a portable wireless device in the service area through this type of wireless link. Communication between the radio base station and the distributed radio base station is performed via a wired line. Thus, a communication system is configured.

  In a conventional communication system, when a wired line connecting a wireless base station and a distributed wireless base station is disconnected, communication between the distributed wireless base station and the wireless base station via the wired line becomes impossible. In that case, as an emergency measure, when communication is performed between the wireless base station and the distributed wireless base station using a wireless line instead of a wired line, the frequency of the signal from the distributed wireless base station, and the wireless base station service area Since the frequency of the signal from the portable wireless device is the same, the signals collide. For this reason, there is a problem in that the wireless channel between the wireless base station and the distributed wireless base station cannot be used, and the portable wireless device in the service area of the distributed wireless base station becomes stand-alone.

  The present invention has been made to solve the above-described problems, and when communication between a wireless base station and a distributed wireless base station via a wired line becomes abnormal, the present invention is made via a wireless line. An object of the present invention is to provide a communication system capable of emergency measure communication.

  A communication system according to the present invention includes a radio base station having different downlink and uplink frequencies, and a distributed radio base station that communicates with the radio base station via a wired line. The wireless base station shifts to the two-wave standby state of the downlink and uplink frequencies when communication via the wired line becomes abnormal.

  According to the communication system of the present invention, when communication between a radio base station and a distributed radio base station via a wired line becomes abnormal, the radio base station enters a two-wave standby state with different downlink and uplink frequencies. Transition. As a result, the frequencies used for standby are different from each other, and there is no signal collision, so emergency communication between the radio base station and the distributed radio base station can be performed via the radio line.

<Embodiment 1>
FIG. 1 shows a schematic diagram of the entire communication system according to the present embodiment. As shown in FIG. 1, the communication system according to the present embodiment includes a radio base station 1, a distributed radio base station 2, and portable radio devices 7 and 8.

  The radio base station 1 has different downlink frequency fa and uplink frequency fb. The channel of the radio base station 1 according to the present embodiment is assumed to be two-wave simplex SCPC (Single Channel Per Carrier) type radio channels 9 and 10 using different downlink frequency fa and uplink frequency fb. As will be described later, the wireless base station 1 according to the present embodiment communicates with the portable wireless device 7 through the two-wave simplex SCPC wireless lines 9 and 10. The distributed radio base station 2 communicates with the radio base station 1 via the wired line 3. Each of the service areas 5 and 6 is a communication area provided by each of the radio base station 1 and the distributed radio base station 2.

  The portable wireless device 7 belongs to the wireless base station 1 and can be used in the service area 5. As described above, the portable radio device 7 communicates with the radio base station 1 in the service area 5 via the two-wave simplex SCPC radio lines 9 and 10 using different downlink frequencies fa and uplink frequencies fb. Do. That is, in the one-way radio line 9 from the radio base station 1 to the portable radio device 7, the downlink frequency fa is used, and in the one-way radio line 10 from the portable radio device 7 to the radio base station 1, the uplink frequency fb is given. Use.

  The portable wireless device 8 belongs to the distributed wireless base station 2 and can be used in the service area 6. In the service area 6, the portable wireless device 8 communicates with the distributed wireless base station 2 via the two-wave simplex SCPC wireless lines 11 and 12 using different downstream frequencies fa and upstream frequencies fb. In other words, the unidirectional radio link 11 from the distributed radio base station 2 to the portable radio 8 uses the downlink frequency fa, and the unidirectional radio link 12 from the portable radio 8 to the distributed radio base station 2 uses the uplink frequency fa. Use fb.

  When the communication via the wired line 3 becomes abnormal, the radio base station 1 shifts to a two-wave standby state with downlink and uplink frequencies fa and fb. In this embodiment, the radio base station 1 sets up a one-wave simplex SCPC system one-way radio line 4 with the distributed radio base station 2 when communication via the wired line 3 becomes abnormal. enable.

  The operation of the communication system according to the present embodiment will be described with reference to FIG. FIG. 2 is a flowchart showing the operation of the radio base station 1 when an abnormality occurs in the wired line 3. First, during normal operation, the radio base station 1 uses the downlink frequency fa for transmission (Tx) to the portable radio 7 via the radio line 9 and uses the uplink frequency fb for the portable radio via the radio line 10. 7 for reception (Rx) from step 7 (step S1). Next, the wireless base station 1 determines whether or not the communication via the wired line 3 is normal (step S2). The case where the communication via the wired line 3 is abnormal here is, for example, a case where the wired line 3 is disconnected or a case where an abnormality occurs in the distributed radio base station 2. The determination in step S2 is performed periodically, for example. If it is determined in step S2 that the operation is normal, the process returns to the normal operation in step S1.

  If it is determined in step S3 that it is not normal, that is, it is determined as abnormal, the radio base station 1 detects the abnormality (step S3). Thereafter, the radio base station 1 performs setting in the radio base station 1 so as to be in standby for two waves of the downlink and uplink frequencies fa and fb (step S4). That is, the radio base station 1 uses the downlink frequency fa for reception (Rx) from the distributed radio base station 2 via the radio line 4, and uses the uplink frequency fb from the portable radio device 7 via the radio line 10. Used for reception (Rx).

  As described above, according to the communication system according to the present embodiment, when communication between the wireless base station 1 and the distributed wireless base station 2 via the wired line 3 becomes abnormal, the wireless base station 1 And it shifts to the two-wave standby state of the upstream frequencies fa and fb. Thereby, since the frequencies fa and fb used for standby are different from each other, there is no signal collision between the radio lines 4 and 10. As a result, if there is no abnormality in the distributed radio base station 2, emergency communication can be performed between the radio base station 1 and the distributed radio base station 2 via the radio line 4.

<Embodiment 2>
The operation of the communication system according to the present embodiment will be described using FIG. FIG. 3 is a diagram illustrating a sequence operation of the communication system when an abnormality, for example, a disconnection occurs in the wired line 3. Step S1, step S3, and step S4 are the same as those described in the first embodiment, and thus are omitted here.

  First, during normal operation, the distributed radio base station 2 uses the downlink frequency fa for transmission (Tx) to the portable radio 8 via the radio line 11 and uses the uplink frequency fb for the portable radio via the radio line 12. Used for reception (Rx) from the machine 8 (step S5). When the distributed radio base station 2 determines that the communication with the radio base station 1 via the wired line 3 is abnormal as in step S3 of the radio base station 1, the distributed radio base station 2 detects the abnormality (step S6). Thereafter, the distributed radio base station 2 waits for a predetermined time sufficient for the radio base station 1 to transition to the two-wave standby state of step S4 (step S7).

  After step S7, the distributed radio base station 2 transmits an abnormality detection to the radio base station 1 via the radio wave 4 of the 1-wave simplex SCPC system with the downlink frequency fa (step S8). When receiving the abnormality detection, the wireless base station 1 detects that the detected abnormality is not an abnormality caused by the distributed wireless base station 2 but an abnormality caused by the wired line 3 (step S9). The abnormality caused by the wired line 3 includes, for example, disconnection of the wired line 3. Thereafter, the distributed radio base station 2 transmits the information of the portable radio device 8 in the service area 6 of the distributed radio base station 2 to the radio base station 1 via the one-wave simplex SCPC system radio line 4 of the downlink frequency fa. Transmit (step S10). For example, information on the state of the portable wireless device 8 corresponds to the information of the portable wireless device 8 here.

  According to the communication system according to the present embodiment having the above-described configuration, when communication between the wireless base station 1 and the distributed wireless base station 2 via the wired line 3 becomes abnormal, the wireless line 4 having the downlink frequency fa. The abnormality detection is transmitted to the radio base station 1 via. As a result, the radio base station 1 can reliably detect an abnormality caused by the wired line 3, for example, a disconnection, not an abnormality caused by the distributed radio base station 2.

  Further, according to the communication system according to the present embodiment, when communication between the radio base station 1 and the distributed radio base station 2 via the wired line 3 becomes abnormal, the radio frequency is transmitted via the radio line 4 having the downlink frequency fa. Then, information on the portable wireless device 8 in the service area 6 of the distributed wireless base station 2 is transmitted to the wireless base station 1. Thereby, the wireless base station 1 can acquire information on the portable wireless device 8, for example, information on the state of the portable wireless device 8.

<Embodiment 3>
FIG. 4 is a block diagram showing a configuration example of the radio base station 1 according to the present embodiment. As shown in FIG. 1, the radio base station 1 includes an antenna 13, a transmission / reception sharing unit (Duplexer) 14, a transmission / reception unit 15, a reception unit 16, a control unit 17, and a failure monitoring unit 18. .

  The transmission / reception unit 15 can switch transmission / reception using the downlink frequency fa by a signal from the control unit 17. The transmission / reception sharing unit 14 distributes the signal received via the antenna 13 to the transmission / reception unit 15 or the reception unit 16 according to the frequency of the signal when waiting for two waves. The control unit 17 is connected to the wired line 3, and the failure monitoring unit 18 monitors whether there is an abnormality in communication via the wired line 3. In the present embodiment, the failure monitoring unit 18 is illustrated as being incorporated inside the control unit 17, but may be provided outside the control unit 17.

  A case where the radio base station 1 according to FIG. 4 performs the operation of the flowchart shown in FIG. 2 will be described. During normal operation, the transmission / reception unit 15 uses the downlink frequency fa for transmission (Tx) (step S1 in FIG. 2). The failure monitoring unit 18 monitors whether or not communication with the distributed radio base station 2 via the wired line 3 is normal (step S2 in FIG. 2). Then, when the failure monitoring unit 18 detects an abnormality in communication with the distributed radio base station 2 via the wired line 3 (step S3 in FIG. 2), the control unit 17 transmits to the transmission / reception unit 15 A transmission / reception switching signal is transmitted. When the transmission / reception unit 15 receives the transmission / reception switching signal from the control unit 17, the transmission / reception unit 15 realizes a two-wave standby state by switching the downlink frequency fa for reception (Rx).

  According to the radio base station 1 having the above configuration, when communication between the radio base station 1 and the distributed radio base station 2 via the wired line 3 becomes abnormal, the radio base station 1 Transition to a two-wave standby state with frequencies fa and fb. Thereby, the effect similar to Embodiment 1 can be acquired.

1 is a schematic diagram illustrating an entire communication system according to a first embodiment. 3 is a flowchart showing an operation of a radio base station of the communication system according to Embodiment 1. FIG. 10 is a diagram showing a sequence operation of the communication system according to the second embodiment. 10 is a block diagram showing a configuration of a radio base station of a communication system according to Embodiment 3. FIG.

Explanation of symbols

  1 wireless base station, 2 distributed wireless base station, 3 wired line, 4, 9, 10, 11, 12 wireless line, 5, 6 service area, 7, 8 portable wireless device, 13 antenna, 14 shared transmission / reception unit, 15 transmission / Receiving unit, 16 receiving unit, 17 control unit, 18 fault monitoring unit.

Claims (4)

Radio base stations having different downlink and uplink frequencies;
A distributed radio base station that communicates with the radio base station via a wired line,
The radio base station is
When communication via the wired line becomes abnormal, the state shifts to the two-wave standby state of the downstream and upstream frequencies.
Communications system. The distributed radio base station is
When communication via the wired line becomes abnormal, the abnormality detection is transmitted to the wireless base station via the downlink frequency wireless line.
The communication system according to claim 1. The distributed radio base station is
When communication via the wired line becomes abnormal, the mobile base station in the service area of the distributed radio base station is transmitted to the radio base station via the downlink frequency radio line,
The communication system according to claim 1. The wireless base station line includes a two-wave simplex SCPC (Single Channel Per Carrier) wireless line,
The wireless base station enables setting of a one-wave simplex SCPC wireless line between the wireless base station and the distributed wireless base station when communication via the wired line becomes abnormal.
The communication system according to any one of claims 1 to 3.

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