JP2002094447A - Radio communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a radio communication system in which communication quality in a radio communication section can be measured without requiring any special tester, or the like, while reducing the installation cost and maintenance cost of the system. SOLUTION: At a base station 100, a maintenance time slot assigning section 116 assigns a maintenance time slot in the uplink direction to an opposite subscriber radio station 200 and then a measurement data transmitting section 115 transmits measurement data through a maintenance time slot in the downlink direction. At the subscriber radio station 200, a measurement data send back section 224 sends back the measurement data, received through the maintenance time slot in the downlink direction, through the maintenance time slot in the uplink direction. The base station 100 receives the measurement data sent back from the subscriber radio station 200, measures the bit error rate(BER) of the measurement data and determines communication quality in a radio communication section in the uplink direction, based on the measurement results.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication system for performing point-to-multipoint (point-to-multipoint) radio communication between a base station and a plurality of subscriber radio stations.
More specifically, the present invention relates to a method of measuring wireless communication quality in a wireless communication section between a base station and a subscriber wireless station.

[0002]

2. Description of the Related Art As one form of a radio communication system, a plurality of subscriber radio stations are arranged opposite to one base station, and a one-to-many (point-to-multipoint) communication is performed between the base station and each subscriber radio station. (Point: P-MP) A device that performs communication is known.

In a conventional wireless communication system based on this P-MP communication, a method of measuring communication quality in a P-MP wireless section includes, for example, a method in which test data is transmitted from a dedicated tester connected to a subscriber wireless station. And the base station determines the connection destination and causes the other subscriber radio station or the tester installed at the remote to receive the test data, and the receiving subscriber radio station or the tester transmits the test data source. There is a method of measuring a bit error rate or the like according to the interface of the tester.

[0004] In this case, the above test requires a dedicated test machine, and the operation of the test machine cannot be dealt with by a technician with specialized skills, so that the cost of introducing and maintaining the system rises. I had no choice.

[0005] The above test can be performed when the system is installed, but cannot be performed after the user has started using the system after the system has been installed. The situation is such that the monitoring of the communication quality in the P-MP wireless section cannot be substantially performed, because only the hardware state itself can be monitored. as a result,
The failure occurred only after receiving a complaint from the user that it could not be used, and in many cases the user suffered a great deal of operational trouble.

Also, due to the nature of radio, if an obstacle occurs in a radio section after installation, there is no means for grasping the effect on communication, and no decision can be made until actual use. That was the current situation.

[0007]

As described above, the P-MP
Conventional wireless communication systems based on communication require a dedicated tester to measure the wireless communication quality in the wireless communication section, and also require engineers with specialized skills to respond. However, there has been a problem that the system introduction cost and the maintenance cost are soaring.

Further, in this type of conventional system, after the user starts using the system after installation, the hardware status itself on the side of the subscriber radio station can be monitored, but the communication quality in the P-MP radio section cannot be monitored. This cannot be practically performed, and as a result, there is a problem that the user is liable to suffer from operational trouble after the start of use, and the quality of the maintenance / operation service is inevitably reduced.

The present invention eliminates the above problems, measures the communication quality of a wireless communication section without the need for a special tester or the intervention of a skilled technician, reduces the cost of introducing and maintaining the system, and It is another object of the present invention to provide a wireless communication system capable of improving the quality of maintenance / operation services.

[0010]

In order to achieve the above object, according to the present invention, a plurality of subscriber radio stations and a plurality of base stations accommodating a predetermined number of the subscriber radio stations are provided. A wireless communication system for performing one-to-many wireless communication using a multiplexing and multiple access method between each of the base stations and each of the subscriber wireless stations accommodated in each of the base stations; A maintenance time slot allocating means for allocating at least one or more maintenance time slots within a communication time slot of the wireless communication section, and using the maintenance time slot between the base station and an opposing subscriber wireless station. Data is transmitted and received, and at least one of a downlink direction from the base station to the subscriber wireless station side or an uplink direction from the subscriber wireless station to the base station side based on a measurement result of the data. Wherein the Re or radio communication quality of one radio communication section allowed determination.

According to a second aspect of the present invention, in the first aspect of the present invention, the maintenance time slot allocating means fixedly allocates the maintenance time slot to the downlink communication time slot, and the uplink communication time slot. The maintenance time slot is assigned to a time slot for each of the subscriber wireless stations as needed.

According to a third aspect of the present invention, in the first or the second aspect of the present invention, the base station includes measurement data transmitting means for transmitting measurement data through the downlink maintenance time slot, A station that receives the measurement data through the downlink maintenance time slot and performs error measurement of the measurement data; and a radio communication quality determination that determines radio communication quality based on a measurement result of the error measurement means. Means, and when the wireless communication quality is determined to be abnormal, comprises an alarm notification means for performing an alarm notification corresponding to the determination result to the opposite base station, wireless communication quality only in the downlink wireless communication section Is determined.

According to a fourth aspect of the present invention, in the first or the second aspect of the present invention, the subscriber radio station transmits measurement data through the upstream maintenance time slot allocated by the maintenance time slot allocating means. The base station, after allocating the upstream maintenance time slot to the opposing subscriber radio station by the maintenance time slot allocating means, through the maintenance time slot allocating means, Error measuring means for receiving the measurement data sent from the subscriber radio station and measuring the error of the measurement data; and radio communication quality judging means for judging radio communication quality based on the measurement result of the error measurement means And when the wireless communication quality is determined to be abnormal, an alarm corresponding to the determination result is issued to the subscriber wireless station. Equipped with an alarm notification means for performing intellectual,
The wireless communication quality is determined only in the uplink wireless communication section.

According to a fifth aspect of the present invention, in the first or second aspect of the present invention, the base station assigns the upstream maintenance time slot to the opposing subscriber radio station by the maintenance time slot allocating means. After allocating, to the subscriber wireless station, measurement data transmitting means for transmitting measurement data through the downlink maintenance time slot,
An error measuring unit that receives the measurement data returned from the subscriber wireless station through the allocated upstream maintenance time slot and performs an error measurement of the measurement data, based on a measurement result of the error measurement unit; Wireless communication quality determination means for determining wireless communication quality, and alarm notification means for issuing an alarm notification corresponding to the determination result to the subscriber wireless station when the wireless communication quality is determined to be abnormal. , The subscriber radio station, the return transmission means for transmitting the measurement data received through the downlink maintenance time slot through the uplink maintenance time slot allocated by the base station, and the downlink maintenance time. An error measuring means for receiving the measurement data through a slot and measuring an error of the measurement data; Wireless communication quality determination means for determining wireless communication quality based on the measurement result of the measurement means, and alarm notification for issuing an alarm notification corresponding to the determination result to the base station when the wireless communication quality is determined to be abnormal Means for determining wireless communication quality in both the downlink and uplink wireless communication sections.

According to a sixth aspect of the present invention, in the fourth or fifth aspect of the present invention, each base station is connected via a network, and operation and operation of each of the base stations and each of the subscriber radio stations are performed through the network. It further includes a network monitoring device that performs control related to maintenance, wherein the alarm notification unit in the base station performs the alarm notification to both the subscriber wireless station and the network monitoring device.

According to a seventh aspect of the present invention, in the sixth aspect of the present invention, the subscriber wireless station includes a network entry requesting unit for requesting that the local station be connected to the network, and the base station includes Receiving the network connection request from the subscriber base station, confirming the validity of the subscriber radio station, correcting the communication level of the uplink radio communication section with the subscriber radio station, and shifting the communication time phase A network entry processing means for performing network entry processing including correction is provided.

[0017]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a diagram showing the overall configuration of a radio communication system according to the present invention. In FIG. 1, a cell A and a cell B each represent one service area of the entire service area of the present system. In cell A, 1
Base station 100A and a plurality of subscriber radio stations 200-1,
200-2, 200-3, and 200-4 are arranged.

The base station 100A and each subscriber radio station 200-
1, 200-2, 200-3, and 200-4, respectively, uplink (from subscriber radio station 200 to base station 100
Direction) and downlink (from base station 100 to subscriber radio station 20)
0 direction), and the base station 100A and each of the subscriber's wireless stations 200-1, 200-2,
P-MP communication between 00-3 and 200-4 is performed.

Similarly, in cell B, one base station 10
OB and a plurality of subscriber wireless stations 200-11, 200-1
2,200-13,200-14 are located, and base station 1
00B and each subscriber's radio station 200-11, 200-12,
P-MP communication using uplink and downlink is performed between 200-13 and 200-14, respectively.

The dotted lines separating the cells A and B indicate the boundaries of the sectors set in the cells A and B, respectively. In this system, cell A and cell B are divided into four sectors, sector 1 to sector 4, respectively.
For each sector, frequencies used for uplink and downlink are allocated.

In the present system, the base station 100
A and 100B are connected to an ATM switch 400 in a public network 600 via a communication line 300.
The ATM switch 400 is an ATM (asynchronous transfer mode)
It has a switching function corresponding to the transmission method.

The ATM switch 400 includes a network management device (network management system:
NMS) 500 is connected. NMS500 is an ATM
By using the switching function of the switch 400 to perform data transmission with the base station 100 and the subscriber wireless station 200 in each of the cells A and B, management and control of the operation of each of the cells A and B are performed. .

Further, the public network 600 has an ATM
Network 610, I-dedicated line network 620, communication network 630 such as the Internet or an intranet, frame relay network 64
0, N-ISDN650 and the like.

Although FIG. 1 discloses only the cell A and the cell B, actually, in addition to the cell A and the cell B, the same mode (one base station 100 and a plurality of There are a plurality of cells including the wireless station 200 performing P-MP communication), and all of these cells cover the entire service provision area described above. Also, there is not one subscriber radio station 200 arranged in each sector of each cell but a plurality of subscriber radio stations 200 as shown in the figure.

FIG. 2 shows a base station 1 of the system in FIG.
FIG. 2 is a diagram showing a detailed configuration of a main part of the subscriber station 200 and the subscriber station 200.

Referring to FIG. 2, base station 100 includes an indoor unit (IDU) 110 and an outdoor unit (ODU) 120.

The IDU 110 has an ODU I / F: ODU Interface having an interface function with the ODU 120.
Unit) 111, an AIU (Ai) having an interface function between the ODU I / F 111 and the ATM switch 400.
r Interface Unit) 112 and a main control unit 113 that controls the operation of the entire IDU 110.

In the base station 100, the ODU12
0 is individually provided for each of the sectors 1, 2, 3, and 4. In this example, four ODUs 120a, 120b, 120c, 1
20d.

Also, in the IDU 110 of the base station 100, the ODU I / F 111
ODUs 120a, 120b, 120c for every 2, 3, 4
4 ODU I / F11 corresponding to each 120d
1a, 111b, 111c, and 111d.

On the other hand, the subscriber's radio station 200 is disposed for each of the sectors 1, 2, 3, and 4, and an outdoor unit (ODU) 210 for performing radio communication opposite to the ODU 120 of the corresponding sector; It comprises an indoor unit (IDU) 220 having an interface function between the ODU 210 and a subscriber terminal 230 provided in the house. As the subscriber terminal 230, for example, a 10Base-T terminal or an IS
A DN terminal or the like is used.

The radio section between the ODU 120 of the base station 100 and the ODU 210 of the subscriber radio station 200 is, for example, 26
It is operated by a TDMA (Time Division Multiple Access) -FDD (Frequency Division Operation) system in the GHz band.

In the above configuration, when the subscriber terminal 230 connected to the subscriber radio station 200 in a certain subscriber home communicates with the base station 100, the data transmitted from the subscriber terminal 230 corresponds to the corresponding subscription. Radio station 200 ID
It is transmitted to the above wireless section via U220 and ODU210. In the base station 100, the data transmitted to the wireless section from the subscriber wireless station 200 is received by the ODU 120, and then the received data is transmitted to the main control unit via the ODU I / F 111 and the AIU 112 corresponding to the ODU 120. 113.

On the other hand, data from base station 100
From U112, the ODU I / F1 is routed in the reverse route to the above.
11, and transmitted to the wireless section via the ODU 120.
In the subscriber radio station 200, the data transmitted to the radio section from the base station 100 is received by the ODU 210,
The corresponding subscriber radio station 200 via the corresponding IDU 220
Is sent to the subscriber terminal 230 connected to.

As described above, the radio communication system according to the present invention divides the entire area for providing the subscriber communication service into a plurality of cells and one base station 1 for each cell.
00 and a plurality of subscriber radio stations 200 are arranged, and P-MP communication is performed between the subscriber radio stations 200 facing the base station 100 for each cell.

Next, the base station 100 and the subscriber radio station 2
The wireless communication quality determination function in the wireless section between 00 will be described.

In the present system, the base station 100 is provided with means for allocating at least one or more maintenance time slots within the communication time slots of the radio section.
00 and the opposing subscriber wireless station 200 using the maintenance time slot to transmit and receive data, and based on the measurement result of the data, transmit data from the base station 100 to the From the wireless station 200 to the base station 10
It has a function of determining the wireless communication quality of at least one of the wireless sections in the upward direction toward the zero side.

As a configuration for realizing this function, the base station 100 includes a network entry processing unit 114 and a measurement data transmission unit 1 in the IDU 100 (see FIG. 2).
15, a maintenance time slot allocating unit 116, a BER measuring unit 117, and a wireless communication quality determining unit 118.

The network entry processing unit 114 performs a network connection process based on a network entry request sent from the subscriber station 200 in a procedure described later.

Measurement data transmitting section 115 transmits a data pattern (measurement data) for measuring a bit error rate used for determining the communication quality of a radio section with subscriber radio station 200.

The maintenance time slot allocating section 116 performs control for allocating at least one or more maintenance time slots in communication time slots in the radio section with the subscriber station 200.

In this example, the maintenance time slot allocating section 116 fixedly allocates a maintenance time slot to a downlink communication time slot from the base station 100 to the subscriber radio station 200, and A maintenance time slot (used for transmitting the measurement data for measuring the wireless communication quality) is assigned to the communication time slot in the upward direction toward 100 as needed, for each subscriber wireless station 200. You.

The BER measuring section 117 receives the measurement data transmitted from the subscriber station 200 through the uplink maintenance time slot allocated as described above, and measures the bit error rate (BER) from the data pattern.

The radio communication quality judging section 118 judges the BER measured by the BER measuring section 117. If the BER is equal to or larger than a predetermined threshold, the NMS 500 and the subscriber radio station 20
Control is performed to notify an abnormality to 0 and display an alarm with the corresponding contents.

The base station 100 performs coding, decoding, and modulation / demodulation processing when transmitting and receiving the measurement data and the like for the BER measurement with the subscriber radio station 200 by the AIU 11.
2 is performed.

On the other hand, on the subscriber radio station 200 side, as a configuration for realizing the radio communication quality judgment function, an ID
In U220, the network entry request processing unit 22
3. Measurement data return processing unit 224, BER measurement unit 22
5. A wireless communication quality determination unit 226 is provided.

Network entry request processing section 223
Performs a process of issuing a network entry request to the base station 100 when a subordinate communication device (subscriber terminal 230) attempts to connect to the network from a state where the network is not connected.

The measurement data loopback processing section 224 is provided from the base station 100 as a downlink maintenance time slot (fixedly provided,
The base station 100 performs a process of returning the measurement data sent using the common station 200 to the uplink maintenance time slot assigned by the base station 100.

The BER measuring unit 225 captures the measurement data transmitted from the base station 100 through the downlink maintenance time slot before the return by the measurement data return processing unit 224, and measures the BER from the data pattern. I do.

Radio communication quality determining section 226 determines the BER measured by BER measuring section 225, and if the BER is equal to or greater than a predetermined threshold, displays a corresponding alarm and notifies base station 100 to that effect. Control.

The data transmission / reception unit 222 performs coding, decoding, and modulation / demodulation processing when the subscriber wireless station 200 transmits and receives the measurement data and the like for the BER measurement to and from the base station 100. The main control unit 221 controls the operation of the entire IDU 220 including the processing units.

Next, a communication operation between the base station 100 and the subscriber wireless station 200 in the present system will be described.

As described above, in the present system, the base station 1
It is possible to perform P-MP communication between 00 and the opposing subscriber wireless station 200.

In the present system, when performing the above communication, the maintenance time slot allocating section 116 in the base station 100 performs a downlink maintenance time slot from the base station 100 to the subscriber radio station 200 and an uplink maintenance time slot in the opposite direction. Assign time slots.

Specifically, the downlink maintenance time slot is fixedly provided, and is commonly used by each of the subscriber radio stations 200. On the other hand, an uplink maintenance time slot is individually allocated to each subscriber radio station 200 as needed.

FIG. 3 is a diagram showing an example of allocation of maintenance time slots (uplink maintenance time slots) on an uplink communication path according to the present invention.

In the figure, FS is a frame start time slot, G is a guard time slot provided for avoiding interference when a plurality of subscriber radio stations 200 conflict.
C is a contention slot for receiving requests from a plurality of subscriber wireless stations 200, and R is a reserved slot for communication allocated in response to a request from the subscriber wireless station 200.

An example of a communication operation between the base station 100 and the subscriber wireless station 200 in such a configuration will be described with reference to a flowchart shown in FIG.

This flowchart is based on the base station 10
0 and the subscriber's wireless station 200 both perform BER measurement (when the uplink and downlink bidirectional wireless communication quality is determined)
Corresponds to the operation from the start of communication.

In this case, the base station 100 continues to periodically transmit a BER measurement data pattern (measurement data) to the downlink maintenance time slot.

In this state, in subscriber radio station 200, network entry request processing section 223 sends a network entry request to base station 100 in response to an instruction from corresponding subscriber terminal 230 (step S41).
1).

On the other hand, in the base station 100, the network entry processing unit 114 receives the network entry request via the AIU 112 and starts the network entry processing (step S421).

In this process, first, the subscriber's radio station 200
, While controlling the output level of the subscriber radio station 200 while exchanging with the subscriber radio station 200 so that the reception level of the signal received from the While exchanging with the subscriber radio station 200 so as to be in timing, the transmission timing of the subscriber radio station 200 is adjusted.

When the processing of the network entry is completed, the base station 100 determines whether there is a vacancy of the above-mentioned uplink maintenance time slot (see FIG. 3) as preparation for starting the processing of determining the radio communication quality (see FIG. 3). It is checked whether or not it has been assigned to a subscriber radio station other than the subscriber radio station 200 that has issued the network entry request this time (step S422).

Here, if there is a free space in the upstream maintenance time slot (step S422 NO), the system waits until a free space is available. The uplink maintenance time slot is allocated to the station 200 (step S423).

On the other hand, in the subscriber's radio station 200, the base station 1
Upon receiving the uplink maintenance time slot allocation from 00 (step S412), the measurement data return processing unit 224
Sets the data return between the allocated uplink maintenance time slot and the fixedly allocated downlink maintenance time slot (step S413), and sets the measurement data received from the downlink maintenance time slot to the uplink maintenance time slot. It is sent back to the slot (step S41)
4).

On the other hand, in the base station 100, the subscriber radio station 2
The measurement data returned from 00 is received through the uplink maintenance time slot (step S424), and the BER is transmitted.
The data is transferred to the measurement unit 117 and the BER measurement process is performed (step S425).

After the start of the measurement, it is checked whether a predetermined time has elapsed (step S426). If the predetermined time has not elapsed (step S426 NO), the reception of the measurement data and the BE
The R measurement processing is continued (steps S424 and S425), and when a predetermined time has elapsed (step S426YE).
S), the uplink maintenance time slot allocated so far is released (step S427).

After that, in the base station 100, the radio communication quality judging section 118 checks whether or not the BER is abnormal (whether or not it is equal to or more than a predetermined threshold) based on the measurement result of the BER measuring section 117 (step S428). Is not abnormal (step S428 NO), the process ends.

When the BER is abnormal (step S428 YES), the abnormality is notified to NMS 500 (step S429), and the abnormality is also notified to subscriber station 200 (step S430). After that, the process ends.

Each of the base station 100 and the subscriber's radio station 200 that has received the notification of the abnormality displays an alarm for notifying the abnormality.

On the other hand, at the same time that the measurement data received from the downlink maintenance time slot is sent back to the uplink maintenance time slot in step S414, the subscriber radio station 200 transmits the measurement data received from the downlink maintenance time slot. Into the BER measurement unit 225
The measurement is started (step S415), and the BER measurement process is continued until the release of the uplink maintenance time slot from the base station 100 is received (step S416 YES).

When the release of the uplink maintenance time slot is received from base station 100 (step S 416)
YES), in the subscriber's radio station 200, the radio communication quality determination unit 226 determines the B based on the measurement result of the BER measurement unit 225.
It is checked whether or not the ER is abnormal (whether or not it is equal to or more than a predetermined threshold) (step S417). If the BER is not abnormal (step S417 NO), the process ends.

If the BER is abnormal (YES in step S417), the BER is notified to the base station 100, and an alarm is displayed on the own station to notify the abnormality. At this time, the base station 100 also performs a predetermined alarm display based on the abnormality notification from the subscriber wireless station 200.

As described above, in this embodiment, the base station 100
BER measurement is performed by both the mobile station 200 and the subscriber radio station 200 to determine the uplink and downlink bidirectional radio communication quality. If the uplink radio communication quality is reduced, an alarm is displayed on the NMS 500 and the subscriber radio station 200. Is performed, and an alarm display is displayed on the base station 100 when the wireless communication quality in the downlink direction decreases.

For this reason, in the present system, when the subscriber radio station 200 is newly installed, the communication probability state is established without actually connecting a communication terminal (subscriber terminal 230) to the subscriber radio station 200 and performing a communication test. And the wireless communication quality can be measured without the need for a dedicated tester. Also,
Even if a communication error occurs in a communication terminal, it is possible to determine whether a communication error has occurred in the wireless communication section or a communication error due to other factors. become able to. In addition, since the communication quality can be constantly monitored, the maintenance and inspection can be automated, and the deterioration of the device can be detected early.

In the above embodiment, the radio communication quality is determined in both the uplink and downlink directions. In another embodiment, the radio communication quality is determined in the uplink alone or in the downlink alone. You may do it.

FIG. 5 is a flowchart showing a radio communication quality determination process by the downlink direction alone, that is, by the subscriber radio station 200 alone.

In this case, base station 100 does not necessarily need to have BER measurement section 117 and radio communication quality determination section 118, and subscriber radio station 200 does not necessarily need to have measurement data return processing section 224.

In this configuration, base station 100 always transmits a data pattern (measurement data) for BER measurement from measurement data transmitting section 115 to a downlink maintenance time slot.

In this situation, the subscriber radio station 200 receives the measurement data from the downlink maintenance time slot which is fixedly allocated and can be used by any of the subscriber radio stations 200 (step S501). Based on the received measurement data, the BER measurement unit 225 performs a BER measurement process (step S502).

After the start of the measurement, it is checked whether a predetermined time has elapsed (step S503). Unless the predetermined time has elapsed (step S503), the reception of the measurement data and the BER measurement process are continued (step S502). Has elapsed (YES in step S503), the process proceeds to the wireless communication quality determination process.

In this wireless communication quality determination processing, the wireless communication quality determination unit 226 of the subscriber wireless station 200 determines whether the BER is abnormal based on the measurement result of the BER measurement unit 225 up to that time (whether the BER is equal to or greater than a predetermined threshold). Is checked (step S504), and if the BER is not abnormal (step S504: NO), the processing from step S501 is continued.

If the BER is abnormal (YES in step S504), B for notifying the abnormality is set.
An ER abnormality display is performed (step S505), and a BER abnormality is notified to the base station 100 (step S5).
06).

At this time, the base station 100 also performs a predetermined alarm display based on the above-mentioned abnormality notification from the subscriber's radio station 200.

According to this embodiment, even if the base station 100 does not have the function of determining the radio communication quality in the uplink direction, the radio communication quality in the downlink direction can be constantly monitored.

FIG. 6 is a flowchart showing the radio communication quality determination processing by the uplink alone, that is, by the base station 100 alone.

In this case, base station 100 does not necessarily need to have measurement data transmitting section 115. Further, the subscriber wireless station 200 includes a measurement data return processing unit 224, a BER
Although it is not necessary to have the measurement unit 225 and the wireless communication quality determination unit 226, it is necessary to add a measurement data transmission unit.

In this configuration, base station 100 checks whether or not there is a free uplink maintenance time slot (see FIG. 3) as preparation for starting the process of determining the radio communication quality in the uplink section (step S1). S601). In addition,
This process is periodically performed, for example, at a preset interval.

If there is a vacancy in the uplink maintenance time slot (YES in step S601), maintenance time slot allocating section 116 allocates the uplink maintenance time slot to subscriber radio station 200 (step S603). .

In this example, the destination of the uplink maintenance time slot is designated to the subscriber radio station A in order to evaluate the radio communication quality of the uplink section with the subscriber radio station A.

Next, base station 100 instructs subscriber radio station A to which the uplink maintenance time slot is assigned, to transmit the measurement data (step S60).
3).

[0093] Upon receiving this instruction, the subscriber's wireless station A sends the measured data from the above-mentioned measurement data transmitting means to step S.
The measurement data is transmitted to the uplink maintenance time slot allocated in 602.

On the other hand, the base station 100 receives the measurement data transmitted from the subscriber station A through the uplink maintenance time slot, transfers the received data to the BER measuring section 117, and
An ER measurement process is performed (Step S604).

After the start of the measurement, it is checked whether a predetermined time has elapsed (step S605). Unless the predetermined time has elapsed (step S605 NO), the reception of the measurement data and the BE
The R measurement process is continued (step S604), and if a predetermined time has elapsed (step S605 YES), the process proceeds to the wireless communication quality determination process.

In this wireless communication quality determination process, the wireless communication quality determination section 118 of the base station 100
It is checked whether or not the BER is abnormal (whether or not it is equal to or more than a predetermined threshold) based on the measurement result in the ER measurement unit 117 (step S606).
06NO), and terminate the process.

If the BER is abnormal (step S606 YES), the abnormality is notified to NMS 500 (step S607), and the abnormality is also notified to subscriber station A (step S608). ,afterwards,
The process ends.

[0098] The base station 100 and the subscriber's radio station A that have received the notification of the abnormality each display an alarm for notifying the abnormality.

The present invention is not limited to the embodiment described above and shown in the drawings, but can be implemented by appropriately modifying it without departing from the scope of the invention.

For example, in the embodiment described above, the number of maintenance time slots is one, but the number of maintenance time slots can be increased in accordance with the ratio to the communication band. Further, the communication channel is a time-division time slot, but a frequency division is also possible.

[0101]

As described above, according to the present invention,
The base station is provided with maintenance time slot allocating means for allocating at least one or more maintenance time slots within a communication time slot of a wireless communication section between the base station and the subscriber wireless station. Send and receive data using the maintenance time slot, based on the measurement result of the data, at least in the downlink direction from the base station to the subscriber radio station or in the uplink direction from the subscriber radio station to the base station side The wireless communication quality of any one wireless communication section can be determined.

According to this configuration, when a new subscriber radio station is installed, the communication probability state can be monitored without actually connecting a communication terminal to the subscriber radio station and conducting a communication test. It is possible to measure the wireless communication quality without the need for wireless communication. In addition, even if a communication error occurs in a communication terminal, it is possible to determine whether a communication error has occurred in the wireless communication section or a communication error due to other factors, and maintenance is possible even if the engineer does not have technical expertise. Be able to respond. In addition, since the communication quality can be constantly monitored, the maintenance and inspection can be automated, and the deterioration of the device can be detected early. For the above reasons, both the installation cost for installation and the maintenance cost for maintenance can be reduced, and the quality of maintenance / operation services can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of a wireless communication system according to the present invention.

FIG. 2 is a diagram showing a detailed configuration of a main part of a base station and a subscriber wireless station of the system in FIG. 1;

FIG. 3 is a diagram showing an example of assignment of maintenance time slots on an uplink communication path according to the present invention.

FIG. 4 is a flowchart showing a communication operation between the base station and the subscriber wireless station when the BER measurement is performed by the both.

FIG. 5 is a flowchart showing a wireless communication quality determination process performed by a subscriber wireless station alone.

FIG. 6 is a flowchart illustrating a wireless communication quality determination process performed by a base station alone.

[Explanation of symbols]

100, 100A, 100B Base station 110 Indoor unit (IDU) 111, 111a, 111b, 111c, 111d O
DU I / F (ODU Interface Unit) 112 AIU (Air Interface Unit) 113 Main control unit 114 Network entry processing unit 115 Measurement data transmission unit 116 Maintenance time slot allocation unit 117 BER measurement unit 118 Wireless communication quality determination unit 120, 120a, 120b, 120c, 120d Outdoor equipment (ODU) 200, 200-1, 200-2, 2
00-3, 200-4, 200-11, 200-12,
200-13, 200-14 Subscriber radio station 210 Outdoor unit (ODU) 220 Indoor unit (IDU) 221 Main control unit 222 Data transmission / reception unit 223 Network entry request processing unit 224 Measurement data return processing unit 225 BER measurement unit 226 Wireless communication Quality judging unit 230 Subscriber terminal 300 Communication line 400 ATM (asynchronous exchange mode) switch 500 Network management device (NMS) 600 Public network 610 ATM network 620 I-dedicated line network 630 Communication network such as Internet or intranet 640 Frame relay network 650 N-ISDN

 ──────────────────────────────────────────────────続 き Continuing on the front page F term (reference) 5K028 AA07 BB04 CC05 EE09 KK01 KK32 LL02 MM14 PP22 QQ02 RR01 TT01 5K042 AA06 BA01 CA13 DA27 EA01 EA09 EA14 FA08 FA11 FA15 HA05 HA13 JA01 JA08 LA11 LA15 A04 5A0CC ACC EE72 LL05 LL13

Claims (7)

[Claims] 1. A plurality of subscriber radio stations, and a plurality of base stations accommodating a predetermined number of the subscriber radio stations, wherein each of the base stations and each of the subscribers accommodated in each of the base stations are provided. In a wireless communication system for performing one-to-many wireless communication with a wireless station using a multiplexing and multiple access method, the base station is provided with at least one or more maintenance time slots within a communication time slot of the wireless communication section. Providing a maintenance time slot allocating means for allocating, transmitting and receiving data using the maintenance time slot between the base station and the opposing subscriber wireless station, and based on the measurement result of the data, It is characterized in that it is possible to determine the radio communication quality in at least one of the radio communication sections in the downlink direction to the radio station side or the uplink direction from the subscriber radio station to the base station side. Wireless communication system to be. 2. The maintenance time slot allocating means, wherein the maintenance time slot is fixedly assigned to the downlink communication time slot, and the uplink communication time slot is assigned to the downlink communication time slot as required.
The wireless communication system according to claim 1, wherein the maintenance time slot is assigned to each of the subscriber wireless stations. 3. The base station comprises a measurement data transmitting means for transmitting measurement data through the downlink maintenance time slot, and the subscriber radio station receives the measurement data through the downlink maintenance time slot. An error measuring unit that performs error measurement of the measurement data, a wireless communication quality determining unit that determines wireless communication quality based on a measurement result of the error measuring unit, and an opposite unit when the wireless communication quality is determined to be abnormal. 3. The radio communication system according to claim 1, further comprising: an alarm notifying unit that performs an alarm notification corresponding to the determination result in the base station, and determines the wireless communication quality only in the downlink wireless communication section. Communications system. 4. The subscriber radio station includes measurement data transmitting means for transmitting measurement data through the uplink maintenance time slot allocated by the maintenance time slot allocating means. By allocating the upstream maintenance time slot to the opposing subscriber radio station by the slot allocating means, receiving the measurement data transmitted from the subscriber radio station through the uplink maintenance time slot, Error measuring means for performing error measurement of the measurement data; wireless communication quality determining means for determining wireless communication quality based on the measurement result of the error measuring means; and if the wireless communication quality is determined to be abnormal, the subscriber radio Alarm notification means for performing alarm notification corresponding to the determination result with respect to the station, wherein the uplink wireless communication section The wireless communication system according to claim 1, wherein the determination of the wireless communication quality is performed only by the wireless communication system. 5. The base station, after allocating the upstream maintenance time slot to the opposing subscriber radio station by the maintenance time slot allocating means, and providing the downlink radio maintenance time to the subscriber radio station. A measurement data transmitting unit for transmitting measurement data through a time slot; receiving the measurement data returned from the subscriber wireless station through the allocated upstream maintenance time slot, and performing error measurement on the measurement data; Error measuring means; wireless communication quality determining means for determining wireless communication quality based on the measurement result of the error measuring means; if the wireless communication quality is determined to be abnormal, the determination result is transmitted to the subscriber wireless station. Alarm notification means for performing an alarm notification corresponding to the above, wherein the subscriber radio station transmits through the maintenance time slot in the downlink direction. Return transmission means for transmitting the received measurement data through an uplink maintenance time slot allocated from the base station, and receiving the measurement data through the downlink maintenance time slot, and performing error measurement of the measurement data. Error measuring means for performing, wireless communication quality determining means for determining the wireless communication quality based on the measurement result of the error measuring means, if the wireless communication quality is determined to be abnormal, the base station, the The wireless communication system according to claim 1 or 2, further comprising: an alarm notification unit that performs a corresponding alarm notification, wherein the determination of the wireless communication quality is performed in both the downlink and the uplink wireless communication sections. . 6. A base station connected to each base station via a network, and further comprising a network monitoring device for controlling operation and maintenance of each base station and each subscriber radio station through the network. The wireless communication system according to claim 4, wherein the alarm notification unit performs the alarm notification to both the subscriber wireless station and the network monitoring device. 7. A subscriber wireless station includes network entry requesting means for requesting connection of the own station to the network, wherein the base station receives the network connection request from the subscriber base station. A network entry processing means for performing network entry processing including confirmation of the validity of the subscriber wireless station, communication level correction in an uplink wireless communication section with the subscriber wireless station, and communication time phase shift correction. 7. The wireless communication system according to claim 6, wherein: