JP2012080312A - Radio communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication system that can prevent interference occurrence and device cost increase and improve frequency utilization efficiency.SOLUTION: In a radio communication system, a frequency management device is connected to a plurality of systems capable of using a particular frequency via a network and manages the use of the frequency. The frequency management device has a frequency management table to store reservation contents about the use of the frequency, and stores, in the frequency management table, the identification number of a base station of a system by associating it with time and an area based on a reservation request from each system, and makes each system operate based on the frequency management table. When the frequency management device receives an emergency interruption requesting to use the frequency for particular time from a particular system, the frequency management device registers the contents with the frequency management table and if the request overlaps with operation of another system, stops the operation of the other system and makes the particular system operate based on the registered contents, and when the particular time expires, returns to the operation based on the table.

Description

  The present invention relates to a cognitive radio communication system in which a plurality of systems share the same frequency, and more particularly to a radio communication system capable of improving frequency utilization efficiency.

[Description of Prior Art]
With the spread of mobile phones and wireless LANs in recent years, demand for advanced mobile communication and high-speed transmission technology has been increasing year by year. Frequency resources to meet that demand are tight and are expected to fail to meet demand.

There is a cognitive radio technology as a technology for effective frequency utilization.
The cognitive radio communication system is used by assigning the same frequency to a plurality of systems by changing the area and time, and aims to improve the frequency utilization efficiency.
In a conventional cognitive radio communication system (hereinafter simply referred to as “radio communication system”), there are a primary use system that has a license and uses a specific frequency preferentially, and a secondary use system that is a non-priority user. is there.
In the secondary usage system, communication is performed without causing interference by sensing the frequency usage status of the primary usage system and selecting and using a frequency not used by the primary usage system.

Therefore, the secondary usage system always requires a base station device with sensing capability. Furthermore, if there is a terminal that cannot be detected due to an obstacle, interference with the primary usage system occurs. (Hidden terminal problem).
Also, if the sensing capability is to be sufficiently increased in order to cope with the hidden terminal problem, the processing capability must be increased, and the device cost of the secondary usage system is increased.

As a technology related to the cognitive radio communication system, there is JP-A 2010-98394 “Spectrum sensor used for cognitive radio communication” (Applicant: National Institute of Information and Communications Technology, Patent Document 1).
Patent Document 1 describes that a spectrum sensor not only transmits sensing information to a cognitive engine, but also transmits information to other spectrum sensors to share the sensing information between the sensors.

JP 2010-98394 A

  However, in the conventional wireless communication system, if the sensing capability of the secondary usage system is insufficient, interference occurs, and if the sensing capability is increased, the device cost increases, and the frequency utilization efficiency is improved without interference. There is a problem that it is difficult to realize a system to be manufactured at a low cost.

  In addition, the conventional wireless communication system has a problem that it is difficult to flexibly cope with a change in radio wave demand due to day and night population changes in a business district and the like, and the frequency use efficiency is lowered.

  The present invention has been made in view of the above circumstances, and provides a wireless communication system capable of preventing occurrence of interference and increase in apparatus cost, flexibly responding to changes in radio wave demand, and improving frequency utilization efficiency. With the goal.

  The present invention for solving the problems of the conventional example described above is a wireless communication system including a plurality of systems that can use a specific frequency, and is connected to the plurality of systems via a network and uses the frequency. The frequency management device has a frequency management table for storing reservation contents for use of the frequency, and receives frequency reservation requests from a plurality of systems. The management table stores the base station identification number, time, and area in association with each other, and uses the frequency for the system stored in the table based on the time and area stored in the frequency management table. Emergency allocation that requires the frequency to be used urgently from a specific system among multiple systems. When it receives a message, it registers the contents of the emergency interrupt in the frequency management table, and if it overlaps with the operation of other systems among multiple systems, it stops the operation of other systems and It is characterized in that the operation is performed based on the registered contents, and the operation is returned to the operation based on the table when a specific time is over.

  According to the present invention, a wireless communication system including a plurality of systems that can use a specific frequency, comprising a frequency management device that is connected to a plurality of systems via a network and manages the use of the frequencies, When the frequency management device has a frequency management table that stores reservation contents for use of the frequency and receives a frequency reservation request from a plurality of systems, the frequency management table stores the frequency management table in the frequency management table based on the request. An identification number, time and area are stored in association with each other, and based on the time and area stored in the frequency management table, the system stored in the table is operated using the frequency, and a plurality of systems If an emergency interrupt requesting that the frequency be used urgently for a specific time is received from a specific system, an emergency interrupt is received. If the contents of the system are registered in the frequency management table and overlap with the operation of other systems among multiple systems, the operation of the other systems is stopped and the contents registered in the specific system based on the contents registered. When the operation is performed and a specific time is over, the wireless communication system returns to the operation based on the table.Therefore, the frequency use time and area can be allocated to multiple systems under the condition that interference does not occur, and sensing is performed. Reduces equipment costs as unnecessary, and makes effective use of multiple systems in a planned manner by using frequencies. In addition, specific systems that can be preferentially used can be communicated without inconvenience even in an emergency due to an emergency interrupt. It is possible to improve the frequency utilization efficiency by promoting free time.

It is a schematic block diagram which shows an example of the radio | wireless communications system which concerns on the 1st Embodiment of this invention. It is a model explanatory drawing of the frequency management table in a 1st system. It is a schematic explanatory drawing which shows the usage example of the license allocation frequency of a certain area. It is explanatory drawing which shows the operation | movement sequence in a 1st system. It is a schematic block diagram which shows an example of the radio | wireless communications system which concerns on the 2nd Embodiment of this invention. It is a schematic explanatory drawing which shows the example of the frequency management table in a 2nd system. It is a schematic explanatory drawing which shows the usage example of the frequency in a certain area. It is explanatory drawing which shows the operation | movement sequence in a 2nd system.

[Outline of the embodiment]
Embodiments of the present invention will be described with reference to the drawings.
In the wireless communication system according to the embodiment of the present invention, the frequency management device includes a frequency management table in which the ID of the base station, the used frequency, the time, and the area are stored, and the primary usage system via the network And the management terminal unit provided in the base station of the secondary usage system, and each management terminal can be written, changed, etc. according to the priority, and the area to be used from the management terminal unit of each system It accepts time zone requests and stores them in the frequency management table, assigns frequencies and areas to each system based on the table, and eliminates the need for secondary usage system sensing. Without increasing, it is possible to reliably prevent the occurrence of interference and to effectively use the frequency.

  In addition, in the wireless communication system according to the embodiment of the present invention, when the frequency management apparatus requests an emergency interrupt from the management terminal unit of the primary usage system, the interrupt request is immediately reflected in the frequency management table. In this case, the secondary usage system in operation is stopped, the frequency is assigned to the primary usage system of the request source, and the frequency is used. By preferentially allocating to the primary usage system, the primary usage system can be operated urgently, the release of the frequency in the idle time can be promoted, and the frequency can be used more effectively.

  Further, the radio communication system according to the embodiment of the present invention includes a macro cell base station and a micro cell base station in the same area, and the frequency management apparatus monitors and uses the frequency use status of the entire area. When the rate is above a certain value, it is switched to a micro cell, and when the usage rate is less than a certain value, it is switched to a macro cell for efficient system operation according to radio wave demand. It is something that can be done.

[First Embodiment]
The wireless communication system according to the first embodiment of the present invention is not made available only when the secondary usage system performs sensing and the primary usage system is not used, but the primary usage and 2 The next-use system registers and reserves the base station ID, use time zone, and use area of the system for each frequency in advance in the time table of the management device that manages the use of the frequency. According to the table, an instruction to start / stop operation is output to each base station. Further, when there is an emergency interrupt request from the primary usage system, the time table is updated based on the request and reserved. The primary usage system interrupted over other systems that have been used is operated preferentially, and the secondary usage system calculates the free time / empty area of the primary usage system. If the primary usage system wants to use it urgently, it can be used preferentially, and the smooth operation of the primary usage system is not disturbed. The utilization efficiency can be improved.

[Configuration of First Embodiment: FIG. 1]
The configuration of the wireless communication system (first system) according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram showing an example of a radio communication system according to the first embodiment of the present invention.
In the example of FIG. 1, the first system includes three primary usage systems (primary usage system (No. 1) to primary usage system (No. 3) and two secondary usage systems (secondary usage systems). The wireless communication system includes a system (No. 1) and a secondary usage system (No. 2).
In FIG. 1, for the sake of simplicity, only the portions related to the areas A1 and A2 are shown in the area sections A1, A2, B1, B2, C1, and C2.

  The first system includes a frequency management device 1 that performs frequency management of the entire system, a base station (“primary (1) base station” in the figure) 11 of the primary usage system (No. 1), 2 Base station (secondary (1) base station in the figure) 21 of the secondary usage system (No. 1) and base station (secondary (2) base station in the figure) of the secondary usage system (No. 2) ”) 22 and a wireless or wired network 3 that connects the base stations 11, 21, 22 and the frequency management device 1. Further, although not shown in the figure, a base station of the primary usage system (No. 2) and a base station of the primary usage system (No. 3) are provided.

Each component will be described.
In the example of FIG. 1, the secondary usage (1) base station 21 manages wireless communication in the area A1, and performs wireless communication with the terminal station 4 in the area A1.
Similarly, the secondary usage (2) base station 22 manages wireless communication in the area A2, and performs wireless communication with the terminal station 4 in the area A2.
Primary use (1) The base station 11 manages the wireless communication in the areas (A1, A2), which is a combination of the area A1 and the area A2, and performs wireless communication with the terminals 4 in the area (A1, A2).
Although not shown, the base station of the primary usage system (No. 2) and the primary usage system (No. 3) manage the areas (B1, B2) and the area C2, respectively. However, the area allocation of each base station is not completely fixed and can be changed at any time by registration in the frequency management device 1.

Furthermore, in this system, each base station 11, 21, 22 not only performs wireless communication control, but also includes a computer (management terminal unit) connected to the network 3, and accesses the frequency management apparatus 1 via the network. Then, the frequency management device 1 is reserved for using the frequency, and the operation is started / stopped according to the instruction from the frequency management device 1.
That is, the base stations 11, 21, and 22 of this system have a function as a network client.

  In the system of FIG. 1, the network client function is assumed to be provided in the base station, but for each system such as primary usage (No. 1) and secondary usage (No. 1), separately from the base station. It is also possible to provide an independent management terminal so that the management terminal accesses the frequency management apparatus 1 via the network and outputs an instruction to the base station that performs communication control.

  The frequency management device 1 is a characteristic part of the first system, and performs processing for managing frequency allocation of the entire system. The frequency management device 1 is configured by a computer, and basically includes a control unit that performs processing, a storage unit that stores processing programs and data, and an interface unit that is connected to a network. Various functions are realized by starting and processing.

  The storage unit of the frequency management device 1 is provided with a database for managing frequencies. For each available use frequency (frequency band), at least a base station ID that uses the frequency, time, and area are stored. A stored frequency management table is stored. The frequency management table will be described later.

The frequency management device 1 refers to the frequency management table based on the frequency use reservation request from each of the base stations 11, 21, 22, and updates the frequency management table according to the priority of the base station. The frequency, time, and area that can be used for the base station are allocated and notified.
Then, the frequency management device 1 transmits a communication service operation start instruction or an operation stop instruction to each base station based on the frequency management table of the database, and the frequency of the entire system is efficiently used. Manage.
That is, the frequency management device 1 has a function as a network server that manages the use of frequencies.

Further, as a feature of the first system, when there is an emergency interrupt from the primary use base station, the frequency management device 1 preferentially registers the interrupt in the frequency management table and has already been scheduled. For time zones and areas that overlap with the system, the primary use base station that is the interrupt source is used preferentially.
The emergency interrupt process will be described in detail later.

Further, in this system, the area managed by each base station can be registered at the frequency management device 1 and can be changed as needed if there is no interference with other systems.
For example, in the example of FIG. 1, the primary use (1) area of the base station 11 is switched to either the area A1 or the area A2 instead of the area (A1, A2), or the secondary use (1) of the base station 21 It is also possible to make the area an area (A1, A2).

The frequency usage time / area reservation is performed in common in the primary usage base station and the secondary usage base station. In the first system, the primary usage base station preferentially assigns the frequency. The secondary use base station reserves use in an empty time or an empty area that is not reserved by the primary use base station.
In this way, by making a reservation system, even if it is a secondary usage system, if a large number of people gather at a special event, etc., a reservation is made in advance to secure the necessary frequency, and the mobile base station It is possible to realize a full communication service using a temporary line.

  Further, in the first system, the primary use base station can transmit an emergency interrupt to the frequency management device 1 in the event of an emergency, and can use the frequency preferentially. This makes it easy for the primary use system to free up idle time and further improves frequency use efficiency.

  The secondary use base stations 21 and 22 are always accessible to the frequency management device 1 and can make a reservation for frequency use. When there is an emergency interrupt from the primary use base station 11, The emergency operation is stopped by an instruction from the frequency management device 1.

At the start of operation, each base station 11, 21, 22 adjusts transmission power, antenna directivity, and the like in order to perform service in an area designated by the frequency management device 1.
Therefore, at the installation location of each base station, the system operator calculates and measures the amount of interference for each communication area in advance to obtain communication conditions such as appropriate transmission power and antenna directivity, and stores them in each base station. Keep it. Thus, at the start of actual operation, the base station only needs to set communication conditions according to the communication area to be used, and it is not necessary to provide a measurement device or the like in the base station, reducing the processing load during operation, Switching between systems can be performed smoothly, enabling efficient system operation.

[Frequency management table of the first system: FIG. 2]
Next, the frequency management table in the first system will be described with reference to FIG. FIG. 2 is a schematic explanatory diagram of a frequency management table in the first system.
As shown in FIG. 2, the frequency management table is stored in the database of the frequency management device 1, and for each frequency (here, frequency F1), the ID, time, and area of the base station that uses the frequency. And the usage state are stored.
In the example of FIG. 2, the “use state” item is also included to simultaneously manage the reservation state and the actual operation state, but the use state may be managed separately.

In FIG. 2, the example of the frequency management table in the time zone of 13: 0 to 13:30 is shown.
First, in the time zone from 12:00 to 14:00, the primary usage (No. 1) reserves and uses the frequency F1 in the areas A1 and A2, and in the same time zone, the primary usage (No. 1). 2) reserves and uses the frequency F1 in the areas B1 and B2.
Further, the secondary use (No. 1) reserved the frequency F1 in the area C2 in the same time zone (12: 0 to 14:00) and operated in accordance with the reservation.

Then, there is an emergency interrupt from the primary use (No. 3) to the frequency management device 1, and the frequency management device 1 preferentially puts the reservation of the emergency interrupt in the frequency management table and updates it.
The content of the emergency interrupt is that the primary use (No. 3) uses the frequency F1 in the area C2 from 13:00 to 13:30.
Since this emergency interrupt overlaps with the secondary usage (No. 1) area, the frequency management apparatus 1 makes an emergency stop before 13:00 on the secondary usage (No. 1) that was operating as reserved. Let

  As a result, the primary use (No. 3) can use the frequency F1 in the area C1 at the time of 13:00 to 13:30. At the current time, the usage status of the primary usage (No. 3) indicates that the usage is “Emergency Interrupt”, and the secondary usage (No. 1) is stopped by the “Emergency Stop”. It shows that.

  When the emergency interrupt time is over, the allocation based on the frequency management table is performed again. In the above-described example, when 13:30 is reached, the primary usage (No. 3) operation is stopped, and based on the frequency management table, the secondary usage (No. 1) is frequency in the area C2 until 14:00. Use F1.

In the frequency management table, the contents reserved by each system are stored thereafter, but since the use start time has not yet been reached, the use state is “waiting”.
In the secondary usage (No. 1), the area is C2 in the reservation from 12:00 to 14:00, but the area is B1 and C1 in the reservation from 14:00 to 16:00. Yes.
This is because the primary usage (No. 1) reserves the area A1 in the same time zone, and the primary usage (No. 3) reserves the area C2, so the secondary usage (No. 1) B1 and C1 are selected and registered based on the information of the reservable free areas A2, B1, B2 and C1 provided from the frequency management device 1 at the time of reservation.
As described above, the area of the base station can be changed at any time as long as it is about the area of the adjacent primary usage system.

[Usage example of license allocation frequency: Fig. 3]
Next, a usage example of the license allocation frequency will be described with reference to FIG. FIG. 3 is a schematic explanatory diagram showing an example of use of a license allocation frequency in a certain area.
The license allocation frequency is a frequency preferentially allocated to the primary usage system.
In the example of FIG. 3, for example, the frequency is initially used by the primary usage system based on the frequency management table, and at the switching time, the next usage reservation is made according to an instruction from the frequency management device 1 2 The use is switched to the next use system.
In the figure, the hatched portion is the interval time required for system switching.

When there is an emergency interrupt from the primary usage system, the frequency management device 1 stops the operation of the secondary usage system in operation and starts the operation of the primary usage system according to the emergency interrupt reservation time.
When the reservation time due to the emergency interrupt ends, the frequency management device 1 again operates the secondary usage system based on the frequency management table.
In this way, the frequency is used in the first system.

[Operation sequence in the first system: FIG. 4]
Next, an operation sequence in the first system will be described with reference to FIG. FIG. 4 is an explanatory diagram showing an operation sequence in the first system, and describes operations related to the primary usage system and secondary usage system that use the same frequency.
As shown in FIG. 4, when the primary usage system (primary user) desires communication at the frequency (license allocation frequency) (100), frequency management is performed from the management terminal unit of the base station via the network. The device 1 is accessed (102), and the usage time and area are reserved in the frequency management table (104). Since the primary usage system can be used preferentially, the frequency management device 1 normally registers it in the frequency management table as requested.

  Then, the frequency management device 1 starts the primary usage system based on the frequency management table reservation, and instructs the frequency management device 1 (network server) to stop the operation when the end time is reached. The frequency release is notified (106).

  On the other hand, when the secondary usage system (secondary user) wishes to communicate in the idle time zone of the primary usage system (200), it accesses the frequency management device 1 via the network (202), and the frequency management table A use time is reserved in the free time zone (204). At this time, the frequency management device 1 does not accept the request from the secondary usage system as it is, but considers the reservation status of the primary usage system and the reservation status of other secondary usage systems, and sets the time zone and area. Allocate and register in the frequency management table, and notify the secondary usage system of the request source.

Then, after the process 106, the frequency management device 1 instructs the secondary usage system to start operation, and the secondary usage system starts communication (206).
Thereafter, when the primary usage system makes a communication request to the frequency management device 1 by an emergency interrupt, the frequency management device 1 writes the emergency interrupt request in the frequency management table (108), and the secondary usage system in operation An operation stop command (communication stop command) is transmitted.

When receiving the operation stop command (208), the secondary usage system stops communication and transmits a frequency release notification to the frequency management device 1 (210).
When receiving the frequency release notification from the secondary usage system, the frequency management device 1 instructs the primary usage system that has issued an emergency interrupt to start operation, and the primary usage system starts communication (110).

  The frequency management device 1 instructs the primary usage system to stop the operation when the reservation time due to the emergency interrupt ends, and the primary usage system notifies the frequency management device 1 of the frequency release when the communication is completed (112). . The primary usage system may spontaneously transmit a frequency release notification to the frequency management device 1 when the communication is terminated earlier than scheduled.

  When receiving the frequency release notification from the primary usage system, the frequency management device 1 refers to the frequency management table, confirms the reservation at that time, instructs the reserved secondary usage system to start operation, The secondary usage system starts communication again (212).

  When the secondary usage system ends communication as reserved and transmits a frequency release notification to the frequency management device 1 (214), the frequency management device 1 refers to the frequency management table and makes the next reservation 1 The next usage system is instructed to start operation, and the primary usage system starts communication from the reserved time (216). In this way, the first system is operated.

[Effect of the first embodiment]
According to the wireless communication system according to the first embodiment of the present invention, a primary usage system that can be preferentially reserved, and a secondary usage system that can make reservations for free time / free area of the primary usage system, A frequency management device 1 that connects to a base station of each system via a network and performs frequency allocation, and the frequency management device 1 includes a frequency management table that stores a reservation content for use for each frequency. Based on the request from the management terminal unit provided in the base station of the usage system and the secondary usage system, the area and time are allocated to the requesting system so that interference does not occur, and the base station ID and usage time are assigned to the frequency management table. Since the reservation contents are registered in association with the area and the frequency is used according to the frequency management table, the secondary usage system The device cost can be reduced by eliminating the need for communication, and interference can be reliably prevented. Further, by reserving the frequency, the secondary usage system can also implement a communication service systematically, improving convenience and frequency utilization efficiency. There is an effect that can be done.

  Further, according to the wireless communication system according to the first embodiment, when an emergency interrupt is requested from the primary usage system, the frequency management is performed when the secondary usage system uses the frequency. Since the device 1 stops the operation of the secondary usage system and permits the operation to the primary usage system that is the interrupt source, the primary usage system is given priority in the event of an emergency even if it is normally reserved. Since the communication service can be realized without delay using the frequency, it is possible to promptly release the frequency positively about the free time, and there is an effect that the frequency use efficiency can be further improved.

[Second Embodiment]
Next, a radio communication system (second system) according to the second embodiment of the present invention will be described.
The second system does not switch between priority / non-priority systems, but switches between microcell operation or macrocell operation in the same area in response to changes in radio wave demand.

  That is, in the second system, when the population and activity level vary greatly depending on the time zone, day of the week, etc., such as in a business district, the radio wave demand (traffic) of a high-speed wireless LAN (Local Area Network) or femtocell is high during the daytime. In addition, frequency is allocated mainly to microcells (femtocells), and operation is performed mainly to macrocells at night when the population is small. Furthermore, such area size switching can be dynamically controlled according to actual fluctuations in radio wave demand.

[Configuration of Second Embodiment: FIG. 5]
The configuration of the radio communication system according to the second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a schematic configuration diagram showing an example of a radio communication system according to the second embodiment of the present invention.
As shown in FIG. 5, the second system has two microcells A1 and A2 and one macrocell that is a combination of A1 and A2, and the base station of the microcell (No. 1) (in the figure, "microcell"). Cell (1) base station ”) 41, a micro cell (No. 2) base station (“ micro cell (2) base station ”in the figure) 42, and a macro cell (No. 1) base station (in the figure“ Macrocell (1) base station ”) 31, frequency management device 1, and network 3.

In the example of FIG. 5, the microcell (1) base station 41 manages wireless communication in the area A1, and performs wireless communication with the terminal station 4 in the area A1.
Similarly, the microcell (2) base station 42 manages wireless communication in the area A2, and performs wireless communication with the terminal station 4 in the area A2.
Further, the macro cell (1) base station 31 manages wireless communication in the areas (A1, A2) and performs wireless communication with the terminal stations 4 in the areas (A1, A2).
In the second system, one of the microcell and the macrocell is not preferred and the other is not preferred, and the priorities are equal. However, here, only a macrocell base station transmits an emergency interrupt described later.

  Each base station 31, 41, 42 includes a management terminal unit having a function as a network client, and registers a reservation in the frequency management device or starts / stops operation according to an instruction from the frequency management device 1. Do.

Furthermore, as a feature of the second system, the macro cell (1) base station 31 has a function of monitoring the traffic volume in the area, and when the traffic volume becomes less than a preset threshold value, A switching reservation requesting switching to the macro cell is transmitted to the frequency management apparatus 1 by an emergency interrupt.
Further, the macro cell (1) base station 31 transmits, to the frequency management apparatus 1, a switching reservation for requesting switching to the micro cell by an emergency interrupt when the traffic amount exceeds a threshold value.

The threshold value when switching from the micro cell to the macro cell and the threshold value when switching from the macro cell to the micro cell may be the same value or different values.
Further, here, the detection of the traffic volume in the macro cell (1) base station 31 is performed based on an instruction input from the outside, but it is detected periodically and transmitted to the frequency management device 1. It may be.

  Similarly to the first system, the frequency management device 1 includes a frequency management table that stores a frequency use schedule, and stores a default operation schedule. As a default schedule, for example, it is conceivable to assign a frequency to a microcell during the day when the population is large, and switch to a macrocell during the night when the population is decreasing.

  The default schedule may be input from the input unit of the frequency management device 1 or, like the first system, accepts a reservation from the management terminal unit of each base station, and the frequency management device 1 causes interference. The time / area may be assigned so that it does not occur and registered in the frequency management table.

  As a feature of the second system, the frequency management device 1 normally operates in a macro cell or a micro cell based on a default schedule, but when a switching reservation is received from a macro cell base station, the switching The frequency management table is updated according to the reservation, and the operating system (micro cell or macro cell) is stopped and the operation is switched to the other system.

  Here, the macro cell (1) base station 31 monitors the traffic volume of the entire area (A1, A2). However, the frequency management device 1 monitors the traffic and the micro cell according to the traffic volume. Alternatively, the operation may be switched to the macro cell. Further, another device that monitors the traffic volume may be provided, and the frequency management device 1 may switch the area size based on information from the device.

[Example of frequency management table of second system: FIG. 6]
Next, an example of a frequency management table in the second system will be described with reference to FIG. FIG. 6 is a schematic explanatory diagram illustrating an example of a frequency management table in the second system.
As shown in FIG. 6, the frequency management table of the second system is stored in the database of the frequency management device 1, and the base station (ID) is used for each frequency (here, the frequency F <b> 1) as in the first system. ), Time, area, and usage state.
In the example of FIG. 6, the “use state” item is included to manage the reservation state and the actual operation state at the same time, but the use state may be managed separately.

  In FIG. 6, in the time zone of 0:00 to 7:00 at night, the macro cell (No. 1) reserves the frequency F1 in the area (A1, A2), and the use is finished. In the time zone of 00, the micro cell (No. 1) reserved the frequency F1 in the area A1 and the micro cell (No. 2) in the area A2, and used it.

Then, a switching reservation is made by an emergency interrupt from the macro cell (No. 1), and the frequency management device 1 registers the interrupt contents in the frequency management table.
The content of the switching reservation is that the macro cell (No. 1) uses the frequency F1 in the area (A1, A2) in the time zone from 10:00:00 to 11:30.
The frequency management device 1 transmits an emergency stop instruction before 10:00 to the microcell (No. 1) and the microcell (No. 2) that are in operation, and causes the emergency stop.

Accordingly, the macro cell (No. 1) can use the frequency F1 in the areas (A1, A2) in the time zone from 10:00 to 11:30. When the reservation time due to interruption ends, the frequency management device 1 operates again based on the reservation in the frequency management table. That is, in the example of FIG. 6, after 11:30, the operation start instruction is output to the micro cell (No. 1) and the micro cell (No. 2), and the operation is performed.
Alternatively, the emergency interrupt may be terminated and switched without waiting until 11:30.

[Example of frequency use: Fig. 7]
Next, an example of frequency use in the second system will be described with reference to FIG. FIG. 7 is a schematic explanatory diagram illustrating an example of using frequencies in a certain area.
As shown in FIG. 7, based on the frequency management table, for example, the frequency is initially used by the macro cell, and when the switching time comes, the frequency is assigned to the micro cell that is reserved for the next use according to an instruction from the frequency management device 1. Usage can be switched.
In the figure, the hatched portion is the interval time required for switching.

When the macro cell base station detects a decrease in radio wave demand and transmits a reservation for switching from the micro cell to the macro cell during operation of the micro cell, the frequency management device 1 operates in accordance with an emergency interrupt of the switching reservation. Stop the microcell and start operating the macrocell.
Thereafter, when the macro cell base station detects an increase in radio wave demand and transmits a reservation for switching from the macro cell to the micro cell, the frequency management apparatus 1 stops the operating macro cell according to the emergency interrupt of the switching reservation. Start operation.
When the reservation time due to the emergency interrupt ends, the frequency management device 1 again operates the macro cell based on the frequency management table.
In this way, the frequency is used in the second system.

[Operation sequence in the second system: FIG. 8]
Next, an operation sequence in the second system will be described with reference to FIG. FIG. 8 is an explanatory diagram showing an operation sequence in the second system, and describes an operation related to a macro cell and an operation related to a micro cell using the same frequency.
As shown in FIG. 8, when the system administrator wishes to reserve a communication operation in the early morning and late night hours when there are few users for the macro cell (302), the management terminal unit of the macro cell base station transmits it via the network. The frequency management device 1 is accessed (304), and the frequency management device 1 reserves the usage time and area in the frequency management table based on the reservation (306).

  Then, the frequency management device 1 causes the macro cell to start operation based on the reservation of the frequency management table, and instructs the operation stop when the end time comes, and the macro cell notifies the frequency management device 1 (network server) of the frequency release. (308).

On the other hand, if the user wishes to reserve communication operation during the daytime and nighttime when there are many users (400), the terminal management unit of the microcell base station accesses the frequency management device 1 via the network (402). The frequency management device 1 reserves the usage time and area in the frequency management table based on the reservation (404).
At this time, the frequency management device 1 makes a reservation by adjusting each usage time so that the operation times of the macro cell and the micro cell do not overlap each other, and in general, no blank time during which neither system performs service. To do.

Then, after the processing 308, the frequency management device 1 instructs the micro cell to start operation, and the micro cell starts communication (406).
After that, it becomes stormy, the macro cell monitors the traffic volume, and if it detects that the traffic volume is smaller than the threshold value and the number of users is low, the switching reservation to switch the operation to the macro cell temporarily is managed by emergency interrupt frequency management It transmits to the apparatus 1 (310).

When receiving the emergency interrupt, the frequency management device 1 writes the content of the switching reservation in the frequency management table, and transmits an operation switching command to the operating microcell.
Upon receiving the operation switching command (408), the micro cell stops communication and transmits a frequency release notification to the frequency management device 1 (410).

When receiving the frequency release notification from the microcell, the frequency management device 1 instructs the macrocell to start operation according to the emergency interrupt, and the macrocell starts communication (312).
Thereafter, when the weather recovers and the macro cell again monitors the traffic volume and detects an increase in traffic, a reservation for switching to the micro cell is transmitted to the frequency management apparatus 1 by an emergency interrupt (314).

Similarly to the process 410, the frequency management device 1 transmits an operation switching command to the operating macro cell, the macro cell stops operating, and starts operating the micro cell when receiving a frequency release notification from the macro cell. (412).
When the reservation time for the micro cell ends, the frequency management device 1 instructs the micro cell to stop the operation, and the micro cell stops the operation and transmits a frequency release notification to the frequency management device 1 (414).
The frequency management device 1 instructs the macro cell for which the next reservation is made based on the frequency management table to start operation, and the macro cell starts operation from the reservation time (316). In this way, the operation of the second system is performed.

[Effect of the second embodiment]
The radio communication system according to the second embodiment of the present invention includes a macro cell communication system and a micro cell communication system having different area sizes, and the frequency management device 1 uses the reservation contents for each frequency. The frequency management table is stored, the micro cell system is reserved during the time when the radio wave demand is high, and the macro cell system is reserved and stored in the frequency management table when the radio wave demand is low. Since the micro cell and the macro cell are switched and operated according to the time according to the table, there is an effect that the efficient system operation can be performed according to the radio wave demand.

  Also, according to the second system, the macro cell base station detects the traffic in the area and monitors the radio wave demand, and the radio wave demand decreases due to a sudden weather change and the traffic falls below the threshold. In this case, an emergency interrupt for switching reservation is transmitted to the frequency management device 1, and if the frequency management device 1 is operating the microcell when receiving the emergency interrupt, the microcell operation is stopped according to the emergency interrupt. When the macro cell base station detects that the demand has increased and the traffic has exceeded the threshold value, it transmits a switching reservation emergency interrupt, and the frequency management device 1 If the macro cell was operated when the emergency interrupt was received, the macro cell was stopped according to the emergency interrupt and Since so as to initiate the use, can be operated dynamically switch between macrocell and the microcell according to the fluctuation of radio demand, there is an effect that it is possible to perform a more efficient system operation.

  Further, the frequency management device 1 monitors the traffic in the area so that the frequency management device 1 operates in the macro cell if the traffic volume is less than the threshold value, and the micro cell if the traffic amount is greater than the threshold value. You may control to operate.

[Features of this embodiment]
A wireless communication system according to an embodiment of the present invention includes a frequency management device that is connected to a plurality of systems that can use a specific frequency via a network and manages the use of the frequency. Has a frequency management table for storing reservation contents for use of the system, and based on reservation requests from a plurality of systems, the frequency management table stores the identification number of the base station of the system in association with the time and area. Then, based on the time and area stored in the frequency management table, each system is operated using the frequency, and an emergency interrupt requesting that the frequency be used for a specific time is received from a specific system. Then, register the contents of the emergency interrupt in the frequency management table and if the contents overlap with the operation of other systems It stops the operation of the other system, to perform the operation on the basis of contents registered in a particular system, when a specific time to end, is characterized in that return to operation based on the table.

  A wireless communication system according to an embodiment of the present invention includes a priority system that can preferentially use a specific frequency and a non-priority system that can use a frequency in a time or area where the priority system does not use the frequency. A wireless communication system, which is connected to a priority system and a non-priority system via a network, includes a frequency management device that manages the use of a frequency, and the frequency management device stores a reservation content for the use of the frequency. Having a management table, when a reservation request for the frequency is received from the priority system, based on the request, the identification number of the base station of the priority system, time and area are stored in association with the frequency management table, and non-priority A reservation request for a frequency that does not overlap the reservation contents of the priority system and at least one of time and area is received from the system. The base station identification number of the non-priority system, the time and the area are stored in association with each other in the frequency management table based on the request, and stored in the table based on the time and area stored in the frequency management table. When an emergency interrupt requesting that the frequency be used for a specific time is received from the priority system, the content of the emergency interrupt is stored in the frequency management table. If it overlaps with the operation of the non-priority system, the operation of the non-priority system is stopped and the priority system is operated based on the registered contents. It is characterized by returning to the operation based on the table.

  A radio communication system according to an embodiment of the present invention includes a frequency management device that manages frequency usage, and a management terminal unit of a base station of a primary usage system accesses the frequency management device to register frequency usage Then, the management terminal unit of the base station of the secondary usage system accesses the frequency management device to make a reservation for the free time / empty area of the primary usage system, and the frequency management device It has a frequency management table that stores the system name (base station ID), usage time zone, and usage area, stores the reserved contents in the frequency management table, and in the management terminal section of each base station according to the reservation contents of the frequency management table Operation start / stop instructions are output, and when there is an emergency interrupt requesting the use of a specific time from the primary usage system, the secondary usage system is operating For example, the operation of the secondary usage system is stopped, the primary usage system of the interrupt source is preferentially operated, and the operation is returned to the operation based on the frequency management table after a specific time due to the emergency interruption. .

  A wireless communication system according to an embodiment of the present invention includes a macro cell system and a micro cell system that provide services in the same area with different area sizes, and usually a macro cell based on reservation contents stored in a frequency management table Alternatively, the microcell base station detects the radio wave demand in the entire area by switching the microcell, and when the radio wave demand is large, the frequency management device 1 switches to the microcell and the reservation emergency is made. When an interrupt is transmitted and the radio wave demand is small, an emergency interrupt for switching reservation is transmitted to the frequency management device 1 so as to switch the operation to the macro cell, and when the frequency management device 1 receives the emergency interrupt, It is characterized by switching between microcell and macrocell based on emergency interrupt. That.

  The present invention is suitable for a radio communication system capable of improving frequency utilization efficiency in a cognitive radio communication system.

  DESCRIPTION OF SYMBOLS 1 ... Frequency management apparatus, 11 ... Primary use (No. 1) base station, 21 ... Secondary use (No. 1) base station, 22 ... Secondary use (No. 2) base station, 3 ... Network, 4 ... Terminal station, 31 ... Macro cell (No. 1) base station, 41 ... Micro cell (No. 1) base station, 42 ... Micro cell (No. 2) base station

Claims (1)

A wireless communication system comprising a plurality of systems that can use a specific frequency,
A frequency management device connected to the plurality of systems via a network and managing use of the frequency;
The frequency management device has a frequency management table for storing reservation contents for use of the frequency,
When receiving the frequency reservation request from the plurality of systems, based on the request, the frequency management table stores the identification number of the base station of the system in association with the time,
Based on the time and area stored in the frequency management table, let the system stored in the table operate using the frequency,
When an emergency interrupt requesting that the frequency be urgently used for a specific time is received from a specific system among the plurality of systems, the contents of the emergency interrupt are registered in the frequency management table, and the plurality of systems If the operation overlaps with the operation of another system, the operation of the other system is stopped, the operation is performed based on the registered contents in the specific system, and the specific time ends. The wireless communication system is returned to the operation based on the table.

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