JP2012034388A - Radio base station, and method of reception at radio base station - Google Patents

Abstract

Provided are a radio base station and a receiving method that do not require carrier sense for each call request when it is expected that call requests will increase in advance.
A radio base station having at least two radio units and operating a diversity function to receive an information signal from one mobile station by the two radio units increases the number of call requests from the mobile station. Storing in advance a time zone to be performed, and releasing the diversity function in the time zone.
[Selection] Figure 4

Description

  The present invention relates to a radio base station that communicates with a mobile station using a time division multiple access method and a reception method in the radio base station.

  In recent years, with an increase in mobile terminals (for example, PHS: Personal Handyphone System terminals), social demands for effective use of radio frequency resources are increasing.

  When a radio base station and a mobile station communicate using a time division multiple access / time division duplex (TDMA / TDD) method, the radio base station activates the diversity function. Thus, stable communication can be maintained. The diversity function is a function of allocating two time slots at the same timing to one mobile station and receiving an information signal transmitted from the one mobile station via two radio units.

  Here, in Patent Document 1, when a radio base station and a mobile station communicate with each other by the TDMA / TDD method, the radio base station receives a reception level of an information signal transmitted from a mobile station in communication, or a new Based on the reception level of the call request transmitted from each mobile station, it is determined for which mobile station the diversity function is to be activated, and by appropriately releasing the diversity function, It has been proposed to make effective use.

JP 2005-150969 A

  However, in Patent Document 1, the type of a new call request from a mobile station, that is, a call request to an emergency number (Police (110), Fire (119), Coast Guard (118), etc.) It is not considered whether or not. Therefore, when communication is started without activating the diversity function in response to a call request to an emergency number, the reception state may be deteriorated due to movement of the mobile station or the like.

  Also, in Patent Document 1, on which mobile station the diversity function is activated based on the reception level of the information signal transmitted from the mobile station in communication and the reception level of the call request from the mobile station Judging. Accordingly, it is necessary to perform carrier sense after a call request from a mobile station until time slot allocation. In particular, it is necessary to perform carrier sense for each call request even when it is expected that the call request will increase in advance, such as in a predetermined time zone when communication congestion occurs or after a disaster occurs. There is.

  Thus, depending on the diversity function that operates in the conventional radio base station, it may be difficult to maintain communication in a stable reception state for a mobile station that has requested a call to an emergency number. In addition, even when it is expected that the number of call requests increases in advance, there is a problem that carrier sense must be performed for each call request.

  Therefore, the present invention has been made in view of the above problems, and maintains a stable reception state communication for a mobile station that has made a call request to an emergency number, and a call request is made in advance. When it is expected to increase, it is an object to provide a radio base station that does not need to perform carrier sense for each call request and a reception method in the radio base station.

  A radio base station according to the first feature of the present invention is a radio base station that includes at least two radio units and communicates with a mobile station using a time division multiple access scheme, and is repeated periodically at the same timing. A diversity function for allocating a time slot of 1 to a mobile station and receiving an information signal transmitted from the mobile station 1 via a radio unit 2 is provided to the first mobile station and the second mobile station. The diversity function that is activated for each of the first mobile station and the second mobile station in response to a call request to the emergency number received from the third mobile station, respectively. A canceling unit for canceling, a first allocation unit for allocating the time slot allocated to the first mobile station, which has been canceled by the cancellation unit, to the second mobile station, and after the allocation by the first allocation unit Oite, and summarized in that and a second assignment unit for assigning said second time slot that has been allocated to the second mobile station before release by the release portion to said third mobile station.

  A second feature of the present invention relates to the first feature, wherein the second time slot is associated with a frequency at which the mobile station transmits an information signal, and after being assigned by the first assigning unit. The frequency selection unit that selects a frequency at which interference power received in the second time slot allocated to the second mobile station before cancellation by the cancellation unit is equal to or lower than a predetermined threshold; and the frequency selection unit And a second allocation unit that allocates the frequency selected by the second mobile station to the third mobile station.

  A radio base station according to a third feature of the present invention relates to the first or second feature, wherein the diversity function is applied to a plurality of mobile stations including the first mobile station and the second mobile station. In the case where each of the release units is operated, the release unit determines whether the first mobile station and the second mobile station are based on at least one of a communication start time or a communication speed with the plurality of mobile stations. The gist is to cancel the diversity function being operated.

  A radio base station according to a fourth feature of the present invention is a radio base station that includes at least two radio units and communicates with a mobile station by a time division multiple access method, and has two time slots at the same timing. When the diversity function for receiving the information signal transmitted from the first mobile station via the second radio unit is operating, the call request from the mobile station increases. The gist of the present invention is to provide a release unit that releases the diversity function based on congestion time information indicating a band.

  A radio base station according to the fifth aspect of the present invention is a radio base station that includes at least two radio units and communicates with a mobile station by a time division multiple access method, and has two time slots at the same timing. Based on disaster occurrence information indicating that a disaster has occurred in a case where a diversity function is activated in which an information signal transmitted from the first mobile station is received via the second radio unit. The gist of the invention is that a release unit for releasing the diversity function is provided.

  A reception method according to a sixth aspect of the present invention is a reception method in a radio communication apparatus that includes at least two radio units and communicates with a mobile station using a time division multiple access method, and is periodically repeated at the same timing. Diversity function for receiving the information signal transmitted from the first mobile station via the radio unit 2 is assigned to the first mobile station and the second mobile station. The divers being activated respectively for the first mobile station and the second mobile station in response to a call request to the emergency number received from the third mobile station Releasing the city function, assigning to the second mobile station the time slot assigned to the first mobile station released in the releasing step; In after the step of assigning a second mobile station, and summarized in that comprises the step of assigning the second time slot that has been allocated to the second mobile station before said step of releasing said third mobile station.

  A reception method according to a seventh aspect of the present invention is a reception method in a radio communication apparatus that includes at least two radio units and communicates with a mobile station by a time division multiple access method, and is periodically repeated at the same timing. When the diversity function for receiving the information signal transmitted from the one mobile station via the two radio units is operating, the time slot from the mobile station is activated. The gist is to provide a step of canceling the diversity function based on congestion time information indicating a time zone in which the call request increases.

  A reception method according to an eighth aspect of the present invention is a reception method in a radio communication apparatus that includes at least two radio units and communicates with a mobile station by a time division multiple access method, and is periodically repeated at the same timing. A disaster occurred when the diversity function of allocating 2 time slots to 1 mobile station and receiving the information signal transmitted from the 1 mobile station via the 2 radio unit is operating And a step of canceling the diversity function based on the disaster occurrence information.

  According to the present invention, for a mobile station that has made a call request to an emergency number, while maintaining communication in a stable reception state, and when the call request is expected to increase in advance, It is possible to provide a radio base station and a reception method in the radio base station that do not require carrier sense for each call request.

It is a block block diagram of the wireless base station 100 which concerns on 1st Embodiment. It is a schematic diagram which shows a mode that the radio base station 100 which concerns on 1st Embodiment allocates a time slot and a frequency with respect to a mobile station. FIG. 6 is an operation flowchart of the radio base station 100 according to the first embodiment. It is a block block diagram of the wireless base station 100 which concerns on 2nd Embodiment. It is an operation | movement flowchart of the radio base station 100 which concerns on 2nd Embodiment. It is a block block diagram of the radio base station 100 which concerns on 3rd Embodiment. It is an operation | movement flowchart of the radio base station 100 which concerns on 3rd Embodiment.

[First embodiment]
Next, a first embodiment of the present invention will be described. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones.

  Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

<< Block Configuration of Radio Base Station 100 >>
The radio base station 100 according to the present invention communicates with a mobile station using the TDMA / TDD scheme. The radio base station 100 according to the present embodiment communicates with the mobile station 10a, the mobile station 10b, the mobile station 10x, and the mobile station 10y (not shown) by operating the diversity function.

  Here, the diversity function means that two time slots that are periodically repeated at the same timing are allocated to one mobile station, and an information signal transmitted from the one mobile station is transmitted via the radio unit 102a and the radio unit 102b. It is a function to receive.

  The time slot is associated with the frequency at which the mobile station transmits the information signal, and the mobile station can communicate with the radio base station 100 by assigning the time slot and frequency to the mobile station. . In particular, when the diversity function is activated, two time slots that are periodically repeated at the same timing are assigned to one mobile station, and the same frequency is assigned to these two time slots. That is, the same frequency is assigned to the same mobile station.

  FIG. 1 shows a block configuration of a radio base station 100 according to the present embodiment. The radio base station 100 according to this embodiment includes a radio unit 102a, a radio unit 102b, a release unit 104, a communication state management unit 106, a first allocation unit 108a, a second allocation unit 108b, and a frequency selection unit 110. . In addition, since the following is an outline of main parts related to the present invention, the radio base station 100 is connected to an essential block (for example, the radio unit 102a and the radio unit 102b that are not illustrated or omitted in the description). Note that the baseband portion may be provided.

  The radio unit 102a includes an antenna composed of four antenna elements, a receiving unit connected to the antenna, and a transmitting unit connected to the antenna. The radio unit 102a can communicate with four mobile stations by forming a TDMA / TDD frame from four reception time slots and four transmission time slots. Since the present invention relates to a reception time slot, “time slot” in this specification indicates a reception time slot.

  The radio unit 102b is configured in the same manner as the radio unit 102a, and can communicate with four mobile stations.

In response to the call request to the emergency number received from the mobile station 10c, the canceling unit 104 selects one of the mobile stations 10a to 10y based on the communication start time and the communication speed managed by the communication state management unit 106. The mobile station 2 is selected and the diversity function is canceled. In addition, when canceling the diversity function, the canceling unit 104 measures the error rate and electric field strength of the information signal received in each time slot to which the two mobile stations that cancel the diversity function are allocated. Select the time slot that should be maintained. In the present embodiment, it is assumed that the time slots allocated to the mobile station 10a and the mobile station 10b among the reception time slots in the radio unit 102b are released.

  The communication state management unit 106 manages the time at which communication with a mobile station performing communication by operating the diversity function and the speed of communication are managed for each mobile station and each time slot.

  The frequency selection unit 110 periodically performs carrier sense for time slots that can be allocated to mobile stations. That is, for a time slot that is not assigned to any mobile station, among frequencies that can be used by the radio base station 100, a frequency at which interference power received from communication in another adjacent radio base station is equal to or less than a predetermined threshold Select. In particular, when the frequency selection unit 110 activates the diversity function for the mobile station, the frequency selection unit 110 selects a frequency at which the interference power received in two time slots periodically repeated at the same timing is equal to or less than a predetermined threshold. select.

  The first assigning unit 108a assigns the time slot assigned to the mobile station 10b, for which the diversity function has been released, to the mobile station 10a. In this case, the first assigning unit 108a obtains a frequency whose interference power is equal to or less than the threshold in the time slot newly assigned to the mobile station 10a from the frequency selecting unit 110, and assigns the frequency to the mobile station 10a.

  The second allocation unit 108b allocates the two time slots allocated to the second mobile station to the mobile station 10c after the allocation by the first allocation unit and before the cancellation by the cancellation unit 104. In this case, the second assignment unit 108b acquires from the frequency selection unit 110 a frequency at which the interference power in the two time slots newly assigned to the mobile station 10c is equal to or less than the threshold, and assigns the frequency to the mobile station 10c.

<< Operation of Radio Base Station 100 >>
Next, the operation of the radio base station 100 according to the present embodiment will be described in detail using FIG. 2 and FIG. FIGS. 2A to 2C show how time slots and frequencies are assigned to mobile stations. FIG. 3 shows an operation flow of the radio base station 100.

  As shown in FIG. 2A, the radio base station 100 communicates with the mobile station 10a, the mobile station 10b, the mobile station 10x, and the mobile station 10y by operating the diversity function. The radio base station 100 uses the frequency f1 for communication with the mobile station 10a and the frequency f2 for communication with the mobile station 10b.

  In step S101, the radio base station 100 receives a call request to the emergency number from the mobile station 10c.

  In step S102, the cancellation unit 104 refers to the communication start time and the communication speed with the mobile stations 10a to 10y managed by the communication state management unit 106, and determines two mobile stations that should cancel the diversity function preferentially. select. The mobile station with the earlier communication start time is more likely to end the communication sooner, and the mobile station with the faster communication speed cancels the diversity function. This is because the standard communication speed can be maintained. In the present embodiment, description will be made assuming that the mobile station 10a and the mobile station 10b are selected.

  In step S103, the cancellation unit 104 measures the error rate and the electric field strength of the information signal transmitted from the mobile station 10a and the mobile station 10b received via the radio unit 102a and the radio unit 102b for each time slot. .

  In step S104, the canceling unit 104 cancels the diversity function operated for the mobile station 10a and the mobile station 10b based on the measured error rate and electric field strength. FIG. 2B shows a state in which reception of the mobile station 10a and the mobile station 10b in the time slot of the radio unit 102b is stopped.

  In step S105, the first assigning unit 108a assigns to the mobile station 10a the time slot assigned to the mobile station 10b whose diversity function has been released. That is, the time slot to which the mobile station 10a is assigned is changed so that the information signal transmitted from the mobile station 10a or the mobile station 10b is received at the same timing via the radio unit 102a and the radio unit 102b, respectively. The arrows in FIG. 2 (b) indicate how time slots at the same timing as the time slots allocated to the mobile station 10b are allocated to the mobile station 10a.

  In step S106, the first assigning unit 108a acquires, from the frequency selecting unit 110, a frequency whose interference power is equal to or less than a threshold in the time slot of the radio unit 102b newly assigned to the mobile station 10a, and sends the frequency to the mobile station 10a. Assign. As shown in FIG. 2 (c), in this embodiment, f3 is selected as an appropriate frequency in the two time slots assigned to the mobile station 10a.

  In step S107, the frequency selection unit 110 selects a frequency at which the interference power in two time slots at the same timing newly assigned to the mobile station 10c is equal to or less than a threshold value. As shown in FIG. 2 (c), in this embodiment, f4 is selected as an appropriate frequency in the two time slots assigned to the mobile station 10c.

  In step S108, the second assigning unit 108b assigns the two time slots assigned to the mobile station 10a before the release of the diversity function by the releasing unit 104 to the mobile station 10c. FIG. 2 (c) shows how the two time slots originally assigned to the mobile station 10a are assigned to the mobile station 10c. Accordingly, the information signal transmitted from the mobile station 10c is received in two time slots that are periodically repeated at the same timing via the radio unit 102a and the radio unit 102b.

  As described above, the radio base station 100 can operate the diversity function with respect to the mobile station 10c that has made a call request to the emergency number.

《Action ・ Effect》
According to the digital broadcast receiver according to the present embodiment, since the diversity function is activated and communication can be performed with respect to the mobile station 10c that has made a call request to the emergency number, the mobile station 10c moves. However, communication in a stable reception state can be maintained.

  Further, since the frequency f4 assigned to the mobile station 10c is selected after the assignment by the first assigning unit 108a, a more appropriate frequency can be selected.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In the following, portions different from the radio base station 100 according to the first embodiment of the present invention described above will be mainly described, and description of similar portions will be omitted.

<< Block Configuration of Radio Base Station 100 >>
FIG. 4 shows a block configuration of the radio base station 100 according to the present embodiment. The radio base station 100 according to the present embodiment includes a radio unit 102a, a radio unit 102b, a release unit 104, and a storage unit 112.

  In this embodiment, since the radio | wireless part 102a and the radio | wireless part 102b have the same function as each block in 1st Embodiment, description is abbreviate | omitted.

  The radio base station 100 according to the present embodiment communicates with the mobile station 10a, the mobile station 10b, and the mobile station 10c by operating the diversity function. In addition, since the diversity function of the radio base station 100 is operating, if there is a call request from another mobile station, two time slots that are periodically repeated at the same timing are allocated to one mobile station. The information signal transmitted from the mobile station is received via the wireless unit 102a and the wireless unit 102b.

  The canceling unit 104 uniformly cancels the diversity function based on the congestion time information indicating the time zone in which the call request from the mobile station increases.

  The storage unit 112 stores the time zone in which the call request from the mobile station increases as a time table. The time zone in which the call request from the mobile station increases is, for example, evening. The storage unit 112 periodically monitors the time using a radio wave IC or the like, and notifies the cancellation unit 104 that the diversity function should be canceled when the time of congestion is reached. In addition, the storage unit 112 notifies the release unit 104 that the diversity function should be activated when a predetermined time period elapses.

<< Operation of Radio Base Station 100 >>
Next, the operation of the radio base station 100 according to this embodiment will be described. FIG. 5 shows an operation flow of the radio base station 100.

  As shown in FIG. 5, in step S <b> 201, the storage unit 112 detects that the call request is in an increasing time zone and notifies the cancellation unit 104 to that effect.

  In step S202, the canceling unit 104 that has received the notification cancels the diversity function operated for the mobile stations 10a to 10c. In this case, the cancellation unit 104 measures the error rate and electric field strength of the information signal received in each time slot, and selects which time slot of the radio unit 102a or the radio unit 102b should be maintained for each mobile station. To do.

  In step S203, the canceling unit 104 stops the diversity function itself so as not to activate the diversity function even when there is a new call request from another mobile station.

《Action ・ Effect》
According to the radio base station 100 according to the present embodiment, the diversity function is uniformly canceled based on the congestion time information indicating the time zone in which the call request from the mobile station increases. When a new call request is made from a mobile station, that is, when there is a new call request from a mobile station, carrier sense can be performed in advance. Accordingly, it is not necessary to perform carrier sense upon each call request from the mobile station, and it is possible to quickly assign time slots to the mobile station in a congested time zone.

[Third embodiment]
Next, a third embodiment of the present invention will be described. In the following, portions different from the radio base station 100 according to the first embodiment of the present invention described above will be mainly described, and description of similar portions will be omitted.

<< Block Configuration of Radio Base Station 100 >>
FIG. 6 shows a block configuration of the radio base station 100 according to the present embodiment. The radio base station 100 according to the present embodiment includes a radio unit 102a, a radio unit 102b, a release unit 104, and a disaster notification management unit 114.

  In this embodiment, since the radio | wireless part 102a and the radio | wireless part 102b have the same function as each block in 1st Embodiment, description is abbreviate | omitted.

  The radio base station 100 according to the present embodiment communicates with the mobile station 10a, the mobile station 10b, and the mobile station 10c by operating the diversity function. In addition, since the diversity function of the radio base station 100 is operating, if there is a call request from another mobile station, two time slots that are periodically repeated at the same timing are allocated to one mobile station. The information signal transmitted from the mobile station is received via the wireless unit 102a and the wireless unit 102b.

  The canceling unit 104 uniformly cancels the diversity function based on the disaster occurrence information indicating that a disaster has occurred.

  The disaster notification management unit 114 acquires disaster occurrence information from the disaster information notification host 200 that is an external device. When a disaster (earthquake, fire, flood, lightning strike, etc.) occurs in the vicinity of the coverage area of the radio base station 100, the disaster information notification host 200 notifies the disaster notification management unit 114 to that effect. When the disaster notification management unit 114 acquires the disaster occurrence information from the disaster information notification host 200, the disaster notification management unit 114 notifies the cancellation unit 104 that the diversity function is canceled.

<< Operation of Radio Base Station 100 >>
Next, the operation of the radio base station 100 according to this embodiment will be described. FIG. 7 shows an operation flow of the radio base station 100.

  As shown in FIG. 7, in step S301, the disaster notification management unit 114 acquires disaster occurrence information and notifies the cancellation unit 104 to that effect.

  In step S302, the canceling unit 104 that has received the notification cancels the diversity function operated for the mobile stations 10a to 10c. In this case, the cancellation unit 104 measures the error rate and electric field strength of the information signal received in each time slot, and selects which time slot of the radio unit 102a or the radio unit 102b should be maintained for each mobile station. To do.

  In step S303, the canceling unit 104 stops the diversity function itself so as not to activate the diversity function even when a call request is newly issued from another mobile station.

《Action ・ Effect》
According to the radio base station 100 according to the present embodiment, since the diversity function is uniformly canceled based on the disaster occurrence information, a time slot that is not allocated to the mobile station, that is, a new call from the mobile station When there is a request, carrier sense can be performed in advance for a time slot to be assigned to the mobile station. Accordingly, it is not necessary to perform carrier sense upon each call request from the mobile station, and it is possible to quickly assign a time slot to the mobile station when a disaster occurs.

[Other Embodiments]
Although the present invention has been described according to the above embodiments, it should not be understood that the description and the drawings, which form a part of this disclosure, limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, in the above embodiment, the radio base station 100 includes the two radio units 102a and 102b, but may include one or more other radio units. Even in this case, the specific two radio units can be used as the radio units 102a and 102b.

  In the first embodiment, the first assigning unit 108a and the second assigning unit 108b are separated from each other. However, these can be configured as one assigning unit.

  In the first embodiment, the first assigning unit 108a assigns one time slot at the same timing as one time slot assigned to the mobile station 10b to the mobile station 10a. One time slot at the same timing as one time slot allocated to 10a may be allocated to the mobile station 10b. The first assigning unit 108a assigns the frequencies in which the interference power that can be assigned to each time slot is equal to or lower than a predetermined threshold in the detected order.

  In the first embodiment, the cancellation unit 104 refers to the communication state management unit 106 and selects two mobile stations that cancel the diversity function. However, the cancellation unit 104 activates the diversity function to perform communication. If there are two or less mobile stations, it is not necessary to refer to the communication state management unit 106.

  In the first embodiment, the communication state management unit 106 manages the communication start time and the communication speed between the mobile station in which the diversity function is operated and the radio base station 100. Only either time or communication speed may be managed. In this case, the cancellation unit 104 selects a mobile station that cancels the diversity function based only on either the communication start time or the communication speed.

  In the third embodiment, the disaster notification management unit 114 acquires the disaster occurrence information from the disaster information notification host 200 that is an external device. However, the disaster occurrence information may be manually input by an administrator or the like. Good.

  DESCRIPTION OF SYMBOLS 10a ... Mobile station, 10b ... Mobile station, 10c ... Mobile station, 100 ... Radio base station, 102a ... Radio | wireless part, 102b ... Radio | wireless part, 104 ... Release | release part, 106 ... Communication state management part, 108a ... 1st allocation part, 108b ... second allocation unit 110 ... frequency selection unit 112 ... storage unit 114 ... disaster notification management unit 200 ... disaster information notification host

Claims (4)

A radio base station that includes at least two radio units, operates a diversity function, and can receive an information signal from one mobile station by the two radio units,
A radio base station that stores in advance a time zone in which call requests from mobile stations increase and cancels the diversity function during the time zone. A radio base station that includes at least two radio units, operates a diversity function, and can receive an information signal from one mobile station by the two radio units,
When the disaster occurrence information indicating that a disaster has occurred is acquired, the diversity function is canceled. A reception method in a radio base station comprising at least two radio units, operating a diversity function and receiving an information signal from one mobile station by the two radio units,
Storing in advance a time period during which call requests from mobile stations increase;
Releasing the diversity function during the time period. A reception method in a radio base station that includes at least two radio units, operates a diversity function, and can receive an information signal from one mobile station by the two radio units,
And receiving the disaster occurrence information indicating that a disaster has occurred, and releasing the diversity function.

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