Management device and communication control method

Abstract

To provide a management device which implements a group talk without a break by appropriately dividing a slot to be used as a channel, and a communication control method.SOLUTION: A management device 12 responds to a case where a new connection request is received by a control slot in a state where all speech slots are used for speeches. The management device comprises: a slot division determination section by which, in a case where there is no free speech slot and in a case where a used terminal using an inquiry target slot in the speech slots being used is capable of changing a bit rate, the inquiry target slot is defined as a dividable slot; and a slot allocation section which allocates the used terminal and a request terminal, which performs a new connection request, to the divided slots. In a case where the inquiry target slot is being used for a group talk, when the number of terminals answering that the bit rate is changeable among the terminals being used fulfills a predetermined condition, the inquiry target slot is defined as the dividable slot.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a management device and a communication control method. [Background technology]

[0002] A trunking wireless communication system including a plurality of wireless terminal devices and a plurality of repeaters For example, Patent Document 1 discloses a wireless terminal device in a trunking system. A technique is disclosed that can shorten the time required for the location registration process. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-2449 A Summary of the Invention [Problem to be solved by the invention]

[0004] In a trunking system, a terminal makes a new connection request, and If there are no available slots, a new connection request from a terminal cannot be established. The system was refusing to connect by sending a busy signal indicating that the slot was busy. If it were possible to generate a new IP address and assign it to a terminal making a new connection request, connection rejections could be reduced. However, to generate a new free slot, you must split an active slot to create a free slot. It generates a new slot and assigns it to a terminal that is using a slot or a terminal that makes a new connection request. A terminal using a slot must be assigned a new slot. If the required bit rate cannot be supported, the call will not be able to continue. In addition, the terminal making the new connection request will be required for communication in the newly assigned slot. If the bit rate cannot be supported, communication is not possible. Confirm that communication is possible, and notify the terminal currently using the slot or the terminal that has requested a new connection. , it is necessary to allocate slots appropriately.

[0005] The present invention relates to a management device and a communication device capable of appropriately allocating slots to terminals. The present invention aims to provide a signal control method. [Means for solving the problem]

[0006] The management device of the present invention has a plurality of slots, and all of the call slots are used for calls. A management device that responds when a new connection request is received in a control slot in the state, a communication unit for communicating with a terminal using a call slot and the control slot; If there is no vacancy and a new connection request is received in the control slot, the slot is used based on the specified conditions. Select the target slot from among the active call slots, and The terminal in use that is using the app will be asked whether the bit rate can be changed, When the terminal in use responds that the bit rate can be changed, A slot division determination unit that determines the target slot as a divisible slot, and a bit A slot division control that performs a rate change command and divides the divisible slot. The divided slots are assigned to the terminal in use and the terminal that has made a new connection request. a slot allocation unit for allocating the slot to a group call When the terminal is in use, the slot division determination unit determines whether the terminal is in use at a bit rate of If the number of terminals in use that have responded that the change is possible satisfies a predetermined condition, The slot to be matched is the divisible slot.

[0007] The communication control method of the present invention has a plurality of slots, and all of the call slots are used for calls. The communication control method corresponds to a case where a new connection request is received in a control slot in a state where the and communicating with a terminal using the call slot and the control slot. If there are no available slots and a new connection request is received in the control slot, Based on the above, a slot to be queried is selected from among the call slots in use, and the selected inquiry Inquiry on whether the bit rate can be changed for the terminal using the target slot If the terminal in use responds that the bit rate can be changed, a step of setting the inquiry target slot as a divisible slot; indicating a rate change and dividing the divisible slot; The currently used terminal and the requesting terminal that has made a new connection request are assigned to the slots thus obtained. and if the queried slot is used in a group call, The number of terminals in use that have responded that the bit rate can be changed is determined as a predetermined number. if the condition is satisfied, the queried slot is set as the divisible slot; , including. Effect of the Invention

[0008] According to the present invention, it is possible to appropriately allocate slots to terminals. [Brief description of the drawings]

[0009] [Figure 1]FIG. 1 is a diagram for explaining a communication system according to the first embodiment. [Diagram 2] FIG. 2 is a diagram illustrating an example of the configuration of the communication system according to the first embodiment. [Diagram 3] FIG. 3 is a block diagram illustrating an example of the configuration of a management device according to the first embodiment. [Figure 4] FIG. 4 is a block diagram illustrating an example of the configuration of a terminal according to the first embodiment. [Diagram 5] FIG. 5 is a flowchart showing the process of the management device according to the first embodiment. [Figure 6] FIG. 6 is a flowchart showing the process of the management device according to the first embodiment. [Figure 7] FIG. 7 is a flowchart showing a flow of the slot division determination process according to the first example of the first embodiment. [Figure 8] FIG. 8 is a flowchart showing a flow of the slot division determination process according to the second example of the first embodiment. [Figure 9] FIG. 9 is a flowchart showing a flow of the slot division determination process according to the third example of the first embodiment. [Figure 10] FIG. 10 is a flowchart showing the flow of the slot division determination process according to the fourth example of the first embodiment. [Figure 11] FIG. 11 is a flowchart showing the flow of the slot division determination process according to the fifth example of the first embodiment. [Figure 12] FIG. 12 is a flowchart showing a flow of the slot division determination process according to the sixth example of the first embodiment. [Figure 13] FIG. 13 is a flowchart showing a flow of the slot division determination process according to the seventh example of the first embodiment. [Figure 14] FIG. 14 is a diagram for explaining a communication system according to the second embodiment. [Figure 15] FIG. 15 is a block diagram illustrating an example of the configuration of a management device according to the second embodiment. [Figure 16]FIG. 16 is a diagram for explaining a method of dividing a slot according to the second embodiment. [Figure 17] FIG. 17 is a flowchart showing a flow of processing by the management device according to the second embodiment. [Figure 18] FIG. 18 is a diagram for explaining a method of returning a divided slot according to the second embodiment to its original state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The present invention is not limited by the embodiment, and in the following embodiments, The same reference numerals are used for the units to avoid redundant explanation.

[0011] [overview] An overview of the communication system according to the first embodiment will be described with reference to FIG. 1. FIG. 1 is a diagram for explaining a communication system according to an embodiment.

[0012] FIG. 1 shows an example of a Land Mobile Radio (LMR) system. The trunking system 1 is, for example, A roller 2, a repeater 3, a repeater 4, a repeater 5, a repeater 6, a terminal 14, Repeater 3 is a repeater for the control channel. Repeater 4 to Repeater 6 is assumed to be a repeater for a communication channel.

[0013] The controller 2 controls the repeaters 3 to 6 and manages the terminals 14. Controller 2 checks the repeater for the communication channel to determine if a new communication is possible. 4 detects the status of each slot in repeater 6.

[0014] Repeater 4 has two communication channels, channel CH1 and channel CH2. Channel CH1 has slot SL1. Channel CH2 has slot S Has L2.

[0015] Repeater 5 has two communication channels, channel CH3 and channel CH4. Channel CH3 has slot SL3. Channel CH4 has slot S Has L4.

[0016] Repeater 6 has two communication channels, channel CH5 and channel CH6. Channel CH5 has slot SL5. Channel CH6 has slot S Has L6.

[0017] The controller 2 detects the terminal 14 that has made a new communication connection request through the repeater 3. Then, the repeater with an empty slot is identified among repeaters 4 to 6. The repeater 2 assigns the terminal 14 that has made a new communication connection request to a repeater that has an empty slot. .

[0018] Repeater 4 manages channels in slots SL1 and SL2. The repeater 4 notifies the controller 2 of the status of the slots SL1 and SL2. Repeater 5 manages channels in slots SL3 and SL4. The repeater 5 notifies the controller 2 of the status of the slots SL3 and SL4. Repeater 6 manages channels in slots SL5 and SL6. The repeater 6 notifies the controller 2 of the status of the slots SL5 and SL6. .

[0019] Repeaters 4 to 6 respond to a request from the controller 2 by providing a repeater number to be used by the terminal 14. The terminal 14 is connected to the network by assigning a slot to the network, and manages the communication of the terminal 14.

[0020] In a typical trunking system, the controller 2 detects the terminal 14 through the repeater 3. If repeater 4 determines that repeater 6 does not have an available slot, it disconnects the terminal 14. In other words, the terminal 14 was receiving an empty slot from the repeater 4 to the repeater 6. If not, communication could not take place.

[0021] The communication system of the present invention uses TDMA (Time Division Multiple Access) depending on the connection status of the terminal. A trunking system that can be used with the IEEE 802.11b Multiple Access (IEEE 802.11b) method Specifically, the communication system of the present invention can achieve the following even when the channel is busy: Even if the The channel in which the signal is being received is divided into active slots and empty slots. The system can increase the number of simultaneous communications by allocating new communications to empty slots. do.

[0022] [First embodiment] (Communications Systems) An example of the configuration of a communication system according to the first embodiment will be described with reference to FIG. 1 is a diagram illustrating an example of the configuration of a communication system according to a first embodiment.

[0023] As shown in FIG. 2, the communication system 10 includes a management device 12 and a plurality of terminals 14 . The management device 12 and a plurality of terminals 14 are communicatively connected via a wireless network N. In the communication system 10, a management device 12 manages group communications among a plurality of terminals 14. It is a communication system that manages

[0024] (Management device) An example of the configuration of a management device according to the first embodiment will be described with reference to FIG. 3. FIG. 2 is a block diagram showing an example of the configuration of a management device according to the embodiment.

[0025] The management device 12 includes a communication unit 20, a storage unit 22, a control unit 24, and a slot management unit 26. The management device 12 is implemented by an information processing device such as a personal computer. It will be revealed.

[0026] The management device 12 realizes the controller 2 and the repeaters 3 to 6 shown in FIG. The control unit 24 realizes the controller 2 and the repeater 3 for the control channel. The slot manager 26 implements repeater 4 to repeater 6 for the communication channels.

[0027] The communication unit 20 is a communication interface that performs communication between the management device 12 and an external device. The communication unit 20 executes communication between the management device 12 and the terminal 14, for example. 20 relays, for example, communication between the terminals 14. The communication of information may be performed using a control channel of the communication unit 20. A control slot is assigned to each of the This control information includes disconnection signals such as busy signals, responses to requests, and CK / NACK signal, a connection request signal from a terminal that is trying to make a new connection request (described later), These are inquiry signals to inquire whether the bit rate can be changed, bit rate change request signals, etc. A call between terminals 14 may be assigned as a communication channel of communication unit 20 for the call. The communication unit 20 may be, for example, a commercial radio, a wireless Wired LAN (Local Area Network), Wi-Fi (registered trademark), etc. This is realized.

[0028] The memory unit 22 stores various information. The memory unit 22 is connected to the control unit 24 and the slot The storage unit 22 stores information such as the calculation contents of the management unit 26 and programs. RAM (Random Access Memory) and ROM (Read Only Main storage devices such as the DDR3 Memory, HDD (Hard Disk Drive), etc. The storage unit 22 includes at least one of an external storage device and a one-to-one individual communication connection. It is preferable to store destination information for group communication and group information for group communication. Since it is used to identify and communicate with the other terminal, This connection destination information and group information are used to identify each terminal that will be the communication partner. This includes information on the frequency and slots that will be assigned to communicate with the terminal. Alternatively, the connection destination information and group information may be stored in association with each other. If each communication terminal is connected via the Internet, communication such as IP address The information for identifying the recipient may be included or may be stored in association with the recipient. The destination information and group information are used to set what other terminals 14 the terminal 14 will connect to. Alternatively, the connection request may be sent to the management device 12. When the terminal 14 that has been communicating with the In this case, the information may be newly stored in the storage unit 22.

[0029] The control unit 24 and the slot management unit 26 control each part of the management device 12. The slot management unit 26 is, for example, a central processing unit (CPU). Information processing such as Micro Processing Unit (MPU) and MPU (Micro Processing Unit) The control unit 24 and the slot management unit The control unit 24 executes a program for controlling the operation of the management device 12 according to the present invention. The slot management unit 26 is implemented, for example, by an ASIC (Application Specific Integrated Circuit). fic Integrated Circuit) and FPGA (Field Progr. The control unit may be realized by an integrated circuit such as a memory-readable gate array. 24 may be implemented as a combination of hardware and software.

[0030] The control unit 24 includes a connection request terminal detection unit 30 .

[0031] The connection request terminal detection unit 30 detects a connection request indicating a connection request from the terminal 14 via the communication unit 20. The connection request terminal detection unit 30 detects a connection based on the received connection request signal. The terminal 14 that made the request is identified.

[0032] The slot management unit 26 manages the slots that the terminal 14 uses for communication. The slots are divided into control slots, which are used as channels for control, and call slots, which are used for calls. Hereinafter, the call slot may be simply called a slot. The slot management unit 26 , it is checked whether there is an empty slot in the call slots under management. The management unit 26 receives a connection request from the terminal 14 and has an empty call slot in the call slot it manages. If there is a slot available, the identified slot is assigned to the terminal that requested the connection. The slot management unit 26 receives a connection request from the terminal 14 and finds an empty slot in the call slots it manages. If there are no slots available, the slots to be split are selected from those currently in use for calls (hereafter, in-use slots). The slot management unit 26 identifies a slot in use (hereinafter, a slot to be divided) that is to be divided. If it is determined that the split target slot can be split, the split process is performed on the split target slot. The free slots after division are allocated to the communication of the terminal 14 that has requested a connection.

[0033] The slot management unit 26 includes an empty slot detection unit 40, a slot division determination unit 42, and a slot The packet division control unit 44 and the slot allocation unit 46.

[0034] The empty slot detection unit 40 detects an empty slot from among a plurality of call slots managed by the slot management unit 26. , and detects whether there is an empty slot.

[0035] The slot division determination unit 42 determines whether an empty slot is included in the call slots managed by the slot management unit 26. If there is no slot, we specify the slot to be queried (hereafter, the queried slot). The terminal 14 using the inquiry target slot is also called the terminal in use. The slot division determination unit 42 assigns a bit to the terminal using the inquiry target slot. The slot division decision unit 42 inquires whether the rate can be changed. Based on the response that the bit rate can be changed, the inquiry response that the terminal in use is using We identify the target slot as a splittable slot. Here, we use the queried slot to If the communication using the in-use slot is a group call, the terminal in use will be the sender. The terminal 14 at the first slot and at least two terminals 14 at the receiving side are the active terminals. If the communication using the above is a normal one-to-one individual call, the sending terminal 14 and the receiving terminal The last 14 devices are in use.

[0036] The slot division determination unit 42 determines whether the bit rate can be changed from the terminal in use among the terminals in use. If the number of terminals that respond that they can divide the queried slot satisfies a certain condition, This predetermined condition may be, for example, a time slot when the bit rate is changed from the terminal in use. Alternatively, the condition may be set to a predetermined number of terminals that have responded that the update is possible. The predetermined condition is, for example, set to change depending on the number of terminals in use. The condition may be the number of terminals that have responded that they can change the bit rate from the For example, a certain percentage may be set, and a certain percentage of the number of terminals in use may be set as the number of terminals in use. The condition may be the number of terminals that have responded that the bit rate can be changed from the intermediate terminal. The slot division determination unit 42 determines whether the inquiry target slot is at least two times longer than the transmission side terminal 14. It is used in a group call consisting of multiple terminals including a receiving terminal 14. When a group call is being made using an in-use slot, the sending terminal 14 and A plurality of terminals 14 including at least two receiving terminals 14 are used as active terminals, and the bit rate is set to The slot division determination unit 42 inquires whether the terminal in use can change the slot. If the sending device and at least two receiving devices respond that the change is possible A slot is a divisible slot. A slot is a divisible slot. It is also called a lot.

[0037] The slot division control unit 44 notifies the communication unit 20 of a user who is using a divisible slot. A bit rate change request signal is sent to the terminal in use to indicate a bit rate change. The bit rate division control unit 44 determines the number of divisible slots while transmitting a bit rate change request signal to the terminal 14. The bits are divided and processed.

[0038] The slot allocation unit 46 allocates the divided slots to terminals currently using the slots and terminals that have made connection requests. The terminal 14 is assigned a divisible slot. This enables communication.

[0039] (Terminal Device) An example of the configuration of a terminal according to the first embodiment will be described with reference to FIG. 4. FIG. 2 is a block diagram showing a configuration example of such a terminal.

[0040] As shown in FIG. 4, the terminal 14 includes an input unit 60, a voice input unit 62, a display unit 64, and an audio The terminal 14 includes a voice output unit 66, a communication unit 68, a storage unit 70, and a control unit 72. For example, commercial wireless communication devices, mobile phones, smartphones, tablet terminals, etc. But not limited to these.

[0041] The input unit 60 accepts various operations for the terminal 14. This can be realized by various input devices such as switches, buttons, and touch panels.

[0042] The voice input unit 62 detects the voice of the user who is using the terminal 14. The audio input unit 62 converts the detected audio into an audio signal. do.

[0043] The display unit 64 displays various information. The display unit 64 is, for example, a liquid crystal display or Displays include organic EL (Electro-Luminescence) displays. This is achieved by spraying.

[0044] The audio output unit 66 is a speaker that outputs various sounds. , and outputs the voice of the communication partner.

[0045] The communication unit 68 is a communication interface that performs communication between the terminal 14 and an external device. The communication unit 68 executes communication between the terminal 14 and the management device 12, for example.

[0046] The storage unit 70 stores various information. The storage unit 70 stores information such as the program and the like. It includes at least one of a main memory device and an external memory device such as a HDD.

[0047] The control unit 72 controls each part of the terminal 14. The control unit 72 includes, for example, a CPU, an MPU, etc. The control unit 72 includes an information processing device such as the one described above and a storage device such as a RAM or a ROM. The control unit 72 executes a program for controlling the operation of the terminal 14 according to the present invention. The control unit 72 may be realized by an integrated circuit such as an IC or an FPGA. It may also be realized in combination with software.

[0048] The control unit 72 includes a communication request unit 80, a bit rate control unit 82, and a slot control unit 84. , is provided.

[0049] When the terminal 14 attempts to communicate, the communication request unit 80 sends a connection request via the communication unit 68. The management device 12 then transmits a connection request signal indicating the request.

[0050] The bit rate control unit 82 changes the bit rate of the communication signal transmitted by the terminal 14 . The bit rate control unit 82 changes the bit rate of the audio signal transmitted by the terminal 14, for example. The bit rate control unit 82 receives a bit rate change request signal from the management device 12. When the bit rate change request signal is received, the bit rate of the audio signal is changed based on the received bit rate change request signal. When the bit rate is changed, the bit rate control unit 82 sends a response indicating the change. A signal is sent to the management device 12.

[0051] The slot control unit 84 connects to a slot assigned by the management device 12. The control unit 84 connects to the slot assigned by the management device 12 and executes communication. .

[0052] (Management device processing) The process of the management device according to the first embodiment will be described with reference to FIG. 4 is a flowchart showing the process of a management device according to one embodiment.

[0053] The connection request terminal detection unit 30 detects a connection request from the terminal 14 (step S10). Specifically, when the connection request terminal detection unit 30 receives a connection request signal from the terminal 14, Then, a connection request from the terminal 14 is detected, and the process proceeds to step S12.

[0054] The empty slot detection unit 40 checks the usage status of the call slots (step S12). Then, the process proceeds to step S14.

[0055] The empty slot detection unit 40 judges whether or not there is an empty slot in the speech slots (step If it is determined that there is an empty slot in the call slot (step S14; Yes If it is not determined that there is an empty slot in the call slot (step S16), Step S14: No), proceed to step S18.

[0056] If the answer to step S14 is Yes, the slot allocation unit 46 issues a connection request. Then, the process of FIG. 5 is completed. do.

[0057] If the answer is No in step S14, the slot management unit 26 divides the slots in use. A slot division determination process is executed to determine whether or not the slot can be divided (step S18 The slot management unit 26 determines that there is no available slot, and that the slot is in use during a call. Then, the slot management unit 26 identifies the slot to be queried from among the identified slots. The slot management unit 26 identifies the terminal 14 that is using the inquiry target slot. In order to identify the terminal 14 using the requested inquiry slot, the slot allocation Alternatively, the terminal 14 may be identified by inquiring to the slot allocation unit 46 about the allocation status of the terminal 14 to the slot. In addition, the storage unit 22 stores connection destination information for one-to-one individual calls assigned to the busy slots. In this case, the slot management unit 26 stores the group information of the group call. When identifying the terminal 14 using the matching target slot, the inquiry target slot is used. The connection destination information and group information of the call being received are read from the storage unit 22 of the management device, and the terminal 14 For example, the slot division determination unit 42 may specify the following for the specified terminal 14: The bit rate is checked and the slot is adjusted based on the response from the terminal 14. The slot division determination process will be described in detail later. Proceed to step S20.

[0058] The slot division determination unit 42 determines whether or not slot division of an in-use slot is possible. If it is determined that the slot division of the in-use slot is possible, (Step S20; Yes), proceed to step S22. If it is not determined that it is possible (step S20; No), the process proceeds to step S28.

[0059] If the result of the determination in step S20 is Yes, the slot division control unit 44 The data set is divided (step S22), and the process proceeds to step S24.

[0060] The slot division control unit 44 sends a bit rate change request signal to the terminal 14 that has made the connection request. Then, the process proceeds to step S26.

[0061] The slot allocation unit 46 sends a slot movement command to the terminal 14 that has made the connection request. and assigns the divided slot to the divided empty slot (step S26). This enables communication with the terminal 14. Then, the process of FIG.

[0062] If the answer is No in step S20, the empty slot detection unit 40 checks other used slots. If it is determined that there is another slot in use, the CPU 11 determines whether there is another slot in use (step S28). If so (step S28; Yes), proceed to step S30. If not (step S28; No), the process proceeds to step S32.

[0063] If the determination in step S28 is Yes, the empty slot detection unit 40 checks other slots in use. The process then proceeds to step S18 to repeat the process.

[0064] If the answer is No in step S28, the control unit 24 In response to this, the management device 12 and the terminal 14 transmit a disconnection signal to the management device 12 (step S32). Then, the communication between the two is disconnected, and the process of FIG. 5 is terminated.

[0065] (Terminal Processing) The processing contents of the terminal according to the first embodiment will be described with reference to FIG. 6. 6 is a flowchart showing the processing contents of the terminal according to the embodiment.

[0066] The communication request unit 80 transmits a connection request signal to the management device 12 (step S40 Then, the process proceeds to step S42.

[0067] The control unit 72 judges whether or not a call slot has been assigned by the management device 12 (slot If it is determined that a call slot has been assigned (step S42; es), proceed to step S54. Step S42: No), proceed to step S44.

[0068] If the result of the determination in step S42 is No, the control unit 72 receives the bit rate from the management device 12. It is determined whether a bit rate change request signal has been received (step S44). If it is determined that a signal has been received (step S44; Yes), the process proceeds to step S48. If it is not determined that a bit rate change request signal has been received (step S44; No), Proceed to step S46.

[0069] If the result of the determination in step S44 is No, the control unit 72 determines whether or not connection is not possible. (Step S46). For example, when the control unit 72 receives a disconnection signal from the management device 12, If a slot is not assigned for a specified period of time after sending a connection request signal, or if the bit rate change request signal cannot be received, it is determined that the connection is not possible. If it is determined that the connection is not possible (step S46; Yes), the process of FIG. 6 is terminated. If it is not judged as acceptable (step S46; No), the process returns to step S44 and the process is repeated. vinegar.

[0070] If the result of the determination in step S44 is Yes, the bit rate control unit 82 transmits the audio signal. The bit rate is changed when transmitting the data (step S48). Then, the process proceeds to step S50. .

[0071] The bit rate control unit 82 transmits a response signal indicating that the bit rate has been changed to the management device 12. (Step S50), and the process proceeds to Step S52.

[0072] The slot control unit 84 receives a slot movement command from the management device 12 (step S52). As a result, a slot is assigned to the terminal 14. Then, in step S54 Proceed to.

[0073] If the determination in step S42 is Yes, or after step S52, the control unit 72 Then, communication is started (step S54), and the process of FIG.

[0074] (Slot division judgment process) Next, the slot division determination process will be described. Query for occupied slots that meet a given condition based on the number of terminals 14 using the slot It is determined to be a target slot and the process is executed. Here, it is determined to be a queried target slot. As a predetermined condition, for example, a slot to be queried is selected from among slots in use. When this happens, lower the priority of the slots in use for group calls to make them the slots to be queried. In other words, the slot division determination unit selects a slot to be queried. When selecting a call slot, the priority of the call slots used for group calls will be lowered. In addition, the slot to be queried should be selected based on the following criteria: As a predetermined condition, for example, when selecting a slot to be queried from among the slots in use, If all the slots in use are group calls, the number of terminals in use that belong to the group call The method may further include selecting the slots to be queried in ascending order of number. As a predetermined condition for determining a slot as a target slot, for example, among the slots in use, When selecting a slot to query, the call frequency or call rate of the occupied slots for a certain period is The method may include selecting the slot to be queried in ascending order of time.

[0075] (First example of slot division determination process) The slot division determination process according to the first example of the first embodiment will be described with reference to FIG. FIG. 7 is a flowchart showing the flow of a slot division determination process according to a first example of the first embodiment. It is.

[0076] The slot division determination unit 42 sets a slot to be queried from among the slots in use ( Step S60), and then the process proceeds to step S62.

[0077] The slot division determination unit 42 determines whether communication using the target slot is being performed between the transmitting terminal 14 and multiple It is determined whether the call is a group call including the receiving terminal 14 (step S62). Here, the slot division determination unit 42 receives, for example, the slot to be queried from the slot allocation unit 46. By acquiring information on the terminal 14 assigned to the same network, the sending terminal 14 and multiple It may be determined whether the call is a group call including the receiving terminal 14. If it is determined that the call is a group call including the sender's terminal 14 and multiple receiver's terminals 14 ( Step S62: Yes), and proceed to step S64. If it is not determined that the call is a group call including the terminal 14 (step S62; No), Proceed to step S72.

[0078] If the determination in step S62 is Yes, the slot division determination unit 42 The terminal 14 using the slot is identified (step S64). The determination unit 42 determines, for example, the number of times a slot is assigned to the inquiry target slot by the slot assignment unit 46. By acquiring information on the terminal 14 that is being used, the terminal 14 on the sending side and the multiple terminals 14 on the receiving side can be connected. In this case, the slot allocation unit 46 determines what kind of The slot division determination unit 42 determines whether a suitable terminal 14 is assigned to the slot. The slot division determination unit 42 notifies the terminal 14 assigned to the slot. When determining whether a call is a group call, the call using the queried slot is The connection destination information and group information of the terminals 14 participating in the call are read from the storage unit 22. It is advisable to specify it, and then the process proceeds to step S66.

[0079] The slot division determination unit 42 transmits a bit rate change request signal to the terminal 14 (step Then, the process proceeds to step S68.

[0080] The slot division determination unit 42 is connected to the transmitting terminal 14 and at least two receiving terminals 14. It is determined whether or not a response indicating that the bit rate can be changed is received from the ) The bit rate can be changed from the sending terminal 14 and at least two receiving terminals 14. If it is determined that the response is positive (step S68; Yes), the process proceeds to step S7. 0. The bit rate is calculated from the transmitting terminal 14 and at least two receiving terminals 14. If it is not determined that the response indicates that the change is possible (step S68; No), Continue to step S72.

[0081] If the result of the determination in step S68 is Yes, the slot division determination unit 42 divides the slots. It is determined that allocation is possible (step S70), and the process in FIG.

[0082] If the determination is No in step S62 or No in step S68, the slot division determination The determination unit 42 determines whether there are other slots in use (step S72). If it is determined that there is a medium slot (step S72; Yes), the process returns to step S60. If it is determined that there is no other slot in use (step S72; N o), proceed to step S74.

[0083] If the result of step S72 is No, the slot division determination unit 42 divides the slot. It is determined that this is not possible (step S74), and the process of FIG.

[0084] (Second example of slot division determination process) The slot division determination process according to the second example of the first embodiment will be described with reference to FIG. FIG. 8 is a flowchart showing the flow of a slot division determination process according to a second example of the first embodiment. It is.

[0085] Processing of steps S80 to S86 and steps S90 to S94 7. Since this is the same as the processing in step S74, the explanation will be omitted.

[0086] After step S86, the slot division determination unit 42 changes the bit rate from the terminal in use. It is judged whether the number of terminals that responded that it is possible satisfies a predetermined condition. As a condition for the determination, a predetermined number of terminals including a transmitting terminal 14 and at least two receiving terminals 14 are required. It is determined whether or not a response has been received from the terminal 14 that the bit rate can be changed (step The predetermined number may be all the people participating in the group call, or any number. A predetermined number including the transmitting terminal 14 and at least two receiving terminals 14 may be used. When it is determined that the terminal 14 has responded that the bit rate can be changed (step If the terminal 14 is a transmitting terminal and at least two receiving terminals, the terminal 14 is a receiving terminal. A response that the bit rate can be changed is received from a predetermined number of terminals 14, including the terminal 14 on the receiving side. If it is not determined that there is one (step S88; No), the process proceeds to step S92.

[0087] (Third example of slot division determination process) The slot division determination process according to the third example of the first embodiment will be described with reference to FIG. FIG. 9 is a flowchart showing the flow of a slot division determination process according to a third example of the first embodiment. It is.

[0088] Steps S100 to S106 and steps S110 to S11 The process of 4 is performed by steps S60 to S66 and step S The process is the same as steps S70 to S74, so the description will be omitted.

[0089] After step S106, the slot division determination unit 42 determines whether the transmitting terminal 1 The bit rate is changed from a predetermined number of terminals 14, including the terminal 14 of the receiving side and at least two terminals of the receiving side. It is determined whether or not there is a response that the update is possible (step S108). For example, the predetermined time is within 1 second, but is not limited to this. For example, the predetermined time is about 1 to 2 seconds. During a given period of time, the transmitting terminal 14 and at least two receiving terminals 14 It is determined that a response that the bit rate can be changed has been received from a predetermined number of terminals 14, including If the determination is affirmative (step S108; Yes), the process proceeds to step S110. A predetermined number of terminals 14, including a terminal 14 at the receiving end and at least two terminals 14 at the receiving end, If it is not determined that the rate can be changed (step S108; No ), proceed to step S112.

[0090] (Fourth example of slot division determination process) The slot division determination process according to the fourth example of the first embodiment will be described with reference to FIG. FIG. 10 is a flow chart showing the flow of a slot division determination process according to a fourth example of the first embodiment. This is a chart.

[0091] Steps S120 to S126 and steps S130 to S13 The process of 4 is performed by steps S60 to S66 and step S The process is the same as steps S70 to S74, so the description will be omitted.

[0092] After step S126, the slot division determination unit 42 receives the packets from the terminal 14 having a priority equal to or higher than a predetermined priority. It is determined whether or not there is a response indicating that the bit rate can be changed (step S128). The priority may be set arbitrarily in advance. For example, For example, the priority of the terminal 14 used by a user with a high position may be set to a high priority. The higher the priority, the higher the bit rate can be set. If it is determined that the response is positive (step S128; Yes), the process proceeds to step S Proceed to 130. A response that the bit rate can be changed from a terminal 14 with a priority level equal to or higher than a predetermined level If it is not determined that there has been a change (step S128; No), the process proceeds to step S132.

[0093] (Fifth example of slot division determination process) The slot division determination process according to the fifth example of the first embodiment will be described with reference to FIG. FIG. 11 is a flow chart showing the flow of a slot division determination process according to a fifth example of the first embodiment. This is a chart.

[0094] The process of step S140 is the same as the process of step S60 shown in FIG. 7, so the description is omitted. The processes in steps S144 and S148 are the same as those shown in FIG. The process is the same as steps S64 and S68, so the description will be omitted. The processes in steps S70 to S74 in FIG. 7 are respectively the same as those in steps S70 to S74 in FIG. Since this is the same as the processing in (1), the explanation will be omitted.

[0095] After step S140, the slot division determination unit 42 determines whether communication using the target slot is It is determined whether the call is between two terminals 14, the calling terminal 14 and the receiving terminal 14. (Step S142). If it is determined that the call is a conversation (step S142; Yes), the process proceeds to step S144. If it is not determined that the call is between the terminal 14 on the sending side and the terminal 14 on the receiving side, If so (step S142; No), the process proceeds to step S152.

[0096] (Sixth example of slot division decision processing) The slot division determination process according to the sixth example of the first embodiment will be described with reference to FIG. FIG. 12 is a flow chart showing the flow of a slot division determination process according to a sixth example of the first embodiment. This is a chart.

[0097] Steps S160 to S166, and steps S170 to S17 The process of step S140 to step S146 and step S147 are shown in FIG. The process is the same as steps S150 to S154, so the explanation will be omitted. The process of step S68 is the same as the process of step S88 shown in FIG. 8, so the explanation will be omitted.

[0098] That is, the sixth example of the slot division process is the same as the second example of the slot division process. This is a combination with the fifth example of division processing.

[0099] (Sixth example of slot division determination process) The slot division determination process according to the sixth example of the first embodiment will be described with reference to FIG. FIG. 12 is a flow chart showing the flow of a slot division determination process according to a sixth example of the first embodiment. This is a chart.

[0100] Steps S160 to S166, and steps S170 to S17 The process of step S140 to step S146 and step S147 are shown in FIG. The process is the same as steps S150 to S154, so the explanation will be omitted. The process of step S68 is the same as the process of step S88 shown in FIG. 8, so the explanation will be omitted.

[0101] That is, the sixth example of the slot division process is the same as the second example of the slot division process. This is a combination with the third example of division processing.

[0102] (Seventh example of slot division determination process) The slot division determination process according to the seventh example of the first embodiment will be described with reference to FIG. FIG. 13 is a flow chart showing the flow of a slot division determination process according to a seventh example of the first embodiment. This is a chart.

[0103] Steps S180 to S186 and steps S190 to S19 The process of step S140 to step S146 and step S147 are shown in FIG. The process is the same as steps S150 to S154, so the explanation will be omitted. The process of step S68 is the same as the process of step S108 shown in FIG. 9, so the description will be omitted.

[0104] That is, the sixth example of the slot division process is the same as the second example of the slot division process. This is a combination with the fifth example of division processing.

[0105] As described above, in the first embodiment, when a slot is being used for group communication, a new When a connection request is received, each terminal is asked whether it is possible to change the bit rate. In the first embodiment, the bit rate can be changed from a specific terminal. When a response is received, the slot is divided and the divided slots are assigned to each terminal. Therefore, the first embodiment appropriately divides slots and realizes uninterrupted group calls. It is possible.

[0106] [Second embodiment] An overview of the communication system according to the second embodiment will be described with reference to FIG. 14. FIG. 1 is a diagram for explaining a communication system according to an embodiment.

[0107] The ton ranking system 1A according to the second embodiment includes, for example, a controller 2 and a repeater. The repeater includes a repeater 3, a repeater 4A, a repeater 5A, a repeater 6A, and a terminal 14.

[0108] Repeater 4A has two communication channels, channel CH1 and channel CH2. The channel CH1 has a slot SL1A and a slot SL1B. Channel CH2 has slot SL2A and slot SL2B.

[0109] Repeater 5A has two communication channels, channel CH3 and channel CH4. The channel CH3 has a slot SL3A and a slot SL3B. Channel CH4 has slot SL4A and slot SL4B.

[0110] Repeater 6A has two communication channels, channel CH5 and channel CH6. The channel CH5 has a slot SL5A and a slot SL5B. Channel CH6 has slot SL6A and slot SL6B.

[0111] That is, in the second embodiment, each communication channel of the repeater 4A to the repeater 6A is as follows: Each communication channel has two slots. Note that the number of slots each communication channel has is limited to two. This communication channel is used for a call, and the slots that the communication channel has are It becomes a story slot.

[0112] In the second embodiment, the status of slots managed by each of the multiple repeaters and the status of the terminal 14 are Based on the response, it is determined whether the number of calls can be expanded.

[0113] (Management device) An example of the configuration of a management device according to the second embodiment will be described with reference to FIG. 15. FIG. 11 is a block diagram showing an example of the configuration of a management device according to a second embodiment.

[0114] As shown in FIG. 15, in the management device 12A, a control unit 24A controls an execution control 3 in that it includes a processing unit 34.

[0115] The extended determination unit 32 determines the status of slots managed by each of the multiple repeaters and the number of repeaters received from the terminal 14. Based on the response, it is determined whether the number of calls can be expanded.

[0116] When the extension determination unit 32 determines that the number of calls should be extended, the execution control unit 34 performs an extension of the number of calls. Execute the process.

[0117] A method of dividing a slot according to the second embodiment will be described with reference to FIG. 6 is a diagram for explaining a method of dividing a slot according to the second embodiment.

[0118] Repeater 4 is conducting the first communication using slot SL1 for channel CH1. Repeater 4 uses slot SL2 for channel CH2 to carry out the second communication. Let's say you are going.

[0119] Repeater 5 is conducting the third communication using slot SL3 for channel CH3. Repeater 5 uses slot SL4 for channel CH4 to carry out the fourth communication. Let's say you are going.

[0120] Repeater 6 is conducting the fifth communication using slot SL5 for channel CH5. Repeater 6 uses slot SL6 for channel CH6 to transmit the sixth communication. Let's say you are going.

[0121] The connection request terminal detection unit 30 detects when all slots of each repeater are in use. In this case, the slot division determination unit 42 detects a seventh communication from the repeater 4. Check whether there is a splittable slot among slots SL1 to SL6 of repeater 6. The slot division control unit 44 determines whether the slot division determination unit 42 repeats the If it is determined that slot SL1 of unit 4 can be divided, slot SL1 is divided into slot SL1A. The slot allocation unit 46 divides the slot division control unit 44 into slots SL1B and SL2B. The seventh communication is assigned to the divided slot SL1B. In this case, the first communication is assigned to slot S In the example shown in FIG. 16, one slot is divided into two. In the present invention, one slot is divided into three slots. The more a slot is divided into, the lower the bit rate becomes. Therefore, in the present invention, the number of slot divisions may be determined within a range in which communication quality is acceptable.

[0122] (Management device processing) The process of the management device according to the second embodiment will be described with reference to FIG. 13 is a flowchart showing a process flow of a management device according to the second embodiment.

[0123] The process of step S200 is the same as the process of step S10 shown in FIG. 5, so the description will be omitted. Omitted.

[0124] The empty slot detection unit 40 checks the usage status of the call slots of each repeater (step S202), and the process proceeds to step S204.

[0125] The empty slot detection unit 40 judges whether or not a repeater has an empty slot in its call slots. (Step S204) If it is determined that there is a repeater with an empty slot in the call slot, If so (step S204; Yes), the process proceeds to step S206. If it is not determined that there is a repeater with the same address (step S204; No), Go to step 8.

[0126] If the result of the determination in step S204 is Yes, the slot management unit 26A manages the call. Then, the repeater that is currently being used is switched to a repeater that has an empty slot (step S206). The processing in FIG. 17 ends.

[0127] If the result of the determination in step S204 is No, the slot management unit 26A determines whether the number of calls needs to be increased. Then, the process proceeds to step S208.

[0128] The slot management unit 26A performs a call number expansion for dividing the slots among the selected repeaters. The command is transmitted (step S210), and the process proceeds to step S212.

[0129] The slot management unit 26A determines whether the repeater that has sent the call number extension request command is using Execute slot division judgment process to judge whether the middle plot can be divided or not ( Step S212). The details of the slot division process are the same as those in the first embodiment, so the explanation is omitted. Omitted.

[0130] The slot division judgment unit 42 divides the slots of the in-use slots to expand the number of calls. If it is determined that the number of calls can be increased, the process determines whether the number of calls can be increased (step S214). If the number of calls can be expanded (step S214; Yes), the process proceeds to step S216. If it is not determined that the saturation is to be increased (step S214; No), the process proceeds to step S224.

[0131] If the result of the determination in step S214 is Yes, the slot management unit 26A extends the number of calls. The terminal that is determined to be available is set as the repeater that manages the terminal 14 that has made a new connection request. (Step S216), and the process proceeds to Step S218.

[0132] The slot division control unit 44 controls the repeater that manages the terminal 14 that has made the connection request to expand the number of calls. Then, the slot is divided by transmitting an extension request execution command (step S218). Proceed to step S220.

[0133] The slot division control unit 44 sends a bit rate change request signal to the terminal 14 that has made the connection request. Then, the process proceeds to step S222.

[0134] The slot allocation unit 46 sends a slot movement command to the terminal 14 that has made the connection request. and assigns it to the divided empty slots (step S222). Then, the process of FIG. 17 ends.

[0135] If the result of the determination in step S214 is No, the empty slot detection unit 40 detects It is determined whether there is another repeater with an empty slot (step S224). If it is determined that there is a peer (step S224; Yes), the process proceeds to step S228. If it is not determined that there is another repeater with an empty slot (step S224; No), Then proceed to step S226.

[0136] If the result of the determination in step S224 is No, the control unit 24A 4 (step S226). The communication with the terminal 14 is then cut off. Then, the process in FIG. 17 ends.

[0137] If the determination in step S224 is Yes, the slot management unit 26A extends the number of calls. The next repeater to which the request is to be made is selected (step S228). Then, the process returns to step S210. move on.

[0138] A method for returning a divided slot to its original state according to the second embodiment will be described with reference to FIG. FIG. 18 is a diagram for explaining a method of returning a divided slot according to the second embodiment to its original state. It is.

[0139] Assume that the seventh communication is being carried out in slot SL1B of repeater 4. When controller 2 detects the seventh communication, it increments the number of slots on channel CH1 by 1 on repeater 4. The call number extension request command is sent to change the number of calls to one.

[0140] The repeater 2 assigns one slot to the terminal 14 that is performing the first communication in the slot SL1A. Send a call number extension request command to change the number of calls to.

[0141] The terminal 14 performing the first communication can change to the original communication method and the original audio bit rate. If so, it sends an ACK to controller 2.

[0142] When the controller 2 receives an ACK from the terminal 14 that is performing the first communication, Send a call number expansion execution command to change the number of slots on channel CH1 of 4 to 1. Believe.

[0143] When the repeater 4 receives the call number extension execution command, the repeater 4 Send a bitrate change request signal to the to change the audio bitrate back to the normal bitrate Repeater 4 combines slots SL1A and SL1B into one slot. Repeater 4 assigns the first communication to slot SL1. Repeater 4 is a slot movement frame for moving to slot SL1 to terminal 14 that is performing the first communication. After that, Repeater 4 changes the control state from the call number expansion mode to the normal mode. Change to.

[0144] When the terminal 14 performing the first communication receives the bit rate change request signal, the terminal The terminal 14 performing the first communication returns the bit rate to the normal bit rate. When it receives the command, it moves to slot SL1 and starts communication.

[0145] As described above, in the second embodiment, when a slot is being used for group communication, a new When a connection request is received, the repeater determines whether there is an empty slot between the repeaters. In the case where there is a repeater with an empty slot, the terminal is connected to the repeater with the empty slot. In the second embodiment, if there is no repeater with an empty slot, the A repeater is selected, and the slot division judgment process is performed on the selected repeater. The second embodiment divides slots appropriately to realize uninterrupted group calls. can.

[0146] [Third embodiment] When a slot is assigned in response to a connection request from a terminal 14 that has made a new connection request, The terminal 14 that is the communication partner of the terminal 14 that has newly issued a connection request (hereinafter also referred to as the partner terminal) ) communicates using a slot assigned to the terminal 14 that has newly made a connection request. The slots allocated to the terminal 14 that has newly made a connection request are divided into In the case of a slot, in order to communicate using a divided slot, the other terminal must also divide It is necessary to be able to handle communication at the later bit rate.

[0147] Then, a new connection request is made from terminal 14, and there are no available slots. In this case, the slot division determination unit 42 selects the connection destination information including the terminal 14 that has newly made a connection request. Alternatively, it is confirmed whether group information is stored in the storage unit 22. The connection destination information or group information including the terminal 14 that has recently made a connection request is stored. In this case, the slot division determination unit 42 uses the stored connection destination information or group information The slot division determination unit 42 determines the destination terminal from the determined destination terminal. This inquires whether it is possible to change the bit rate to be used in the next slot. If there are no free slots and the specified remote terminal is unable to receive data at the specified bit rate, If the number of terminals that have responded that the number of terminals that can change the number of terminals satisfies a predetermined condition, the slot division determination process In other words, as a preprocessing of the slot division judgment process, It is advisable to inquire of the other terminal whether the bit rate can be changed. Here, the predetermined condition is, for example, whether the bit rate can be changed from the specified remote terminal. The condition may be that the number of terminals that have responded to the request is a predetermined number. For example, the number of the identified remote terminals is set to change according to the number of the remote terminals. Alternatively, the condition may be the number of terminals that have responded that the bit rate can be changed. For example, a predetermined ratio is set, and a predetermined ratio of the number of remote terminals is transferred from the remote terminal to the remote terminal. Alternatively, the condition may be the number of terminals that respond that the bit rate can be changed.

[0148] If you want to add the third embodiment to the processing of the first embodiment, please do the following: For example, in the process of the first embodiment shown in FIG. 5, As a preprocessing of the slot division judgment process, the bit rate is set to the specified remote terminal. If you want to check whether the object can be changed, you need to add the following process: Specifically, when it is determined that there is no free slot in FIG. 4 No), before proceeding to step S18, the slot division determination unit 42 first The connection destination information or group information including the terminal 14 that has made the connection request is stored in the storage unit 22. The connection destination information including the terminal 14 that has newly made a connection request is stored in the storage unit 22. If the information or group information is stored, the slot division determination unit 42 The remote terminal is identified from the destination information or group information stored in the slot. The division determination unit 42 determines which slots are to be used for the identified terminal. Inquire whether the bit rate can be changed. The number of terminals that responded that the bit rate can be changed from the other terminals meets the specified conditions. If so, the process proceeds to the next slot division determination process (step S18). Among the terminals that were identified, a terminal that responded that it was possible to change the bit rate If the number of terminals does not meet the specified conditions, the allocation of divided slots will not be sufficient. Since the terminal 14 is unable to communicate with the other terminal, it sends a disconnection signal to the terminal 14 that has newly requested a connection (step Then, the process proceeds to step S32) and ends.

[0149] If you want to add the third embodiment to the second embodiment, do the following: For example, in the process of the second embodiment shown in FIG. 17, As a preprocessing of the slot division judgment process such as the state of the When processing to inquire whether a port can be changed, the following processing is added: Specifically, in FIG. 17, if it is determined that there is no vacant slot for the revitas, If the answer is No in step S204, before proceeding to step S208, the slot division determination unit 42 is first connected to the terminal 14 that has made a new connection request, or group information. A check is made to see if a new connection request has been sent to the storage unit 22. When the connection destination information or group information including the terminal 14 is stored, The division determination unit 42 identifies the other terminal from the stored connection destination information or group information. After that, the slot division determination unit 42 determines the divided slots for the identified remote terminal. The bit rate that will be used in the specified Among the terminals, the terminals that responded that they could change the bit rate from the specified terminal If the number of machines satisfies the predetermined condition, a revita having an empty slot is selected (step S208 ), transmits a call number extension request command (step S210), and starts the next slot division judgment process. It is advisable to proceed to the process (step S18). The number of terminals that responded that the bit rate can be changed from the other terminal meets the specified condition. If there is no such slot, communication with the other terminal will not be possible even if a divided slot is assigned. A disconnection signal is sent to the terminal 14 that has newly requested the connection (step S226), and the process is terminated. Complete.

[0150] [Modification of the third embodiment] In the third embodiment, the slot division determination unit 42 determines whether the newly connected Identifying the other terminal from the connection destination information or group information including the terminal 14 that has made the connection request, For the specified remote terminal, change the bit rate to the one to be used in the divided slots. In the past, the system would ask whether the remote terminal could be updated. The information indicating whether the profile can be changed is stored in the storage unit 22, and the profile is sent to the other terminal. Instead of inquiring whether the bit rate can be changed, the slot division decision unit 42 The bit rate for each identified remote terminal stored in the storage unit 22 can be changed. The information indicating whether the bit rate can be changed is referred to. If the number of vehicles is specified and a predetermined condition is satisfied, the process may proceed to slot division determination processing. .

[0151] As described above, in the third embodiment and its modified example, When a new connection request is received from a terminal and there are no available slots, Identify the other terminal from the connection destination information or group information, and , inquire whether it is possible to change the bit rate to be used in the divided slots. If there are no free slots and the bit rate is low, If the number of terminals that respond that they can change the bit rate meets a certain condition, the bit rate is changed. If the number of the terminals that can be changed is specified and a predetermined condition is satisfied, a slot division determination process is performed. This allows a new connection request to be made even if a split slot is assigned. After confirming in advance that the terminal 14 can communicate with the other terminal, the slot is By splitting appropriately, it is possible to realize uninterrupted group calls.

[0152] The components of each device shown in the figures are conceptual and functional, and are not necessarily physically depicted as shown in the figures. In other words, the specific form of distribution and integration of each device does not need to be as shown in the figure. Not limited to the above, all or part of it may be expressed in any unit depending on various loads and usage conditions. It can be configured by distributing and integrating functionally or physically. The configuration may be done dynamically.

[0153] Although the embodiments of the present invention have been described above, the present invention is not limited to the contents of these embodiments. In addition, the above-mentioned components are not those that a person skilled in the art can easily imagine, and are not substantially different from the above-mentioned components. In addition, the above-mentioned components are appropriately Furthermore, the above-described embodiments may be combined without departing from the spirit of the present invention. Various omissions, substitutions or modifications of components may be made. [Explanation of symbols]

[0154] 1 Trunking System 2. Controller 3,4,5,6 Repeater 10. Communication Systems 12,12A management device 14 Terminals 20,68 Communications Department 22,70 Storage part 24, 24A, 72 Control section 26,26A Slot management section 30 Connection request terminal detection unit 32 Extended Judgment Section 34 Execution Control Unit 40 Empty slot detector 42 Slot division judgement unit 44 Slot division control unit 46 Slot allocation section 60 Input section 62 Audio input section 64 Display section 66 Audio output section 80 Communication request section 82 Bit rate control section 84 Slot control section

Claims

1. It has multiple slots, and when all the call slots are in use, a new connection request is made. a management device that responds when the request is received in a control slot, a communication unit that communicates with a terminal using the call slot and the control slot; When there are no free call slots and a new connection request is received in a control slot, Select a slot to be queried from among the available call slots based on the conditions, and Whether the bit rate can be changed for the terminal using the queried slot If the terminal in use responds that the bit rate can be changed, a slot division determination unit that determines the queried slot as a divisible slot when the queried slot is a divisible slot; Instruct the terminal in use to change the bit rate and the divisible slot a slot division control unit for dividing the slots; The divided slots are assigned to the terminal in use and the terminal that has made a new connection request. a slot allocation unit for allocating a slot to a Equipped with If the queried slot is used in a group call, The slot division determination unit The number of terminals that responded that the bit rate can be changed among the terminals that are in use If the slot satisfies a predetermined condition, the queried slot is set as the divisible slot. Management device.

2. The slot division determination unit determines whether or not a call slot is used based on the number of terminals currently using the call slot. and selecting the interrogated slot by The management device according to claim 1 .

3. The slot division determination unit, when selecting the inquiry target slot, Lower the priority of selecting a call slot that is in use, The management device according to claim 2 .

4. The slot division determination unit determines whether the bit rate of a terminal in use that has responded that the bit rate can be changed. If the number of the queried slots satisfies a predetermined condition within a predetermined time, the queried slot is divided into the divisible slots. Slots, The management device according to claim 1 .

5. A storage unit for storing destination information or group information used to identify a terminal to be a communication partner. Further comprising: The slot division determination unit determines whether there is a free call slot and whether a new connection request is to be assigned to a control slot. When the information is received by the host computer, the connection destination information or group information stored in the storage unit is It is possible to change the bit rate by identifying the terminal that has made a new connection request and the other terminal that is communicating with it. The other terminal responds that the bit rate can be changed. If there is, the slot to be queried is selected from among the active call slots based on the specified conditions. Select to change the bit rate to the terminal using the selected queried slot. The terminal in use inquires whether the bit rate can be changed and whether the bit rate can be changed from the terminal in use. If there is a response that there is a divisible slot, the queried slot is determined to be a divisible slot. The management device according to claim 1 .

6. It has multiple slots, and when all the call slots are in use, a new connection request is made. A communication control method for responding to a request received in a control slot, comprising: communicating with a terminal using said speech slot and said control slot; When there are no free call slots and a new connection request is received in a control slot, Select a slot to be queried from among the available call slots based on the conditions, and Whether the bit rate can be changed for the terminal using the queried slot If the terminal in use responds that the bit rate can be changed, if so, determining that the queried slot is a divisible slot; Instruct the terminal in use to change the bit rate and the divisible slot A dividing step; The divided slots are assigned to the terminal in use and the terminal that has made a new connection request. and If the queried slot is used in a group call, The number of terminals that responded that the bit rate can be changed among the terminals that are in use If the slot satisfies a predetermined condition, the slot to be queried is selected as the divisible slot. Tep and A communication control method comprising:

Images