JP7081636B2 - Base stations, terminal stations, communication systems, and communication methods - Google Patents

Description

The present invention relates to a base station device, a terminal device, a communication system, and a communication method.

In a 5G mobile network, a network slice architecture for allocating resources of a wired network or a wireless network according to a service desired to be enjoyed by a terminal (User Equipment, UE) is being studied. For example, when applying network slices to a radio network, it has been proposed to optimize RAN (Radio Access Network) resources such as frequency spectrum, power, and antennas. Further, since there are a plurality of slices in the network, it is proposed as one of the desirable conditions that traffic and QoS (Quality of Service) control according to each slice can be performed. For example, it is also required that each slice can be monitored by PM (Performance Management) or KPI (Key Performance Indicator). Further, it is preferable that it is possible to control the influence of CM (Configuration Management) and FM (Fault Management) for each slice on the entire network. Further, in order to make up for the resource shortage of one slice, it has been proposed as a desirable property for applying a network slice that the service of another slice is not affected (for example, Non-Patent Document 1). ..

“RAN support for network slicing” 3GPP TSG-RAN WG2 # 93bis Tdoc R2-162758 [online], April 11, 2016, [Search on September 23, 2016], Internet <URL: http: // www .3gpp.org/ftp/TSG_RAN/WG2_RL2/TSGR2_93bis/Docs/>

Even if the network slice is applied to the wireless network, the base station does not recognize the service to be used by the terminal or the communication quality suitable for the service to be used by the terminal. Therefore, in the base station, the connection suitable for the service to be used by the terminal may not be established, and the communication quality may deteriorate.

As one aspect of the present invention, it is an object of the present invention to provide a method for a base station to recognize the quality of communication that a terminal intends to use.

The base station according to one embodiment includes the base station and the base station together with information on the divided resources related to the resources divided in association with the service provided via the core network and information on the connection method corresponding to the divided resources. Information indicating an offset value included in the measured value of the received power from the base station as information regarding the priority of selecting the base station as the connection destination when the terminal station communicating with the divided resource is connected to the divided resource. Is included in the broadcast information and transmitted, and a receiver that receives a connection request from the terminal station that has received the broadcast information using a connection method corresponding to the selected divided resource.

The base station can recognize the quality of communication that the terminal intends to use.

It is a figure explaining the example of the system to which the communication which concerns on embodiment is applied. It is a sequence diagram explaining the example of the communication method which concerns on embodiment. It is a figure explaining the example of the configuration of a base station. It is a figure explaining the example of the configuration of a terminal. It is a figure explaining the example of the hardware configuration of a base station. It is a figure explaining the example of the hardware configuration of a terminal. It is a sequence diagram explaining the example of the notification of information from a base station. It is a sequence diagram explaining an example of the process performed at the time of a connection request. It is a flowchart explaining the example of the processing of a base station. It is a flowchart explaining the example of the change processing of the notification information. It is a flowchart explaining the example of the processing of a terminal. It is a sequence diagram explaining the application example of the communication method which concerns on 1st Embodiment. It is a sequence diagram explaining the application example of the communication method which concerns on 1st Embodiment. It is a figure which shows the comparative example of the communication method which concerns on 1st Embodiment and other communication methods. It is a sequence diagram explaining the communication method which concerns on 2nd Embodiment. It is a flowchart explaining the example of the processing of a terminal. It is a figure explaining the application example of the communication method which concerns on 2nd Embodiment. It is a sequence diagram explaining the communication method which concerns on 3rd Embodiment. It is a figure explaining the example of the information used in 3rd Embodiment. It is a sequence diagram explaining the communication method which concerns on 4th Embodiment.

FIG. 1 is a diagram illustrating an example of a system to which communication according to an embodiment is applied. In the system to which the communication according to the embodiment is applied, the network slice is applied to both the core network and the wireless network. In the example of FIG. 1, both the core network and the wireless network are divided into slices 1 to 4. In the base station 10, the resources used for the connection processing of the base station 10 are divided into slices 1 to 4 according to the network slices set in the core network and the wireless network. Here, the resource divided by the base station 10 may be, for example, a frequency spectrum, power, an antenna, or the like. Since each slice set in the base station 10 is a part obtained by dividing the resource held by the base station 10, it may be described as "divided resource". The slice set in the base station 10 shall provide a connection with a communication quality suitable for communication with the slice assigned the same number among the slices set in the core network. For example, slice 1 of base station 10 provides a suitable connection for services via slice 1 of the core network. In the example of FIG. 1, the terminal 40 connects to the base station 10 by using the resource of the slice 4 of the base station 10 and accesses the slice 4 in the core network.

FIG. 2 is a sequence diagram illustrating an example of a communication method according to an embodiment. In the communication system shown in FIG. 2, the base station 10 previously provides a service provided by a slice on the core network side to which each slice provides a suitable connection, and a connection used to connect each slice to the terminal 40. I remember the method.

In step S1, the base station 10 checks the resources of the base station 10 for each slice to determine whether the connection of the new terminal 40 can be permitted using each slice. In the example of step S1, a new terminal 40 can be connected to slices 1 to 3, but there is no resource left in slice 4 for establishing a new connection. Further, it is assumed that the slice 1 has a communication quality suitable for providing the service α. Similarly, it is assumed that the slice 2 has a communication quality suitable for providing the service β, and the slice 3 has a communication quality suitable for providing the service γ. Further, the base station 10 uses the information stored in advance to specify the connection method to each slice. In the example of FIG. 2, the base station 10 stores the connection method correspondence list 33. In the connection method correspondence list 33, the connection method A is used for the connection to the slice 1, the connection method B is used for the connection to the slice 2, and the connection method C is used for the connection to the slice 3. It is recorded to use. Further, it is recorded that the terminal 40 that does not particularly specify the slice (connects by default) uses the connection method X. Using the result of the resource check, the base station 10 creates notification information including the corresponding service and connection method for each slice to which the new terminal 40 can be connected (step S2). The base station 10 broadcasts the generated broadcast information (step S3). Therefore, the notification information informs the service α and the connection method A in association with the slice 1, and informs the service β and the connection method B in association with the slice 2. Further, the service γ and the connection method C are notified in association with the slice 3, and it is also notified that the terminal (default) that does not specify the slice can use the connection method X. The terminal 40 stores the information notified by the notification information.

The terminal 40 selects the service to be used according to the user's processing, setting conditions, and the like (step S4). In the example of FIG. 2, it is assumed that the terminal 40 selects the service γ. The terminal 40 identifies the slice associated with the selected service by using the broadcast information (step S5). In the example of FIG. 2, the terminal 40 identifies that the service γ is associated with the slice 3. Next, the terminal 40 specifies the connection method associated with the specified slice using the broadcast information (step S6). In the example of FIG. 2, since the terminal 40 is trying to connect to the slice 3, the terminal 40 specifies that the connection method C can be used. The terminal 40 is initially connected to the base station 10 using the connection method C (step S7).

The terminal 40 allocates the resource of the slice associated with the initial connection method to the terminal 40 (step S8). Since the initial connection in step S7 is performed by the connection method C, the base station 10 allocates the resource of the slice 3 to the terminal 40 (step S9). After that, the base station 10 performs a resource check (step S10). In the process of step S10, since the resource usage status is changed by allocating the resource to the terminal 40, the resource usage status is updated.

As described above, in the method according to the embodiment, the base station 10 notifies the terminal 40 of the service and the connection method for each slice by using the broadcast information. Further, since the terminal 40 accesses the base station 10 by using the connection method associated with the slice that provides the service to be used, the base station 10 connects using the slice suitable for the service used by the terminal 40. Processing can be performed. Therefore, the base station 10 can recognize the quality of the communication to be used by the terminal 40 from the communication quality in the slice associated with the connection method. Therefore, the base station 10 can allocate slices according to the communication quality to be used by the terminal 40 to the terminal 40, and can avoid deterioration of the communication quality due to the connection to the slice to which the terminal 40 is not trying to connect.

<Device configuration>
FIG. 3 is a diagram illustrating an example of the configuration of the base station 10. The base station 10 includes a radio wave transmission / reception unit 11, a communication unit 12, a calculation unit 20, and a storage unit 30. The calculation unit 20 includes a resource information acquisition unit 21, a notification unit 22, a connection method determination unit 23, and an allocation processing unit 24. The storage unit 30 stores the resource information 31. The resource information 31 includes the slice resource information 32 and the connection method correspondence list 33.

The radio wave transmission / reception unit 11 has a transmission unit 13 and a reception unit 14. The transmitting unit 13 performs signal transmission processing, and the receiving unit 14 performs signal reception processing. The communication unit 12 performs communication processing with other base stations 10 and communication processing with devices in the core network. The resource information acquisition unit 21 periodically confirms the usage status of the resource held by the base station 10 for each slice, and records the obtained result as the slice resource information 32. The resource usage status may be recorded in the slice resource information 32 as a result of determining whether the connection of the new terminal 40 can be permitted. The notification unit 22 determines whether to change the content of the notification information by using the result acquired by the resource information acquisition unit 21. For example, when resource exhaustion occurs in a certain slice, the notification unit 22 deletes the information of the connection method to the slice and the service associated with the slice from the broadcast information. The notification unit 22 may determine whether the cause of the change in the notification information has occurred by periodically accessing the resource information acquisition unit 21 and the storage unit 30. Further, the resource information acquisition unit 21 may notify the notification unit 22 of the occurrence of the cause of the change in the notification information, and the notification unit 22 may change the notification information when the notification from the resource information acquisition unit 21 is received.

When the connection method determination unit 23 receives the connection request from the terminal 40 via the reception unit 14, the connection method determination unit 23 determines the slice to be connected by the terminal 40 according to the requested connection method. At this time, the connection method determination unit 23 uses the connection method correspondence list 33. An example of the connection method correspondence list 33 is shown in FIG. The connection method determination unit 23 requests the allocation processing unit 24 to allocate resources divided as slices to be connected by the terminal 40. The allocation processing unit 24 performs resource allocation processing and establishes a connection with the terminal 40.

FIG. 4 is a diagram illustrating an example of the configuration of the terminal 40. The terminal 40 includes a radio wave transmission / reception unit 41, a calculation unit 50, and a storage unit 60. The calculation unit 50 includes an available slice determination unit 51, a service request unit 52, and a connection method determination unit 53. The storage unit 60 stores the available slice information 61.

The radio wave transmission / reception unit 41 has a transmission unit 42 and a reception unit 43. The transmitting unit 42 transmits a signal, and the receiving unit 43 receives the signal. When the available slice determination unit 51 acquires the broadcast information via the reception unit 43, the available slice information 61 records the information included in the broadcast information in the available slice information 61 for each slice. The service request unit 52 identifies the service used by the terminal 40 based on the contents of the settings made in advance, the user's operation, and the like, and outputs the service start request to the connection method determination unit 53. The connection method determination unit 53 selects a slice suitable for providing the requested service by referring to the information in the available slice information 61 using the service requested by the service request unit 52 as a key. Further, the connection method determination unit 53 also specifies a connection method for making a connection via the selected slice by using the available slice information 61. When the connection method determination unit 53 generates a connection request using the specified connection method, the connection method determination unit 53 transmits the connection request to the base station 10 via the transmission unit 42.

FIG. 5 is a diagram illustrating an example of a hardware configuration of the base station 10. The base station 10 includes an antenna 101, an RF (Radio Frequency) circuit 102, a baseband processing circuit 103, a processor 104, a memory 105, and a transmission line interface 106. The RF circuit 102 processes a signal including a carrier wave, and transmits / receives a signal to / from the terminal 40 via the antenna 101. The baseband processing circuit 103 processes the baseband signal. The processor 104 is an arbitrary processing circuit, and may be, for example, a CPU (Central Processing Unit). The processor 104 uses the memory 105 as a working memory to execute various processes by executing a program. The memory 105 includes a RAM (Random Access Memory), and further includes a non-volatile memory such as a ROM (Read Only Memory). The memory 105 is used to store data used for processing by the program or the processor 104. The transmission line interface 106 performs communication processing with the devices in the network 120. The device in the network 120 is, for example, a device in the core network or another base station 10.

The antenna 101, the RF circuit 102, and the baseband processing circuit 103 operate as the radio wave transmission / reception unit 11. The processor 104 operates as a calculation unit 20. The memory 105 operates as a storage unit 30. The transmission line interface 106 operates as a communication unit 12.

FIG. 6 is a diagram illustrating an example of the hardware configuration of the terminal 40. The terminal 40 includes an antenna 115, an RF circuit 111, a baseband (BB, baseband) processing circuit 112, a processor 113, and a memory 114. The RF circuit 111 processes a signal including a carrier wave. The baseband processing circuit 112 processes the baseband signal. The processor 113 is an arbitrary processing circuit, and may be, for example, a CPU. The processor 113 uses the memory 114 as a working memory to execute a program to execute various processes. The memory 114 includes a RAM and a ROM.

The antenna 115, the RF circuit 111, and the baseband processing circuit 112 realize the radio wave transmission / reception unit 41. The processor 113 operates as a calculation unit 50. The memory 114 operates as a storage unit 60.

<First Embodiment>
FIG. 7 is a sequence diagram illustrating an example of information notification from the base station 10. Also in the following example, it is assumed that the base station 10 divides resources such as a frequency band that can be used for communication into slices 1 to 4. Here, it is assumed that each slice has a communication quality suitable for the service to which the slice is associated. For example, slice 1 may be suitable for communication in which the amount of data to be transmitted / received is small and the access frequency is low, such as communication in a sensor network by IoT. On the other hand, slice 2 is suitable for communication with a relatively high throughput, while slice 3 is suitable for communication with a medium throughput. As described above, since the communication quality differs depending on the slice, it is desirable that the terminal 40 is connected to the base station 10 using a slice suitable for the nature of the communication generated by the service provided to the terminal 40.

In step S21, the resource information acquisition unit 21 updates the slice resource information 32 for each slice by checking the resources of the base station 10 for each slice. The resource information acquisition unit 21 identifies the availability of resources in each slice and identifies the service associated with the slice to which the new terminal 40 can be connected. In the example of FIG. 7, it is assumed that the slice 4 does not have the resource for establishing a new connection, but the slices 1 to 3 can be connected to the new terminal 40. Further, it is assumed that slice 1 is associated with service α, slice 2 is associated with service β, and slice 3 is associated with service γ. The resource information acquisition unit 21 notifies the notification unit 22 of the obtained information.

The notification unit 22 generates notification information using the information notified from the resource information acquisition unit 21, and transmits the generated notification information via the transmission unit 13 (step S22). In the example of FIG. 7, in the notification unit 22, slice 1 is associated with service α, slice 2 is associated with service β, and slice 3 is associated with service γ. It is notified by the notification information. The broadcast information is not limited to the information of slices to which resources can be allocated, and may include the availability of resources for all slices. When the information of all slices is notified, the following information is notified.
Slice 1: Connection OK, service α
Slice 2: Connection OK, service β
Slice 3: Connection OK, service γ
Slice 4: Connection NG
The terminal 40 receives the broadcast information on the receiving unit 43. The available slice determination unit 51 stores the information notified by the broadcast information as the available slice information 61 for each slice.

In step S23, the resource information acquisition unit 21 identifies the connection method newly associated with each of the slices to which the terminal 40 can be connected by referring to the connection method correspondence list 33. In the example of FIG. 7, the resource information acquisition unit 21 specifies that the slice 1 is associated with the connection method A, the slice 2 is associated with the connection method B, and the slice 3 is associated with the connection method C. The resource information acquisition unit 21 notifies the notification unit 22 of the obtained information.

The notification unit 22 transmits the notification information generated by using the information notified from the resource information acquisition unit 21 via the transmission unit 13 (step S24). In the example of FIG. 7, the terminal 40 connected to the slice 1 uses the connection method A, the terminal 40 connected to the slice 2 uses the connection method B, and the terminal 40 connected to the slice 3 uses the connection method. The use of C is included in the broadcast information. Further, the notification information includes information indicating that the terminal 40 (default) that does not specify the slice uses the connection method X.

When the available slice determination unit 51 of the terminal 40 acquires the broadcast information via the reception unit 43, the information in the broadcast information is added to the available slice information 61 for each slice.

FIG. 8 is a sequence diagram illustrating an example of processing performed at the time of a connection request. The available slice information 61 held by the terminal 40 that has received the broadcast information described with reference to FIG. 7 is as shown in FIG.

It is assumed that the request for the service γ is input from the service request unit 52 to the connection method determination unit 53. Further, it is assumed that the connection method determination unit 53 identifies that the slice 3 is associated with the service γ by referring to the available slice information 61. Then, the connection method determination unit 53 selects the slice 3 associated with the service γ as the connection destination slice (step S31). Further, the connection method determination unit 53 selects the connection method C associated with the slice 3 by referring to the available slice information 61 (step S32). The connection method determination unit 53 requests the base station 10 to perform the connection process in the connection method C via the transmission unit 42 (step S33).

The receiving unit 14 of the base station 10 receives the connection request transmitted from the terminal 40. The connection method determination unit 23 identifies the connection method requested by the terminal 40 using the information included in the connection request, and the allocation processing unit 24 uses the slice associated with the specified connection method. Perform connection processing. In the example of FIG. 8, since the terminal 40 has requested the connection by the connection method C, the allocation processing unit 24 starts allocating the resource of the slice 3 (step S34). After the processing in step S34, the notification information may be changed as appropriate.

FIG. 9 is a flowchart illustrating an example of processing of the base station 10. The receiving unit 14 receives the connection request from the terminal 40 (step S41). The connection method determination unit 23 determines whether or not a connection with a specified slice of the connection destination is requested by using the type of connection method requested in the connection request (step S42). When a connection with a specified slice of the connection destination is requested, the allocation processing unit 24 allocates the resource of the slice to be connected by the terminal 40 (Yes in step S42, step S43). After that, the notification unit 22 appropriately changes the notification information (step S44). On the other hand, when the connection in which the slice of the connection destination is specified is not requested, the allocation processing unit 24 performs the resource allocation processing of the slice with a relatively large margin to the terminal 40 (No in step S42, step S45). ).

FIG. 10 is a flowchart illustrating an example of the notification information change processing. FIG. 10 is a flowchart showing the details of step S44 of FIG. The resource information acquisition unit 21 specifies a state such as a resource usage status for each slice (step S51). The resource information acquisition unit 21 determines whether the information in the broadcast information and the state of the resource are consistent (step S52). When the information in the broadcast information and the state of the resource match, the resource information acquisition unit 21 ends the process (Yes in step S52). On the other hand, when the information in the notification information and the state of the resource do not match, the resource information acquisition unit 21 requests the notification unit 22 to change the notification information (No in step S52). The notification unit 22 updates the content of the notification information in response to a request from the resource information acquisition unit 21 (step S53).

FIG. 11 is a flowchart illustrating an example of processing of the terminal 40. Note that FIG. 11 is an example of processing, and the processing procedure may be changed depending on the implementation. For example, the order of steps S61 and S62 can be changed arbitrarily.

The service request unit 52 determines the type of service requested by the terminal 40 (step S61). The available slice determination unit 51 acquires the broadcast information transmitted from the base station 10 via the radio wave transmission / reception unit 41, and records the obtained information in the available slice information 61 (step S62). The connection method determination unit 53 refers to the available slice information 61 and identifies the slice associated with the service specified by the service request unit 52 as the optimum slice (step S63). When the optimum slice is specified, the connection method determination unit 53 performs an initial connection process for connecting to the specified slice (Yes in step S64, step S65). On the other hand, when the optimum slice is not specified, the connection method determination unit 53 processes the initial connection using the connection method specified for the default initial connection (No in step S64, step S66). In step S66, the default connection method for initial connection is the initial connection method used when performing connection processing without specifying a slice.

FIG. 12 is a sequence diagram illustrating an application example of the communication method according to the first embodiment. FIG. 12 shows an example in which the first embodiment is realized in LTE (Long Term Evolution). Hereinafter, an example will be shown in which the slice to be connected is specified by using the first message (Random Access Preamble, RAPreamble) transmitted from the terminal 40 to the base station 10. In the example of FIG. 12, the base station 10 is realized as an eNB (evolved Node B), and the terminal 40 is realized as a UE (User Equipment).

The notification unit 22 of the base station 10 includes a slice that can be used for the System Information to be notified, and RACH-CONFIG and service identification information corresponding to the slice (step S71). The notification unit 22 notifies the notification information via the transmission unit 13 (step S72).

The receiving unit 43 of the terminal 40 receives the broadcast information. The available slice determination unit 51 records the information included in the broadcast information in the available slice information 61. Therefore, for each slice, the identification information of the service suitable for the use of the slice and the RACH-CONFIG used for the connection to each slice are stored. When the requested service is selected in the service request unit 52, the connection method determination unit 53 selects RACH-CONFIG associated with the slice corresponding to the selected service (step S73). The connection method determination unit 53 transmits a RAP dream using the selected RACH-CONFIG from the transmission unit 42 (step S74).

The connection method determination unit 23 of the base station 10 acquires the RAPreamble via the radio wave transmission / reception unit 11, and determines that the connection to the slice associated with the RACH-CONFIG in the RAPreamble is requested. The connection method determination unit 23 notifies the allocation processing unit 24 of the slice associated with the RACH-CONFIG in the RAPplay. Then, the allocation processing unit 24 allocates the resource of the slice associated with RACH-CONFIG in RAPreamble to the communication with the terminal 40 (step S75).

After that, by sending and receiving messages according to the LTE procedure, a connection using the resources allocated in step S75 is established. That is, RA Response is transmitted from the base station 10 to the terminal 40 (step S76). Upon receiving the RA Response, the terminal 40 transmits an RRC Connection Request to the base station 10 (step S77). The base station 10 transmits the RRCConceptionStep to the terminal 40 in response to the RRCConceptionRequest (step S78). Then, the terminal 40 transmits the RRCConceptionSetupComplete to the base station 10 (step S79).

When the connection process between the terminal 40 and the base station 10 is completed, the resource information acquisition unit 21 in the base station 10 updates the slice resource information 32 according to the resource usage status. When the resource is exhausted in the slice to which the resource is allocated to the terminal 40, the notification unit 22 updates the notification information (step S80).

In this way, the first embodiment can be applied to LTE. The terminal 40 can establish a connection via the slice suitable for the service selected by the terminal 40 by designating the slice using the RAPreamble transmitted and received according to the LTE communication procedure.

FIG. 13 is a sequence diagram illustrating an application example of the communication method according to the first embodiment. Although the case of specifying a slice using RAPreamble has been described with reference to FIG. 12, the message used to specify the slice is not limited to RAPreamble. FIG. 13 shows an example in which the slice to be connected is specified by using the third message (RRCCconnectionRequest) transmitted / received between the terminal 40 and the base station 10. Also in FIG. 13, it is assumed that the base station 10 is realized as an eNB and the terminal 40 is realized as a UE.

The notification unit 22 of the base station 10 includes a slice that can be used for the System Information to be notified, and information of the Information Element (IE) and the service corresponding to the slice (step S91). The notification unit 22 notifies the notification information via the transmission unit 13 (step S92).

The receiving unit 43 of the terminal 40 receives the broadcast information. The available slice determination unit 51 records the information included in the broadcast information in the available slice information 61. Therefore, for each slice, the identification information of the service suitable for the use of the slice and the Information Element used for the connection to each slice are stored.

The connection method determination unit 53 transmits the RAP dream to the base station 10 via the radio wave transmission / reception unit 11 (step S93). The base station 10 transmits a RA Response as a response to the RAP dream (step S94).

When the requested service is selected in the service request unit 52, the connection method determination unit 53 selects the Information Element associated with the slice corresponding to the selected service. Further, the connection method determination unit 53 generates a message (RRCCconnectionRequest) to which the selected Information Element is added (step S95). The connection method determination unit 53 transmits an RRC Connection Request including the selected Information Element via the transmission unit 42 (step S96).

The connection method determination unit 23 of the base station 10 acquires the RRC Connection Request via the reception unit 14. The connection method determination unit 23 determines that the connection to the slice associated with the Information Element in the RRC Connection Request is requested. The connection method determination unit 23 notifies the allocation processing unit 24 of the slice associated with the Information Element notified from the terminal 40. Then, the allocation processing unit 24 allocates the resource of the slice associated with the Information Element notified from the terminal 40 to the communication with the terminal 40 (step S97). After that, by sending and receiving messages according to the LTE procedure, a connection using the resource allocated in step S97 is established. The processing of steps S98 to S100 is the same as the processing of steps S78 to S80 described with reference to FIG.

In this way, the terminal 40 can establish a connection via the slice suitable for the service selected by the terminal 40 by designating the slice using the RRCConnectionRequest sent and received according to the LTE communication procedure.

FIG. 14 is a diagram showing a comparative example of the communication method according to the first embodiment and another communication method. Case C1 of FIG. 14 shows an example of a resource allocation status in the communication method according to the first embodiment. On the other hand, Case C2 shows an example of the resource allocation status by another communication method.

In the communication method shown in Case C2, the type of service that the terminal 5 intends to enjoy is not notified to the base station. Therefore, even if the resource is divided into a plurality of slices, the base station does not recognize which slice the terminal 5 wants to connect to. Therefore, for example, a connection with the terminal 5 is established according to the availability of resources for each slice. In the example of case C2, it is assumed that the service used by the terminal 5 is provided by the slice 2 of the core network, but the base station applies the resource of the slice 3 to the connection with the terminal 5. In this case, since the communication quality is different between the slice 2 and the slice 3, the communication quality at the terminal 5 may deteriorate. For example, if slice 2 gives a high throughput but slice 3 gives only a moderate throughput, the terminal 5 gets only the communication quality of slice 3 used for communication between the terminal 5 and the base station. I can't do it. Therefore, communication suitable for the service is not performed.

In order to unify the quality of the slices set in the base station and the slices in the core network, it is conceivable that the core network side notifies the base station of the slices. In this case, the device in the core network identifies the type of service requested by the terminal, determines the slice, and notifies the base station of the slice to be used. However, even if such processing is performed, the devices in the core network do not know the resource usage status of each base station. Therefore, for example, when the device in the core network decides to use the slice 2 in the core network for communication with the terminal 40, the resource of the slice 2 may be exhausted in the base station. In such a case, since new communication using slice 2 is not performed at the base station, after all, between the slice used for communication between the base station and the terminal and the slice used for communication in the core network. Will cause a discrepancy.

In the method according to the first embodiment, as shown in case C1, the terminal 40 may notify the base station 10 of the slice associated with the service used by the terminal 40 by specifying the connection method. can. Since the terminal 40 specifies the slice by specifying the connection method, according to the first embodiment, the terminal 40 notifies the base station 10 of the quality required for the communication to be established by the terminal 40. You can get the same effect as you do. Therefore, the allocation processing unit 24 in the base station 10 can establish communication between the terminal 40 and the base station 10 with the communication quality desired by the terminal 40 by using the slice notified from the terminal 40. Further, the slice notified from the terminal 40 is a slice whose communication quality is consistent with the slice used for communication on the core network side. In the example of case C1, since the terminal 40 uses the service provided by the slice 3, it is possible to establish a connection using the slice 3 for both the communication with the base station 10 and the communication on the core network. can. Therefore, it is possible to avoid deterioration of communication quality due to a difference in the types of slices used for communication between the terminal 40 and the base station 10 and slices used for communication in the core network.

<Second embodiment>
In the second embodiment, an example will be described in which the base station 10 notifies the communication characteristics and the connection method obtained by the slices that can be connected by the broadcast information.

FIG. 15 is a sequence diagram illustrating a communication method according to the second embodiment. When the notification unit 22 in the base station 10 acquires the information of the connectable slices from the resource information acquisition unit 21, the notification unit 22 includes the characteristics of communication via the slices in the broadcast information for each of the connectable slices (step S111). ). For example, in the example of FIG. 15, slices 1 to 3 can establish a connection with a new terminal 40, but other slices do not have resources for establishing a connection with a new terminal 40. And. Then, the notification unit 22 includes the feature X of the slice 1, the feature Y of the slice 2, and the feature Z of the slice 3 in the notification information in association with each slice. In the example of FIG. 15, the characteristics of each slice include maximum throughput, access frequency, release time, and guaranteed latency. Here, the maximum throughput is the maximum value of the data transfer rate obtained by communication when the slice is used. The access frequency is the expected access frequency from the terminal 40 in the communication via the slice. The release time is the waiting time until the resource allocation for the terminal 40 is deleted when there is no communication of the terminal 40 in the communication via the slice. Guaranteed latency is the maximum delay in data transfer over a network for communication over slices.

In the example of FIG. 15, the maximum communication throughput obtained when slice 1 is used is 100 Mbps, the access frequency is about 10 times per hour, the release time is 1 hour, and the guaranteed latency is 1 second. In the communication obtained when the slice 2 is used, the maximum throughput is 10 Mbps, the access frequency is about once an hour, the release time is 30 seconds, and the guaranteed latency is 10 milliseconds. Further, in the communication obtained when the slice 3 is used, the maximum throughput is 1 Mbps, the access frequency is about 100 times per hour, the release time is 30 minutes, and the guaranteed latency is 100 milliseconds. The notification unit 22 transmits the generated notification information from the transmission unit 13 (step S112). Although not shown in FIG. 15, the broadcast information includes a connection method used for connection to each slice, as in the first embodiment.

For each of the accessible slices, the terminal 40 can identify the nature of the communication obtained when the slices are used. For example, in the case of FIG. 15, when the slice 1 is used, the available slice determination unit 51 and the connection method determination unit 53 in the terminal 40 have a relatively large maximum throughput but a long guaranteed latency, and the access frequency is set to a medium level. You can recognize that it is done. Similarly, information such as that the maximum throughput of slice 2 is medium but the release time is short, and that the maximum throughput of slice 3 is small but the access frequency is set high can also be used by the slice determination unit 51 and the connection. It can be recognized by the method determination unit 53. Further, the connection method used for connecting to each slice is also recorded in the available slice information 61 by the same processing as in the first embodiment.

Therefore, the connection method determination unit 53 can select the slice most suitable for the characteristics of the service notified from the service request unit 52 as the connection destination. Further, even if a slice that best matches the characteristics of the service cannot be found, the connection method determination unit 53 determines the communication characteristics required for the service used by the terminal 40 according to the communication characteristics of each slice. You can select the slice that gives the closest communication as the connection destination. The connection method determination unit 53 performs connection processing via the radio wave transmission / reception unit 41 using the connection method used for connecting to the selected slice. The process after the base station 10 receives the connection request from the terminal 40 is the same as that of the first embodiment.

FIG. 16 is a flowchart illustrating an example of terminal processing. Note that FIG. 16 is an example of processing, and the processing procedure may be changed depending on the implementation. For example, the order of steps S115 and S116 can be changed arbitrarily.

The service request unit 52 determines the type of service requested by the terminal 40 (step S115). The available slice determination unit 51 acquires information indicating communication quality for each connectable slice using the broadcast information transmitted from the base station 10 (step S116). At this time, the available slice determination unit 51 records the obtained information in the available slice information 61. The connection method determination unit 53 refers to the available slice information 61 and selects the slice having the communication quality closest to the communication property used in the service specified by the service request unit 52 as the optimum slice (step). S117). The connection method determination unit 53 performs connection processing to the selected slice (step S118).

FIG. 17 is a diagram illustrating an application example of the communication method according to the second embodiment. For example, as shown in case C11, it is assumed that the core network is divided into slices 1 to 4, and the resources of the base station 10 are also divided into slices 1 to 4. The slice set in the base station 10 provides a connection with a communication quality suitable for communication with the slice assigned the same number among the slices set in the core network. For example, slice 1 of a base station provides communication quality suitable for communication of slice 1 of a core network. In the example of FIG. 17, it is assumed that the resources of the slice 2 of the base station 10 are exhausted, and the resources for connecting the new terminal 40 to the slice 2 do not remain. Then, the base station 10 transmits the notification information including the communication quality obtained when each slice is used for each of the slice 1, the slice 3, and the slice 4, but the communication quality obtained when the slice 2 is used is notified. Not included in the information. Further, the base station 10 also notifies the connection method used for connection to each of the slice 1, the slice 3, and the slice 4 by the broadcast information.

The available slice determination unit 51 that has acquired the broadcast information transmitted in the case C11 records the obtained information as the available slice information 61. Here, it is assumed that a service suitable for slice 2 is selected from the service request unit 52. The connection method determination unit 53 selects as the connection destination the slice that provides the communication closest to the nature of the communication required for the selected service. For example, in case C12, it is assumed that the connection method determination unit 53 selects slice 3 as the connection destination. The connection method determination unit 53 transmits a connection request using the connection method used for connecting the slice 3.

In case C13, the base station 10 uses the slice 3 to perform connection processing with the terminal 40. Further, the slice in the core network used for the communication of the terminal 40 is determined in association with the slice used for the connection at the base station 10. Therefore, as shown in the case C13, since the slice 3 is used in both the core network and the base station 10 for the communication of the terminal 40, the communication quality is the quality provided by the slice 3.

Since the communication quality of the slice used on the RAN side such as the base station 10 and the communication quality obtained by the slice used in the core network are combined to be optimum, the communication of the entire system is streamlined. There is also the effect. For example, when slice 3 is used in the base station 10 and slice 2 is used in the core network, even if the quality of slice 2 is better than that of slice 3, the communication quality that the terminal 40 can enjoy is slice 3. It becomes the quality of. Further, in the description so far, one base station 10 has been focused on for the sake of clarity, but the communication system may include a plurality of base stations 10. Therefore, for example, even if the resource of the slice 2 is exhausted in the base station 10a, the connection to the slice 2 may be possible in another base station 10b. In this case, rather than allocating slice 2 to the communication from the base station 10a via the slice 3, the core network side also to the communication of the other terminal 40 connected from the base station 10b via the slice 2. It is more efficient to allocate slice 2. Therefore, by selecting both the slice set in the base station 10 and the slice in the core network according to the connection method when the terminal 40 connects to the base station 10, resources in the entire communication system are selected. Allocation is streamlined.

<Third embodiment>
In the third embodiment, in a system including a plurality of base stations 10, the base station 10 in which the resources are not exhausted is prioritized as the connection destination over the base stations 10 in which the resources of a certain slice are exhausted. The processing in the case of

FIG. 18 is a sequence diagram illustrating a communication method according to the third embodiment. In the example of FIG. 18, it is assumed that the base station 10a and the base station 10b are included in the system, and the resource of the slice 3 is exhausted in the base station 10a (step S121). The notification unit 22 notified by the resource information acquisition unit 21 that the resources of the slice 3 have been exhausted notifies the information that makes it difficult for the terminal 40 to select the slice 3 as the connection destination to connect to the base station 10a. Include in. In other words, it can be said that the base station 10a transmits information that reduces the priority of the base station 10a as the connection destination of the terminal 40. For example, the notification unit 22 notifies the terminal 40 to which the slice 3 is connected to notify the offset so that the measured value of the received power from the base station 10a is set to a value worse than the measured value by a predetermined value. can do. The notification unit 22 transmits the generated notification information via the radio wave transmission / reception unit 11 (step S122). Since the notification information also includes the information described in the first or second embodiment, the terminal 40 that has received the notification information can select the connection method for each service.

The available slice determination unit 51 of the terminal 40 records the information included in the broadcast information in the available slice information 61. It is assumed that the connection method determination unit 53 decides to use the slice 3 as the connection destination in response to a request from the service request unit 52. Here, it is assumed that the method of determining the slice based on the service is the same as the process described in the first or second embodiment. The connection method determination unit 53 determines a connection destination for making a connection using the slice 3 (step S123). For example, it is assumed that the received power from the base station 10a at the terminal 40 is −20 dBm, and the received power from the base station 10b at the terminal 40 is −30 dBm. Further, it is assumed that -30dbm is specified from the base station 10a and 0dbm is specified from the base station 10b as the offset value when the slice 3 is connected. Then, the connection method determination unit 53 calculates the received power when communicating via the slice 3 from the equation (1) for each base station.

R = Rm + Roff ・ ・ ・ (1)

Here, R is a calculated value of the received power to be used for selecting the connection destination, and Rm is an actually measured value of the received power from each base station. Roff is an offset notified from each base station. Therefore, when making a connection using the slice 3, the terminal 40 calculates the received power from the base station 10a as −20dbm + (-30dbm) = −50dbm. On the other hand, the terminal 40 calculates the received power from the base station 10b as −30dbm + 0dbm = −30dbm. As a result, when the connection is made via the slice 3, the received power from the base station 10a including the offset is weaker than the received power from the base station 10b including the offset. Therefore, the connection method determination unit 53 in the terminal 40 determines the connection destination in the case of making a connection via the slice 3 to the base station 10b.

The connection method determination unit 53 transmits a connection request to the determined connection destination via the transmission unit 42 (step S124). The process after the connection request from the terminal 40 is made is the same as that of the first embodiment. Therefore, instead of the base station 10a in which the resources of the slice 3 are exhausted, the terminal 40 can be connected to the base station 10b in which a new connection using the slice 3 can be established.

In the example of FIG. 18, the case where the resources are depleted has been described as an example, but when the resources of a certain slice are used more than a predetermined ratio, the base station 10 selects the slice as the connection destination. You may send information to make it harder to get rid of.

FIG. 19 is a diagram illustrating an example of information used in the third embodiment. Table T1 is an example of offset notification. In the example of FIG. 18, for the sake of clarity, an example in which the offset for one slice is notified by the broadcast information has been described, but the broadcast information may include the offset for a plurality of slices. For example, in the base station 10a, it is assumed that the resource of the slice 1 is not used and the resource of the slice 2 is used to some extent. Further, it is assumed that the resources of slice 3 are exhausted. In this case, it is assumed that the notification unit 22 in the base station 10a sets the offset of the slice 1 to 0dbm, the offset of the slice 2 to -10dbm, and the offset of the slice 3 to -50dbm, as shown in the table T1. The notification unit 22 of the base station 10a transmits the notification information including the information in the table T1.

In this case, the terminal 40 to be connected to the slice 2 sets the received power of the base station 10a to be 10 dBm lower than the measured value. For example, if the measured value of the received power from the base station 10a at the terminal 40 is −90 dBm, the terminal 40 trying to connect to the slice 2 estimates the received power from the base station 10a to be −100 dbm. Similarly, the terminal 40 to be connected to the slice 3 sets the received power of the base station 10a to be 50 dBm lower than the measured value. For example, if the measured value of the received power from the base station 10a at the terminal 40 is −90 dBm, the terminal 40 trying to connect to the slice 3 estimates the received power from the base station 10a to be −140 dBm. After that, since the terminal 40 uses the received power including the offset when determining the connection destination, the base station 10 having a large surplus resource is preferentially selected as the connection destination.

Although the case where the information according to the resource usage status is transmitted by using the broadcast information is described with reference to FIG. 18, in order to select the base station 10 according to the resource usage status by another control signal. Information may be transmitted. For example, an LTE ReportConfig or the like may notify an event that facilitates base station movement.

Table T2 shows an example of information used when a handover (HO) event is notified. In the example of table T2, the identifier and the event of the adjacent cell are set for each slice. For example, assume that the cell formed by the base station 10a is A, and the adjacent cell of A is B. Further, it is assumed that the cell B is formed by the base station 10b. The notification unit 22 in the base station 10a sets an event in which the ease of handover is changed depending on the resource filling state of each slice. In the example of table T2, the slice 3 whose resources are already depleted has an event that is difficult to hand over, the slice 2 that uses a certain amount of resources has a normal event, and the slice 1 that does not use resources has an event that is easy to hand over. It is set. Here, when the handover is suppressed, the threshold power used in the terminal 40 to determine whether to notify the adjacent cell as a candidate for the handover destination by the Measurement Report or the like is set to a very high value. On the other hand, in the case of promoting handover, the threshold power used by the terminal 40 when determining whether to notify an adjacent cell as a candidate for the handover destination by Measurement Report or the like is set to a very low value. The notification unit 22 notifies the terminal 40 of the set information by using ReportConnect or the like.

The available slice determination unit 51 in the terminal 40 includes the information of the table T2 notified by ReportConfig in the available slice information 61. The connection method determination unit 53 appropriately generates a handover process according to the slice being connected. For example, when the terminal 40 is connected to the base station 10a using the slice 3, the connection method determination unit 53 performs a process for performing a handover with respect to the base station 10b forming the adjacent cell B. .. On the other hand, when the terminal 40 is connected to the base station 10a using the slice 1, the connection method determination unit 53 does not perform the processing for handover.

As described above, in the third embodiment, the terminal 40 can be prompted to connect to another base station 10 according to the resource usage status, so that the resource usage efficiency of the entire system is further improved. ..

<Fourth Embodiment>
In the fourth embodiment, processing when each base station 10 changes the distribution of resources according to the usage status of resources in neighboring base stations 10 will be described.

FIG. 20 is a sequence diagram illustrating a communication method according to the fourth embodiment. Also in FIG. 20, it is assumed that the base station 10a and the base station 10b are included in the system. In the following description, in order to clarify the operating base station 10, the alphabet assigned to the operating base station 10 may be described at the end of the reference numeral. For example, the communication unit 12a is the communication unit 12 in the base station 10a.

It is assumed that the resources of the slice 5 are exhausted in the base station 10a (step S131). Then, the communication unit 12a notifies the base station 10b that the resources of the slice 5 are exhausted in the base station 10a (step S132).

When the communication unit 12b of the base station 10b receives the notification from the base station 10a, the communication unit 12b notifies the allocation processing unit 24b of the obtained information. When the allocation processing unit 24b obtains the resource usage status at the base station 10b with reference to the available slice information 61b, the allocation processing unit 24b determines whether the resources allocated to the slice 5 can be expanded. In the example of FIG. 20, it is assumed that the allocation processing unit 24b determines that the resources allocated to the slice 5 can be expanded. Then, the allocation processing unit 24b expands the resources of the slice 5 by canceling the setting of allocating the unused resource to another slice and allocating the resource for which the setting is canceled to the slice 5 (step). S133). When the allocation process in the allocation processing unit 24b is completed, the communication unit 12b notifies the communication unit 12a in the base station 10a that the resources for the slice 5 have been expanded (step S134).

The communication unit 12a notifies the notification unit 22a that the resources for the slice 5 have been expanded in the base station 10b. Then, the notification unit 22a generates an event that facilitates the handover of the terminal 40 that communicates using the slice 5 to the base station 10b, and notifies the terminal 40 by ReportConfig or the like (steps S135 and S136).

The available slice determination unit 51 in the terminal 40 records the information notified from the base station 10a in the available slice information 61. After that, the connection method determination unit 53 selects the base station 10b as the connection destination when it is determined that there is a high possibility of communication using the slice 5 or when communication is performed using the slice 5 (step). S137). The connection method determination unit 53 performs inter-cell movement from the cell formed by the base station 10a to the cell formed by the base station 10b by performing a handover with respect to the base station 10b (step S138). ..

In the fourth embodiment, the amount of resources included in each slice by another base station can be changed according to the resource usage status of the neighboring base station 10. Further, after the resource allocation amount is changed, the base station 10 whose resources are depleted can prompt the terminal 40 to connect to another base station 10. Therefore, the efficiency of resource usage in the entire system is further improved.

In the example of FIG. 20, the case where the resources are depleted has been described as an example, but when the resources of a certain slice are used in a predetermined ratio or more, the base station 10 is connected to the own device for the slice. You may send information to make it difficult to be selected.

<Others>
The embodiment is not limited to the above, and can be variously modified. Some examples are given below.

For example, the table and the like described in the above description are examples, and the information elements included in the table can be changed according to the implementation.

In the fourth embodiment, since the base station 10 knows the resource usage status of the adjacent cells, the event of each slice may be set and notified to each of the plurality of adjacent cells. For example, it is assumed that the adjacent cell A has sufficient resources for slice 3, but the adjacent cell B is running out of resources for slice 3. In this case, the base station 10 sets an event in which the terminal 40 that communicates using the slice 3 for the adjacent cell A is likely to hand over, but the terminal 40 that communicates using the slice 3 for the adjacent cell B sets the event. Set an event that is difficult to hand over.

Further, the third embodiment and the fourth embodiment may be used in combination.
In any embodiment, the slice set in the base station 10 may be physically identified by frequency, such as F-OFDMA (filtered orthogonal frequency division multiple access). Further, in any of the embodiments, the slice set in the base station 10 may be set logically without any physical restriction due to frequency or the like.

5, 40 Terminal 10 Base station 11, 41 Radio wave transmission / reception unit 12 Communication unit 20, 50 Calculation unit 21 Resource information acquisition unit 22 Notification unit 23 Connection method determination unit 24 Allocation processing unit 30, 60 Storage unit 31 Resource information 32 Slice resource information 33 Connection method correspondence list 51 Available slice judgment unit 52 Service request unit 53 Connection method determination unit 101, 115 Antenna 102, 111 RF circuit 103, 112 Base band processing circuit 104, 113 Processor 105, 114 Memory 106 Transmission line interface

Claims (7)

It ’s a base station,
The terminal station that communicates with the base station is divided along with the information on the divided resources related to the resources divided in association with the service provided via the core network and the information on the connection method corresponding to the divided resources . As information on the priority of selecting the base station as a connection destination when connecting to a resource, information indicating an offset value to be included in the measured value of the received power from the base station is included in the broadcast information and transmitted. Department and
A base station including a receiving unit that receives a connection request from the terminal station that has received the broadcast information by using a connection method corresponding to the selected divided resource. It is characterized by further comprising an allocation processing unit that establishes a connection with the terminal station that is the source of the connection request by allocating the divided resource corresponding to the connection method used in the connection request to the terminal station. The base station according to claim 1. Claim 1 or 2 is characterized in that, as information for specifying a service associated with each of the divided resources, information indicating the quality of communication obtained when the divided resources are connected is included in the broadcast information. The base station described in. It ’s a terminal station,
Broadcast information transmitted by a base station that communicates with the terminal station, information on divided resources related to resources divided in association with services provided via the core network, and connection methods corresponding to the divided resources. As information on the priority of selecting the base station as a connection destination when the terminal station connects to the divided resource, an offset value included in the measured value of the received power from the base station. A receiver that receives the broadcast information, which includes information indicating
The connection method for connecting to the divided resources corresponding to the service to be used is determined , and the base station as the connection destination is the measured value of the received power from each base station and the offset for each base station. A decision unit that determines based on the value and
A terminal station comprising a transmitter that transmits a connection request to a base station determined as the connection destination using a determined connection method. As information for specifying the service associated with each of the divided resources, information indicating the communication quality obtained when the divided resource is connected is notified, and the determination unit determines the communication required for the service to be used. The terminal station according to claim 4, wherein the quality and the communication quality are used to determine the connection method to be used when connecting to the base station. Terminal stations that use the services provided by devices in the core network,
A base station having the resources required for communication with the terminal station is provided.
The base station is
Connection when a terminal station communicating with the base station connects to the divided resource together with information on the divided resource related to the resource divided in association with the service and information on the connection method corresponding to the divided resource. As information regarding the priority of selection of the base station as a destination, information indicating an offset value to be included in the measured value of the received power from the base station is included in the broadcast information and transmitted.
A communication system characterized in that a connection request is received from the terminal station that has received the broadcast information using a connection method corresponding to the selected divided resource. The base station
The terminal station that communicates with the base station is divided along with the information on the divided resources related to the resources divided in association with the service provided via the core network and the information on the connection method corresponding to the divided resources . As information regarding the priority of selecting the base station as a connection destination when connecting to a resource, information indicating an offset value to be included in the measured value of the received power from the base station is included in the broadcast information and transmitted.
A communication method comprising a process of receiving a connection request from the terminal station that has received the broadcast information using a connection method corresponding to the selected divided resource.

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