JP2018191091A - Radio base station apparatus, radio communication system, and radio communication control method - Google Patents

Abstract

A radio base station apparatus, a radio communication system, and a radio communication control method for improving service quality are provided. An APP (Application) -driven HO (Hand Over) execution unit 134 acquires communication performance required for communication processing executed by a wireless terminal device, and provides a plurality of communication environments provided based on the communication performance. A specific cell type is selected from the cell types. The RRC function unit 11 causes the wireless terminal device to switch the connection to the cell having the specific cell type selected by the APP-driven HO execution unit 134. [Selection] Figure 2

Description

  The present invention relates to a radio base station apparatus, a radio communication system, and a radio communication control method.

  In recent years, a fifth-generation mobile communication system (hereinafter referred to as “5G (5 Generation)”) is being studied as a next-generation mobile communication system. As one of the 5G network requirements, there is an ultra-high speed communication (EMBB: Enhanced Mobile Broad Band) in which the transmission rate of LTE (Long Term Evolution) is further improved. In EMBB, the maximum transmission speed is set to 10 Gbps, which is 100 times that of LTE. By achieving the transmission speed of EMBB, high-definition video such as 4K / 8K can be transmitted at a very high speed.

  Furthermore, in 5G, it is also a requirement to have a new network requirement that becomes a basic technology of IoT (Internet of Things) service. IoT services include, for example, services such as Ultra-Reliable and Low Latency Communications (URLLC) and Massive Machine-Type Communications (mMTC).

  URLLC is a network requirement for services that use real-time operations such as automated driving and remote robots. In order to satisfy the requirements of URLLC, it is important to reduce the end-to-end delay time. The requirement for the delay time of the LTE radio section is 10 ms, but 5G aims to reduce this to 1 ms or less. In 3GPP (3rd Generation Partnership Project), which implements standardization work, reduction of the TTI (Transmission Time Interval) length, which is the minimum unit of scheduling, is being studied as a specific measure for reducing the delay time. By shortening the TTI length, the waiting time for data processing in the radio base station apparatus and the communication terminal is shortened, and as a result, the delay time of the radio section is shortened.

The mMTC is a network requirement for services in which small packets such as data management by a smart meter are transmitted in large quantities. In order to satisfy the requirements of mMTC, it is important to design a control channel that does not require control information in order to improve the number of simultaneously connected terminals, in addition to expanding coverage. As a technique for designing a control channel that does not require control information, for example, there is a channel access technique called Grant Free Access that does not require prior permission for data transmission. In 5G, the number of simultaneously connected terminals is 1,000,000 / km ² which is 1000 times that of LTE.

  Furthermore, regarding the cell arrangement for communication services using 5G, at the beginning of service introduction, existing LTE cells covering areas nationwide are overlaid as macro cells, and cells for 5G services arranged in spots are overlaid as small cells. A plan to develop this is under consideration.

  In addition, handover in the wireless communication system is performed in the order of handover setting, measurement report transmission, handover necessity determination, and handover execution.

  The handover setting is executed by the following procedure. The radio base station apparatus performs a measurement report trigger setting for a connection target UE based on context information acquired when establishing a connection with a subordinate UE (User Equipment). The trigger setting is set using an event type and a process corresponding to the event.

  The Measurement Report transmission is executed in the following procedure. When the trigger condition set in the handover setting is satisfied, the UE transmits a Measurement Report to the radio base station apparatus.

  The handover necessity determination is executed in the following procedure. The radio base station apparatus determines whether or not to perform handover from the received report value of Measurement Report.

  The handover is executed according to the following procedure. When it is determined that handover is to be performed in the handover necessity determination, the radio base station apparatus transmits a handover request to the handover target UE. Thereafter, the UE switches the connection destination to another radio base station apparatus.

  Further, QoS (Quality of Service) control in the conventional LTE is performed by a P-GW (Packet data network Gateway) that is a component of the core network. The P-GW performs QoS control using a parameter called QCI (QoS Class Identifier) that can be set in nine steps according to the presence / absence of bandwidth control, allowable delay time, packet error loss rate, and the like. The QCI is notified in an ACTIVATED DERAULT EPS (Evolved Packet System) BEARER CONTEXT REQUEST message transmitted from the MME (Mobility Management Entry) to the UE.

  As a technique related to handover, there is a conventional technique in which cell quality is measured at the time of cell reselection, and cell reselection is performed in consideration of a load state together with a quality parameter including received field strength. As a radio resource management method, there is a conventional technique in which packet traffic is analyzed for each TCP port number using a statistical model and radio resources are allocated.

JP 2013-518493 A JP 2005-512431 A

  However, in the conventional handover process, the handover necessity determination is performed by the radio base station apparatus based on the Measurement Report notified when the trigger condition set in the UE is satisfied. Therefore, when there is no change in the radio conditions around the UE, for example, the UE is stationary, the measurement report transmission trigger condition is not satisfied, and the handover process does not occur. Therefore, in the environment of cell arrangement corresponding to 5G, it may be difficult to maintain appropriate quality in the service provided to the UE as shown below.

  Here, an example when it becomes difficult to maintain appropriately the quality of the service provided to UE is demonstrated. Here, it is assumed that the wireless communication network is in the following environment. A specific communication terminal is placed in an environment in which three cells that satisfy the condition of the radio wave intensity at which communication can be performed are overlaid. Each of the three cells is an existing LTE cell, a 5G cell capable of EMBB service (hereinafter referred to as “EMBB cell”), and a 5G cell capable of URLLC service (hereinafter referred to as “URLLC cell”). Moreover, the specific communication terminal is used in a stationary state, and the surrounding wireless quality is stable.

  In this environment, when a specific communication terminal is turned on, a cell is selected based on the cell selection logic defined in the prior art. Here, a case where a specific communication terminal is accommodated in an existing LTE cell is considered. When a specific communication terminal uses a service such as mail transmission / reception or browsing using low-rate data communication such as 10 Mbps, the throughput performance of the existing LTE cell satisfies the service conditions in use, so that appropriate service quality is achieved. Is maintained. Next, a specific terminal device switches to an application that performs large-capacity data communication such as 5 Gbps. Large-capacity data communication includes 4K video appreciation. In this case, the specific terminal device does not perform the measurement report transmission because the radio quality is stable. That is, the handover to the EMBB cell does not occur, and the specific terminal device remains accommodated in the existing LTE cell even though the service using the large-capacity data communication is used. As a result, the throughput performance of the cell in which the specific terminal apparatus is accommodated is lower than the recommended throughput performance of the service, and it is difficult for the radio base station apparatus to maintain appropriate service quality for the specific terminal apparatus.

  In addition, even when using the conventional technology that performs cell reselection in consideration of the load condition together with the quality parameter, the radio quality does not change in the above-described situation, so handover does not occur, and the appropriate quality of service for the terminal device does not occur. Maintenance becomes difficult. In addition, even in the conventional technology that analyzes traffic for each TCP port number and allocates radio resources, the radio quality does not change in the situation described above, so handover does not occur. It is difficult to maintain an appropriate quality of service for the device.

  The disclosed technology has been made in view of the above, and an object thereof is to provide a radio base station apparatus, a radio communication system, and a radio communication control method that improve service quality.

  One aspect of the wireless base station device, the wireless communication system, and the wireless communication control method disclosed in the present application includes the following units. The selection unit acquires the communication performance required in the communication processing executed by the wireless terminal device, and selects a specific cell type from a plurality of cell types provided with different communication environments based on the communication performance. The connection switching unit causes the wireless terminal device to switch the connection to the cell having the specific cell type selected by the selection unit.

  In one aspect, the present invention can improve service quality.

FIG. 1 is a system configuration diagram of a wireless communication system. FIG. 2 is a block diagram of the eNB according to the embodiment. FIG. 3 is a diagram illustrating a cell environment around a UE located in a cell having a plurality of different communication performances. FIG. 4 is a diagram showing the format of the NAS message. FIG. 5 is a diagram illustrating an example of a message type of the NAS message. FIG. 6 is a diagram illustrating an example of a protocol recommended throughput correspondence table. FIG. 7 is a diagram illustrating an example of the recommended cell type table. FIG. 8 is a diagram illustrating a QCI list. FIG. 9 is a diagram for explaining the change of the accommodation cell of the UE by the application initiated handover. FIG. 10 is a sequence diagram of application-driven handover processing by the wireless communication system according to the embodiment. FIG. 11 is a flowchart of application-driven handover processing by the eNB according to the embodiment. FIG. 12 is a hardware configuration diagram of the eNB.

  Embodiments of a radio base station apparatus, a radio communication system, and a radio communication control method disclosed in the present application will be described below in detail with reference to the drawings. The radio base station apparatus, the radio communication system, and the radio communication control method disclosed in the present application are not limited by the following embodiments.

  FIG. 1 is a system configuration diagram of a wireless communication system. As shown in FIG. 1, the radio communication system 10 includes eNBs (evolved Node B) 1 and 2, UE 3, MME 4, S-GW (Serving Gateway) 5, P-GW 6, and PDN (Packet Data Network) 7.

  The PDN 7 is a packet network outside the core network that transmits and receives data. The P-GW 6 is a gateway device serving as a connection point with the PDN 7 of the core network. The P-GW 6 performs IP (Internet Protocol) address assignment and the like. The P-GW 6 performs packet transmission quality control and the like. Furthermore, the P-GW 6 performs QoS control using QCI that can be set in nine steps according to the presence / absence of bandwidth control, the allowable delay time, the packet error loss rate, and the like.

  The S-GW 5 is a packet gateway that transmits user data, and transmits and receives user data to and from the eNBs 1 and 2. In addition, the S-GW 5 sets and releases a communication path in units of PDN 7 to be connected in the sections of the S-GW 5 and the P-GW 6. The S-GW 5 performs packet transmission quality control and the like.

  The MME 4 performs UE 3 mobility management in wireless communication, authentication processing including security control, user data transfer path setting processing between the S-GW 5 and the eNBs 1 and 2, and transmission / reception of control signals. Further, the MME 4 manages which cell of which radio base station apparatus including the eNB 1 and the UE 3 is accommodated. Further, the MME 4 performs policy management for performing QoS control. For example, the MME 4 notifies the QCI applied to each UE 3 to the eNB 1 or 2 that accommodates each UE 3. The MME 4 is an example of a “communication control device”.

  eNB1 and 2 are radio base station apparatuses. In FIG. 1, eNB1 has the cell 100 which is a communication area. The eNB 1 can communicate with the UE 3 residing in the cell 100. Similarly, the eNB 2 has a cell 200.

  The eNBs 1 and 2 convert IP packets and radio signals, and relay communication between the UE 3 and the core network. Moreover, eNB1 and 2 schedule transmission / reception of the signal with respect to UE3, and perform transmission / reception of a radio signal between UE3.

  Furthermore, eNB1 and 2 perform handover control of UE3. In the present embodiment, the handover includes a normal handover due to a deterioration in radio wave quality and an application-driven handover that is performed due to a required change in communication performance.

  For example, as shown in FIG. 1, a normal handover will be described in the case where the UE 3 is located in both the cells 100 and 200 and is connected to the eNB 1. In the state of FIG. 1, when UE3 moves in the direction from cell 100 to cell 200 and the radio wave quality between UE3 and eNB1 deteriorates, eNB1 instructs UE3 to perform handover to cell 200, and performs handover. Let UE3 carry out.

  Here, in FIG. 1, the handover between the cell 100 and the cell 200 included in each of the different eNBs 1 and 2 has been described. However, for example, the eNB 1 or 2 may have both the cells 100 and 200. Even in that case, the eNB 1 or 2 can perform the handover of the UE 3 between the cell 100 and the cell 200. The functions of the eNBs 1 and 2 including the application-driven handover process will be described later in detail.

  UE3 is a wireless terminal device. UE3 performs radio communication with the connected radio base station apparatus of eNB1 or 2. Further, the UE 3 receives a handover instruction from the eNB 1 or 2 that is a connected radio base station apparatus, and executes the handover.

  Next, details of the eNBs 1 and 2 according to the present embodiment will be described with reference to FIG. FIG. 2 is a block diagram of the eNB according to the embodiment. Since eNB1 and 2 have the same function, eNB1 will be described as an example. That is, the case where UE3 is connected to eNB1 is demonstrated. Further, regarding the handover of UE3, it is assumed that eNB1 is a source base station that is connected before the handover is executed, and eNB2 is a target base station that is a connection destination after the handover.

  As illustrated in FIG. 2, the eNB 1 includes an RRC function unit 11, a radio processing unit 12, a baseband processing unit 13, a transmission path processing unit 14, and a data storage unit 15.

  The wireless processing unit 12 forms the cell 100 using an antenna. And the radio | wireless processing part 12 transmits / receives a radio signal between UE3 accommodated in the cell 100 via the antenna. The wireless processing unit 12 performs wireless signal processing.

  Details of the wireless signal processing by the wireless processing unit 12 will be described. The radio processing unit 12 receives a baseband signal input from the baseband processing unit 13. Then, the wireless processing unit 12 converts the received baseband signal that is a digital signal into an analog signal. Next, the radio processing unit 12 generates an RF (Radio Frequency) signal by mixing the baseband signal converted into the analog signal with the output frequency of the local oscillator and performing orthogonal modulation. Next, the wireless processing unit 12 performs a filtering process on the acquired RF signal to acquire an RF signal in a predetermined frequency band. Thereafter, the radio processing unit 12 amplifies the RF signal and transmits it to the UE 3 via the antenna.

  Further, the radio processing unit 12 receives an RF signal transmitted from the UE 3 via an antenna. The wireless processing unit 12 amplifies the acquired RF signal. Next, the wireless processing unit 12 performs filter processing on the amplified RF signal, and acquires an RF signal in a predetermined frequency band. Next, the wireless processing unit 12 generates a baseband signal by mixing the output frequency of the local oscillator with the RF signal and performing orthogonal demodulation. Then, the wireless processing unit 12 converts the generated baseband signal from an analog signal to a digital signal. Thereafter, the wireless processing unit 12 outputs the baseband signal converted into the digital signal to the baseband processing unit 13.

  The baseband processing unit 13 includes a signal processing unit 131, a NAS message monitoring unit 132, an APP (Application) led HO (Hand Over) state management unit 133, and an APP led HO execution unit 134.

  The signal processing unit 131 receives an input of a signal such as an IP packet from the transmission path processing unit 14. Then, the signal processing unit 131 modulates the received signal to generate a baseband signal. Furthermore, the signal processing unit 131 determines a radio resource for transmitting the baseband signal and performs scheduling. Further, the signal processing unit 131 maps the baseband signal to the determined radio resource. Thereafter, the signal processing unit 131 performs inverse Fourier transform on the baseband signal and outputs the result to the wireless processing unit 12.

  Further, the signal processing unit 131 receives an input of a baseband signal from the wireless processing unit 12. Then, the signal processing unit 131 performs a Fourier transform on the baseband signal and then performs a demodulation to generate a signal such as an IP packet. Thereafter, the signal processing unit 131 outputs the generated signal to the transmission path processing unit 14.

  Further, the signal processing unit 131 performs normal handover control. Specifically, the signal processing unit 131 receives the Measurement Report via the wireless processing unit 12 and the antenna. And the signal processing part 131 determines the target cell made into the connection destination after switching of UE3 from the cells in which reception sensitivity satisfy | fills a threshold value using Measurement Report. Here, the signal processing unit 131 selects the cell 202 as the target cell, and sets the eNB 2 as the target base station.

  Next, the signal processing unit 131 transmits a handover request message to the target base station eNB 2 via the transmission path processing unit 14. This handover request message includes RRC context information including QoS information held by the eNB 1. Thereafter, the signal processing unit 131 receives a response from the eNB 2 to the handover request message via the transmission path processing unit 14. This response includes information such as a security algorithm used for the UE 3 to connect to the eNB 2. And the signal processing part 131 notifies the instruction | indication of the connection switching to eNB2 with respect to UE3 to the RRC function part 11. FIG. This notification includes information used for connection included in the response from the eNB 2.

  When executing application-driven handover, the signal processing unit 131 receives input of recommended cell information, which will be described later, from the APP-driven HO execution unit 134. Then, the signal processing unit 131 executes the same process as the normal handover process. However, in the selection of the target base station, a cell whose reception sensitivity satisfies the threshold and which corresponds to the recommended cell type is selected as the target cell.

  Next, the function of application-driven handover execution in the baseband processing unit 13 will be described. Here, UE3 is demonstrated when it is set | placed on the cell environment shown in FIG. FIG. 3 is a diagram illustrating a cell environment around a UE located in a cell having a plurality of different communication performances. It is conceivable that the cells 100, 201, and 202 having different communication performance overlap as shown in FIG.

  For example, the cell 100 is a cell formed by the eNB 1 as in FIG. 1 and is a cell that performs existing LTE communication. The cell 100 has a throughput of 150 Mbps and a TTI value of 1.0 ms.

  Moreover, the cell 201 and the cell 202 are cells corresponding to the cell 200 formed by the eNB 2 in FIG. The cell 201 is a URLLC cell having network requirements for communication by URLLC. The cell 201 has a throughput of 150 Mbps and a TTI value of 0.2 ms. The cell 202 is an EMBB cell having network requirements for communication using EMBB. The cell 202 has a throughput of 5 Gbps and a TTI value of 1.0 ms.

  As described above, the throughput and the TTI value in each of the cells 100, 201, and 202 correspond to an example of “provided communication environment”. The cell type is a cell type that is classified into conventional LTE, URLLC, EMBB, and the like corresponding to the network requirements that each of the cells 100, 201, and 202 satisfies.

  The UE 3 is located in a place where the cell 100 which is an existing LTE cell, the cell 201 which is a URLLC cell, and the cell 202 which is an EMBB cell are superimposed. In this case, the UE 3 can be accommodated in any of the cell 100, the cell 201, and the cell 202. In this environment, when the UE 3 is powered on, the UE 3 selects any one of the cell 100, the cell 201, and the cell 202 based on the cell selection logic, and is accommodated in the selected cell. Here, UE3 is demonstrated by the case where it accommodates in the cell 100 which is an existing LTE cell.

  The NAS message monitoring unit 132 monitors a NAS (Non Access Stratum) message transmitted from the MME 4 when an EPS (Evolved Packet System) bearer is set. For example, the NAS message monitoring unit 132 performs monitoring by specifying a NAS message from the signals received by the signal processing unit 131 and confirming the content of the specified NAS message. The NAS message is a message for transmitting and receiving information between the UE 3 and the MME 4.

  FIG. 4 is a diagram showing the format of the NAS message. The NAS message has a format 300 shown in FIG. The NAS message stores information indicating what kind of message it is in the message type area in the format 300. FIG. 5 is a diagram illustrating an example of a message type of the NAS message. The NAS message has an 8-bit value on the left side of the table 301 corresponding to the message type. Therefore, the NAS message stores an 8-bit value representing its message type in the message type area in the format 300. This NAS message corresponds to an example of “communication control information”.

  The NAS message monitoring unit 132 has in advance a message type representing a message for setting the QCI value. For example, message types 311 to 313 in FIG. 5 represent messages for setting a QCI value. The message type 311 has an 8-bit value of “11000001”. The message type 312 has an 8-bit value of “11000101”. The message type 313 has an 8-bit value of “11100001”. That is, the NAS message monitoring unit 132 has an 8-bit value corresponding to the message types 311 to 313 in advance.

  The NAS message monitoring unit 132 confirms the message type of the NAS message received by the signal processing unit 131 and determines whether the message is for setting the QCI value. That is, the NAS message monitoring unit 132 determines whether or not the message type of the NAS message matches any of the message types 311 to 313 in FIG.

  When the NAS message is a message for setting the QCI value, the NAS message monitoring unit 132 acquires the QCI value from the NAS message. Then, the NAS message monitoring unit 132 determines whether or not the current QCI value set for the UE 3 is different from the QCI value of the UE 3 that is newly set.

  If the current QCI value set for UE3 is different from the newly set UE3 QCI value, the NAS message monitoring unit 132 changes the QCI together with the newly set UE3 QCI value in the APP-driven HO state. Notify the management unit 133.

  The data storage unit 15 is a storage device. The data storage unit 15 stores a UE management table 151, a protocol recommended throughput correspondence table 152, a recommended cell type table 153, and an accommodated cell management table 154.

  The UE management table 151 is a table in which the IP address of each terminal device, the QCI value set in each terminal device, the cell ID, and the state of handover are associated with all terminal devices including UE3 accommodated in the eNB1. is there. As the IP address, the IP address assigned when each terminal apparatus including the UE 3 registers the UE context information to the network (sometimes referred to as “ATTACH”) is registered. The cell ID is a physical cell ID in which each terminal device is accommodated. The physical cell ID is included in the broadcast information that eNB1 notifies UE3. The handover state is information indicating whether an application-driven handover is executed or a normal handover is executed.

  The recommended protocol throughput correspondence table 152 is a table in which a recommended throughput index representing a recommended throughput, which is a requirement required in the case of performing communication using each protocol, is registered. FIG. 6 is a diagram illustrating an example of a protocol recommended throughput correspondence table.

  The accommodated cell management table 154 is a table in which cell types are associated with all the cells 100, 201, and 202 generated by the eNBs 1 and 2. In the accommodated cell management table 154, each cell 100, 201, and 202 is specified by a cell ID. The cell types of the cells 100, 201, and 202 are determined according to the hardware specifications of the eNBs 1 and 2 that are the corresponding radio base station apparatuses. For example, the accommodated cell management table 154 may be fixedly set by the administrator according to the hardware specifications of the eNBs 1 and 2. In addition, the eNB 1 may acquire and variably set the respective hardware configurations when each of the own device and the eNB 2 is activated.

  As shown in the recommended protocol throughput correspondence table 152 of FIG. 6, the recommended throughput varies depending on the combination of protocols in the Internet layer, the transport layer, and the application layer. That is, the recommended throughput is determined according to the combination of protocols in the Internet layer, transport layer, and application layer.

  The recommended cell type table 153 is a table in which cell types are registered in association with combinations of allowable delay amounts and recommended throughput indexes. FIG. 7 is a diagram illustrating an example of the recommended cell type table. As shown in FIG. 7, the cell type is determined according to the combination of the allowable delay amount and the recommended throughput index.

  The APP-driven HO state management unit 133 acquires from the signal processing unit 131 an IP address assigned to the UE 3 during ATTACH. Then, the APP-driven HO state management unit 133 registers the acquired IP address of UE3 in the UE management table 151. The APP-driven HO state management unit 133 identifies each terminal device including the UE 3 by this IP address.

  The APP-led HO state management unit 133 receives a QCI change notification from the NAS message monitoring unit 132 together with the newly set UE 3 QCI value. Then, the APP-driven HO state management unit 133 registers information on the QCI value newly set for the UE 3 in the UE management table 151.

  Next, the APP-driven HO state management unit 133 notifies the APP-driven HO execution unit 134 of the change in the QCI value of the UE 3. Thereafter, upon receiving a notification of application-driven handover from the APP-driven HO execution unit 134, the APP-driven HO state management unit 133 changes the handover state of the UE 3 in the UE management table 151 to application-driven handover. Furthermore, when the application-driven handover of UE3 is completed, if UE3 is still accommodated in eNB1, APP-driven HO state management unit 133 changes the handover state of UE3 in UE management table 151 to normal handover. However, since the case where eNB1 is a source base station and eNB2 is a target base station is described here, UE3 is not yet accommodated in eNB1 after application-driven handover. Moreover, when UE3 is not accommodated in eNB1 by being accommodated in eNB2, the APP initiative HO state management part 133 deletes the information of UE3 in the UE management table 151. The APP-led HO state management unit 133 is an example of an “information acquisition unit”. The QCI value is an example of “service quality information”.

  The APP-driven HO execution unit 134 has an allowable delay amount corresponding to each QCI value in advance. The allowable delay amount corresponding to each QCI value is determined in advance as shown in FIG. FIG. 8 is a diagram illustrating a QCI list. The GBR (Guaranteed Bit Rate) in the resource type of FIG. 8 represents a resource type in which the transfer rate is guaranteed. Non-GBR represents a resource type whose transfer rate is not guaranteed. The QCI value is determined in correspondence with each resource type, priority, allowable delay amount, and packet error loss rate. Further, FIG. 8 shows an example of a service in which each QCI value is set. That is, the APP-driven HO execution unit 134 stores the allowable delay amount corresponding to each QCI value in the information illustrated in FIG.

  The APP-driven HO execution unit 134 receives a notification of the change in the QCI value of the UE 3 from the APP-driven HO state management unit 133. Then, the APP-driven HO execution unit 134 acquires an allowable delay amount corresponding to the QCI value of UE3.

  After that, the APP-driven HO execution unit 134 acquires the first packet received by the signal processing unit 131 in the communication between the radio processing unit 12 and the P-GW 6 after the QCI update of the UE 3. Then, the APP-driven HO execution unit 134 analyzes the acquired packet and acquires a protocol higher than the Internet layer in the packet.

  Next, the APP-driven HO execution unit 134 acquires a recommended throughput value corresponding to the protocol from the protocol recommended throughput correspondence table 152. Then, the APP-driven HO execution unit 134 acquires the cell type corresponding to the combination of the acquired allowable delay amount and the recommended throughput value from the recommended cell type table 153. This allowable delay amount and recommended throughput are examples of “communication performance”.

  Next, the APP-driven HO execution unit 134 acquires from the UE management table 151 the cell ID of the cell 100 that is the current cell in which the UE 3 is currently accommodated. Next, the APP-driven HO execution unit 134 acquires the cell type corresponding to the acquired cell ID from the accommodated cell management table 154. Thereby, APP initiative HO implementation part 134 specifies that the cell classification of cell 100 which is the current cell of UE3 is an existing LTE cell. Hereinafter, the cell type of the current cell is referred to as “current cell type”.

  Then, the APP-driven HO execution unit 134 determines whether the current cell type and the recommended cell type do not match. If the current cell type matches the recommended cell type, the APP-driven HO execution unit 134 ends the process without performing application-driven handover.

  On the other hand, if the current cell type and the recommended cell type do not match, the APP-driven HO execution unit 134 determines to perform application-driven handover. For example, when the cell 100 that is the current cell is an existing LTE cell and the recommended cell type is an EMBB cell, the APP-driven HO execution unit 134 determines to perform application-driven handover.

  Then, the APP-driven HO execution unit 134 notifies the APP-driven HO state management unit 133 of the application-driven handover. Thereafter, the APP-driven HO execution unit 134 instructs the RRC function unit 11 to execute application-driven handover. Further, the APP-driven HO execution unit 134 notifies the signal processing unit 131 of the recommended cell type. This APP-led HO execution unit 134 is an example of a “selection unit”. The recommended cell type corresponds to an example of “specific cell type”.

  The RRC function unit 11 performs control and setting of a wireless connection. Further, the RRC function unit 11 receives an instruction to switch connection to the eNB 2 for the UE 3 from the signal processing unit 131. Then, the RRC function unit 11 transmits an RRC connection Reconfiguration message, and instructs the UE 3 to set the RRC connection to the eNB 2 that is the target base station. The RRC connection Reconfiguration message includes information used for connection included in the response to the handover request received from the eNB 2. Thereafter, UE3 performs handover to eNB2.

  In addition, the RRC function unit 11 receives an application-initiated handover execution instruction from the APP-driven HO execution unit 134 when performing application-driven handover. Then, the RRC function unit 11 transmits an RRC connection Reconfiguration message to the UE 3 via the radio processing unit 12, and changes the trigger setting so that the UE 3 immediately reports the Measurement Report. For example, the RRC function unit 11 sets the report period in the period report setting of the UE 3 to 0 s.

  FIG. 9 is a diagram for explaining the change of the accommodation cell of the UE by the application initiated handover. A state 501 in FIG. 9 is a state before execution of application-driven handover. A state 502 is a state after execution of application-driven handover. And in FIG. 9, the cell by which UE3 is arrange | positioned is a cell which accommodates UE3.

  In the state 501, UE3 is accommodated in the cell 100 which is an existing LTE cell. Here, when the UE 3 receives a service using EMBB communication, the QCI is changed. In response to the change in the QCI, the APP-driven HO execution unit 134 acquires, for example, 300 ms as the allowable delay amount. Further, the APP-driven HO execution unit 134 analyzes the first packet after the QCI change, and the Internet layer protocol is IP, the transport layer protocol is UNNAP (Universal Network Acceleration Protocol), and the application layer Know that the protocol is HTTP. Then, the APP-driven HO execution unit 134 specifies the recommended throughput index as 5 using the protocol recommended throughput correspondence table 152. Thereafter, the APP-driven HO execution unit 134 uses the recommended cell type table 153 to specify that the cell type whose allowable delay amount satisfies 300 ms and the recommended throughput index is 5 is the EMBB cell. In this case, since the current cell type is an existing LTE cell and is different from the recommended cell type, the APP-driven HO execution unit 134 determines to perform application-driven handover.

  Thereafter, the trigger setting of the UE 3 is changed so that the RRC function unit 11 immediately reports the Measurement Report, and the signal processing unit 131 receives the Measurement Report from the UE 3. Then, the signal processing unit 131 extracts the cells 100, 201, and 202 as cells whose reception sensitivity exceeds the threshold value in the UE3. Furthermore, the signal processing unit 131 identifies the cell 202 that is the EMBB cell that is the recommended cell type from among the extracted cells 100, 201, and 202 as the target cell. Then, the signal processing unit 131 notifies the RRC function unit 11 of an instruction to hand over UE3 to the cell 202 of the eNB2. And the RRC function part 11 hands over UE3 to the cell 202 of eNB2. Thereby, as shown in the state 502, UE3 is accommodated in the cell 202 which is an EMBB cell.

  Next, with reference to FIG. 10, the flow of application-driven handover processing by the wireless communication system 10 according to the present embodiment will be described. FIG. 10 is a sequence diagram of application-driven handover processing by the wireless communication system according to the embodiment. In eNB1, communication between UE3 and MME4 and RRC function unit 11 and signal processing unit 131 is performed via radio processing unit 12 and transmission path processing unit 14, but here, for convenience of explanation, radio processing unit 12 In the following description, relaying by the transmission path processing unit 14 is omitted.

  The administrator registers the protocol recommended throughput correspondence table 152 in the eNB 1 (step S1). In addition, the administrator registers the recommended cell type table 153 in the eNB 1 (step S2).

  The RRC function unit 11 of the eNB 1 connects to the UE 3 that has been ATTACHed (step S3).

  The APP-driven HO state management unit 133 acquires the IP address assigned to the UE 3 during the ATTACH from the RRC function unit 11. Further, the APP-driven HO state management unit 133 acquires the cell ID of the cell 100 in which the UE 3 is accommodated from the RRC function unit 11. Further, the APP-driven HO state management unit 133 acquires the QCI value set for the UE 3 from the NAS message monitoring unit 132. Then, the APP-driven HO state management unit 133 registers the IP address of the UE 3, the cell ID of the cell 100, and the QCI value in the UE management table 151 (Step S4). Further, the APP-driven HO state management unit 133 sets the HO state of the UE 3 to normal handover.

  And UE3 performs packet data communication between P-GW6 via eNB1, MME4, and S-GW5 (step S5).

  Thereafter, the application to be executed by the UE 3 is changed (step S6). For example, the application executed on the UE 3 is changed from an Internet browsing application to an automatic driving application. The service to be supplied to the UE 3 is changed by changing the application to be executed.

  UE3 transmits BEARER RESOURCE ALLOCATION REQUEST including the information of QoS used for receiving the changed service to MME4 (step S7).

  The MME 4 receives the REARER BESOURCE ALLOCATION REQUEST from the UE 3. And the bearer setting request | requirement which requests | requires the setting to UE3 of QoS designated by BEARER RESOURCE ALLOCATION REQUEST is transmitted to P-GW6 (step S8).

  The P-GW 6 receives a bearer setting request from the MME 4. Then, the P-GW 6 confirms the request QoS requested for setting from the UE 3 and determines whether or not the setting can be permitted. If the setting is permitted, it is determined to set the requested QoS in the UE 3 (step S9).

  Thereafter, the P-GW 6 transmits a bearer setting response notifying the setting of the request QoS to the UE 3 to the MME 4 (Step S10).

  The MME 4 receives the bearer setting response from the P-GW 6. And MME4 produces | generates ACTIVATED DEDICATED EPS BEARER CONTEXT REQUEST which is a NAS message which stored the QCI value of QoS for which setting to UE3 was determined by P-GW6. Thereafter, the MME 4 transmits the generated ACTIVATED DEDICATED EPS BEARER CONTEXT REQUEST to the eNB 1 in order to notify the UE 3 of the QCI value (step S11).

  The signal processing unit 131 of the eNB 1 receives ACTIVATED DEDICATED EPS BEARER CONTEXT REQUEST from the MME 4. The NAS message monitoring unit 132 detects a change in the QCI of the UE 3 by detecting the NAS message for changing the QCI value (step S12). Then, the NAS message monitoring unit 132 notifies the APP-led HO state management unit 133 of the change in the QCI.

  The APP-driven HO state management unit 133 receives a notification of QCI change from the NAS message monitoring unit 132. Then, the APP-driven HO state management unit 133 updates the QCI value of UE3 in the UE management table 151 to the QCI value of QCI newly set in UE3 (step S13). Thereafter, the APP-driven HO state management unit 133 notifies the APP-driven HO execution unit 134 of the change in the QCI value.

  The APP-driven HO execution unit 134 receives a notification of a change in the QCI value from the APP-driven HO state management unit 133. Then, the APP-driven HO execution unit 134 acquires the allowable delay amount corresponding to the QCI value newly set in the UE 3 (Step S14).

  The signal processing unit 131 transmits ACTIVATED DEDICATED EPS BEARER CONTEXT REQUEST to the UE 3 (step S15).

  UE3 receives ACTIVATED DEDICATED EPS BEARER CONTEXT REQUEST from eNB1. And UE3 transmits ACTIVATED DEDICATED EPS BEARER CONTEXT ACCEPT which is a reception response to MME4 via eNB1 (step S16).

  Thereafter, the UE 3 performs packet data communication with the P-GW 6 via the eNB 1, the MME 4, and the S-GW 5 under the newly set QoS conditions (step S17).

  The APP-driven HO execution unit 134 of the eNB 1 acquires the packet transmitted from the MME 4 to the UE 3 from the signal processing unit 131 under the newly set QoS condition. Then, the APP-driven HO execution unit 134 performs protocol analysis of the acquired packet (step S18). Thereby, the APP-driven HO execution unit 134 acquires the protocol of each layer used in the acquired packet.

  Next, the APP-driven HO execution unit 134 acquires a recommended throughput index corresponding to the protocol of each layer from the protocol recommended throughput correspondence table 152 (step S19).

  Next, the APP-driven HO execution unit 134 acquires the recommended cell type for the UE 3 from the recommended cell type table 153 using the allowable delay amount and the recommended throughput index (step S20).

  Next, if the cell type of the current cell in which the UE 3 is accommodated is different from the recommended cell type, the APP-driven HO execution unit 134 determines to perform application-driven handover (step S21). Here, the case where the cell type of the current cell in which UE3 is accommodated and the recommended cell type are different will be described.

  Next, the APP-driven HO execution unit 134 notifies the APP-driven HO state management unit 133 of the application-driven handover with respect to the UE 3. The APP-driven HO state management unit 133 receives a notification of application-driven handover from the APP-driven HO execution unit 134. Then, the APP-driven HO execution unit 134 outputs a request for executing an application-driven handover for the UE 3 to the RRC function unit 11 (step S22).

  The RRC function unit 11 receives an input of an application-driven handover execution request for the UE 3 from the APP-driven HO execution unit 134. And the RRC function part 11 transmits RRC connection Reconfig Request for changing the trigger setting of Measurement Report to UE3 (step S23). Thereby, the RRC function unit 11 changes the trigger setting of the Measurement Report so that the UE 3 immediately reports the Measurement Report.

  UE3 receives RRC connection Reconfig Request from eNB1. And UE3 transmits RRC connection Reconfig Accept which is a reception response to eNB1 (step S24).

  Then, UE3 changes the trigger of Measurement Report to the setting instruct | indicated to eNB1 (step S25).

  Due to the change of the trigger of Measurement Report, UE3 immediately transmits the Measurement Report to eNB1 (step S26).

  The signal processing unit 131 of the eNB 1 receives the Measurement Report from the UE 3. In addition, the signal processing unit 131 acquires the recommended cell type for the UE 3 from the APP-driven HO execution unit 134. Then, the signal processing unit 131 confirms the contents of Measurement Report, and determines the target cell using the reception sensitivity and the recommended cell type (Step S27). Here, the signal processing unit 131 determines the cell 202 formed by the eNB 2 as the target cell.

  Thereafter, the signal processing unit 131 outputs a request to execute handover of the UE 3 to the eNB 2 to the RRC function unit 11. The RRC function unit 11 transmits a Handover Request, which is a handover execution request, to the eNB 2 (step S28).

  Thereafter, the RRC function unit 11 receives a Handover Request Ack (Acknowledgement) that is an affirmative response to the handover execution request from the eNB 2 (step S29).

  And the RRC function part 11 transmits RRC configuration Reconfig Request which is a message for instruct | indicating switching of the RRC connection to eNB2 to UE3 (step S30).

  UE3 receives RRC configuration Reconfig Request from eNB1. And UE3 performs a hand-over and connects to eNB2 (step S31).

  Next, with reference to FIG. 11, the flow of the application initiative handover process by eNB1 which concerns on a present Example is further demonstrated. FIG. 11 is a flowchart of application-driven handover processing by the eNB according to the embodiment.

  The NAS message monitoring unit 132 acquires the message type of the NAS message transmitted from the MME 4 received by the signal processing unit 131 to the UE 3 (Step S101).

  Next, the NAS message monitoring unit 132 determines whether or not the acquired message type is a predetermined type stored in advance (step S102). If the message type is not a predetermined type (No at Step S102), the NAS message monitoring unit 132 returns to Step S101.

  On the other hand, if the message type is a predetermined type (step S102: affirmative), the NAS message monitoring unit 132 determines whether there is an update of the QCI value of the UE3 (step S103). If there is no update of the QCI value (No at Step S103), the NAS message monitoring unit 132 returns to Step S101.

  On the other hand, when the QCI value is updated (step S103: affirmative), the NAS message monitoring unit 132 notifies the APP-led HO state management unit 133 of the new UE3 QCI value (step S104).

  The APP-driven HO state management unit 133 receives a notification of the new UE 3 QCI value from the NAS message monitoring unit 132. Then, the APP-driven HO state management unit 133 changes the HO state of UE3 in the UE management table 151 to application-driven handover. Thereafter, the APP-driven HO state management unit 133 notifies the APP-driven HO execution unit 134 of the change in the QCI value of the UE 3. The APP-driven HO execution unit 134 receives the notification of the change in the QCI value of the UE 3 and acquires an allowable delay amount corresponding to the QCI value (step 105).

  Next, the APP-driven HO execution unit 134 acquires the first packet sent from the MME 4 to the UE 3 after changing the QCI value, and analyzes the protocol of the acquired packet (step S106). As a result, the APP-driven HO execution unit 134 acquires the protocol of each layer used in the application executed by the UE 3.

  Thereafter, the APP-driven HO execution unit 134 acquires a recommended throughput index corresponding to the acquired protocol from the protocol recommended throughput correspondence table 152 (step S107).

  Next, the APP-driven HO execution unit 134 acquires a recommended cell type for the UE 3 from the recommended cell type table 153 using the allowable delay amount and the recommended throughput index (step S108).

  Next, the APP-driven HO execution unit 134 determines whether the current cell type and the recommended cell type of the UE 3 are different (Step S109). If the current cell type matches the recommended cell type (No at Step S109), the APP-driven HO execution unit 134 ends the application-driven handover process.

  On the other hand, when the current cell type and the recommended cell type are different (step S109: affirmative), the APP-driven HO execution unit 134 determines to perform application-driven handover in the UE3. Then, the APP-driven HO execution unit 134 instructs the RRC function unit 11 to perform application-driven handover for the UE 3.

  The RRC function unit 11 receives from the APP-driven HO execution unit 134 an instruction to perform application-driven handover for the UE 3. Then, the RRC function unit 11 notifies the UE 3 of the change of the trigger setting of the Measurement Report, and requests the UE 3 for the Measurement Report (Step S110).

  The signal processing unit 131 receives the Measurement Report from the UE 3. In addition, the signal processing unit 131 acquires the recommended cell type for the UE 3 from the APP-driven HO execution unit 134. Then, the signal processing unit 131 confirms the contents of Measurement Report, and determines a target cell using the reception sensitivity and the recommended cell type (Step S111).

  Thereafter, the signal processing unit 131 outputs a request for executing handover to the target cell of the UE 3 to the RRC function unit 11. The RRC function unit 11 instructs the UE 3 to perform handover. In response to the handover instruction from the RRC function unit 11, the UE 3 performs the handover for the designated target cell (step S112).

  As described above, when the application is changed and the QCI value changes, the eNB according to the present embodiment specifies a recommended cell type suitable for the changed application, and the current cell type and the recommended cell type are different. If so, cause the UE to perform a handover. As a result, the UE is accommodated in a cell having an environment suitable for the application to be executed, an optimal service environment can be provided to the UE, and the service quality can be improved.

(Hardware configuration)
FIG. 12 is a hardware configuration diagram of the eNB. For example, as illustrated in FIG. 12, the eNB 1 includes a CPU (Central Processing Unit) 91, a memory 92, a NIC (Network Interface Card) 93, and a storage 94.

  The CPU 91 is connected to the memory 92, the NIC 93, and the storage 94 via a bus. The NIC 93 is an interface for communicating with the UE 3, MME 4 and S-GW 5.

  The storage 94 is an auxiliary storage device including a hard disk. The storage 94 implements the function of the data storage unit 15 illustrated in FIG. The storage 94 is a program for realizing the functions of the RRC function unit 11, the signal processing unit 131, the NAS message monitoring unit 132, the APP-driven HO state management unit 133, and the APP-driven HO execution unit 134 illustrated in FIG. Various programs including are stored.

  The CPU 91 reads various programs stored in the storage 94, expands them on the memory 92, and executes them. Accordingly, the CPU 91 and the memory 92 realize the functions of the RRC function unit 11, the signal processing unit 131, the NAS message monitoring unit 132, the APP-driven HO state management unit 133, and the APP-driven HO execution unit 134 illustrated in FIG. .

1, 2 eNB
3 UE
4 MME
5 S-GW
6 P-GW
7 PDN
DESCRIPTION OF SYMBOLS 10 Radio communication system 11 RRC function part 12 Radio processing part 13 Baseband processing part 14 Transmission path processing part 15 Data storage part 100 Cell 131 Signal processing part 132 NAS message monitoring part 133 APP-led HO state management part 134 APP-led HO execution part 151 UE management table 152 Recommended protocol throughput correspondence table 153 Recommended cell type table 154 Accommodated cell management table 200 to 202 cells

Claims (7)

A communication unit required for communication processing executed by a wireless terminal device is acquired, and based on the communication performance, a selection unit that selects a specific cell type from a plurality of cell types that provide different communication environments;
A wireless base station device comprising: a connection switching unit that causes the wireless terminal device to switch connection to a cell having the specific cell type selected by the selection unit. The selection unit instructs execution of connection switching of the wireless terminal device when the inoculation of the cell being connected by the wireless terminal device is different from the specific cell type,
The radio base station apparatus according to claim 1, wherein the connection switching unit causes the radio terminal apparatus to perform connection switching based on an instruction from the selection unit.   The radio base station apparatus according to claim 1, wherein the selection unit acquires an allowable delay amount allocated to the radio terminal apparatus as the communication performance. An information acquisition unit that acquires service quality information according to communication processing executed by the wireless terminal device;
The radio base station apparatus according to claim 3, wherein the selection unit acquires the allowable delay amount corresponding to the service quality information acquired by the information acquisition unit.   The selection unit acquires a packet to be transmitted to the wireless terminal device, specifies a protocol used for communication with the wireless terminal device from the acquired packet, and sets a data transfer capability according to the specified protocol as the communication performance. The radio base station apparatus according to claim 1, wherein the radio base station apparatus is acquired. A wireless communication system having a wireless base station device, a wireless terminal device, and a communication control device,
The communication control device transmits communication control information related to communication processing executed by the wireless terminal device to the wireless terminal device via the wireless base station device,
The wireless base station device
Based on the communication control information received from the communication control device, the communication performance required by the communication processing executed by the wireless terminal device is acquired, and a plurality of cells having different communication environments to be provided based on the communication performance A selection unit for selecting a specific cell type from the types;
A wireless communication system comprising: a connection switching unit that causes the wireless terminal device to switch connection to a cell having the specific cell type selected by the selection unit. Obtain the communication performance required by the communication processing executed by the wireless terminal device,
Based on the acquired communication performance, select a specific cell type from a plurality of cell types that provide different communication environments,
A wireless communication control method, characterized by causing the wireless terminal device to switch connection to a cell having the specific cell type.

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