WO2016003113A1 - Method and system for controlling service continuity in wireless communication system - Google Patents

Abstract

The present invention relates to a communication technology combining 5G communication system, which supports a higher data transmission rate beyond the 4G system, with IoT technology, and a system therefor. The present invention, on the basis of 5G communication and IoT-related technologies, can be applied to intelligent services (for example, smart home, smart building, smart city, smart or connected car, healthcare, digital education, retail businesses, services related to security and safety, and the like). An embodiment of the present invention provides a method and a system for controlling service continuity when a terminal is receiving a particular service from a wireless communication system. An embodiment of the present invention provides a method and a system for controlling service continuity when a handover occurs while a user terminal is receiving a service having a particular QoS requirement. An embodiment of the present invention provides a method and a system for operating a core network node, a base station and a terminal in order to support service continuity when a handover occurs.

Description

Method and apparatus for controlling service continuity in wireless communication system

Embodiments of the present disclosure relate to a method and apparatus for controlling service continuity when a terminal receives a specific service in a wireless communication system. In addition, an embodiment of the present disclosure relates to a control method and apparatus for supporting service continuity when a handover occurs while a user terminal receives a service having a specific QoS requirement.

In order to meet the increasing demand for wireless data traffic since the commercialization of 4G communication systems, efforts are being made to develop improved 5G communication systems or pre-5G communication systems. For this reason, a 5G communication system or a pre-5G communication system is called a system after a 4G network (Beyond 4G Network) or a system after an LTE system (Post LTE). In order to achieve high data rates, 5G communication systems are being considered for implementation in the ultra-high frequency (mmWave) band (eg, such as the 60 Gigabit (60 GHz) band). In order to mitigate the path loss of radio waves in the ultra-high frequency band and increase the propagation distance of radio waves, beamforming, massive array multiple input / output (FD-MIMO), and FD-MIMO are used in 5G communication systems. Array antenna, analog beam-forming, and large scale antenna techniques are discussed. In addition, in order to improve the network of the system, 5G communication systems have advanced small cells, advanced small cells, cloud radio access network (cloud RAN), ultra-dense network (ultra-dense network) , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation The development of such technology is being done. In addition, in 5G systems, Hybrid FSK and QAM Modulation (FQAM) and Slide Window Superposition Coding (SWSC), Advanced Coding Modulation (ACM), and FBMC (Filter Bank Multi Carrier) and NOMA are advanced access technologies. (non orthogonal multiple access), and sparse code multiple access (SCMA) are being developed.

Meanwhile, the Internet is evolving from a human-centered connection network in which humans create and consume information, and an Internet of Things (IoT) network that exchanges and processes information between distributed components such as things. The Internet of Everything (IoE) technology, which combines big data processing technology through connection with cloud servers and the like, is emerging. In order to implement the IoT, technical elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology are required, and recently, a sensor network for connection between things, a machine to machine , M2M), Machine Type Communication (MTC), etc. are being studied. In an IoT environment, intelligent Internet technology (IT) services can be provided that collect and analyze data generated from connected objects to create new value in human life. IoT is a field of smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart home appliances, advanced medical services, etc. through convergence and complex of existing information technology (IT) technology and various industries. It can be applied to.

Accordingly, various attempts have been made to apply the 5G communication system to the IoT network. For example, technologies such as sensor network, machine to machine (M2M), machine type communication (MTC), and the like, are implemented by techniques such as beamforming, MIMO, and array antennas. It is. Application of cloud radio access network (cloud RAN) as the big data processing technology described above may be an example of convergence of 5G technology and IoT technology.

In general, wireless communication systems have been developed to provide voice services while guaranteeing user activity. However, wireless communication systems are gradually expanding to not only voice but also data services, and to the extent that they can provide high speed data services. However, in a wireless communication system in which a service is currently provided, a shortage of resources and users require faster services, and thus, a more advanced wireless communication system is required.

In response to these demands, one of the systems being developed as a next-generation wireless communication system, the specification work for Long Term Evolution (LTE) is being progressed in the 3GPP (The 3rd Generation Partnership Project). LTE is a technology that implements high-speed packet-based communication with a transmission rate of up to 100 Mbps. To this end, various methods are discussed. For example, the network structure can be simplified to reduce the number of nodes located on the communication path, or the wireless protocols can be as close to the wireless channel as possible.

An embodiment of the present invention is to provide a method and apparatus for controlling service continuity when a terminal receives a specific service in a wireless communication system. An embodiment of the present invention also provides a control method and apparatus for supporting service continuity when a handover occurs while a user terminal receives a service having a specific Quality of Service (QoS) requirement.

According to an embodiment of the present invention, in a method for supporting handover of a core network node, receiving a handover request including a handover target base station identifier for a terminal, the handover target Determining, by the base station, whether the terminal supports a quality of service (QoS) condition for a service currently in use, and if the handover target base station does not support a QoS condition for a service currently used by the terminal, And mapping a QCI for a service and transmitting a handover progress message including the QCI mapping information to a core node of a handover target of the terminal.

In addition, according to an embodiment of the present invention, in the apparatus of the core network node (core network node) for handover (handover), the handover target base station identifier for the communication unit and the terminal for communicating with at least one network node Receives a handover request, the handover target base station determines whether the terminal supports a Quality of Service (QoS) condition for the service currently in use, the handover target base station for the service currently being used by the terminal If it does not support the QoS condition, the control unit for mapping the QCI for the currently used service (mapping), and transmits a handover progress message including the QCI mapping information to the handover target core network node of the terminal; It provides a device comprising a.

In addition, according to an embodiment of the present invention, in the method for supporting a handover of a base station, determining whether a handover is required for a user terminal using a specific bearer, if it is determined that the handover is necessary, And selecting a handover target base station supporting the specific bearer and performing a handover procedure for the terminal with respect to the selected handover target base station.

In addition, according to an embodiment of the present invention, in the apparatus of the base station for the handover support, it is determined whether the handover is required for the communication unit and at least one user terminal using a specific bearer to communicate with at least one network node, If it is determined that the over is necessary, the control unit for selecting a handover target base station that supports the specific bearer from the neighbor base station list, and including a control unit for performing a handover procedure for the terminal to the selected handover target base station; It provides a device characterized by.

Further, according to an embodiment of the present invention, in the handover method of the terminal, using a specific bearer to communicate with the base station, reporting the cell measurement result to the base station and based on the measurement result And receiving a handover request message including handover target base station information from the base station, wherein the handover target base station supports the specific bearer being used by the terminal.

In addition, according to an embodiment of the present invention, in the device of the terminal for handover,

Communicate with a base station using a communication unit and a specific bearer to communicate with at least one network node, report a cell measurement result to the base station, and include the handover target base station information based on the measurement result from the base station And a control unit controlling to receive a handover request message, wherein the handover target base station supports the specific bearer being used by the terminal.

Further, according to an embodiment of the present invention, in the method for supporting handover of a core network node, determining whether a horse uses a bearer having a specific QCI (QoS Class Identifier) value, and the terminal is preset If using a bearer having a specific QCI value, generating handover restriction information for the terminal and transmitting the generated handover restriction information to a serving base station of the terminal; The terminal provides at least one neighbor base station information capable of supporting a bearer having the specific QCI value to the terminal.

According to an embodiment of the present invention, in a device of a core network node for handover support, a communication unit and a terminal communicating with at least one network node have a specific QCI (QoS Class Identifier) value. Determining whether to use a bearer, if the terminal is using a bearer having a predetermined specific QCI value, generates handover restriction information for the terminal, and transmits the generated handover restriction information to the serving base station of the terminal And a control unit configured to control the control unit, wherein the handover restriction information includes at least one neighbor base station information capable of supporting a bearer having the specific QCI value.

In addition, according to an embodiment of the present invention, in the handover support method of the base station, the step of communicating with the terminal using a bearer (bearer) having a specific QCI value, handover restriction information for the terminal from the core network node And a step of determining whether a handover is required for the terminal and selecting a base station to be handed over to the terminal based on the received handover restriction information.

In addition, according to an embodiment of the present invention, in the apparatus of the base station for the handover support, communication with the terminal using a communication unit for communicating with at least one network node and a bearer having a specific QCI value, the core network A control unit configured to receive handover restriction information for the terminal from a node, determine whether the terminal requires handover, and control to select a base station to be handed over to the terminal based on the received handover restriction information; It provides a device comprising a.

According to an embodiment of the present invention, when handover is required for a user terminal having a specific QoS requirement, the QoS of the service is limited by limiting candidates of the base station or area to be handed over to those that can satisfy the same QoS requirements. It can be guaranteed continuously.

According to an embodiment of the present invention, when handover is required for a user terminal having a specific QoS requirement, when the same base station or area cannot satisfy the same QoS requirement, a QoS that can be supported by the target base station or area By converting to the most similar QoS among them, service continuity can be guaranteed with minimal degradation of service quality.

1 is a view showing the structure of a communication system according to an embodiment of the present disclosure.

2 is a table illustrating QoS parameters that can be used in an operator network.

3 is a diagram illustrating an operation of an operator network node according to an embodiment of the present invention.

4 is a diagram illustrating an operation of an operator network node according to a second embodiment of the present invention.

5 is a diagram illustrating information exchange between base stations.

6 is a diagram illustrating the operation of an operator network node according to a third embodiment of the present invention.

7 is a diagram illustrating an operation of an operator network node that occurs when a user terminal switches from an idle mode to a connected mode according to a fourth embodiment of the present invention.

8 is a diagram illustrating a core network node according to an embodiment of the present invention.

9 is a diagram illustrating a base station according to an embodiment of the present invention.

10 is a view showing a terminal according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In describing the embodiments, descriptions of technical contents which are well known in the technical field to which the present invention belongs and are not directly related to the present invention will be omitted. This is to more clearly communicate without obscure the subject matter of the present invention by omitting unnecessary description.

For the same reason, in the accompanying drawings, some components are exaggerated, omitted or schematically illustrated. In addition, the size of each component does not fully reflect the actual size. The same or corresponding components in each drawing are given the same reference numerals.

Advantages and features of the present invention, and methods for achieving them will be apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various forms, and only the embodiments of the present invention make the disclosure of the present invention complete and the general knowledge in the technical field to which the present invention belongs. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

At this point, it will be understood that each block of the flowchart illustrations and combinations of flowchart illustrations may be performed by computer program instructions. Since these computer program instructions may be mounted on a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, those instructions executed through the processor of the computer or other programmable data processing equipment may be described in flow chart block (s). It creates a means to perform the functions. These computer program instructions may be stored in a computer usable or computer readable memory that can be directed to a computer or other programmable data processing equipment to implement functionality in a particular manner, and thus the computer usable or computer readable memory. It is also possible for the instructions stored in to produce an article of manufacture containing instruction means for performing the functions described in the flowchart block (s). Computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operating steps may be performed on the computer or other programmable data processing equipment to create a computer-implemented process to create a computer or other programmable data. Instructions for performing the processing equipment may also provide steps for performing the functions described in the flowchart block (s).

In addition, each block may represent a portion of a module, segment, or code that includes one or more executable instructions for executing a specified logical function (s). It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of order. For example, the two blocks shown in succession may in fact be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending on the corresponding function.

In this case, the term '~ part' used in the present embodiment refers to software or a hardware component such as an FPGA or an ASIC, and '~ part' performs certain roles. However, '~' is not meant to be limited to software or hardware. '~ Portion' may be configured to be in an addressable storage medium or may be configured to play one or more processors. Thus, as an example, '~' means components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, procedures, and the like. Subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided within the components and the 'parts' may be combined into a smaller number of components and the 'parts' or further separated into additional components and the 'parts'. In addition, the components and '~' may be implemented to play one or more CPUs in the device or secure multimedia card.

In the following description of the embodiments of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

In addition, in describing the embodiments of the present invention in detail, the basic Third Generation Partnership Project (3GPP) LTE system will be the main target, but the embodiments of the present invention have a similar technical background and system form of other communication / computer system In addition, it is possible to apply in a range that does not significantly deviate from the scope of the present invention, which will be possible in the judgment of those skilled in the art of the present invention.

For example, the present technology targeting the LTE system may be applied to a UTRAN / GERAN system having a similar system structure. In this case, the ENB (RAN node) may be replaced by the RNC / BSC, the S-GW may be omitted or included in the SGSN, and the P-GW may correspond to the GGSN. In addition, the EPS bearer concept of the LTE system may correspond to the PDP context of the UTRAN / GERAN system.

If a handover occurs while the user terminal is receiving a service having a specific QoS requirement, it is necessary to keep the service that the user terminal was receiving. In the area subject to handover, it is difficult to support service continuity for the user terminal unless they have the same QoS requirements. If service continuity is not supported when a user terminal occurs in the user terminal, the user experience service quality is lowered, and in particular, when the service is a public safety net service or an emergency service, the basic requirements of the service cannot be satisfied.

In an embodiment of the present invention, when a handover occurs while a user terminal receives a service having a specific Quality of Service (QoS) requirement in order to satisfy the requirements in the communication system, a control method for supporting service continuity And the apparatus will be described.

1 is a view showing the structure of a communication system according to an embodiment of the present disclosure. According to an embodiment, the communication system may be a mobile communication system based on LTE.

Referring to FIG. 1, as shown, a radio access network of an LTE mobile communication system includes a next-generation base station (Evolved Node B, EUTRAN, hereinafter referred to as ENB or Node B) 130, a mobility management entity (MME) 150, and It consists of S-GW (Serving-Gateway) (140).

The user equipment (hereinafter referred to as UE) 100 is connected to the external network through the ENB 130 and the S-GW 140 and the P-GW (P-GW) 160. In order to transmit and receive data through the PGW, the user terminal needs to create a PDN connection, and one PDN connection may include one or more EPS bearers.

AF (Application Function) 110 is a device for exchanging information associated with the application at the user (application) level.

The PCRF 120 is a device for controlling a policy related to a quality of service (QoS) of a user, and a policy and charging control (PCC) rule corresponding to the policy is transmitted to the P-GW 160. Is applied.

The ENB 130 is a Radio Access Network (RAN) node and corresponds to the RNC of the UTRAN system and the BSC of the GERAN system. The ENB 130 is connected to the UE 100 through a radio channel and performs a role similar to that of the existing RNC / BSC.

In LTE, all user traffic including a real-time service such as Voice over IP (VoIP) through the Internet protocol is serviced through a shared channel, so an apparatus for collecting and scheduling situation information of UEs 100 is required. This is done by the ENB 130.

The S-GW 140 is a device that provides a data bearer, and generates or removes a data bearer under the control of the MME 150.

The MME 150 is a device for various control functions. One MME 150 may be connected to a plurality of base stations.

Policy Charging and Rules Function (PCRF) 120 is an entity that collectively controls QoS and billing for traffic.

2 is a table illustrating QoS parameters that can be used in an operator network.

Referring to FIG. 2, QoS parameters are divided by QCI (QoS Class Index), and resource allocation type (priority), packet delay rate (PDB), and packet error rate (packet error) for each QCI. loss rate) and representative services. For example, an EPS bearer using QCI No. 1 is used for a service having a low PDB value and a relatively high priority, for example, a voice call service.

QCI 65 is commonly used for Mission Critical Push To Talk (MCPTT) voice services and can be used to provide public safety services in emergency or disaster situations. Depending on the purpose of the service, the EPS bearer for MCPTT using QCI 65 has a low priority and a very small PDB value.

Meanwhile, in describing the embodiments of the present invention, the EPS bearer for the MCPTT / nMCPTT service will be considered to use 65/66 as the QCI value, but this is for convenience of description and the main points of the embodiments of the present invention. The same may be applied even when the EPS bearer for the MCPTT / nMCPTT service uses different QCI values, for example, 11/12.

Specific problem situations are as follows. The user terminal is receiving a service with specific QoS requirements (ie has an EPS bearer for a specific QCI). At this time, a handover has occurred according to the location or channel state of the user terminal, but it may not be possible to support the EPS bearer having the QCI in a base station or an area (cell) that may be the target of the handover. For example, a user terminal is using an EPS bearer for MCPTT using QCI 65 in an E-UTRAN network, but a handover has occurred, and a base station or area (cell) that can be a target of handover in the vicinity is a UTRAN network. In this case, the UTRAN network may not support the EPS bearer whose QCI is 65. In this case, EPS bearer using QCI 65 cannot be used after handover, so it is difficult to continuously support the service.

According to an embodiment of the present invention, when a handover occurs for a user terminal having a service having a specific QoS requirement (that is, having an EPS bearer having a specific QCI) to solve the above problem, If the target base station or area (cell) candidates cannot support the EPS bearer having the QCI, the core network performs mapping to the QCI having the QoS parameter most similar to the existing QoS parameter, and accordingly the EPS bearer context is set to the new QCI. It is renewed to provide service continuously.

Meanwhile, in the drawings and the description of the embodiments of the present invention, it is assumed that the service used by the user terminal is MCPTT (that is, when using the EPS bearer with the QCI of 65). It is for explaining the operation based on the service having, and the main gist of the present embodiment is not limited to the EPS bearer of the MCPTT service and QCI 65.

3 is a diagram illustrating an operation of an operator network node according to an embodiment of the present invention. Referring to FIG. 3, a communication system includes a user terminal (UE) 310, a base station (eNB) 320, a radio network controller (RNC) 330, a mobility management entity (MME) 340. And a serving GPRS support node 350 (SGSN). Although the original base station is set to the eNB, the handover target base station to the RNC, the one core network node to the MME, the handover target core network node to SGSN, but this is only one embodiment of the entities constituting the network, the scope of the embodiment It is not limited to this. Depending on the nature of the network (eg, E-UTRAN or UTRAN), the base station and the handover target base station may be an eNB, RNC, BSC. Also, depending on the characteristics of the network, the core network node and the handover target core network node may be MME or SGSN.

The user terminal 310 receives a service having a specific quality of service (QoS) requirement and, accordingly, has an EPS bearer having a specific QoS Class Identifier (QCI) (S310). In an embodiment of the present invention, the service may be an MCPTT or a Non Mission Critical Push To Talk Voice (nMCPTT) service. Therefore, the QCI for the service may be 65 or 66.

The original base station (eNB or RNC / BSC) 320 recognizes that handover is required for the user terminal. The original base station sends a handover required message to the core network node (MME or SGSN, 340), which includes an identifier of the base station 330 or the area (cell) to be handovered ( S320).

After receiving the handover request, the core network node (MME or SGSN) 340 checks an EPS bearer context (EPS bearer context) that the user terminal uses or a service being used by the user terminal (S330). In addition, the core network node 340 is based on the identifier information of the base station 330 or the area (cell) that is the target of the handover received from the original base station 310, in the handover target base station or area (cell) It is checked whether the user terminal 310 supports the QoS requirement for the service being used or the QCI of the EPS bearer for supporting the service (S330).

In the present embodiment, the service being used by the user terminal 310 may be MCPTT or nMCPTT, so the QCI of the EPS bearer may be 65 or 66. In addition, in the present embodiment, the core network node 340 may determine whether QCI 65 or 66 is supported in the base station 330 or the cell (cell) to be handed over. If the QoS requirement or QCI for the original user terminal 310 service is not supported in the base station or the area (cell) to be handed over, the core network node 340 performs a QoS mapping operation. At this time, the QoS mapping operation may be performed according to the local configuration of the core network node.

The mapping operation is to perform mapping in the core network node 340 to a QCI having a QoS parameter most similar to an existing QoS parameter for a service currently used by the terminal. This is to continuously provide services by updating EPS bearer context with QCI. The QoS parameter may include a QoS class indicator (QCI), an allocation and retention priority (ARP), a guaranteed bit rate (GBR), or an MBR. For example, in the present embodiment, the configuration information of the core network node 340 is set such that an EPS bearer having a QCI of 65 is mapped to an EPS bearer having a QCI of 1, and an EPS bearer having a QCI of 64 is mapped to an EPS bearer having a QCI of 1. It may be (S330). This means that the EPS error of the EPS bearer with QCI 1 and the EPS bearer with QCI 65 is the same, and although the PDB of the EPS bearer with QCI 1 is greater than the PDB of the EPS bearer with QCI 65, the EPS bearer with QCI 1 This is because GBR bearer is the highest among GBR bearers except EPS bearer, which is QCI 65.

The original core network node 340 may transmit a message for handover progress to the handover target core network node 350. The message for the handover process may be a forward relocation request message. This message contains the EPS bearer context according to the result mapped in step S330 above.

The handover target core network node 350 may transmit a message for requesting handover to the handover target base station 330. The message for handover may be a relocation request or a handover request message. This message contains the EPS bearer context according to the result mapped in step S330.

The handover target base station node 330 transmits a response message to the handover target core network node 350. This message contains the EPS bearer context according to the result mapped in step S330 above.

If it is determined in step S330 that the original core network node 340 supports the service QoS requirement for the handover user terminal 310 or the EPS bearer for supporting the handover, the process proceeds to step S340 without a separate mapping operation. A message may be sent for over progress.

Meanwhile, in the above embodiment, it has been described that the original core network node 340 performs mapping for QoS parameters. However, as a variation of the above embodiment, the mapping to the QoS parameter may be performed in the handover target core network node 350. That is, in S330 of FIG. 3, the original core network node 340 may transmit a message for handover progress to the handover target core network node 350 based on the original EPS bearer context without performing QoS mapping. The message for the handover process may be a forward relocation request message. The handover target core network node 350 that receives the message for handover progress may support QoS parameters for the EPS bearer received from the original core network node 340 in the base station or cell (cell) to which the handover is to be performed. Determine if there is. That is, it is determined whether the handover target user terminal 310 can support the QoS requirement for the service being used or the EPS bearer for supporting the handover target base station or region (cell). If it is determined not to support, the handover target core network node 350 may perform QoS mapping. The QoS mapping operation is the same as described in S330. After mapping, it may operate as described in S350 and S360.

Meanwhile, when the EPS bearer context is changed for the user terminal according to the embodiment, a process for modifying the EPS bearer context may be additionally performed. In order to modify the EPS bearer context, the core network node may transmit a UE context setup message for the changed EPS bearer context to the base station. The base station and the terminal may perform an RRC connection reconfiguration procedure based on the UE context setup message, and may apply the changed EPS bearer context through this.

In addition, in the above embodiment, when the user terminal originally received the service or the network targeted for handover is UTRAN or GERAN, the PDP context may be used instead of the EPS bearer.

The second embodiment of the present invention selects a target base station or area (cell) when a handover occurs for a user terminal having a service having a specific QoS requirement (that is, having an EPS bearer having a specific QCI). When the base station or areas (cells) that can not support the EPS bearer having the QCI is excluded.

4 is a diagram illustrating an operation of an operator network node according to a second embodiment of the present invention. In the figure and the description thereof, it is assumed that the service used by the user terminal 410 is MCPTT (that is, when using an EPS bearer with a QCI of 65), but this is based on a service having a specific QoS requirement. To describe one operation, a main point of the present embodiment is not limited to the EPS bearer having the MCPTT service and the QCI of 65.

The user terminal 410 is using the MCPTT or nMCPTT service, and therefore has a EPS bearer with a QCI of 65 or 66 (S410).

The base station 420 may perform a measurement for measuring a channel state of the user terminal (S420).

The base station 420 determines that handover is necessary based on the measurement result, and selects a base station or an area (cell) to be the handover target (S430). The base station 420, if the user terminal 410 is using an EPS bearer having a predetermined specific QCI value, the base station or area (cell) to be a handover target to search the neighbor cell list and support the specific QCI value Can be selected. For example, when the user terminal 410 is using an EPS bearer of QCI 65 or 66, the base station 420 searches for a neighbor cell list (NCL) to determine whether the EPS bearer of QCI 65 or 66 is supported. . The base station 420 may perform a handover process by selecting a base station or an area (cell) capable of supporting an EPS bearer of QCI 65 or 66. That is, in the present embodiment, the base station 420 is storing the NCL including information indicating whether the neighboring base station or region (cell) can support the EPS bearer of QCI 65/66, and selects the target of the handover based on this. do. Whether the QCI supports the EPS bearer having 65 or 66 may include determining whether it can support the MCPTT or nMCPTT service.

Meanwhile, neighbor base station information may be stored to determine whether the neighbor base station supports an EPS bearer having a QCI of 65 or 66. For example, as shown in FIG. 5, neighbor base station information may be stored through information exchange between base stations.

On the other hand, if no neighboring base station can support the EPS bearer having the same QCI value, the neighboring base station having the highest QoS similarity may be selected as the base station for handover. This may also be applied to the following third and fourth embodiments.

5 is a diagram illustrating information exchange between base stations. In this figure and the description thereof, it is assumed that the service used by the user terminal is MCPTT (that is, when using an EPS bearer with QCI of 65), but this is based on a service based on a service having a specific QoS requirement. For the purpose of explanation, the main points of the present embodiment are not limited to the EPS bearer having the MCPTT service and the QCI of 65.

If the base station 510 needs X2 connection with another base station 520, it transmits an X2 setup request to the base station (S510). This message includes information indicating whether the MCPTT or nMCPTT service can be supported, that is, whether the QCI supports the EPS bearer having 65 or 66.

The neighbor base station 520 receiving this stores whether the other base station supports MCPTT or nMCPTT in the NCL (S520).

The neighbor base station 520 transmits a response message for the request to the base station 510 (S530). The response message may be an X2 configuration response message. In this case, the X2 configuration response message may include information indicating whether the neighbor base station 520 supports MCPTT or nMCPTT.

The base station 510 stores whether the neighbor base station supports MCPTT or nMCPTT in the NCL.

According to a third embodiment of the present invention, when a handover occurs for a user terminal having a service having a specific QoS requirement (that is, having an EPS bearer having a specific QCI), the base station or area (cell) to which the handover is to be performed When selecting the method to exclude those that can not support the EPS bearer having the QCI. The difference from the second embodiment is that the base station node does not perform the operation based on the NCL, but performs the operation based on a HRL (Handover Restriction List) received from the MME (or SGSN).

6 is a diagram illustrating the operation of an operator network node according to a third embodiment of the present invention. In this figure and the description thereof, it is assumed that the service used by the user terminal is MCPTT (that is, when using an EPS bearer with QCI of 65), but this is based on a service based on a service having a specific QoS requirement. For the purpose of explanation, the main points of the present embodiment are not limited to the EPS bearer having the MCPTT service and the QCI of 65.

The user terminal 610 is registered in the operator network, and has not set up an EPS bearer for MCPTT or nMCPTT during the basic registration procedure (S610).

The user terminal 610 and the operator's network set an EPS bearer for MCPTT or nMCPTT service, that is, an EPS bearer having a QCI of 65 or 66 according to the service request (S620).

In the core network node (MME or SGSN, 630) of the operator network, EPS bearer is configured for the user terminal 610, it can be seen that the QCI is 65 or 66 (S630). Therefore, when generating a handover restriction list (HRL) for the user terminal, the base station or region (cell) that does not support the MCPTT or nMCPTT of the base station or region (cell) that is the target of the handover is excluded (S630). That is, the base station or area (cell) that does not support the EPS bearer with the QCI of 65 or 66 is set to be excluded from the handover target. For example, if the UTRAN is considered as a handover target for the user terminal 610, and MCPTT or nMCPTT is not supported in the UTRAN, the core network node 630 is UTRAN as a prohibited RAT (Radio Access Technology) of the HRL. Set.

The HRL generated by the core network node 630 is transmitted to the base station 620 (S640). The generated HRL may be transmitted through an S1_AP or Iu message. The message may be one of a downlink NAS transport and an E-RAB setup request. The base station 620 may store the received HRL.

When handover is required, the base station 620 selects a base station or an area (cell) to be subjected to handover based on the HRL received from the core network node 620 (S650).

FIG. 7 is a diagram illustrating an operation of an operator network node that occurs when a user terminal switches from an idle mode to a connected mode according to a fourth embodiment of the present invention. In this figure and the description thereof, it is assumed that the service used by the user terminal is MCPTT (that is, when using an EPS bearer with QCI of 65), but this is based on a service based on a service having a specific QoS requirement. For the purpose of explanation, the main points of the present embodiment are not limited to the EPS bearer having the MCPTT service and the QCI of 65.

Referring to FIG. 7, the user terminal 710 transmits a request message and a service request message to the core network node 730 in order to switch to a connection state for receiving a service from an idle state (S710).

The core network node (MME or SGSN, 730) of the operator's network may know that the user terminal has an EPS bearer with a QCI of 65 or 66 according to the EPS bearer context of the user terminal 710 (S720). In this case, when generating the HRL for the user terminal 710, the core network node 730 does not support MCPTT or nMCPTT among base stations or areas (cells) that are subject to handover, that is, QCI is 65 or 66. A base station or an area (cell) not supporting the EPS bearer is set to be excluded from the handover target (S720). For example, if UTRAN is considered as a handover target for a user terminal, but MCPTT or nMCPTT is not supported in the UTRAN, the core network node configures the UTRAN as a prohibited RAT (Radio Access technology) of the HRL.

The HRL generated by the core network node 730 is transmitted to the base station 720 through the S1_AP or Iu message (S730). The message may be an Initial context setup request message.

When handover is required, the base station 720 selects a base station or an area (cell) to be subjected to handover based on the HRL received from the core network node 730 (S740).

On the other hand, in the fifth embodiment of the present invention, by determining the connection mode and the detailed connection state of the user terminal in consideration of the traffic characteristics of the user terminal, a method of reducing the battery consumption of the user terminal, increasing the availability of the operator network added To present. More specifically, if the user terminal has completed the data transmission and reception, the probability of the subsequent data traffic transmission is low, it is notified to the base station control node may cause a transition to a low battery consumption state. If embodiments of the present invention are applied to a user terminal accessing an LTE network, the layer on which an operation is performed is changed (for example, a request message for changing a connection state from a NAS instead of RRC) or used for a request The message may be changed (for example, a UE Assistance Information message or an RRC Release Request message instead of the SCRI message of the RRC layer), or some steps / operations of the embodiments of the present invention may be omitted or the order may be changed.

If the user terminal uses the E-UTRAN network, the user terminal may transmit a request message for changing the connection state to the base station. This operation, according to embodiments of the present invention, the upper layer (traffic monitoring unit, application synchronizer, or NAS layer) has finished sending and receiving traffic, the PS data session has ended, user inactivity, or RRC disconnection is required It may be performed when at least one or more pieces of information for notifying the communication to the communication control unit (RRC layer).

In a higher layer, determining whether to notify one or more of the above information may be determined by embodiments of the present invention. The user terminal may use the UE Assistance Information message as a request message, which includes information indicating that the transmission and reception of traffic has ended, the PS data session has ended, the RRC connection needs to be disconnected, user inactivity, or low power consumption is required. One or more may be included.

Upon receiving the message including the information from the user terminal, the base station may transmit an operation for releasing the RRC connection to the user terminal, that is, an RRC connection release message to the user terminal. In addition, the base station may transmit a request message to release the UE context to the MME. Meanwhile, the UE Assistance Information may be replaced with an RRC connection release request message.

Alternatively, the information may be included in a header or a control element used when the user terminal transmits a user plane data packet, rather than a separate control message transmitted by the user terminal to the base station. Meanwhile, the base station may delay performing the operation of releasing the RRC connection until the user plane data transmission and reception for the user terminal is terminated.

As a variant of the present embodiment, if the user terminal uses the E-UTRAN network, the user terminal may transmit a request message for changing the connection state to the MME. According to embodiments of the present invention, at least one of information indicating that the upper layer (traffic monitoring unit) has finished transceiving traffic, the PS data session has ended, user inactivity, or needs to release the RRC connection, according to embodiments of the present invention. This may be performed when the communication control unit (NAS layer) is informed.

In a higher layer, determining whether to notify one or more of the above information may be determined by embodiments of the present invention. The user terminal may use a NAS message as a request message, and the message may include one or more pieces of information indicating that the transmission and reception of the traffic has ended, the PS data session has ended, the RRC connection needs to be disconnected, user inactivity, or low power consumption is required. This may be included.

In one embodiment of the present invention, the NAS message may be an EMM status message, indicating that the traffic transmission and reception is terminated, the PS data session is terminated, the RRC connection needs to be released, user inactivity, or low power consumption is required. The information may be included in the EMM cause information element.

MME receiving the NAS message including the information from the user terminal performs an operation for releasing the RRC connection to the user terminal. RRC connection release to the user terminal may mean that the MME releases the logical connection associated with the user terminal. To this end, the MME may transmit a UE context release command message to the base station. The message may include one of information indicating that traffic transmission and reception is terminated due to disconnection, PS data session is terminated, RRC connection release is required, user inactivity, or low power consumption is required.

If the base station receives the UE context release command message from the MME, the base station performs an operation for releasing the RRC connection for the user terminal. If the message received by the base station includes information indicating that the transmission and reception of the traffic is terminated, the PS data session is terminated, the RRC connection needs to be released, user inactivity, or low power consumption is required, the base station is a user terminal. After waiting for all user plane data transmission and reception to, the RRC connection may be released.

Next, a sixth embodiment of the present invention will be described. When the operator network provides the RAN rule for WLAN offloading control for the user terminal, the user terminal may transmit the WLAN through a system information block (SIB) or an RRC connection reconfiguration (RRC message) transmitted by a base station (E-UTRAN or UTRAN). Offloading control information (ie, RAN rule) may be received. The WLAN offloading control information includes a list of WLANs to which the user terminal can connect, various parameters (eg, signal strength, congestion, offloading preference indicator, etc.) that the user terminal can use to select the WLAN or determine whether to offload traffic. Includes timer values to apply when performing an offloading operation.

However, the user terminal camps in the E-UTRAN or the UTRAN to receive the service and receives the information and is in operation, and may move to the base station or the area that does not provide the information. For example, a user terminal receives a service from a Release-12 base station capable of transmitting a System Information Block (SIB) or an RRC message including the WLAN offloading control information to an area of a Release-11 base station having no information providing function. You may have moved. In addition, a user terminal may receive a service from an E-UTRAN / UTRAN base station capable of transmitting an SIB or RRC message including the WLAN offloading control information and then move to an area of the GERAN base station.

In this situation, since the user terminal cannot receive the WLAN offloading control information from the base station, it may be in an unclear state how to perform the WLAN offloading operation.

In order to solve the above problem, in the sixth embodiment of the present invention, when the base station capable of providing WLAN offloading control information provides WLAN offloading control information to a user terminal through an SIB or RRC message, the WLAN offloading control information is provided. Characterized by including information that can be used in the area that can not provide.

That is, the WLAN offloading control information (wlan-offloadcommon IE included in the SIB17 message or wlan-OffloadDedicated IE included in the RRC connection reconfiguration message) provided by the base station to the user terminal may be applied by the terminal receiving the information. Contains condition information. More specifically, the WLAN offloading control information includes an applicable RAT (UTRAN / GERAN) condition or an applicable location identifier (Tracking area ID, Routing area ID, base station ID, or cell ID) condition. For example, if the user terminal includes the GERAN as the applicable RAT information in the wlan-offloadDedicated IE received from the base station, the user terminal is WLAN offloading according to the control information included in the wlan-offloadDedicated IE received in the GERAN region. You can perform the operation.

According to another embodiment of the present invention, the mobility controlInfo IE of the RRC connection release message or the RRC connection reconfiguration message for switching the user terminal to another RAT or Cell, the user terminal has finished switching or handover WLAN offloading control information that can be applied later.

That is, when the user terminal needs to switch / hand over to another RAT or base station or area, the base station performs WLAN offloading control to be applied in the target base station or area to a command message (the RRC connection release or RRC connection reconfiguration) sent to the user terminal. Include information (wlan-offloadDedicated IE or wlan-offloadCommon IE). Determining whether the base station includes the information in a message sent to the user terminal may be limited to a specific RAT or a base station / area. That is, the base station may include the information only when a switching or handover operation is required for a specific RAT or a base station / area for the user terminal. For example, when the user terminal is switched or handed over to the GERAN region, the base station may include the WLAN offloading control information in an RRC connection release message or an RRC connection reconfiguration message.

If the user terminal performs a WLAN offloading operation based on the WLAN offloading control information provided by the base station and then switches / hands over to a base station or an area that does not provide the WLAN offloading control information, the user terminal is stored. If the applicable RAT condition or location condition is included in the WLAN offloading control information, it is determined whether this condition is satisfied. If the condition is met, the user terminal can continue using the stored WLAN offloading information (ie, received from the previous base station) to perform the WLAN offloading operation.

On the other hand, if the user terminal receives the WLAN offloading control information (wlan-offloadDedicated IE or wlan-offloadCommon IE) to be used in the target base station or area in the RRC connection release or handover command message (RRC connection reconfiguration message), the user terminal When the switching or handover process is completed, the WLAN offloading operation may be performed based on the received WLAN offloading control information. The WLAN offloading control information transmitted to the user terminal during the RRC connection release process or the handover process may be information that is limitedly applied to the target RAT or the base station / area.

8 is a diagram illustrating a base station according to an embodiment of the present invention. The base station may be an eNB, RNC or BSC. Referring to FIG. 8, the base station 800 may include a communication unit 810 and a control unit 830. The communication unit 810 may communicate with at least one network node. The controller 830 may control the overall operation of the base station 800.

The controller 830 may control to perform a handover operation for the corresponding terminal based on the QCI mapping information received from the core network node.

According to an embodiment of the present invention, the controller 830 determines whether a handover is necessary for a user terminal using a specific bearer, and if it is determined that the handover is necessary, a hand supporting the specific bearer in a neighbor base station list. An over-target base station may be selected, and the selected handover target base station may be controlled to perform a handover procedure for the terminal. In this case, the specific bearer may be a bearer supporting a Mission Critical Push To Talk Voice (MCPTT) or a Non Mission Critical Push To Talk Voice (nMCPTT) service.

In addition, the controller 830 may control to establish an X2 interface connection with at least one neighboring base station and update the neighbor base station list based on a message for setting the X2 interface connection. In this case, the message for establishing the X2 connection may include information indicating whether to support the MCPTT or nMCPTT.

In addition, the controller 830 communicates with a terminal using a bearer having a specific QCI value, receives handover restriction information for the terminal from a core network node, and determines whether the terminal requires handover. Based on the received handover restriction information, it may be controlled to select a base station for handover for the terminal. In this case, the handover restriction information may include at least one neighbor base station information capable of supporting a bearer having the specific QCI value to the terminal. In addition, the bearer having the specific QCI value may be a bearer supporting a Mission Critical Push To Talk Voice (MCPTT) or Non Mission Critical Push To Talk Voice (nMCPTT) service.

Although the block and the configuration of the base station 800 has been described above by dividing the block, this is for convenience of description and the scope of the present invention is not limited thereto. In addition, the base station 800 may perform not only the operation described with reference to FIG. 8 but also the operation of the base station according to the embodiment of the present invention described with reference to FIGS. 1 to 7.

9 is a diagram illustrating a core network node according to an exemplary embodiment of the present invention. The core network node may be an MME or SGSN. Referring to FIG. 9, the core network node 900 may include a communication unit 910 and a control unit 930. The communication unit 910 may communicate with at least one network node. The controller 930 may control the overall operation of the core network node 900.

According to an embodiment of the present disclosure, the control unit 930 receives a handover request including a handover target base station identifier for a terminal, and the handover target base station provides QoS (Quality) for a service currently used by the terminal. If the handover target base station does not support the QoS condition for the service currently used by the terminal, it maps the QCI for the currently used service, and the hand of the terminal. The handover progress message including the QCI mapping information may be transmitted to the over-target core network node.

In addition, the controller 930 may control the terminal to map the QIC to a QCI having a QoS parameter most similar to an existing QoS parameter for a service currently being used. In this case, the QCI mapping information may be used to form an EPS bearer of the handover target core network node and the handover target base station for a service currently in use for the terminal.

In addition, the controller 930 is an EPS (Evolved Packet System) bearer having a QCI value of 1 if the service currently being used by the terminal is a Mission Critical Push To Talk Voice (MCPTT) or a Non Mission Critical Push To Talk Voice (nMCPTT). Can be controlled to map QCI.

In addition, the controller 930 determines whether the terminal uses a bearer having a specific QCI (QoS Class Identifier) value, and if the terminal is using a bearer having a predetermined specific QCI value, handover restriction for the terminal. Information may be generated and control may be performed to transmit the generated handover restriction information to a serving base station of the terminal. In this case, the handover restriction information may include at least one neighbor base station information capable of supporting a bearer having the specific QCI value to the terminal.

In addition, the controller 930 may control to exclude the base station that does not support the bearer having the specific QCI value from the handover restriction information. In this case, the handover restriction information may be used by the serving base station to select a handover target base station when there is a handover request for the terminal.

In the above, the configuration and function of the core network node 900 are divided and described, but this is for convenience of description and the scope of the present invention is not limited thereto. In addition, the core network node 900 may perform not only the operation described with reference to FIG. 9 but also an operation of the core network node according to an embodiment of the present invention described with reference to FIGS. 1 to 7.

10 is a view showing a terminal according to an embodiment of the present invention. Referring to FIG. 10, the terminal 1000 may include a communication unit 1010 and a control unit 1030. The communication unit 1010 may communicate with at least one network node. The controller 1030 may control the overall operation of the terminal 1000.

According to an embodiment of the present invention, the controller 1030 may control to perform a handover procedure for the base station to be handed over based on QCI mapping information and handover restriction information exchanged between the base station and the core network node. In addition, based on the new bearer configuration information, it is possible to perform the RRC connection reconfiguration process.

The controller 1030 communicates with a base station using a specific bearer, reports a cell measurement result to the base station, and includes the handover target base station information based on the measurement result from the base station. It can be controlled to receive the over request message. In this case, the handover target base station may support the specific bearer being used by the terminal.

In this case, the specific bearer may be a bearer supporting a Mission Critical Push To Talk Voice (MCPTT) or a Non Mission Critical Push To Talk Voice (nMCPTT) service.

Although the block and the configuration of the terminal 1000 have been described above, this is for convenience of description and the scope of the present invention is not limited thereto. In addition, the terminal 1000 may perform not only the operation described with reference to FIG. 10 but also an operation according to the embodiment of the present invention described with reference to FIGS. 1 to 7.

The embodiments of the present invention have been described with reference to the drawings. However, the embodiments are provided for convenience of description, and each embodiment can be performed independently and can also operate in a combination of different embodiments.

On the other hand, the present specification and the drawings have been described with respect to the preferred embodiments of the present invention, although specific terms are used, it is merely used in a general sense to easily explain the technical details of the present invention and help the understanding of the invention, It is not intended to limit the scope of the invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention can be carried out in addition to the embodiments disclosed herein.

Claims (32)

1. In the handover (supporting method) of the core network node (core network node),

   Receiving a handover request including a handover target base station identifier for the terminal;

   Determining, by the handover target base station, whether the terminal supports a quality of service (QoS) condition for a service currently used by the terminal;

   Mapping, by the base station to which the handover target does not support a QoS condition for a service currently used by the terminal, the QCI for the currently used service; And

   And transmitting a handover progress message including the QCI mapping information to a handover target core network node of the terminal.
2. The method of claim 1, wherein the mapping of the QCI comprises:

   And mapping to a QCI having a QoS parameter most similar to an existing QoS parameter for a service currently used by the terminal.
3. The method of claim 1, wherein the QCI mapping information is used to form an EPS bearer of the handover target core network node and the handover target base station for a service currently in use for the terminal.
4. The method of claim 1, wherein the mapping of the QCI comprises:

   If the service currently being used by the terminal is a Mission Critical Push To Talk Voice (MCPTT) or Non Mission Critical Push To Talk Voice (nMCPTT), the method characterized by mapping to an Evolved Packet System (EPS) bearer having a QCI value of 1. .
5. In the apparatus of the core network node (node network node) for handover,

   A communication unit communicating with at least one network node; And

   Receiving a handover request including a handover target base station identifier for the terminal, determining whether the handover target base station supports a Quality of Service (QoS) condition for a service currently used by the terminal, and performing the handover target If the base station does not support the QoS conditions for the service currently used by the terminal, the terminal maps the QCI for the currently used service and includes the QCI mapping information to the handover target core network node of the terminal. And a controller for controlling to transmit an over progress message.
6. The method of claim 5, wherein the control unit,

   And controlling the terminal to map the QIC to a QCI having a QoS parameter most similar to an existing QoS parameter for a service currently being used.
7. The apparatus of claim 5, wherein the QCI mapping information is used to form an EPS bearer of the handover target core network node and the handover target base station for a service currently in use for the terminal.
8. The method of claim 5, wherein the control unit,

   If the service currently being used by the terminal is a Mission Critical Push To Talk Voice (MCPTT) or Non Mission Critical Push To Talk Voice (nMCPTT), the QCI is mapped to an Evolved Packet System (EPS) bearer having a QCI value of 1. How to.
9. In the handover support method of the base station,

   Determining whether a handover is necessary for a user terminal using a specific bearer;

   If it is determined that a handover is necessary, selecting a handover target base station supporting the specific bearer from a neighbor base station list; And

   And performing a handover procedure for the terminal with respect to the selected handover target base station.
10. The method of claim 9, wherein the specific bearer is a bearer supporting a Mission Critical Push To Talk Voice (MCPTT) or a Non Mission Critical Push To Talk Voice (nMCPTT) service.
11. The method of claim 9,

    Establishing an X2 interface connection with at least one neighboring base station; And

    Updating the neighbor base station list based on the message for establishing the X2 interface connection;

    The message for establishing the X2 connection is characterized in that it comprises information indicating whether to support MCPTT or nMCPTT.
12. In the apparatus of the base station for handover support,

    A communication unit communicating with at least one network node; And

    If it is determined whether a handover is necessary for a user terminal using a specific bearer, and if it is determined that the handover is necessary, a handover target base station supporting the specific bearer is selected from the neighbor base station list, and the selected handover target base station And a control unit for controlling to perform a handover procedure for the terminal.
13. The apparatus of claim 12, wherein the specific bearer is a bearer supporting a Mission Critical Push To Talk Voice (MCPTT) or a Non Mission Critical Push To Talk Voice (nMCPTT) service.
14. The method of claim 12, wherein the control unit,

    Establish an X2 interface connection with at least one neighboring base station, control to update the neighbor base station list based on the message for establishing the X2 interface connection,

    The message for establishing the X2 connection is characterized in that it comprises information indicating whether or not support MCPTT or nMCPTT.
15. In the handover method of the terminal,

    Communicating with a base station using a particular bearer;

    Reporting a cell measurement result to the base station; And

    Receiving a handover request message including handover target base station information from the base station based on the measurement result;

    The handover target base station is characterized in that the terminal supports the specific bearer in use.
16. The method of claim 15, wherein the specific bearer is a bearer supporting a Mission Critical Push To Talk Voice (MCPTT) or a Non Mission Critical Push To Talk Voice (nMCPTT) service.
17. In the device of the terminal for handover,

    A communication unit communicating with at least one network node; And

    Communicating with a base station using a specific bearer, reporting a cell measurement result to the base station, and controlling to receive a handover request message including the handover target base station information from the base station based on the measurement result Including a control unit,

    The handover target base station is characterized in that the terminal supports the specific bearer in use.
18. The apparatus of claim 15, wherein the specific bearer is a bearer supporting a Mission Critical Push To Talk Voice (MCPTT) or a Non Mission Critical Push To Talk Voice (nMCPTT) service.
19. In the handover support method of the core network node (core network node),

    Determining whether the terminal uses a bearer having a specific QCI (QoS Class Identifier) value;

    If the terminal is using a bearer having a predetermined specific QCI value, generating handover restriction information for the terminal; And

    Transmitting the generated handover restriction information to a serving base station of the terminal,

    The handover restriction information includes at least one neighbor base station information capable of supporting a bearer having the specific QCI value to the terminal.
20. The method of claim 19, wherein generating the handover restriction information comprises:

    The base station that does not support the bearer having the specific QCI value is excluded from the handover restriction information.
21. The method of claim 19, wherein the handover restriction information,

    When the handover request is made for the terminal, the serving base station is used for selecting a handover target base station.
22. The method of claim 19, wherein the bearer having a predetermined specific QCI value is a bearer supporting a Mission Critical Push To Talk Voice (MCPTT) or a Non Mission Critical Push To Talk Voice (nMCPTT) service.
23. In the apparatus of the core network node (core network node) for handover support,

    A communication unit communicating with at least one network node; And

    Determine whether the terminal uses a bearer having a specific QCI (QoS Class Identifier) value, and if the terminal is using a bearer having a predetermined specific QCI value, handover restriction information for the terminal is generated, And a control unit for controlling to transmit the generated handover restriction information to a serving base station, wherein the handover restriction information includes at least one neighbor base station information capable of supporting a bearer having the specific QCI value. Characterized in that the device.
24. The method of claim 23, wherein the control unit,

    And control the base station that does not support the bearer having the specific QCI value to be excluded from the handover restriction information.
25. The method of claim 23, wherein the handover restriction information,

    When the handover request for the terminal, the device characterized in that the serving base station is used to select the base station to be handed over.
26. 24. The apparatus of claim 23, wherein the bearer having a predetermined specific QCI value is a bearer supporting a Mission Critical Push To Talk Voice (MCPTT) or a Non Mission Critical Push To Talk Voice (nMCPTT) service.
27. In the handover support method of the base station,

    Communicating with a terminal using a bearer having a specific QCI value;

    Receiving handover restriction information for the terminal from a core network node;

    Determining whether the terminal requires a handover; And

    And selecting a base station to be handed over to the terminal based on the received handover restriction information.
28. 28. The method of claim 27, wherein the handover restriction information includes at least one neighbor base station information capable of supporting a bearer having the specific QCI value to the terminal.
29. 28. The method of claim 27, wherein the bearer having a specific QCI value is a bearer supporting a Mission Critical Push To Talk Voice (MCPTT) or a Non Mission Critical Push To Talk Voice (nMCPTT) service.
30. In the apparatus of the base station for handover support,

    A communication unit communicating with at least one network node; And

    Communicate with the terminal using a bearer having a specific QCI value, receive handover restriction information for the terminal from a core network node, determine whether the terminal needs handover, and receive the received handover restriction information And a control unit controlling to select a base station to be handed over to the terminal.
31. 31. The apparatus of claim 30, wherein the handover restriction information includes at least one neighbor base station information capable of supporting a bearer having the specific QCI value to the terminal.
32. 31. The apparatus of claim 30, wherein the bearer having a specific QCI value is a bearer supporting a Mission Critical Push To Talk Voice (MCPTT) or a Non Mission Critical Push To Talk Voice (nMCPTT) service.

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