WO2014098393A1 - Procédé de commande d'extension de support dans un système de communication sans fil de réseau hétérogène et appareil pour ce procédé - Google Patents

Procédé de commande d'extension de support dans un système de communication sans fil de réseau hétérogène et appareil pour ce procédé Download PDF

Info

Publication number
WO2014098393A1
WO2014098393A1 PCT/KR2013/011214 KR2013011214W WO2014098393A1 WO 2014098393 A1 WO2014098393 A1 WO 2014098393A1 KR 2013011214 W KR2013011214 W KR 2013011214W WO 2014098393 A1 WO2014098393 A1 WO 2014098393A1
Authority
WO
WIPO (PCT)
Prior art keywords
eps bearer
base station
terminal
bearer
macro
Prior art date
Application number
PCT/KR2013/011214
Other languages
English (en)
Korean (ko)
Inventor
허강석
권기범
안재현
정명철
Original Assignee
주식회사 팬택
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 주식회사 팬택 filed Critical 주식회사 팬택
Publication of WO2014098393A1 publication Critical patent/WO2014098393A1/fr

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W28/00—Network traffic management; Network resource management
    • H04W28/02—Traffic management, e.g. flow control or congestion control
    • H04W28/08—Load balancing or load distribution
    • H04W28/086—Load balancing or load distribution among access entities
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/20—Manipulation of established connections
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W28/00—Network traffic management; Network resource management
    • H04W28/02—Traffic management, e.g. flow control or congestion control
    • H04W28/08—Load balancing or load distribution
    • H04W28/09—Management thereof
    • H04W28/0958—Management thereof based on metrics or performance parameters
    • H04W28/0967—Quality of Service [QoS] parameters
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/20—Manipulation of established connections
    • H04W76/27—Transitions between radio resource control [RRC] states
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W76/00—Connection management
    • H04W76/30—Connection release
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
    • H04W16/24—Cell structures
    • H04W16/32—Hierarchical cell structures

Definitions

  • the present invention relates to wireless communications, and more particularly, to a method and apparatus for controlling bearer expansion in a heterogeneous network wireless communication system.
  • a multiple component carrier system refers to a wireless communication system capable of supporting carrier aggregation.
  • Carrier aggregation is a technique for efficiently using fragmented small bands.
  • a base station uses a logically large band by grouping a plurality of physically continuous or non-continuous bands in the frequency domain. It is intended to produce the same effect.
  • the multi-component carrier system supports a plurality of component carriers (CCs) distinguished in the frequency domain.
  • the component carrier includes an uplink component carrier used for uplink and a downlink component carrier used in downlink.
  • One serving cell may be configured by combining the downlink component carrier and the uplink component carrier. Alternatively, one serving cell may be configured only with a downlink component carrier.
  • HetNet heterogeneous network
  • a macro cell In a heterogeneous network environment, a macro cell is a large coverage cell, and a small cell such as a femto cell and a pico cell is a small coverage cell. Coverage overlap occurs between multiple macro cells and small cells in a heterogeneous network environment.
  • a terminal connected to a network may communicate with any cell according to a channel environment or a mobile state, and may perform cell change.
  • a handover may be performed to solve a problem of call disconnection that occurs when moving to an adjacent cell.
  • Handover refers to a new call channel of an adjacent communication service area when the terminal moves out of the current communication service area (source cell) and moves to an adjacent communication service area (target cell). It is a function that automatically tunes to a traffic channel to maintain a call state continuously. That is, a terminal communicating with a specific base station is linked to another neighboring base station (target base station) when the signal strength of the specific base station (hereinafter referred to as a source base station) is weakened. .
  • the terminal may be disconnected from the macro cell and connected to another macro cell or pico cell due to a deterioration of the channel state while being connected to the macro cell.
  • the terminal may be disconnected from the macro cell and connected to another macro cell or pico cell.
  • the terminal may perform wireless communication through any one of base stations constituting at least one serving cell.
  • a terminal that is connected to one base station constituting a macro cell may be serviced by the other base station without a handover procedure even when the signal quality of the other base station constituting the small cell is excellent and the radio resource utilization is low. Is not provided.
  • the UE is connected to the base station constituting the small cell through a handover procedure, there is a problem that the handover occurs frequently as the UE moves because the coverage of the small cell is relatively small. This is also the case when the terminal supports the multi-component carrier. Accordingly, there is a need for a method for distributing an excessive load or a load requiring a specific QoS to a small cell without a handover procedure in a heterogeneous network environment and efficiently transmitting data.
  • An object of the present invention is to provide a method and apparatus for setting and operating a bearer extension in a wireless communication system.
  • Another technical problem of the present invention is to provide a cell planning technique for efficient transmission of data to a terminal without generating unnecessary load on a cell in a heterogeneous network environment.
  • Another technical problem of the present invention is to efficiently transmit data to a terminal through an extension of a radio bearer (RB).
  • RB radio bearer
  • Another technical problem of the present invention is to provide specific data through a small cell to the terminal connected to the macro cell.
  • Another technical problem of the present invention is to provide a service through a small cell suitable for service operation of a specific Quality of Service (QoS).
  • QoS Quality of Service
  • Another technical problem of the present invention is to prevent frequent handover of a terminal and provide data seamlessly.
  • a method for supporting bearer extension by a terminal in a heterogeneous network system reserves a parameter for configuring a radio bearer (RB) mapped to an extended EPS system bearer between the terminal and a small eNB, and uplink transmission using the extended EPS bearer.
  • RB radio bearer
  • the first RRC includes a parameter for configuring a radio bearer (RB) mapped to an extended EPS bearer between the terminal and the small base station and UL Tx reservation information indicating that the uplink transmission using the extended EPS bearer is reserved.
  • a terminal receiver configured to receive a connection reconfiguration message from the macro base station, a terminal processor configuring the radio bearer based on the parameter, and a first RRC connection reconfiguration complete message indicating that configuration of the radio bearer is completed to the macro base station; It includes a terminal transmission unit.
  • the terminal receiver may receive a second RRC connection reconfiguration message from the macro base station including UL Tx start information (ULTxStartInfo) indicating to start the uplink transmission using the extended EPS bearer.
  • ULTxStartInfo UL Tx start information
  • a method for supporting bearer extension by a macro base station in a heterogeneous network system reserves a parameter for configuring a radio bearer (RB) mapped to an extended EPS (Evoled Packet System) bearer between a terminal and a small eNB, and uplink transmission using the extended EPS bearer.
  • RB radio bearer
  • EPS Extended Packet System
  • a macro base station supporting bearer expansion in a heterogeneous network system.
  • the macro base station includes a parameter for configuring a radio bearer (RB) mapped to an extended EPS bearer between a terminal and a small base station, and UL Tx reservation information indicating that the uplink transmission using the extended EPS bearer is reserved.
  • a base station transmitter for transmitting a connection reconfiguration message to the terminal, and a base station receiver for receiving a first RRC connection reconfiguration complete message from the terminal indicating that the configuration of the radio bearer is completed based on the parameter.
  • the base station transmitter may transmit a second RRC connection reconfiguration message including UL Tx start information (ULTxStartInfo) indicating to start the uplink transmission using the extended EPS bearer.
  • ULTxStartInfo UL Tx start information
  • an excessive load or a load requiring a specific QoS may be distributed to small cells without a handover procedure, and data may be efficiently transmitted or received.
  • FIG. 1 shows a wireless communication system to which the present invention is applied.
  • FIG. 2 is a block diagram illustrating a radio protocol architecture for a user plane.
  • FIG. 3 is a block diagram illustrating a radio protocol structure for a control plane.
  • FIG. 4 shows a structure of a bearer service in a wireless communication system to which the present invention is applied.
  • FIG. 5 is a diagram schematically illustrating a concept of a heterogeneous network including a macro base station, a femto base station, and a pico base station according to the present invention.
  • FIG. 6 is a conceptual diagram illustrating a connection configuration between a macro base station and a small base station according to the present invention.
  • FIG. 7 is a flowchart illustrating signaling between a terminal, a macro base station, and a small base station according to an embodiment of the present invention.
  • FIG. 8 is a flowchart illustrating signaling between a terminal, a macro base station, and a small base station according to another example of the present invention.
  • FIG. 9 is a flowchart illustrating signaling between a terminal, a macro base station, and a small base station according to another example of the present invention.
  • FIG. 10 is an operation flowchart of a terminal according to an example of the present invention.
  • FIG. 11 is a flowchart illustrating operations of a terminal according to another embodiment of the present invention.
  • FIG. 12 is an operation flowchart of a macro base station according to an example of the present invention.
  • FIG. 13 is a flowchart illustrating operations of a macro base station according to another embodiment of the present invention.
  • FIG. 14 is a flowchart illustrating operations of a small base station according to an example of the present invention.
  • 15 is a block diagram illustrating a terminal, a macro base station and a small base station according to the present invention.
  • the present specification describes a wireless communication network
  • the operation performed in the wireless communication network is performed in the process of controlling the network and transmitting data in the system (for example, the base station) that is in charge of the wireless communication network, or the corresponding wireless Work may be done at the terminal coupled to the network.
  • E-UMTS Evolved-Universal Mobile Telecommunications System
  • LTE Long Term Evolution
  • LTE-A Advanced
  • Wireless communication systems are widely deployed to provide various communication services such as voice, packet data, and the like.
  • CDMA Code Division Multiple Access
  • TDMA Time Division Multiple Access
  • FDMA Frequency Division Multiple Access
  • OFDMA Orthogonal Frequency Division Multiple Access
  • SC-FDMA Single Carrier-FDMA
  • OFDM-FDMA OFDM-TDMA
  • various multiple access schemes such as OFDM-CDMA may be used.
  • the uplink transmission and the downlink transmission may use a time division duplex (TDD) scheme that is transmitted using different times, or may use a frequency division duplex (FDD) scheme that is transmitted using different frequencies.
  • TDD time division duplex
  • FDD frequency division duplex
  • the E-UTRAN includes a base station (BS) 20 that provides a control plane and a user plane to a user equipment (UE).
  • the terminal 10 may be fixed or mobile and may be called by other terms such as mobile station (MS), advanced MS (AMS), user terminal (UT), subscriber station (SS), and wireless device (Wireless Device). .
  • the base station 20 generally refers to a station communicating with the terminal 10, and includes an evolved-NodeB (eNodeB), a Base Transceiver System (BTS), an Access Point, an femto-eNB, It may be called other terms such as a pico-eNB, a home eNB, and a relay.
  • the base station 20 may provide at least one cell to the terminal.
  • the cell may mean a geographic area where the base station 20 provides a communication service or may mean a specific frequency band.
  • the cell may mean a downlink frequency resource and an uplink frequency resource. Alternatively, the cell may mean a combination of a downlink frequency resource and an optional uplink frequency resource.
  • the base stations 20 may be connected to each other through an X2 interface.
  • the base station 20 is connected to a Serving Gateway (S-GW) through an MME (Mobility Management Entity) and an S1-U through an Evolved Packet Core (EPC) 30, more specifically, an S1-MME through an S1 interface.
  • S-GW Serving Gateway
  • MME Mobility Management Entity
  • EPC Evolved Packet Core
  • S1 interface exchanges OAM (Operation and Management) information for supporting the movement of the terminal 10 by exchanging signals with the MME.
  • OAM Operaation and Management
  • EPC 30 includes MME, S-GW and P-GW (Packet Data Network-Gateway).
  • the MME has access information of the terminal 10 or information on the capability of the terminal 10, and this information is mainly used for mobility management of the terminal 10.
  • the S-GW is a gateway having an E-UTRAN as an endpoint
  • the P-GW is a gateway having a PDN (Packet Data Network) as an endpoint.
  • Integrating the E-UTRAN and the EPC 30 may be referred to as an EPS (Evoled Packet System), and the traffic flows from the radio link that the terminal 10 accesses the base station 20 to the PDN connecting to the service entity are all IP. It works based on (Internet Protocol).
  • EPS Evoled Packet System
  • the radio interface between the terminal and the base station is called a Uu interface.
  • Layers of the radio interface protocol between the terminal and the network are based on the lower three layers of the Open System Interconnection (OSI) reference model, which is widely known in communication systems.
  • OSI Open System Interconnection
  • L2 second layer
  • L3 third layer
  • the RRC Radio Resource Control
  • the RRC layer located in the third layer plays a role of controlling radio resources between the terminal and the network.
  • the RRC layer exchanges an RRC message between the terminal and the base station.
  • FIG. 2 is a block diagram illustrating a radio protocol architecture for a user plane.
  • 3 is a block diagram illustrating a radio protocol structure for a control plane.
  • the user plane is a protocol stack for user data transmission
  • the control plane is a protocol stack for control signal transmission.
  • a physical layer (PHY) layer provides an information transfer service to a higher layer using a physical channel.
  • the physical layer is connected to the upper layer Medium Access Control (MAC) layer through a transport channel.
  • MAC Medium Access Control
  • Transport channels are classified according to how and with what characteristics data is transmitted over the air interface. Data moves between the physical layers, that is, between the physical layers of the transmitter and the receiver.
  • the physical channel may be modulated by an orthogonal frequency division multiplexing (OFDM) scheme and utilizes time and frequency as radio resources.
  • OFDM orthogonal frequency division multiplexing
  • the physical downlink control channel informs the terminal of resource allocation of a paging channel (PCH) and downlink shared channel (DL-SCH) and hybrid automatic repeat request (HARQ) information related to the DL-SCH.
  • the PDCCH may carry an uplink scheduling grant informing the UE of resource allocation of uplink transmission.
  • the physical control format indicator channel (PCFICH) informs the UE of the number of OFDM symbols used for PDCCHs and is transmitted every subframe.
  • PHICH physical Hybrid ARQ Indicator Channel
  • PHICH physical Hybrid ARQ Indicator Channel
  • Physical uplink control channel (PUCCH) carries uplink control information such as HARQ ACK / NAK, scheduling request, and CQI for downlink transmission.
  • Physical uplink shared channel carries an uplink shared channel (UL-SCH).
  • the functions of the MAC layer include mapping between logical channels and transport channels and multiplexing / demultiplexing into transport blocks provided as physical channels on transport channels of MAC service data units (SDUs) belonging to the logical channels.
  • the MAC layer provides a service to a Radio Link Control (RLC) layer through a logical channel.
  • RLC Radio Link Control
  • the logical channel may be divided into a control channel for transmitting control region information and a traffic channel for delivering user region information.
  • RLC layer Functions of the RLC layer include concatenation, segmentation, and reassembly of RLC SDUs.
  • the RLC layer In order to guarantee the various quality of service (QoS) required by the radio bearer (RB), the RLC layer has a transparent mode (TM), an unacknowledged mode (UM), and an acknowledged mode (Acknowledged Mode). Three modes of operation (AM).
  • AM RLC provides error correction through an automatic repeat request (ARQ).
  • PDCP Packet Data Convergence Protocol
  • Functions of the Packet Data Convergence Protocol (PDCP) layer in the user plane include delivery of user data, header compression, and ciphering.
  • the functionality of the Packet Data Convergence Protocol (PDCP) layer in the control plane includes the transfer of control plane data and encryption / integrity protection.
  • the RRC layer is responsible for the control of logical channels, transport channels, and physical channels in connection with configuration, re-configuration, and release of RBs.
  • RB means a logical path provided by the first layer (PHY layer) and the second layer (MAC layer, RLC layer, PDCP layer) for data transmission between the terminal and the network.
  • the configuration of the RB means a process of defining characteristics of a radio protocol layer and a channel to provide a specific service, and setting each specific parameter and operation method.
  • the RB may be further classified into a signaling RB (SRB) and a data RB (DRB).
  • SRB is used as a path for transmitting RRC and NAS messages in the control plane
  • DRB is used as a path for transmitting user data in the user plane.
  • the non-access stratum (NAS) layer located above the RRC layer performs functions such as session management and mobility management.
  • the UE If there is an RRC connection between the RRC layer of the UE and the RRC layer of the E-UTRAN, the UE is in an RRC connected state, otherwise it is in an RRC idle state. do.
  • the downlink transmission channel for transmitting data from the network to the UE includes a BCH (Broadcast Channel) for transmitting system information and a downlink shared channel (SCH) for transmitting user traffic or control messages.
  • Traffic or control messages of a downlink multicast or broadcast service may be transmitted through a downlink SCH or may be transmitted through a separate downlink multicast channel (MCH).
  • the uplink transport channel for transmitting data from the terminal to the network includes a random access channel (RACH) for transmitting an initial control message and an uplink shared channel (SCH) for transmitting user traffic or control messages.
  • RACH random access channel
  • SCH uplink shared channel
  • BCCH broadcast control channel
  • PCCH paging control channel
  • CCCH common control channel
  • MCCH multicast control channel
  • MTCH multicast traffic
  • the physical channel is composed of several symbols in the time domain and several sub-carriers in the frequency domain.
  • One sub-frame consists of a plurality of OFDM symbols in the time domain.
  • One subframe consists of a plurality of resource blocks, and one resource block consists of a plurality of symbols and a plurality of subcarriers.
  • each subframe may use specific subcarriers of specific symbols (eg, the first symbol) of the corresponding subframe for the physical downlink control channel (PDCCH).
  • the transmission time interval (TTI) which is a unit time for transmitting data, is 1 ms corresponding to one subframe.
  • a terminal In order for a terminal to transmit user data (eg, an IP packet) to an external internet network or to receive user data from an external internet network, the terminal exists between mobile communication network entities existing between the terminal and the external internet network. Resources must be allocated to different paths. Thus, a path in which resources are allocated between mobile communication network entities and data transmission and reception is possible is called a bearer.
  • a bearer a path in which resources are allocated between mobile communication network entities and data transmission and reception is possible.
  • FIG. 4 shows a structure of a bearer service in a wireless communication system to which the present invention is applied.
  • the end-to-end service refers to a service that requires a path between the terminal and the P-GW (EPS Bearer) and a P-GW and an external bearer for the Internet network and data service.
  • the external path is a bearer between the P-GW and the Internet network.
  • the terminal In order for the terminal to transmit data to the external internet network, the terminal first transmits data to the base station eNB through the RB on the radio. The base station then transmits data to the S-GW through the S1 bearer. S-GW transmits data to P-GW through S5 / S8 bearer, and finally through external bearer to destinations in P-GW and external internet network.
  • the data can be delivered to the terminal through each bearer in the reverse direction as described above.
  • each bearer is defined for each interface to ensure independence between the interfaces.
  • the bearer at each interface will be described in more detail as follows.
  • the bearers provided by the wireless communication system are collectively called an Evolved Packet System (EPS) bearer.
  • An EPS bearer is a delivery path established between a UE and a P-GW for transmitting IP traffic with a specific QoS.
  • the P-GW may receive IP flows from the Internet or send IP flows to the Internet.
  • Each EPS bearer is set with QoS decision parameters that indicate the nature of the delivery path.
  • One or more EPS bearers may be configured per UE, and one EPS bearer uniquely represents a concatenation of one E-RAB and one S5 / S8 bearer.
  • the S5 / S8 bearer is a bearer of the S5 / S8 interface. Both S5 and S8 are bearers present at the interface between the S-GW and the P-GW.
  • the S5 interface exists when the S-GW and the P-GW belong to the same operator, and the S8 interface belongs to the provider (Visited PLMN) roamed by the S-GW, and the P-GW has subscribed to the original service (Home). PLMN).
  • the E-RAB uniquely represents the concatenation of the S1 bearer and the corresponding RB.
  • one-to-one mapping is established between the E-RAB and one EPS bearer. That is, one EPS bearer corresponds to one RB, S1 bearer, and S5 / S8 bearer, respectively.
  • the S1 bearer is a bearer at the interface between the base station and the S-GW.
  • RB means two types of data RB (Data Radio Bearer (DRB)) and signaling RB (Signaling Radio Bearer (SRB)).
  • DRB Data Radio Bearer
  • SRB Signaling Radio Bearer
  • the expression RB without distinction refers to data RB provided in the Uu interface to support a service of a user. to be. Therefore, an RB expressed without distinction is distinguished from a signaling radio bearer (SRB).
  • the RB is a path through which data of the user plane is transmitted
  • the SRB is a path through which data of the control plane, such as the RRC layer and NAS control messages, are delivered.
  • One-to-one mapping is established between RB, E-RAB and EPS bearer.
  • EPS bearer types include a default bearer and a dedicated bearer.
  • an IP address is assigned and a default EPS bearer is created while creating a PDN connection. That is, a default bearer is first created when a new PDN connection is created.
  • a service for example, the Internet, etc.
  • VoD for example, VoD, etc.
  • a dedicated bearer is created. In this case, the dedicated bearer may be set to a different QoS from the bearer that is already set.
  • QoS decision parameters applied to the dedicated bearer are provided by a Policy and Charging Rule Function (PCRF).
  • PCRF Policy and Charging Rule Function
  • the PCRF may receive subscription information of a user from a Subscriber Profile Repository (SPR) to determine QoS determination parameters.
  • SPR Subscriber Profile Repository
  • Up to 15 dedicated bearers may be created, for example, and four of the 15 are not used in the LTE system. Therefore, up to 11 dedicated bearers can be created.
  • the EPS bearer includes a QoS Class Identifier (QCI) and Allocation and Retention Priority (ARP) as basic QoS determination parameters.
  • EPS bearers are classified into GBR (Guaranteed Bit Rate) bearers and non-GBR bearers according to QCI resource types.
  • the default bearer is always a non-GBR type bearer, and the dedicated bearer may be set as a GBR type or non-GBR type bearer.
  • the GBR bearer has GBR and MBR (Maximum Bit Rate) as QoS decision parameters in addition to QCI and ARP.
  • small cells such as pico cells, femto cells, and wireless relays may be used to operate data services for indoor and outdoor small areas.
  • pico cells can generally be used in communication shadow areas that are not covered by macro cells alone, or in areas with high data service demands, so-called hot spots or hot zones.
  • a femto eNB is generally used in an indoor office or home.
  • the wireless relay can supplement the coverage of the macro cell.
  • FIG. 5 is a diagram schematically illustrating a concept of a heterogeneous network including a macro base station, a femto base station, and a pico base station according to the present invention.
  • FIG. 5 illustrates a heterogeneous network including a macro base station, a femto base station, and a pico base station for convenience of description
  • the heterogeneous network may include a micro, relay, or other type of base station.
  • the base station may include the aforementioned macro base station, femto base station, pico base station, micro base station, relay, and other types of base stations.
  • a macro base station 510, a femto base station 520, and a pico base station 530 are operated together in a heterogeneous network.
  • the macro base station 510, the femto base station 520, and the pico base station 530 each provide their cell coverage of the macro cell, femto cell, and pico cell to the terminal.
  • the femto base station 520 is a low power wireless access point, and is a micro mobile base station for indoor use such as a home or an office.
  • the femto base station 520 may access a mobile communication core network using a DSL or cable broadband of a home or office.
  • the femto base station 520 may be supported with a self-organization function. Self-organization functions are classified into a self-configuration function, a self-optimization function, and a self-monitoring function.
  • the femtocell may distinguish registered users from unregistered users and allow access only to registered users.
  • Cells that allow access only to registered users are called Closed Subscriber Groups (hereinafter referred to as "CSGs"), and those that allow access to general users are also called Open Subscriber Groups (“OSGs"). It is called. It is also possible to mix these two methods.
  • a base station providing a femtocell service is called a home node b (HNB) or home enode b (henb) in 3GPP.
  • the femto base station 520 basically aims to provide specialized services only to members belonging to the CSG. In terms of providing a service, when the femto base station 520 provides a service only to the CSG group, the cell provided by the femto base station 520 is referred to as a CSG cell.
  • Each CSG has its own unique identifier, which is called a CSG identity (CSG identity).
  • the UE may have a list of CSGs belonging to its members, which is also called a white list. You can check which CSG your CSG cell supports by reading the CSG ID included in the system information.
  • the terminal reading the CSG ID is regarded as a cell that can access the cell only when the UE is a member of the CSG cell, that is, when the CSG corresponding to the CSG ID is included in its CSG whitelist.
  • picocells for coverage holes hereinafter referred to as coverage hole picocells
  • coverage hole picocells pictureocells for hot spots
  • hotspot picocells There is).
  • the coverage hole picocell is used for the UE to transmit and receive data through the pico cell in place of the macro cell when the UE cannot transmit or receive data through the macro cell.
  • the hot spot picocell is capable of transmitting and receiving data through the macro cell, but is used for the terminal to transmit and receive data through the pico cell instead of the macro cell in order to reduce the load of the macro cell.
  • Hot spots can also refer to areas with a high concentration of floating or permanent population, or areas with very high demand traffic. In general, hot spot regions can occur regardless of the electro-magnetic field of the macro, where the pico cell is divided into two types: intra-frequency picocells and inter-frequency picocells. It can be divided into forms.
  • An intra-frequency pico cell refers to a picocell using the same frequency band as the macro cell. By reusing the same frequency resources in spatially separated areas, it is possible to secure the same radio resources as the macro cells within pico cell coverage.
  • the pico cell for most coverage holes corresponds to an intra-frequency pico cell.
  • Inter-frequency picocells are picocells that use a different frequency band than macro cells.
  • performance degradation may occur due to an interference problem between the pico cell and the macro cell. It can be used when there is a hot spot at a position close to the center of the macro cell.
  • a small cell serves a smaller area than a macro cell, it is advantageous to a macro cell in terms of throughput that can be provided for a single terminal.
  • the terminal connected to the macro cell is located in the service area of the small cell, the terminal cannot receive the service from the small cell without performing the handover.
  • the handover may occur frequently because the small cell coverage is small, which is not preferable in terms of network efficiency.
  • embodiments of the present invention will be described in detail, and embodiments of the present invention can be applied to a heterogeneous network system including a macro cell and a small cell.
  • One embodiment includes a method for supporting data service or load distribution through a small cell while maintaining an EPS bearer including a wireless connection between a terminal and a macro cell in a heterogeneous network system.
  • the above method may be applied when the terminal connected to the macro cell is located in an area over-laid with the service area of the macro cell and the service area of the small cell.
  • This method is referred to as a procedure for configuring multiple wireless connections.
  • the method may be called an extended bearer establishment procedure or a bearer extension procedure.
  • the control plane (RRC layer, NAS) for the terminal is provided by the EPS bearer of the macro cell, and the user plane is provided by the EPS bearer of the small cell.
  • the terminal may receive a downlink signal from the small cell or transmit an uplink signal to the small cell without handover in the state of accessing the macro cell.
  • the downlink signal includes data of the user plane transmitted through the downlink
  • the uplink signal includes data of the user plane transmitted through the uplink. Data in the control plane is transmitted and received through the macro cell.
  • the extended bearer establishment procedure or bearer extension procedure is a macro base station used to negotiate expansion bearer setup between the macro base station and the small base station, and to create an RB and suspend uplink transmission between the small base station and the terminal. And performing first RRC signaling between the terminal and the second RRC signaling between the macro base station and the terminal used to allow uplink transmission to the small base station when the bearer expansion is completed. have.
  • FIG. 6 is a conceptual diagram illustrating a connection configuration between a macro base station and a small base station according to the present invention.
  • data is transmitted from the packet data network 600 to the P-GW 605, and the data is transmitted to the macro base station 620 via the S-GW 610.
  • QoS for the data may be set at a particular level.
  • the macro base station 620 and the terminal 640 are configured with an EPS bearer of the macro cell.
  • the macro base station 620 includes an RRC entity 621, a PDCP entity 622, an RLC entity 623, a MAC entity 624, and a PHY layer 625.
  • the structure and operation of each entity include the contents described with reference to FIGS. 2 and 3.
  • the small base station 630 includes a PDCP entity 632, an RLC entity 633, a MAC entity 634, and a PHY layer 635.
  • the macro base station 620 receives the data at the PDCP entity 622, processes the data based on control of the RRC entity 621, and the like. 623, the MAC entity 624 and the PHY layer 625 to the terminal 640.
  • the terminal 640 there are entities forming the EPS bearer of the macro cell in the terminal 640.
  • the MAC entity and the PHY layer exist on the terminal 640 side.
  • the extended EPS bearer for the small base station 630 and the terminal 640 may be generated.
  • the creation of the extended EPS bearer is made by the above-described extended bearer setup procedure.
  • An operation mode of the small base station 630 and the terminal 640 after the extended EPS bearer is generated is called a bearer extended mode.
  • the S-GW 610 may forward the data to the PDCP entity 632 of the small base station 630 via the backhaul network.
  • the RLC entity 633 of the small base station 630 then transmits it to the terminal 640 via the MAC entity 634 and the PHY layer 635.
  • entities that form an extended EPS bearer are also created in the terminal 640.
  • the terminal 640 may receive the service through the EPS bearer of the small base station 630 that the service was provided through the EPS bearer of the macro base station 620.
  • the control plane (RRC layer, NAS) for the terminal is provided by the macro cell
  • the user plane is provided by the extended EPS bearer of the small cell.
  • the present embodiment includes an operation of maintaining the EPS bearer of the macro cell without deleting it. According to this, the following effects are obtained.
  • the user data exchanged between the terminal and the core network is transmitted to the base station or the core.
  • a large amount of user data must be exchanged through the interface between the macro cell and the small cell or buffered at the network side. This problem can be solved.
  • the radio configuration such as handover is frequently changed.
  • the EPS bearer of the macro cell may be released, and again when the UE returns to the macro cell within a short time, the EPS bearer of the macro cell may be generated again. .
  • this may cause signaling overhead between the terminal and the base station.
  • the terminal can easily reuse it at any time while maintaining the EPS bearer of the macro cell until the terminal is completely determined as a macro cell or a small cell, it is possible to stably provide a data transmission / reception service of the terminal. For example, if the extended EPS bearer is deleted because the terminal is out of the coverage of the small cell (or the use of the extended EPS bearer is stopped), it can be quickly reused without resetting the radio configuration corresponding to the EPS bearer of the macro cell. have.
  • the terminal does not need to perform a random access procedure accompanying the handover, and thus does not cause service interruption in the wireless section during random access.
  • FIG. 6 shows only data transmission in the downlink direction with an arrow, the technical content of FIG. 6 may be similarly applied to data transmission in the uplink direction.
  • the terminal may be located in an overlapped region of the macro cell operated by the macro base station and the small cell operated by the small base station.
  • the terminal measures the signal strength of the small cell and transmits a measurement report to the macro base station when the measured signal strength satisfies a specific criterion (S700). For example, for the measured signal strength to meet a certain criterion, the signal strength of the small cell must be greater than the signal strength of the macro cell, or the signal strength of the small cell must be greater than the threshold.
  • a specific criterion For example, for the measured signal strength to meet a certain criterion, the signal strength of the small cell must be greater than the signal strength of the macro cell, or the signal strength of the small cell must be greater than the threshold.
  • the macro base station determines to generate an extended EPS bearer between the small base station and the terminal in addition to the EPS bearer of the macro cell formed between itself and the terminal, and starts the bearer expansion procedure.
  • the bearer extension procedure starts by sending a bearer extension request message to the small base station (S705).
  • the bearer extension request message may be transmitted from the macro base station to the small base station through the X2 interface.
  • the purpose of the macro base station to create an extended EPS bearer is to perform load balancing or to provide a better QoS to the terminal when the signal strength of the small cell is large enough.
  • the macro base station can be expected to generate an extended EPS bearer of the same level as the QoS provided by the existing macro base station, or to generate an extended EPS bearer capable of providing a higher level of QoS to the terminal.
  • the macro base station may also want to create an extended EPS bearer that satisfies a lower level of QoS.
  • the purpose or needs of generating the extended EPS bearer may be determined by comprehensively considering factors such as QoS or load balancing of the macro cell service.
  • the bearer extension request message in step S705 may include at least one information element (IE).
  • the information element may be a UE identifier or an EPS bearer identifier or QoS decision parameter of a macro cell.
  • the terminal identifier is an identification number for identifying the terminal and may include a Cell-Radio Network Temporary Identifier (C-RNTI), an International Mobile Subscriber Identity (IMSI), a Globally Unique Temporary Identity (GUTI), and the like.
  • C-RNTI Cell-Radio Network Temporary Identifier
  • IMSI International Mobile Subscriber Identity
  • GUI Globally Unique Temporary Identity
  • the EPS bearer identifier of the macro cell is information for identifying the EPS bearer of the macro cell formed between the macro base station and the terminal.
  • the QoS determination parameter is a parameter used to determine the QoS to be expected for the extended EPS bearer or the QoS applied to the EPS bearer of the macro cell.
  • QoS determination parameters include, for example, values that can characterize QoS, such as QoS Class Identifiers (QCI), Guaranteed Bit Rate (GBR) QoS information, and Maximum Bit Rate (MBR).
  • QCI QoS Class Identifiers
  • GRR Guaranteed Bit Rate
  • MRR Maximum Bit Rate
  • QCI is a scalar that is used as a reference to access node-specific parameters that control bearer level packet forwarding treatment, and the scalar value is assigned to an operator owning a base station.
  • the scalar may be preconfigured with any one of integer values 1 to 9.
  • the main purpose of ARP is to determine whether a bearer's establishment / modification request is accepted or needs to be rejected in case of resource limitations.
  • ARP may also be used to determine which bearer (s) to drop by the base station at exceptional resource limitations, for example at handover.
  • GBR means that fixed resources are allocated for each bearer (bandwidth guarantee).
  • non-GBR has an aggregated maximum bit rate (AMBR) as a QoS decision parameter in addition to QCI and ARP, and instead of not being allocated resources per bearer, it is allocated the maximum bandwidth that can be used like other non-GBR bearers. Means.
  • AMBR aggregated maximum bit rate
  • the small base station Upon receiving the bearer extension request message, the small base station extracts information elements included in the bearer extension request message. And the small base station generates, with the core network side, an extended EPS bearer that satisfies the QoS determination parameter, instead of the EPS bearer of the macro cell identified by the terminal bearer identifier of the macro cell. Prepare a procedure (S710).
  • the small base station and the core network determine an identifier of the extended EPS bearer and determine an E-RAB identifier associated with the extended EPS bearer identifier. Then, the newly created extended EPS bearer and the E-RAB are performed in preparation for using the EPS bearer of the macro cell instead.
  • the small base station transmits a bearer extension response message including radio configuration parameter values satisfying QoS of the extended EPS bearer and its associated E-RAB to the macro base station (S715).
  • the bearer extension response message is a message that informs the UE of the availability or activation of the extended EPS bearer. This may include messages coming from the core network.
  • the X2 interface may be used for delivery of the bearer extension response message.
  • the radio configuration parameter values included in a bearer extension response message are parameters configuring an RB, and may include system information, PHY, and MAC layer information necessary to provide a service to a terminal on a small cell. .
  • the bearer extension response message may include at least one of a terminal identifier, system information of a small cell, physical layer information of a small cell, information of a MAC layer of a small cell, an EPS bearer identifier of a macro cell, and an extended EPS bearer identifier. It may include.
  • the bearer extension response message may include parameters for DRB configuration, for example, DRB identifier (drb-Identity), PDCH configuration information (pdcp-Config), RLC configuration information (rlc-Config), and extended EPS bearer. It may further include at least one of the identifier.
  • the bearer extension response message may include information according to the combination of the first embodiment and the second embodiment, may include information according to the combination of the first embodiment and the third embodiment, and The information according to the combination of the third embodiment may be included, or the information according to the combination of the first to third embodiments may be included.
  • the macro base station transmits a first RRC connection reconfiguration message to the terminal (S720).
  • the first RRC connection reconfiguration message includes control information required between the small base station and the terminal to complete the extended EPS bearer.
  • the first RRC connection reconfiguration message may include UL Tx reservation information (ULTxSuspendInfo) indicating that the uplink transmission using the extended EPS bearer is suspended.
  • the first RRC connection reconfiguration message may include UL Tx reservation information meaning that uplink transmission is not performed using the extended EPS bearer. If the extended EPS bearer is not used in the generation of the extended EPS bearer in the entire period from the terminal to the core network, the user data exchanged between the terminal and the core network is buffered at the base station or the core network, or the macro base station is used. This is because a problem that a large amount of data must be exchanged through the interface between the and the small base station may occur.
  • the uplink transmission may not include transmission of PUCCH and HARQ ACK / NACK information. In other words, despite the UL Tx reservation information, the terminal may transmit the PUCCH and HARQ ACK / NACK information.
  • the first RRC connection reconfiguration message may include all radio configuration parameter values of the bearer extension response message.
  • the first RRC connection reconfiguration message may include detailed information indicating availability or activation of an extended EPS bearer formed between the small base station and the terminal.
  • the first RRC connection reconfiguration message includes a dedicated NAS list information element used for transferring UE specific NAS layer information between the core network and the terminal.
  • the dedicated NAS list information element may include detailed information indicating availability or activation of the extended EPS bearer formed between the small base station and the terminal.
  • the first RRC connection reconfiguration message may include information according to the combination of the first embodiment and the second embodiment, may include information according to the combination of the first embodiment and the third embodiment, and the first embodiment. It may include information according to a combination of an example and a fourth embodiment, may include information according to a combination of a second embodiment and a third embodiment, and include information according to a combination of a second embodiment and a fourth embodiment. In addition, the information according to the combination of the third and fourth embodiments may be included, and the information according to the combination of the first to fourth embodiments may be included.
  • This embodiment is not limited to the transmission of the UL Tx reservation information (ULTxSuspendInfo) included in the first RRC connection reconfiguration message. That is, the UL Tx reservation information may be transmitted independently of the first RRC connection reconfiguration message.
  • the UL Tx reservation information may be transmitted independently of the first RRC connection reconfiguration message.
  • the terminal completes the radio configuration with the small base station based on the first RRC connection reconfiguration message, and transmits a first RRC connection reconfiguration complete message to the macro base station indicating that the radio configuration corresponding to the extended EPS bearer was successfully completed ( S725).
  • the terminal that has received the UL Tx reservation information may transmit and process uplink (UL) data through the EPS bearer of the macro cell since the extended EPS bearer is not yet completed in the core network. That is, in the preparation for generating the extended EPS bearer, the UE performs uplink transmission using the EPS bearer of the macro cell which is not deleted. However, the UE may transmit PUCCH and HARQ ACK / NACK information using an extended EPS bearer as an exception. The terminal receives and processes downlink (DL) data through the EPS bearer of the macro cell.
  • DL downlink
  • the radio configuration is completed in the terminal (that is, the RB configuration is completed) and the extended EPS bearer can be used
  • the reason why the uplink transmission is still performed through the EPS bearer of the macro cell is to ensure the reliability of the uplink transmission.
  • the terminal may use only the EPS bearer of the macro cell until the extended EPS bearer completes generation of not only the RB but also the core network.
  • the macro base station transmits an RB generation completion message indicating that generation of the RB is completed between the terminal and the small base station to the small base station (S730).
  • the RB creation complete message is a message transmitted through the X2 interface.
  • the small base station can confirm that the configuration of the RB corresponding to the extended EPS bearer has been successfully completed. Finally, generation of the RB is completed between the terminal and the small base station (S735).
  • the small base station completes generation of an extended EPS bearer for the core network (S740). After the extended EPS bearer is generated in the core network, the P-GW among the components of the core network starts transmitting user data coming from the PDN through the P-GW toward the terminal to the terminal using the extended EPS bearer. The small base station transmits the user data flowing through the P-WG to the terminal using the extended EPS (S745). Since the generation of the RB is completed between the small base station and the terminal, the small base station transmits the user data through the extended EPS bearer. There is no problem in transmitting data to the terminal, and the terminal also has no problem in receiving the user data through the extended EPS bearer.
  • the macro base station transmits a second RRC connection reconfiguration message indicating that the uplink transmission is started in the extended EPS bearer (S750). Accordingly, the UE can perform uplink transmission using the extended EPS bearer (S755).
  • the second RRC connection reconfiguration message includes UL Tx reservation information indicating that uplink transmission is stopped in the EPS bearer of the macro cell and UL Tx start information (ULTxStartInfo) indicating that uplink transmission is started in the extended EPS bearer. It includes.
  • the second RRC connection reconfiguration message may include UL Tx reservation information indicating that uplink transmission is stopped in the EPS bearer of the macro cell and UL Tx start information (ULTxStartInfo) indicating that uplink transmission is started in the extended EPS bearer. ), And may include an identifier of the EPS bearer of the macro cell and an identifier of the extended EPS bearer.
  • This embodiment is not limited to the transmission of the UL Tx start information (ULTxStartInfo) included in the second RRC connection reconfiguration message. That is, the UL Tx start information may be transmitted independently of the second RRC connection reconfiguration message.
  • the UL Tx start information may be transmitted independently of the second RRC connection reconfiguration message.
  • step S750 another embodiment of the present invention transmits the PDCCH instead of transmitting the second RRC connection reconfiguration message of step S750. It may include. That is, the terminal may receive downlink assignment information from the macro small base station through the PDCCH. In this case, the terminal may determine that uplink transmission is possible. Therefore, when uplink transmission is required, the terminal may perform uplink transmission through an extended EPS bearer.
  • the terminal does not release the EPS bearer of the macro cell, so that the terminal does not reset the EPS bearer of the macro cell even if the terminal returns to the area of the macro cell only within a short time. That is, the EPS bearer of the macro cell can be quickly and simply used by releasing and reusing an uplink suspend state of the EPS bearer of the macro cell. As a result, the terminal can be stably provided with a service without burden of signaling and battery consumption due to wireless configuration. Maintaining the EPS bearer of the macro cell in this way may burden the management of the terminal or the network, but does not continue to use the actual radio resources.
  • the UE may operate an EPS bearer timer, which is a timer related to the release of the EPS bearer of the macro cell.
  • the terminal may be located in an overlapped region of the macro cell operated by the macro base station and the small cell operated by the small base station.
  • the signaling and operation of the terminal, the macro base station, and the small base station before step S805 may be equally applied to the signaling and operation of steps S700 to S750.
  • the macro base station transmits a second RRC connection reconfiguration message to the terminal (S750).
  • the UE Upon receiving the second RRC connection reconfiguration message, the UE can perform both uplink transmission and downlink reception using the extended EPS bearer.
  • the terminal drives the EPS bearer timer (S805).
  • the EPS bearer timer provides a time for the UE to continue without releasing the EPS bearer of the macro cell.
  • the terminal and the macro base station maintain the EPS bearer of the macro cell while the EPS bearer timer is in progress, and release the EPS bearer of the macro cell when the EPS bearer timer expires.
  • the length of the EPS bearer timer can range from a few seconds to a few minutes.
  • the EPS bearer timer may have a value of 3 seconds, 5 seconds, 10 seconds, ..., 1 minute, 3 minutes, ..., and the value of the EPS bearer timer may be a QoS determination parameter or communication situation. It may be selected or changed as appropriate.
  • the value of the EPS bearer timer may be provided by RRC signaling from the macro base station or the small base station to the terminal.
  • the terminal checks whether the EPS bearer timer has expired (S810). If the terminal stays in the overlapped region until the EPS bearer timer expires, and the terminal does not return to the macro cell region and exits the overlapped region, it is determined that the terminal has moved to the overlapped region.
  • the terminal transmits an EPS bearer release request message of the macro cell requesting release of the EPS bearer of the macro cell to the macro base station (S815).
  • the EPS bearer release request message of the macro cell may include, for example, a terminal identifier, an EPS bearer identifier of the macro cell, and a release indication field.
  • the UE and / or the macro base station Upon receiving the EPS bearer release request message of the macro cell, the UE and / or the macro base station releases the EPS bearer of the macro cell (S820).
  • the terminal if the terminal is surely moved to the overlapped region and the likelihood of ping-pong phenomenon is very low or not, it is efficient to release the EPS bearer of the macro cell, so that the exact criterion for releasing the EPS bearer of the macro cell is effective. To provide.
  • the embodiment of Figure 8 although the terminal operates and manages the EPS bearer timer, the macro base station may be the subject of the operation and management of the EPS bearer timer.
  • the EPS bearer timer may be driven based on a different time point than the embodiment of FIG. 8. This is illustrated in FIG. 9.
  • FIG. 9 is a flowchart illustrating signaling between a terminal, a macro base station, and a small base station according to another example of the present invention.
  • the terminal may be located in an overlapped region of the macro cell operated by the macro base station and the small cell operated by the small base station.
  • the macro base station When the macro base station confirms generation (or activation) of an extended EPS bearer (S745), the macro base station starts an EPS bearer timer (S905).
  • the EPS bearer timer may have a value of 3 seconds, 5 seconds, 10 seconds, ..., 1 minute, 3 minutes, ..., and the value of the EPS bearer timer may be a QoS determination parameter or communication situation. It may be selected or changed as appropriate.
  • the value of the EPS bearer timer may be directly managed by the macro base station. If the UE stays in the overlapped area until the EPS bearer timer expires (S910), the macro base station determines that the UE has moved to the overlapped area. Afterwards, the EPS bearer of the macro cell is released (S915).
  • FIG. 10 is an operation flowchart of a terminal according to an example of the present invention.
  • the terminal transmits a measurement report to the macro base station (S1000).
  • the signal strength of the small cell must be greater than the signal strength of the macro cell, or the signal strength of the small cell must be greater than the threshold.
  • the terminal receives the first RRC connection reconfiguration message from the macro base station (S1005).
  • the first RRC connection reconfiguration message includes control information required between the small base station and the terminal to complete the extended EPS bearer.
  • the first RRC connection reconfiguration message may include UL Tx reservation information (ULTxSuspendInfo) indicating that the uplink transmission using the extended EPS bearer is suspended.
  • the first RRC connection reconfiguration message may include UL Tx reservation information meaning that uplink transmission is not performed using the extended EPS bearer.
  • the uplink transmission may not include transmission of PUCCH and HARQ ACK / NACK information.
  • the terminal may transmit the PUCCH and HARQ ACK / NACK information.
  • the first RRC connection reconfiguration message may include all radio configuration parameter values of the bearer extension response message.
  • the first RRC connection reconfiguration message may include detailed information indicating availability or activation of an extended EPS bearer formed between the small base station and the terminal.
  • the first RRC connection reconfiguration message includes a dedicated NAS list information element used for transferring UE specific NAS layer information between the core network and the terminal.
  • the dedicated NAS list information element may include detailed information indicating availability or activation of the extended EPS bearer formed between the small base station and the terminal.
  • the first RRC connection reconfiguration message may include information according to the combination of the first embodiment and the second embodiment, may include information according to the combination of the first embodiment and the third embodiment, and the first embodiment. It may include information according to a combination of an example and a fourth embodiment, may include information according to a combination of a second embodiment and a third embodiment, and include information according to a combination of a second embodiment and a fourth embodiment. In addition, the information according to the combination of the third and fourth embodiments may be included, and the information according to the combination of the first to fourth embodiments may be included.
  • the terminal completes the radio configuration with the small base station based on the first RRC connection reconfiguration message, and transmits a first RRC connection reconfiguration complete message to the macro base station indicating that the radio configuration corresponding to the extended EPS bearer was successfully completed ( S1010).
  • the macro base station receiving the first RRC connection reconfiguration complete message transmits the message to the small base station.
  • an RB is generated between the terminal and the small base station (S1015).
  • the terminal transmits uplink data using the generated RB even though the extended EPS bearer is not yet completed in the core network side, the uplink data is buffered in a small base station or the EPS bearer of the macro cell is used. This may cause a problem of being transmitted back to the macro base station.
  • the UE since the UE has not yet completed the EPS bearer of the small cell in the core network, the DL data is received and processed through the EPS bearer of the macro cell, and the UL data is also small cell. Since the EPS bearer is in a suspended state, it is transmitted and processed through the EPS bearer of the macro cell. That is, in the preparation step of generating the extended EPS bearer, the UE performs uplink transmission and downlink reception using the EPS bearer of the macro cell which is not deleted.
  • the UE may transmit PUCCH and HARQ ACK / NACK information using an extended EPS bearer as an exception.
  • the radio configuration is completed in the terminal (that is, the RB configuration is completed) and the extended EPS bearer can be used, the reason why the uplink transmission is still performed through the EPS bearer of the macro cell is to ensure the reliability of the uplink transmission.
  • the UE stops using the extended EPS bearer when it leaves the coverage of the small cell it can be quickly reused without resetting the RB corresponding to the EPS bearer of the macro cell.
  • the macro base station Upon confirming that generation of the extended EPS bearer for the core network is completed, the macro base station transmits a second RRC connection reconfiguration message to the terminal, and the terminal receives the second RRC connection reconfiguration message from the macro base station (S1020).
  • the second RRC connection reconfiguration message is for the UE to allow uplink transmission using the extended EPS bearer.
  • the second RRC connection reconfiguration message includes UL Tx reservation information indicating that uplink transmission is stopped in the EPS bearer of the macro cell and UL Tx start information (ULTxStartInfo) indicating that uplink transmission is started in the extended EPS bearer. It includes.
  • the second RRC connection reconfiguration message may include UL Tx reservation information indicating that uplink transmission is stopped in the EPS bearer of the macro cell and UL Tx start information (ULTxStartInfo) indicating that uplink transmission is started in the extended EPS bearer. ), And may include an identifier of the EPS bearer of the macro cell and an identifier of the extended EPS bearer.
  • This embodiment is not limited to the transmission of the UL Tx start information (ULTxStartInfo) included in the second RRC connection reconfiguration message. That is, the UL Tx start information may be transmitted independently of the second RRC connection reconfiguration message.
  • the UL Tx start information may be transmitted independently of the second RRC connection reconfiguration message.
  • the UE can perform both uplink transmission and downlink reception using the extended EPS bearer.
  • another embodiment of the present invention may include transmission of the PDCCH instead of transmission of the second RRC connection reconfiguration message of step S1025. That is, the terminal may receive downlink assignment information (downlink assignment) from the small base station through the PDCCH, the terminal may determine that uplink transmission is also possible. Therefore, when uplink transmission is required, the terminal may perform uplink transmission through an extended EPS bearer.
  • downlink assignment information downlink assignment
  • FIG. 11 is a flowchart illustrating operations of a terminal according to another embodiment of the present invention.
  • operations of the terminal before step S1100 may include signaling and operations of steps S1000 to S1025 of FIG. 10.
  • the UE may perform both uplink transmission and downlink reception using the extended EPS bearer.
  • the terminal drives the EPS bearer timer (S1105).
  • the EPS bearer timer provides a time for the UE to continue without releasing the EPS bearer of the macro cell.
  • the terminal and the macro base station maintain the EPS bearer of the macro cell while the EPS bearer timer is in progress, and release the EPS bearer of the macro cell when the EPS bearer timer expires.
  • the length of the EPS bearer timer can range from a few seconds to a few minutes.
  • the EPS bearer timer may have a value of 3 seconds, 5 seconds, 10 seconds, ..., 1 minute, 3 minutes, ..., and the value of the EPS bearer timer may be a QoS determination parameter or communication situation. It may be selected or changed as appropriate.
  • the value of the EPS bearer timer is provided by the RRC signaling from the macro base station or the small base station to the terminal.
  • the UE operation according to the EPS bearer timer is as follows.
  • the UE checks whether the EPS bearer timer has expired (S1110). If the terminal stays in the overlapped region until the EPS bearer timer expires, and the terminal does not return to the macro cell region and exits the overlapped region, it is determined that the terminal has moved to the overlapped region.
  • the terminal transmits an EPS bearer release request message of the macro cell requesting release of the EPS bearer of the macro cell to the macro base station (S1115).
  • the EPS bearer release request message of the macro cell may include, for example, a terminal identifier, an EPS bearer identifier of the macro cell, and a release indication field.
  • the terminal and / or the macro base station Upon receiving the EPS bearer release request message of the macro cell, the terminal and / or the macro base station releases the EPS bearer of the macro cell (S1120).
  • the terminal if the terminal is surely moved to the overlapped region and the likelihood of ping-pong phenomenon is very low or not, it is efficient to release the EPS bearer of the macro cell, so that the exact criterion for releasing the EPS bearer of the macro cell is effective. To provide.
  • FIG. 12 is an operation flowchart of a macro base station according to an example of the present invention.
  • the macro base station receives a measurement report from the terminal (S1200).
  • the macro base station determines to generate an extended EPS bearer between the small base station and the terminal in addition to the EPS bearer of the macro cell formed between itself and the terminal, and starts the bearer expansion procedure.
  • the bearer extension procedure starts by sending a bearer extension request message to the small base station (S1205).
  • the bearer extension request message may be transmitted from the macro base station to the small base station through the X2 interface.
  • the purpose of the macro base station to create an extended EPS bearer is to perform load balancing or provide better QoS to the terminal when the signal strength of the small cell is large enough.
  • the macro base station can be expected to generate an extended EPS bearer of the same level as the QoS provided by the existing macro base station, or to generate an extended EPS bearer capable of providing a higher level of QoS to the terminal.
  • the macro base station may also want to create an extended EPS bearer that satisfies a lower level of QoS.
  • the purpose or needs of generating the extended EPS bearer may be determined by comprehensively considering factors such as QoS or load balancing of the macro cell service.
  • the bearer extension request message may include at least one information element (IE).
  • the information element may be a UE identifier or an EPS bearer identifier or QoS decision parameter of a macro cell.
  • the macro base station receives from the small base station a bearer extension response message including radio configuration parameter values satisfying QoS of the extended EPS bearer and its associated E-RAB (S1210).
  • the bearer extension response message is a message that informs the UE of the availability or activation of the extended EPS bearer. This may be a message coming from the core network.
  • the X2 interface may be used for delivery of the bearer extension response message.
  • the radio configuration parameter values included in a bearer extension response message are parameters configuring an RB, and may include system information, PHY, and MAC layer information necessary to provide a service to a terminal on a small cell. .
  • the bearer extension response message may include at least one of a terminal identifier, system information of a small cell, physical layer information of a small cell, information of a MAC layer of a small cell, an EPS bearer identifier of a macro cell, and an extended EPS bearer identifier. It may include.
  • the bearer extension response message may include parameters for DRB configuration, for example, DRB identifier (drb-Identity), PDCH configuration information (pdcp-Config), RLC configuration information (rlc-Config), and extended EPS bearer. It may further include at least one of the identifier.
  • the bearer extension response message may include information according to the combination of the first embodiment and the second embodiment, may include information according to the combination of the first embodiment and the third embodiment, and The information according to the combination of the third embodiment may be included, or the information according to the combination of the first to third embodiments may be included.
  • the macro base station transmits a first RRC connection reconfiguration message to the terminal (S1215).
  • the first RRC connection reconfiguration message includes control information required between the small base station and the terminal to complete the extended EPS bearer.
  • the first RRC connection reconfiguration message may include UL Tx reservation information (ULTxSuspendInfo) indicating that the uplink transmission using the extended EPS bearer is suspended.
  • the first RRC connection reconfiguration message may include UL Tx reservation information meaning that uplink transmission is not performed using the extended EPS bearer.
  • the uplink transmission may not include transmission of PUCCH and HARQ ACK / NACK information.
  • the terminal may transmit the PUCCH and HARQ ACK / NACK information.
  • the first RRC connection reconfiguration message may include all radio configuration parameter values of the bearer extension response message.
  • the first RRC connection reconfiguration message may include detailed information indicating usage or activation of an extended EPS bearer formed between the small base station and the terminal.
  • the first RRC connection reconfiguration message includes a dedicated NAS list information element used for transferring UE specific NAS layer information between the core network and the terminal.
  • the dedicated NAS list information element may include detailed information indicating availability or activation of the extended EPS bearer formed between the small base station and the terminal.
  • the first RRC connection reconfiguration message may include information according to the combination of the first embodiment and the second embodiment, may include information according to the combination of the first embodiment and the third embodiment, and the first embodiment. It may include information according to a combination of an example and a fourth embodiment, may include information according to a combination of a second embodiment and a third embodiment, and include information according to a combination of a second embodiment and a fourth embodiment. In addition, the information according to the combination of the third and fourth embodiments may be included, and the information according to the combination of the first to fourth embodiments may be included.
  • the macro base station receives from the terminal a first RRC connection reconfiguration complete message indicating that the terminal has successfully completed a radio configuration corresponding to the extended EPS bearer (S1220).
  • the macro base station transmits to the small base station an RB generation complete message indicating that the terminal has completed the generation of the RB for the small base station (S1225).
  • the RB creation complete message is a message transmitted through the X2 interface.
  • the small base station can confirm that the configuration of the RB corresponding to the extended EPS bearer has been successfully completed.
  • the radio configuration corresponding to the extended EPS bearer and generation of the RB are completed, when the extended EPS bearer is not yet completed in the core network side, when the terminal transmits uplink data using the generated RB, the uplink Data may be buffered at the small base station or may be transmitted back to the macro base station to use the EPS bearer of the macro cell.
  • the terminal receiving the UL Tx reservation information UL data is received and processed through the EPS bearer of the macro cell. That is, in the preparation stage for generating the extended EPS bearer, the macro base station performs uplink reception using the EPS bearer of the macro cell which is not deleted.
  • the PUCCH and HARQ ACK / NACK information may be exceptionally received by the small base station using the extended EPS bearer.
  • the reason why the uplink transmission is still performed through the EPS bearer of the macro cell is to ensure the reliability of the uplink transmission. Accordingly, when the UE stops using the extended EPS bearer when it leaves the coverage of the small cell, it can be quickly reused by only releasing the uplink suspension state without resetting the RB corresponding to the EPS bearer of the macro cell. . Until the extended EPS bearer completes generation of not only the RB but also the core network, only the EPS bearer of the macro cell is used.
  • the small base station may perform downlink transmission to the terminal using the extended EPS bearer.
  • the macro base station When the macro base station confirms that generation of the extended EPS bearer for the core network of the small base station is completed, the macro base station transmits a second RRC connection reconfiguration message to the terminal (S1230). From this time, the terminal may perform uplink transmission using the extended EPS bearer, and the small base station may receive the uplink data from the terminal using the extended EPS bearer.
  • the second RRC connection reconfiguration message includes UL Tx reservation information indicating that uplink transmission is stopped in the EPS bearer of the macro cell and UL Tx start information (ULTxStartInfo) indicating that uplink transmission is started in the extended EPS bearer. It includes.
  • the second RRC connection reconfiguration message may include UL Tx reservation information indicating that uplink transmission is stopped in the EPS bearer of the macro cell and UL Tx start information (ULTxStartInfo) indicating that uplink transmission is started in the extended EPS bearer. ), And may include an identifier of the EPS bearer of the macro cell and an identifier of the extended EPS bearer.
  • step S1230 another embodiment of the present invention instead of transmitting the second RRC connection reconfiguration message of step S1230, transmits the PDCCH. It may include. That is, the small base station may transmit downlink assignment information (downlink assignment) to the terminal through the PDCCH, the terminal may determine that uplink transmission is also possible to the small base station. Therefore, when uplink transmission is required, the terminal may perform uplink transmission through an extended EPS bearer.
  • the small base station may transmit downlink assignment information (downlink assignment) to the terminal through the PDCCH
  • the terminal may determine that uplink transmission is also possible to the small base station. Therefore, when uplink transmission is required, the terminal may perform uplink transmission through an extended EPS bearer.
  • FIG. 13 is a flowchart illustrating operations of a macro base station according to another embodiment of the present invention.
  • the basic operation of the macro base station is applied in the same manner as the embodiment of FIG. 12, and there is a difference in that the macro base station operates the EPS bearer timer.
  • the macro base station When the macro base station confirms generation (or activation) of the extended EPS bearer (S1300), the macro base station starts the EPS bearer timer (S1305).
  • the EPS bearer timer may have a value of 3 seconds, 5 seconds, 10 seconds, ..., 1 minute, 3 minutes, ..., and the value of the EPS bearer timer may be a QoS determination parameter or communication situation. It may be selected or changed as appropriate.
  • the value of the EPS bearer timer may be directly managed by the macro base station. Until the EPS bearer timer confirms the expiration (S1310), if the terminal stays in the overlapped area without returning to the macro cell area in the overlapped area, the macro base station surely moves to the overlapped area. After determining that the determination is made, the EPS bearer of the macro cell is released (S1315).
  • FIG. 14 is a flowchart illustrating operations of a small base station according to an example of the present invention.
  • the macro base station determines to create an extended EPS bearer and starts a bearer extension procedure.
  • the bearer extension procedure starts with the small base station receiving a bearer extension request message from the macro base station (S1400).
  • the bearer extension request message may be transmitted from the macro base station to the small base station through the X2 interface.
  • the bearer extension request message may include at least one information element (IE).
  • the information element may be a UE identifier or an EPS bearer identifier or QoS determination parameter of a macro cell.
  • the small base station Upon receiving the bearer extension request message, the small base station extracts information elements included in the bearer extension request message. And the small base station generates an additional extended EPS bearer satisfying the QoS determination parameter together with the core network side, in addition to the EPS bearer of the macro cell identified by the terminal identified by the terminal identifier, by the EPS bearer identifier of the macro cell. Prepare the procedure (S1405).
  • the small base station and the core network determine an identifier of the extended EPS bearer and determine an E-RAB identifier associated with the extended EPS bearer identifier. Then, the newly created extended EPS bearer and the E-RAB are performed in preparation for using the EPS bearer of the macro cell instead.
  • the small base station transmits a bearer extension response message including radio configuration parameter values satisfying QoS of the extended EPS bearer and its associated E-RAB to the macro base station (S1410).
  • the bearer extension response message is a message for notifying the terminal of the availability or activation of the extended EPS bearer. This may be a message coming from the core network.
  • the X2 interface may be used for delivery of the bearer extension response message.
  • the radio configuration parameter values included in a bearer extension response message are parameters configuring an RB, and may include system information, PHY, and MAC layer information necessary to provide a service to a terminal on a small cell. .
  • the bearer extension response message may include at least one of a terminal identifier, system information of a small cell, physical layer information of a small cell, information of a MAC layer of a small cell, an EPS bearer identifier of a macro cell, and an extended EPS bearer identifier. It may include.
  • the bearer extension response message may include parameters for DRB configuration, for example, DRB identifier (drb-Identity), PDCH configuration information (pdcp-Config), RLC configuration information (rlc-Config), and extended EPS bearer. It may further include at least one of the identifier.
  • the bearer extension response message may include information according to the combination of the first embodiment and the second embodiment, may include information according to the combination of the first embodiment and the third embodiment, and The information according to the combination of the third embodiment may be included, or the information according to the combination of the first to third embodiments may be included.
  • the small base station receives an RB generation complete message from the macro base station indicating that the terminal has completed generation of the RB for the small base station (S1415).
  • the RB creation complete message is a message transmitted through the X2 interface.
  • the small base station can confirm that the configuration of the RB corresponding to the extended EPS bearer has been successfully completed.
  • the small base station generates an RB for the terminal (S1420). If the terminal transmits uplink data using the generated RB even though the extended EPS bearer is not yet completed in the core network side, the uplink data is buffered in a small base station or the EPS bearer of the macro cell is used. This may cause a problem of being transmitted back to the macro base station.
  • the terminal processes both uplink (UL) data and downlink (DL) data to the macro base station through the EPS bearer of the macro cell until the extended EPS bearer is completed on the core network side. That is, in the preparation step of generating the extended EPS bearer, the UE performs uplink transmission and downlink reception using the EPS bearer of the macro cell which is not deleted. That is, the terminal uses only the EPS bearer of the macro cell until generation of the extended EPS bearer is completed not only for the RB but also for the core network.
  • the small base station completes generation of an extended EPS bearer for the core network (S1425).
  • the P-GW among the components of the core network may transmit user data coming from the PDN through the P-GW toward the terminal to the terminal using the extended EPS bearer. Since generation of the RB is completed between the base station and the terminal, there is no problem in the terminal performing uplink transmission to the small base station through the extended EPS bearer. Accordingly, the small base station also receives and processes uplink (UL) data from the terminal through the extended EPS bearer (S1430).
  • UL uplink
  • 15 is a block diagram illustrating a terminal, a macro base station and a small base station according to the present invention.
  • the terminal 1500 includes a terminal receiver 1505, a terminal processor 1510, and a terminal transmitter 1515.
  • the macro base station 1530 includes a macro transmitter 1535, a macro receiver 1540, and a macro processor 1545.
  • the small base station 1560 includes a small transmitter 1565, a small receiver 1570, and a small processor 1575.
  • the terminal processor 1510 measures the signal strength of the small cell, and generates a measurement report when the measured signal strength satisfies a specific criterion.
  • the transmitter 1515 transmits a measurement report to the macro base station 1530. For example, if the measured signal strength satisfies a specific criterion, the signal strength of the small cell is larger than the signal strength of the macro cell. The signal strength of the large or small cell must be greater than the threshold.
  • the macro processor 1454 determines to generate an extended EPS bearer between the small base station 1560 and the terminal 1500 in addition to the EPS bearer of the macro cell formed between the macro base station 1530 and the terminal 1500 and starts the bearer expansion procedure. do.
  • the bearer extension procedure starts by the macro transmitter 1535 transmitting a bearer extension request message to the small base station 1560.
  • the bearer extension request message may be transmitted from the macro base station 1530 to the small base station 1560 through the X2 interface.
  • the purpose of the macro processor 1545 to generate the extended EPS bearer is to perform load balancing or provide better QoS to the terminal when the signal strength of the small cell is large enough.
  • the macro base station 1530 may generate an extended EPS bearer having the same level of QoS as that provided by the existing macro base station 1530, or provide an extended EPS bearer capable of providing a higher level of QoS to the terminal 1500. You can expect to produce.
  • the macro base station 1530 may also want to create an extended EPS bearer that satisfies a lower level of QoS. As such, the purpose or needs of generating the extended EPS bearer may be determined by comprehensively considering factors such as QoS or load balancing of the macro cell service.
  • the bearer extension request message may include at least one information element (IE).
  • the information element may be a UE identifier or an EPS bearer identifier or QoS decision parameter of a macro cell.
  • the terminal identifier is an identification number for identifying the terminal and may include a Cell-Radio Network Temporary Identifier (C-RNTI), an International Mobile Subscriber Identity (IMSI), a Globally Unique Temporary Identity (GUTI), and the like.
  • C-RNTI Cell-Radio Network Temporary Identifier
  • IMSI International Mobile Subscriber Identity
  • GUI Globally Unique Temporary Identity
  • the EPS bearer identifier of the macro cell is information for identifying the EPS bearer of the macro cell formed between the macro base station 1530 and the terminal 1500.
  • the QoS determination parameter is a parameter used to determine the QoS to be expected for the extended EPS bearer or the QoS applied to the EPS bearer of the macro cell.
  • QoS determination parameters include, for example, values that can characterize QoS, such as QoS Class Identifiers (QCI), Guaranteed Bit Rate (GBR) QoS information, and Maximum Bit Rate (MBR).
  • QCI QoS Class Identifiers
  • GRR Guaranteed Bit Rate
  • MRR Maximum Bit Rate
  • the small processor 1575 Upon receiving the bearer extension request message, the small processor 1575 extracts information elements included in the bearer extension request message.
  • the small processor 1575 may further include an additional extended EPS bearer that satisfies the QoS determination parameter, in addition to the EPS bearer of the macro cell identified by the terminal bearer identifier of the macro cell. Prepare the procedure to create with the network side.
  • the small base station 1560 and the core network determine an identifier of the extended EPS bearer and determine an E-RAB identifier associated with the extended EPS bearer identifier.
  • the small processor 1575 performs preparatory work necessary to use the newly created extended EPS bearer and the E-RAB in place of the EPS bearer of the macro cell.
  • the small processor 1575 generates a bearer extension response message including the extended EPS bearer and radio configuration parameter values satisfying QoS of the associated E-RAB, and the small transmitter 1565 sends this to the macro base station 1530. send.
  • the bearer extension response message is a message for notifying the terminal 1500 of availability or activation of the extended EPS bearer. This may be a message coming from the core network.
  • the X2 interface may be used for delivery of the bearer extension response message.
  • the radio configuration parameter values included in a bearer extension response message are parameters configuring an RB, and include system information necessary to provide a service to the terminal 1500 on a small cell, and information of a PHY and MAC layer. can do.
  • the bearer extension response message may include at least one of a terminal identifier, system information of a small cell, physical layer information of a small cell, information of a MAC layer of a small cell, an EPS bearer identifier of a macro cell, and an extended EPS bearer identifier. It may include.
  • the bearer extension response message may include parameters for DRB configuration, for example, DRB identifier (drb-Identity), PDCH configuration information (pdcp-Config), RLC configuration information (rlc-Config), and extended EPS bearer. It may further include at least one of the identifier.
  • the bearer extension response message may include information according to the combination of the first embodiment and the second embodiment, may include information according to the combination of the first embodiment and the third embodiment, and The information according to the combination of the third embodiment may be included, or the information according to the combination of the first to third embodiments may be included.
  • the macro processor 1545 generates a first RRC connection reconfiguration message, and the macro transmitter 1535 transmits the first RRC connection reconfiguration message to the terminal 1500.
  • the first RRC connection reconfiguration message includes control information required between the small base station 1560 and the terminal 1500 to complete the extended EPS bearer.
  • the first RRC connection reconfiguration message may include UL Tx reservation information (ULTxSuspendInfo) indicating that the uplink transmission using the extended EPS bearer is suspended.
  • the first RRC connection reconfiguration message may include UL Tx reservation information meaning that uplink transmission is not performed using the extended EPS bearer.
  • the first RRC connection reconfiguration message may include all radio configuration parameter values of the bearer extension response message.
  • the first RRC connection reconfiguration message may include detailed information indicating availability or activation of an extended EPS bearer formed between the small base station 1560 and the terminal 1500. .
  • the first RRC connection reconfiguration message includes a dedicated NAS List information element used for transferring UE specific NAS layer information between the core network and the terminal 1500.
  • the dedicated NAS list information element may include detailed information indicating availability or activation of the extended EPS bearer formed between the small base station and the terminal.
  • the first RRC connection reconfiguration message may include information according to the combination of the first embodiment and the second embodiment, may include information according to the combination of the first embodiment and the third embodiment, and the first embodiment. It may include information according to a combination of an example and a fourth embodiment, may include information according to a combination of a second embodiment and a third embodiment, and include information according to a combination of a second embodiment and a fourth embodiment. In addition, the information according to the combination of the third and fourth embodiments may be included, and the information according to the combination of the first to fourth embodiments may be included.
  • This embodiment is not limited to the transmission of the UL Tx reservation information (ULTxSuspendInfo) included in the first RRC connection reconfiguration message. That is, the UL Tx reservation information may be transmitted independently of the first RRC connection reconfiguration message.
  • the UL Tx reservation information may be transmitted independently of the first RRC connection reconfiguration message.
  • the terminal processor 1510 completes the radio configuration and the RB generation for the small base station 1560, generates a first RRC connection reconfiguration complete message indicating that the RRC connection reconfiguration has been successfully completed, and the terminal transmitter 1515 The first RRC connection reconfiguration complete message is transmitted to the macro base station 1530.
  • the macro transmitter 1535 transmits an RB generation completion message indicating that the generation of the RB is completed between the terminal 1500 and the small base station 1560 to the small base station 1560.
  • the RB creation complete message is a message transmitted through the X2 interface.
  • the small receiver 1570 may confirm that the configuration of the RB corresponding to the extended EPS bearer has been successfully completed.
  • the terminal 1500 transmits uplink data using the generated RB even though the extended EPS bearer is not yet completed in the core network side, the uplink data is buffered in the small base station 1560 or macros. There may be a problem of being transmitted back to the macro base station 1530 in order to use the EPS bearer of the cell.
  • the terminal 1500 processes both uplink (UL) data and downlink (DL) data to the macro base station through the EPS bearer of the macro cell. That is, in the preparation stage of generating the extended EPS bearer, the terminal 1500 performs uplink transmission and downlink reception using the EPS bearer of the macro cell remaining without being deleted. That is, the terminal 1500 uses only the EPS bearer of the macro cell until the extended EPS bearer is completely created not only the RB but also the core network.
  • the small processor 1575 completes the creation of the extended EPS bearer for the core network.
  • the P-GW among the components of the core network transmits user data coming in through the P-GW from the PDN toward the terminal 1500 to the terminal 1500 using the extended EPS bearer.
  • generation of the RB is completed between the small base station 1560 and the terminal 1500, the small transmitter 1565 transmits user data to the terminal 1500, and the terminal receiver 1505 transmits the user through an extended EPS bearer. There is no problem in receiving data.
  • the macro processor 1545 When the generation of the extended EPS bearer for the core network is completed, the macro processor 1545 generates a second RRC connection reconfiguration message, and the macro transmitter 1535 transmits the second RRC connection reconfiguration message to the terminal 1500. To send. Accordingly, the terminal processor 1510 may use an extended EPS bearer for uplink transmission, and the small receiver 1570 may also receive uplink data from the terminal 1500 using the extended EPS bearer.
  • the second RRC connection reconfiguration message includes UL Tx reservation information indicating that uplink transmission is stopped in the EPS bearer of the macro cell and UL Tx start information (ULTxStartInfo) indicating that uplink transmission is started in the extended EPS bearer. It includes.
  • the second RRC connection reconfiguration message may include UL Tx reservation information indicating that uplink transmission is stopped in the EPS bearer of the macro cell and UL Tx start information (ULTxStartInfo) indicating that uplink transmission is started in the extended EPS bearer. ), And may include an identifier of the EPS bearer of the macro cell and an identifier of the extended EPS bearer.
  • This embodiment is not limited to the transmission of the UL Tx start information (ULTxStartInfo) included in the second RRC connection reconfiguration message. That is, the UL Tx start information may be transmitted independently of the second RRC connection reconfiguration message.
  • the UL Tx start information may be transmitted independently of the second RRC connection reconfiguration message.
  • the macro transmitter 1535 may transmit the PDCCH instead of transmitting the second RRC connection reconfiguration message. That is, the terminal 1500 may receive downlink assignment information from the macro base station through the PDCCH. In this case, the terminal 1500 may determine that uplink transmission is possible. Therefore, the terminal 1500 may perform uplink transmission through an extended EPS bearer when uplink transmission is required.
  • the terminal 1500 does not release the EPS bearer of the macro cell, so that the terminal 1500 does not reset the EPS bearer of the macro cell even if the terminal 1500 returns to the macro cell only area within a short time.
  • the terminal 1500 can be stably provided with a service without burden of signaling and battery consumption due to wireless configuration.
  • maintaining the EPS bearer of the macro cell does not continue to use the actual radio resources, but may burden management with the terminal 1500 or the network.
  • the terminal processor 151 may operate an EPS bearer timer.
  • the terminal processor 151 may process both uplink transmission and downlink reception using the extended EPS bearer.
  • the terminal processor 151 drives the EPS bearer timer.
  • the EPS bearer timer provides a time for the terminal processor 151 to continue without releasing the EPS bearer of the macro cell.
  • the terminal processor 151 maintains the EPS bearer of the macro cell while the EPS bearer timer is in progress, and releases the EPS bearer of the macro cell when the EPS bearer timer expires.
  • the length of the EPS bearer timer can range from a few seconds to a few minutes.
  • the EPS bearer timer may have a value of 3 seconds, 5 seconds, 10 seconds, ..., 1 minute, 3 minutes, ..., and the value of the EPS bearer timer may be a QoS determination parameter or communication situation. It may be selected or changed as appropriate.
  • the terminal processor 151 checks whether the EPS bearer timer has expired. If the terminal 1500 stays in the overlapped area until the EPS bearer timer expires and does not return to the macro cell area beyond the overlapped area, the terminal processor 151 may determine the area in which the terminal 1500 overlaps. I think I've moved on.
  • the terminal processor 151 generates an EPS bearer release request message of the macro cell requesting release of the EPS bearer of the macro cell, and the terminal transmitter 1515 sends the EPS bearer release request message of the macro cell to the macro base station 1530. ).
  • the EPS bearer release request message of the macro cell may include, for example, a terminal identifier, an EPS bearer identifier of the macro cell, and a release indication field.
  • the terminal processor 1510 and / or the macro processor 1545 releases the EPS bearer of the macro cell.
  • the macro processor 1545 may also operate an EPS bearer timer.
  • macro processor 1545 confirms creation (or activation) of an extended EPS bearer
  • macro processor 1545 starts an EPS bearer timer.
  • the EPS bearer timer may have a value of 3 seconds, 5 seconds, 10 seconds, ..., 1 minute, 3 minutes, ..., and the value of the EPS bearer timer may be a QoS determination parameter or communication situation. It may be selected or changed as appropriate.
  • the value of the EPS bearer timer may be directly managed by the macro processor 1545. If it is determined that the terminal 1500 stays in the overlapped region until the EPS bearer timer expires, the macro processor 1545 may determine that the terminal 1500 remains in the overlapped region. After determining that it has moved to the overlapped region, the EPS bearer of the macro cell is released.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Quality & Reliability (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

La présente invention concerne un procédé pour commander une extension de support dans un système de communication sans fil de réseau hétérogène et un appareil pour ce procédé. La présente invention présente un équipement d'utilisateur pour prendre en charge une extension de support dans le système de réseau hétérogène comprenant : une unité de réception d'équipement d'utilisateur pour recevoir, d'une macro station de base, un premier message de reconfiguration de connexion RRC, qui contient un paramètre pour configurer un support radio (RB) qui est mappé vers un support EPS étendu entre l'équipement d'utilisateur et une petite station de base, et des informations de retenue de transmission de liaison montante qui indiquent la retenue d'une transmission de liaison montante en utilisant le support EPS étendu ; un processeur d'équipement d'utilisateur pour configurer le support radio sur la base du paramètre ; et une unité de transmission d'équipement d'utilisateur pour transmettre, à la macro station de base, un premier message d'achèvement de reconfiguration de connexion RRC qui indique l'achèvement de la configuration du support radio.
PCT/KR2013/011214 2012-12-20 2013-12-05 Procédé de commande d'extension de support dans un système de communication sans fil de réseau hétérogène et appareil pour ce procédé WO2014098393A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
KR1020120149730A KR20140080192A (ko) 2012-12-20 2012-12-20 이종 네트워크 무선 통신 시스템에서 베어러 확장 제어 방법 및 그 장치
KR10-2012-0149730 2012-12-20

Publications (1)

Publication Number Publication Date
WO2014098393A1 true WO2014098393A1 (fr) 2014-06-26

Family

ID=50978659

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2013/011214 WO2014098393A1 (fr) 2012-12-20 2013-12-05 Procédé de commande d'extension de support dans un système de communication sans fil de réseau hétérogène et appareil pour ce procédé

Country Status (2)

Country Link
KR (1) KR20140080192A (fr)
WO (1) WO2014098393A1 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016195450A1 (fr) * 2015-06-05 2016-12-08 엘지전자 주식회사 Procédé d'émission de données par un terminal dans un système de communication sans fil prenant en charge une liaison montante à grande vitesse, et appareil associé
WO2017047878A1 (fr) * 2015-09-16 2017-03-23 엘지전자(주) Procédé de paramétrage de support et dispositif prenant en charge celui-ci pour émettre/recevoir des données dans un système de communication sans fil
WO2017082682A1 (fr) * 2015-11-11 2017-05-18 엘지전자(주) Procédé pour sélectionner un nœud de transmission de données dans un système de communication sans fil et appareil associé
CN107734563A (zh) * 2016-08-12 2018-02-23 电信科学技术研究院 切换场景下的QoS参数处理的方法及设备
WO2020060224A1 (fr) * 2018-09-19 2020-03-26 Samsung Electronics Co., Ltd. Procédé et appareil d'émission et de réception de données dans un système de communication sans fil

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11076436B2 (en) * 2018-04-13 2021-07-27 T-Mobile Usa, Inc. QCI change via bearer release and reestablishment

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120142278A1 (en) * 2009-08-20 2012-06-07 Jing Wang Method, system and transmission distribution network element for indicating data-distribution
US20120250601A1 (en) * 2011-03-28 2012-10-04 Hyung-Nam Choi Communication terminal, method for exchanging data, communication device and method for establishing a communication connection
WO2012138094A2 (fr) * 2011-04-03 2012-10-11 엘지전자 주식회사 Procédé de transmission d'informations de localisation et équipement utilisateur
WO2012136311A1 (fr) * 2011-04-05 2012-10-11 Panasonic Corporation Détachement d'un terminal mobile à partir d'un système de communication mobile
US20120281566A1 (en) * 2011-04-01 2012-11-08 Interdigital Patent Holdings, Inc. Method and apparatus for controlling connectivity to a network

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120142278A1 (en) * 2009-08-20 2012-06-07 Jing Wang Method, system and transmission distribution network element for indicating data-distribution
US20120250601A1 (en) * 2011-03-28 2012-10-04 Hyung-Nam Choi Communication terminal, method for exchanging data, communication device and method for establishing a communication connection
US20120281566A1 (en) * 2011-04-01 2012-11-08 Interdigital Patent Holdings, Inc. Method and apparatus for controlling connectivity to a network
WO2012138094A2 (fr) * 2011-04-03 2012-10-11 엘지전자 주식회사 Procédé de transmission d'informations de localisation et équipement utilisateur
WO2012136311A1 (fr) * 2011-04-05 2012-10-11 Panasonic Corporation Détachement d'un terminal mobile à partir d'un système de communication mobile

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016195450A1 (fr) * 2015-06-05 2016-12-08 엘지전자 주식회사 Procédé d'émission de données par un terminal dans un système de communication sans fil prenant en charge une liaison montante à grande vitesse, et appareil associé
US10368277B2 (en) 2015-06-05 2019-07-30 Lg Electronics Inc. Method for transmitting data by terminal in wireless communication system supporting high-speed uplink, and apparatus for same
WO2017047878A1 (fr) * 2015-09-16 2017-03-23 엘지전자(주) Procédé de paramétrage de support et dispositif prenant en charge celui-ci pour émettre/recevoir des données dans un système de communication sans fil
US10736153B2 (en) 2015-09-16 2020-08-04 Lg Electronics Inc. Bearer setting method and device supporting same for transmitting/receiving data in wireless communication system
WO2017082682A1 (fr) * 2015-11-11 2017-05-18 엘지전자(주) Procédé pour sélectionner un nœud de transmission de données dans un système de communication sans fil et appareil associé
US10602380B2 (en) 2015-11-11 2020-03-24 Lg Electronics Inc. Method for selecting data transmission mode in wireless communication system and apparatus therefor
CN107734563A (zh) * 2016-08-12 2018-02-23 电信科学技术研究院 切换场景下的QoS参数处理的方法及设备
US10959133B2 (en) 2016-08-12 2021-03-23 China Academy Of Telecommunications Technology Method and device for processing quality of service parameter in handover scenario
WO2020060224A1 (fr) * 2018-09-19 2020-03-26 Samsung Electronics Co., Ltd. Procédé et appareil d'émission et de réception de données dans un système de communication sans fil
US11212867B2 (en) 2018-09-19 2021-12-28 Samsung Electronics Co., Ltd. Method and apparatus for transmitting and receiving data in wireless communication system

Also Published As

Publication number Publication date
KR20140080192A (ko) 2014-06-30

Similar Documents

Publication Publication Date Title
WO2019160342A1 (fr) Procédé et appareil prenant en charge une mobilité sans rach utilisant des faisceaux préalablement attribués dans un système de communication sans fil
WO2016047904A1 (fr) Procédé de gestion d'émission et de réception de données pour libération de supports liés à des senb au niveau d'un équipement d'utilisateur dans un système à double connectivité et dispositif associé
WO2019098663A1 (fr) Procédé et appareil permettant de déclasser une transmission de paquets dupliqués dans un système de communication sans fil
WO2018044080A1 (fr) Procédé de transmission d'informations de commande de liaison descendante dans un système de communication sans fil, et dispositif associé
WO2019059673A1 (fr) Procédé et appareil d'émission et de réception de données dans un système de communication sans fil
WO2019194486A1 (fr) Procédé et appareil pour éliminer des données en tampon tout en maintenant une connexion dans une séparation cp-up
WO2014163288A1 (fr) Procédé servant à réaliser une attribution de priorité de canal logique et son dispositif de communication
WO2016048076A2 (fr) Procédé d'émission d'un signal d2d et terminal correspondant
WO2017026844A1 (fr) Procédé de fonctionnement d2d exécuté par un terminal dans un système de communication sans fil et terminal utilisant celui-ci
WO2016108680A1 (fr) Procédé pour l'exécution d'une exploitation d2d dans un système de communication sans fil et terminal utilisant ledit procédé
WO2016175639A1 (fr) Procédé de réalisation d'opération d2d par un terminal dans un système de communication sans fil et terminal utilisant le même procédé
WO2015046976A1 (fr) Procédé et appareil d'émission et de réception de données au moyen de plusieurs porteuses dans un système de communication mobile
WO2018182254A1 (fr) Procédé et dispositif permettant de transmettre un message d'informations de défaillance de groupe scg dans un système de communication sans fil
WO2012091450A2 (fr) Procédés et appareils de requête de coordination de brouillage et de traitement de requête de coordination de brouillage entre cellules
WO2019004667A1 (fr) Procédé et appareil de signalisation de résultat de mesurage
WO2019160281A1 (fr) Procédé et appareil pour réaliser un transfert basé sur dc
WO2014098393A1 (fr) Procédé de commande d'extension de support dans un système de communication sans fil de réseau hétérogène et appareil pour ce procédé
WO2016126029A1 (fr) Procédé pour appliquer une nouvelle configuration de pucch dans un système d'agrégation de porteuses, et dispositif associé
WO2014142491A1 (fr) Procédé et appareil pour déterminer une cellule de compensation d'économie d'énergie dans un système d'accès sans fil fondé sur de petites cellules
WO2017196095A2 (fr) Procédé de configuration de double connectivité par un terminal, et appareil associé
WO2016163856A1 (fr) Procédé, réalisé par un terminal, pour émettre un psbch dans un système de communication sans fil et terminal employant le procédé
WO2017131495A1 (fr) Procédé d'exploitation de terminal en fonction d'une planification semi-persistante dans un système de communication sans fil, et dispositif terminal utilisant ledit procédé
WO2015064885A1 (fr) Procédé pour une procédure d'accès aléatoire et terminal associé
WO2017030422A1 (fr) Procédé de commande v2x exécuté par un terminal dans un système de communications sans fil, et terminal l'utilisant
WO2016167559A1 (fr) Procédé et dispositif pour activer ou désactiver un guidage de trafic basé sur un terminal

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 13863731

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 13863731

Country of ref document: EP

Kind code of ref document: A1