WO2016032146A1

WO2016032146A1 - Method for processing paging and method for transmitting downlink data

Info

Publication number: WO2016032146A1
Application number: PCT/KR2015/008374
Authority: WO
Inventors: 류진숙; 김현숙; 김래영; 김재현; 김태훈
Original assignee: 엘지전자 주식회사
Priority date: 2014-08-28
Filing date: 2015-08-11
Publication date: 2016-03-03

Abstract

Provided are a method for processing paging and a method for transmitting downlink data. A method for processing paging, in an entity that is in charge of a control plane in a mobile communication network, comprises the steps of: receiving a downlink data notification (DDN) message from a network node; transmitting a first DDN ACK message to the network node; and, if received is a context request message for a terminal from another entity that is in charge of a control plane after the DNN message has been received, transmitting a second DDN ACK message to the network node, wherein the second DDN ACK message can comprise information that indicates temporary rejection.

Description

How to Handle Paging and How to Pass Downlink Data

The present invention relates to a paging processing method and a downlink data delivery method.

The 3GPP, which enacts the technical specifications of the mobile communication system, has been trying to optimize and improve the performance of 3GPP technologies since late 2004 in order to respond to various forums and new technologies related to 4G mobile communication. Started research on Term Evolution / System Architecture Evolution technology.

SAE, centered on 3GPP SA WG2, is a study on network technology aimed at determining network structure and supporting mobility between heterogeneous networks in parallel with LTE work of 3GPP TSG RAN. Recent important standardization issues of 3GPP Is one of. This is a work to develop a 3GPP system into a system supporting various radio access technologies based on IP, and has been aimed at an optimized packet-based system that minimizes transmission delay with improved data transmission capability.

The Evolved Packet System (EPS) high-level reference model defined by 3GPP SA WG2 includes non-roaming cases and roaming cases in various scenarios. See TS 23.401 and TS 23.402. The network structure diagram of FIG. 1 is a simple reconfiguration.

도 1은 진화된 이동 통신 네트워크의 구조도이다.1 is a structural diagram of an evolved mobile communication network.

An Evolved Packet Core (EPC) may include various components, and in FIG. 1, some of them correspond to a Serving Gateway (S-GW) 52, a Packet Data Network Gateway (PW GW) 53, and an MME. (Mobility Management Entity) 51, Serving General Packet Radio Service (GPRS) Supporting Node (SGSN), and Enhanced Packet Data Gateway (ePDG) are shown.

The S-GW 52 acts as a boundary point between the radio access network (RAN) and the core network, and is an element that functions to maintain a data path between the eNodeB 22 and the PDN GW 53. In addition, when the terminal (or user equipment: UE) moves over the area served by the eNodeB 22, the S-GW 52 serves as a local mobility anchor point. That is, packets may be routed through the S-GW 52 for mobility in the E-UTRAN (Universal Mobile Telecommunications System (Evolved-UMTS) Terrestrial Radio Access Network defined in 3GPP Release-8 or later). In addition, the S-GW 52 may be connected to other 3GPP networks (RANs defined before 3GPP Release-8, for example, UTRAN or GERAN (GSM (Global System for Mobile Communication) / EDGE (Enhanced Data rates for Global Evolution) Radio Access). It can also serve as an anchor point for mobility with a network).

PDN GW (or P-GW) 53 corresponds to the termination point of the data interface towards the packet data network. The PDN GW 53 may support policy enforcement features, packet filtering, charging support, and the like. In addition, mobility management between 3GPP networks and non-3GPP networks (for example, untrusted networks such as Interworking Wireless Local Area Networks (I-WLANs), code-division multiple access (CDMA) networks, or trusted networks such as WiMax) Can serve as an anchor point for.

Although the example of the network structure of FIG. 1 shows that the S-GW 52 and the PDN GW 53 are configured as separate gateways, two gateways may be implemented according to a single gateway configuration option. have.

The MME 51 is an element that performs signaling and control functions to support access to the network connection of the UE, allocation of network resources, tracking, paging, roaming and handover, and the like. . The MME 51 controls control plane functions related to subscriber and session management. The MME 51 manages a number of eNodeBs 22 and performs signaling for the selection of a conventional gateway for handover to other 2G / 3G networks. In addition, the MME 51 performs security procedures, terminal-to-network session handling, idle terminal location management, and the like.

SGSN handles all packet data such as user's mobility management and authentication for other 3GPP access networks (eg GPRS network, UTRAN / GERAN).

The ePDG acts as a secure node for untrusted non-3GPP networks (eg, I-WLAN, WiFi hotspots, etc.).

As described with reference to FIG. 1, a terminal (or UE) having IP capability is provided by an operator (ie, an operator) via various elements in the EPC, based on 3GPP access as well as non-3GPP access. Access to an IP service network (eg, IMS).

1 illustrates various reference points (eg, S1-U, S1-MME, etc.). In the 3GPP system, a conceptual link defining two functions existing in different functional entities of E-UTRAN and EPC is defined as a reference point. Table 1 below summarizes the reference points shown in FIG. 1. In addition to the examples of Table 1, there may be various reference points according to the network structure.

Table 1

Reference point	Explanation
S1-MME	Reference point for control plane protocol between E-UTRAN and MME
S1-U	Reference point between E-UTRAN and SGW for inter-eNB eNB switching and per-bearer user plane tunneling during handover
S3	Reference point between MME and SGSN that provides user and bearer information exchange for mobility between 3GPP access networks in idle and / or active state. This reference point can be used in PLMN-to-PLMN-to-for example (for PLMN-to-PLMN handover))
S4	Reference point between SGW and SGSN that provides relevant control and mobility support between the GPRS core and SGW's 3GPP anchor functionality. It also provides user plane tunneling if no direct tunnel is established.
S5	Reference point providing user plane tunneling and tunnel management between the SGW and PDN GW. Used for SGW reselection (or relocation) due to UE mobility and when a connection to the PDN GW where the SGW is not located is required for the required PDN connectivity.
S11	Reference point between MME and SGW
SGi	Reference point between the PDN GW and the PDN. The PDN may be an operator external public or private PDN or, for example, an in-operator PDN for the provision of IMS services.

Among the reference points shown in FIG. 1, S2a and S2b correspond to non-3GPP interfaces. S2a is a reference point that provides the user plane with associated control and mobility support between trusted non-3GPP access and PDN GW. S2b is a reference point that provides the user plane with relevant control and mobility support between the ePDG and PDN GW.

도 2는 일반적으로 E-UTRAN과 일반적인 EPC의 주요 노드의 기능을 나타낸 예시도이다.Figure 2 is an exemplary view showing the functions of the main nodes of the E-UTRAN and the general EPC in general.

As shown, the eNodeB 20 may route to a gateway, schedule and transmit paging messages, schedule and transmit a broadcaster channel (BCH), uplink and downlink while an RRC (Radio Resource Control) connection is active. Dynamic allocation of resources in the UE, configuration and provision for the measurement of the eNodeB (20), radio bearer control, radio admission control (radio admission control), and can perform functions for connection mobility control. In the EPC, paging occurrence, LTE_IDLE state management, user plane can perform encryption, EPS bearer control, encryption and integrity protection of non-access stratum (NAS) signaling.

도 3은 UE과 eNodeB 사이의 제어 평면에서의 무선 인터페이스 프로토콜(Radio Interface Protocol)의 구조를 나타낸 예시도이고, 도 4는 단말과 기지국 사이에 사용자 평면에서의 무선 인터페이스 프로토콜(Radio Interface Protocol)의 구조를 나타낸 다른 예시도이다. 3 is an exemplary diagram illustrating a structure of a radio interface protocol in a control plane between a UE and an eNodeB, and FIG. 4 is a structure of a radio interface protocol in a user plane between a terminal and a base station. Another example is shown.

The radio interface protocol is based on the 3GPP radio access network standard. The air interface protocol is composed of a physical layer, a data link layer, and a network layer horizontally, and a user plane and control for data information transmission vertically. It is divided into a control plane for signal transmission.

The protocol layers are based on the lower three layers of the Open System Interconnection (OSI) reference model, which is well known in communication systems, and includes L1 (first layer), L2 (second layer), and L3 (third layer). ) Can be separated.

Hereinafter, each layer of the radio protocol of the control plane shown in FIG. 3 and the radio protocol in the user plane shown in FIG. 4 will be described.

The physical layer, which is the first layer, provides an information transfer service using a physical channel. The physical layer is connected to a medium access control layer on the upper side through a transport channel, and data between the medium access control layer and the physical layer is transmitted through the transport channel. In addition, data is transferred between different physical layers, that is, between physical layers of a transmitting side and a receiving side through a physical channel.

The physical channel is composed of several subframes on the time axis and several sub-carriers on the frequency axis. Here, one subframe includes a plurality of symbols and a plurality of subcarriers on the time axis. One subframe consists of a plurality of resource blocks, and one resource block consists of a plurality of symbols and a plurality of subcarriers. The transmission time interval (TTI), which is a unit time for transmitting data, is 1 ms corresponding to one subframe.

According to 3GPP LTE, the physical channels existing in the physical layer of the transmitting side and the receiving side are physical downlink shared channel (PDSCH), physical uplink shared channel (PUSCH) and physical downlink control channel (PDCCH), which are control channels, It may be divided into a Physical Control Format Indicator Channel (PCFICH), a Physical Hybrid-ARQ Indicator Channel (PHICH), and a Physical Uplink Control Channel (PUCCH).

The PCFICH transmitted in the first OFDM symbol of the subframe carries a control format indicator (CFI) regarding the number of OFDM symbols (that is, the size of the control region) used for transmission of control channels in the subframe. The wireless device first receives the CFI on the PCFICH and then monitors the PDCCH.

Unlike the PDCCH, the PCFICH does not use blind decoding and is transmitted on a fixed PCFICH resource of a subframe.

The PHICH carries a positive-acknowledgement (ACK) / negative-acknowledgement (NACK) signal for a UL hybrid automatic repeat request (HARQ). The ACK / NACK signal for uplink (UL) data on the PUSCH transmitted by the wireless device is transmitted on the PHICH.

The Physical Broadcast Channel (PBCH) is transmitted in the preceding four OFDM symbols of the second slot of the first subframe of the radio frame. The PBCH carries system information necessary for the wireless device to communicate with the base station, and the system information transmitted through the PBCH is called a master information block (MIB). In comparison, system information transmitted on the PDSCH indicated by the PDCCH is called a system information block (SIB).

The PDCCH includes resource allocation and transmission format of downlink-shared channel (DL-SCH), resource allocation information of uplink shared channel (UL-SCH), paging information on PCH, system information on DL-SCH, and random access transmitted on PDSCH. Resource allocation of higher layer control messages such as responses, sets of transmit power control commands for individual UEs in any UE group, activation of voice over internet protocol (VoIP), and the like. A plurality of PDCCHs may be transmitted in the control region, and the terminal may monitor the plurality of PDCCHs. The PDCCH is transmitted on an aggregation of one or several consecutive control channel elements (CCEs). CCE is a logical allocation unit used to provide a PDCCH with a coding rate according to a state of a radio channel. The CCE corresponds to a plurality of resource element groups. The format of the PDCCH and the number of bits of the PDCCH are determined according to the correlation between the number of CCEs and the coding rate provided by the CCEs.

Control information transmitted through the PDCCH is called downlink control information (DCI). DCI is a resource allocation of PDSCH (also called DL grant), a PUSCH resource allocation (also called UL grant), a set of transmit power control commands for individual UEs in any UE group. And / or activation of Voice over Internet Protocol (VoIP).

There are several layers in the second layer. First, the Medium Access Control (MAC) layer is responsible for mapping various logical channels to various transport channels, and also for multiplexing logical channel multiplexing to map multiple logical channels to one transport channel. Play a role. The MAC layer is connected to the RLC layer, which is the upper layer, by a logical channel. The logical channel includes a control channel for transmitting information of a control plane according to the type of information to be transmitted. It is divided into a traffic channel that transmits user plane information.

The Radio Link Control (RLC) layer of the second layer adjusts the data size so that the lower layer is suitable for transmitting data to the radio section by segmenting and concatenating data received from the upper layer. It plays a role. In addition, in order to guarantee various QoS required by each radio bearer (RB), TM (Transparent Mode), UM (Un-acknowledged Mode), and AM (Acknowledged Mode, Response mode). In particular, the AM RLC performs a retransmission function through an automatic repeat and request (ARQ) function for reliable data transmission.

The Packet Data Convergence Protocol (PDCP) layer of the second layer is an IP containing relatively large and unnecessary control information for efficient transmission in a wireless bandwidth where bandwidth is small when transmitting an IP packet such as IPv4 or IPv6. Performs Header Compression which reduces the packet header size. This transmits only the necessary information in the header portion of the data, thereby increasing the transmission efficiency of the radio section. In addition, in the LTE system, the PDCP layer also performs a security function, which is composed of encryption (Ciphering) to prevent third-party data interception and integrity protection (Integrity protection) to prevent third-party data manipulation.

The radio resource control layer (hereinafter RRC) layer located at the top of the third layer is defined only in the control plane, and the configuration and resetting of radio bearers (abbreviated as RBs) are performed. It is responsible for the control of logical channels, transport channels and physical channels in relation to configuration and release. In this case, RB means a service provided by the second layer for data transmission between the terminal and the E-UTRAN.

When there is an RRC connection (RRC connection) between the RRC of the terminal and the RRC layer of the wireless network, the terminal is in the RRC connected mode (Connected Mode), otherwise it is in the RRC idle mode (Idle Mode).

Hereinafter, the RRC state and the RRC connection method of the UE will be described. The RRC state refers to whether or not the RRC of the UE is in a logical connection with the RRC of the E-UTRAN. If the RRC state is connected, the RRC_CONNECTED state is called, and the RRC_IDLE state is not connected. Since the UE in the RRC_CONNECTED state has an RRC connection, the E-UTRAN can grasp the existence of the UE in units of cells, and thus can effectively control the UE. On the other hand, the UE in the RRC_IDLE state cannot identify the existence of the UE by the E-UTRAN, and the core network manages the unit in a larger tracking area (TA) unit than the cell. That is, the terminal in the RRC_IDLE state is only detected whether the terminal exists in a larger area than the cell, and the terminal must transition to the RRC_CONNECTED state in order to receive a normal mobile communication service such as voice or data. Each TA is identified by a tracking area identity (TAI). The terminal may configure a TAI through a tracking area code (TAC), which is information broadcast in a cell.

When the user first turns on the power of the terminal, the terminal first searches for an appropriate cell, then establishes an RRC connection in the cell, and registers the terminal's information in the core network. Thereafter, the terminal stays in the RRC_IDLE state. The terminal staying in the RRC_IDLE state (re) selects a cell as needed and looks at system information or paging information. This is called camping on the cell. When it is necessary to establish an RRC connection, the UE staying in the RRC_IDLE state makes an RRC connection with the RRC of the E-UTRAN through an RRC connection procedure and transitions to the RRC_CONNECTED state. There are several cases in which a UE in RRC_IDLE state needs to establish an RRC connection. For example, a user's call attempt, a data transmission attempt, etc. are required or a paging message is received from E-UTRAN. Reply message transmission, and the like.

A non-access stratum (NAS) layer located above the RRC layer performs functions such as session management and mobility management.

The following describes the NAS layer shown in FIG. 3 in detail.

ESM (Evolved Session Management) belonging to the NAS layer performs functions such as default bearer management and dedicated bearer management, and is responsible for controlling the terminal to use the PS service from the network. The default bearer resource is characterized in that it is allocated from the network when it is connected to the network when it first accesses a specific Packet Data Network (PDN). At this time, the network allocates an IP address usable by the terminal so that the terminal can use the data service, and also allocates QoS of the default bearer. LTE supports two types of bearer having a guaranteed bit rate (GBR) QoS characteristic that guarantees a specific bandwidth for data transmission and reception, and a non-GBR bearer having a best effort QoS characteristic without guaranteeing bandwidth. In case of Default bearer, Non-GBR bearer is assigned. In the case of a dedicated bearer, a bearer having a QoS characteristic of GBR or non-GBR may be allocated.

The bearer allocated to the terminal in the network is called an evolved packet service (EPS) bearer, and when the EPS bearer is allocated, the network allocates one ID. This is called EPS Bearer ID. One EPS bearer has QoS characteristics of MBR (maximum bit rate) and GBR (guaranteed bit rate) or AMBR (aggregated maximum bit rate).

도 5는 3GPP LTE에서 랜덤 액세스 과정을 나타낸 흐름도이다. 5 is a flowchart illustrating a random access procedure in 3GPP LTE.

The random access procedure is used for the UE 10 to obtain UL synchronization or to allocate UL radio resources to the base station, that is, the eNodeB 20.

The UE 10 receives a root index and a physical random access channel (PRACH) configuration index from the eNodeB 20. Each cell has 64 candidate random access preambles defined by a Zadoff-Chu (ZC) sequence, and the root index is a logical index for the UE to generate 64 candidate random access preambles.

Transmission of the random access preamble is limited to a specific time and frequency resource for each cell. The PRACH configuration index indicates a specific subframe and a preamble format capable of transmitting the random access preamble.

UE 10 transmits a randomly selected random access preamble to eNodeB 20. The UE 10 selects one of the 64 candidate random access preambles. Then, the corresponding subframe is selected by the PRACH configuration index. UE 10 transmits the selected random access preamble in the selected subframe.

Upon receiving the random access preamble, the eNodeB 20 sends a random access response (RAR) to the UE 10. The random access response is detected in two steps. First, the UE 10 detects a PDCCH masked with a random access-RNTI (RA-RNTI). The UE 10 receives a random access response in a medium access control (MAC) protocol data unit (PDU) on the PDSCH indicated by the detected PDCCH.

도 6은 무선자원제어(RRC) 계층에서의 연결 과정을 나타낸다.6 shows a connection process in a radio resource control (RRC) layer.

As shown in FIG. 6, the RRC state is shown depending on whether the RRC is connected. The RRC state refers to whether or not an entity of the RRC layer of the UE 10 is in a logical connection with an entity of the RRC layer of the eNodeB 20. If the RRC state is connected, the RRC state is connected. A state that is not connected is called an RRC idle state.

Since the UE 10 in the connected state has an RRC connection, the E-UTRAN may determine the existence of the corresponding UE in units of cells, and thus may effectively control the UE 10. On the other hand, the UE 10 in the idle state cannot be understood by the eNodeB 20, and is managed by a core network in units of a tracking area, which is a larger area than a cell. The tracking area is a collection unit of cells. That is, the idle state UE (10) is identified only in the presence of a large area unit, in order to receive the normal mobile communication services such as voice or data, the terminal must transition to the connected state (connected state).

When the user first powers up the UE 10, the UE 10 first searches for a suitable cell and then remains in an idle state in that cell. When the UE 10 staying in the idle state needs to establish an RRC connection, the UE 10 establishes an RRC connection with the RRC layer of the eNodeB 20 through an RRC connection procedure and performs an RRC connection state ( connected state).

There are several cases in which the UE in the idle state needs to establish an RRC connection. For example, a user's call attempt or an uplink data transmission is necessary, or a paging message is received from EUTRAN. In this case, the response message may be transmitted.

In order to establish an RRC connection with the eNodeB 20, the UE 10 in an idle state must proceed with an RRC connection procedure as described above. The RRC connection process is largely a process in which the UE 10 sends an RRC connection request message to the eNodeB 20, and the eNodeB 20 transmits an RRC connection setup message to the UE 10. And a process in which the UE 10 sends an RRC connection setup complete message to the eNodeB 20. This process will be described in more detail with reference to FIG. 6 as follows.

1) When the UE 10 in idle state attempts to establish an RRC connection due to a call attempt, a data transmission attempt, or a response to the paging of the eNodeB 20, the UE 10 first performs an RRC connection. A RRC connection request message is transmitted to the eNodeB 20.

2) When the RRC connection request message is received from the UE 10, the eNB 10 accepts the RRC connection request of the UE 10 when the radio resources are sufficient, and establishes an RRC connection, which is a response message (RRC connection). setup) message is transmitted to the UE 10.

3) When the UE 10 receives the RRC connection setup message, the UE 10 transmits an RRC connection setup complete message to the eNodeB 20. When the UE 10 successfully transmits an RRC connection establishment message, the UE 10 establishes an RRC connection with the eNodeB 20 and transitions to an RRC connected state.

도 7은 ISR이 활성화 되어 있는 경우에 하향링크의 데이터 전달을 도시한 신호 흐름도이다.7 is a signal flow diagram illustrating downlink data transmission when ISR is activated.

FIG. 7 assumes that ISR (Idle mode Signaling Reduction) is activated. In addition, FIG. 7 shows how downlink data is delivered to a UE in idle mode (or ECM_IDLE state) when the ISR is activated.

Hereinafter, the UE 100 will be described centering on a state where the E-UTRAN cell is camped on.

1. The Serving Gateway (Serving GW: hereinafter referred to as 'S-GW') 520 receives the downlink data packet for the UE 100 via the P-GW 530.

2a. The S-GW 50 buffers a downlink data packet and serves a mobility management node or a mobility management entity (MME) serving a UE 100 that is a receiver of the downlink data packet. identify the mobility management entity. By the identification procedure of the S-GW 520, after confirming that the ISR is activated for the UE 100, the mobility management node, that is, the MME 510 and the SGSN 410, both of the UE ( Identify that it is servicing 100). Therefore, the S-GW 520 must make a paging request to both the MME 510 and the SGSN 410 serving the UE 100.

That is, the S-GW 520 sends a downlink data notification message (DDN) to the MME 510 and the SGSN 410, respectively.

2b. In response to the downlink data notification message, each of the MME 510 and SGSN 410 sends a downlink data notification acknowledgment message (DDN ACK) to the S-GW 520. send.

3a (3b). In addition, each of the MME 510 and the SGSN 410 sends a paging message to the UE 100 through its network.

That is, the MME 510 sends a paging message to each of the eNodeBs 200 belonging to the tracking area (s) registered by the UE 100 (2a). Meanwhile, SGSN 410 sends a paging message to RNC / BSC 300 (2b).

4a (4b). The eNodeBs 200 that receive the paging message from the MME 510 page the UE 100 (4a). Meanwhile, the RNC / BSC 300 that receives the paging message from the SGSN 410 makes a paging to the UE 100 (4b).

However, it is assumed that the UE 100 is currently camping on the E-UTRAN cell, so that the UE 100 eventually paging through the E-UTRAN (that is, the above-mentioned 3a ~). Answer step 4a).

5. The terminal 10 sets up a user plane as a path via the E-UTRAN by performing a service request procedure.

6a (6b). Next, when the ISR is activated and a paging response is received, the S-GW 520 transmits stop paging for each of the MME 510 and SGSN 410.

The S-GW 520 then transmits downlink data to the UE 100 via the E-UTRAN (ie, via the eNodeB 200).

On the other hand, if the UE 100 is camping on the UTRAN / GERAN cell, not the E-UTRAN, the UE 100 is paging via the UTRAN / GERAN (ie, 3b described above) ~ Step 4b). Then, if the user plane of step 5 described above is set, downlink data is transmitted from the S-GW 520 via UTRAN / GERAN (that is, through the RNC / BSC 300 and NodeB (not shown)). 100).

As described above, the network manages the location of the UE in units of an ISR, thereby paging to the ISR region in order to transmit downlink data to the UE 100 in an idle mode. do.

For the detailed description of the above service request procedure, use the items described in Section 5.3.4 of 3GPP TS 23.401.

On the other hand, if the terminal is to move geographically and change from the existing MME (or SGSN) to the new MME (or SGSN), the existing MME (source MME or Old MME) before the change is downlink data notification (DDN) After receiving the downlink data notification acknowledgment (DDN ACK) and receiving the context request (Context Request) from a new MME (New MME or target MME) to recognize the mobility (mobility) of the MME / SGSN of the terminal There is no way to inform this to the serving gateway (S-GW).

That is, after the downlink data notification acknowledgment (DDN ACK) is transmitted to the serving gateway (S-GW), a paging procedure will be performed and if there is no response from the corresponding terminal, the downlink data notification failure indication (DDN failure indication) is transmitted so that the serving gateway can drop downlink packet data for the corresponding UE.

Therefore, when the existing MME recognizes the change of the MME / SGSN after transmitting the downlink data notification acknowledgment (DDN ACK), a method for transmitting paging to the new MME may be needed.

Therefore, one disclosure of the present specification is intended to propose a solution that can solve the above problems.

In order to achieve the above object, the method according to the present disclosure, a method for processing paging in the entity that is in charge of the control plane in the mobile communication network, receiving a DDN (Downlink Data Notification) message from the network node Wow; Sending a first DDN ACK message to the network node; If a context request message for a terminal is received from another entity in charge of a control plane after the DDN message is received, transmitting a second DDN ACK message to the network node; The DDN ACK message may include information indicating Temporally Reject.

In addition, when the context request message is received before the paging process to the terminal, the paging process may not be performed.

In addition, when the context request message is received after the paging process is performed, the method may further include transmitting a paging cancellation message indicating the cancellation of the paging process to the base station requested for paging.

In addition, when the second DDN ACK message is received, the network node may buffer packet data.

In addition, the network node may buffer the packet data until a guard timer expires.

In addition, when a Bearer Change Request (Modify Bearer Request) is received from the other entity, the network node may transmit a DDN message for transmitting the packet data to the other entity.

In order to achieve the above object, the network entity according to the disclosure of the present disclosure, the entity that is in charge of the control plane in the mobile communication network, the transceiver unit for receiving a DDN (Downlink Data Notification) message from the network node; When a first DDN ACK message is transmitted to the network node and a context request message is received from the other entity in charge of a control plane after the DDN message is received, a second DDN is transmitted to the network node. A controller for controlling the transceiver to transmit an ACK message, wherein the second DDN ACK message may include information indicating a temporary reject (Temporally Reject).

According to the disclosure of the present specification, if the terminal is to move geographically and change from the existing MME (or SGSN) to the new MME (or SGSN), the mobility of the MME / SGSN after the transmission of the downlink data notification confirmation (DDN ACK) Even if this is recognized, downlink data can be transmitted through the changed MME, thereby improving the quality of service for the user.

1 is a structural diagram of an evolved mobile communication network.

Figure 2 is an exemplary view showing the functions of the main nodes of the E-UTRAN and the general EPC in general.

3 is an exemplary diagram illustrating a structure of a radio interface protocol in a control plane between a UE and an eNodeB.

4 is another exemplary diagram illustrating a structure of a radio interface protocol in a user plane between a terminal and a base station.

5 is a flowchart illustrating a random access procedure in 3GPP LTE.

6 shows a connection process in a radio resource control (RRC) layer.

7 is a signal flow diagram illustrating downlink data transmission when ISR is activated.

8 is an exemplary diagram illustrating a paging processing scheme in the case where MME relocation is recognized after paging transmission according to the first disclosure of the present specification.

9 is an exemplary diagram illustrating a paging processing scheme in the case where MME re-arrangement before paging transmission is recognized according to the first disclosure of the present specification.

FIG. 10 is an exemplary diagram illustrating a paging processing scheme when MME relocation is recognized after paging transmission according to the second disclosure of the present specification.

FIG. 11 is an exemplary diagram illustrating a paging processing scheme in a case where MME relocation before paging transmission is recognized according to a second disclosure of the present specification.

12 is an exemplary diagram illustrating an interface and a protocol between a UE, an eNodeB, and an MME.

13 is a block diagram illustrating a configuration of a UE 100 and an MME / SGSN 510 according to an embodiment of the present invention.

Although the present invention is described based on the Universal Mobile Telecommunication System (UMTS) and the Evolved Packet Core (EPC), the present invention is not limited to such a communication system, but also to all communication systems and methods to which the technical spirit of the present invention can be applied. Can be applied.

It is to be noted that the technical terms used herein are merely used to describe particular embodiments, and are not intended to limit the present invention. In addition, the technical terms used in the present specification should be interpreted as meanings generally understood by those skilled in the art unless they are specifically defined in this specification, and are overly inclusive. It should not be interpreted in the sense of or in the sense of being excessively reduced. In addition, when the technical terms used herein are incorrect technical terms that do not accurately represent the spirit of the present invention, it should be replaced with technical terms that can be understood correctly by those skilled in the art. In addition, the general terms used in the present invention should be interpreted as defined in the dictionary or according to the context before and after, and should not be interpreted in an excessively reduced sense.

Also, the singular forms used herein include the plural forms unless the context clearly indicates otherwise. In the present application, terms such as “consisting of” or “having” should not be construed as necessarily including all of the various components, or various steps described in the specification, and some of the components or some of the steps are included. It should be construed that it may not be, or may further include additional components or steps.

In addition, terms including ordinal numbers, such as first and second, as used herein may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

When a component is said to be "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but other components may be present in between. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, and the same or similar components will be given the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted. In addition, in describing the present invention, when it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, it should be noted that the accompanying drawings are only for easily understanding the spirit of the present invention and should not be construed as limiting the spirit of the present invention by the accompanying drawings. The spirit of the present invention should be construed to extend to all changes, equivalents, and substitutes in addition to the accompanying drawings.

In the accompanying drawings, although a user equipment (UE) is illustrated as an example, the illustrated UE may be referred to in terms of terminal, mobile equipment (ME), and the like. In addition, the UE may be a portable device such as a laptop, a mobile phone, a PDA, a smart phone, a multimedia device, or a non-portable device such as a PC or a vehicle-mounted device.

용어의 정의Definition of Terms

Before describing with reference to the drawings, in order to help the understanding of the present invention, terms used herein will be briefly defined.

UMTS stands for Universal Mobile Telecommunication System and means 3rd generation mobile communication network.

UE / MS: means User Equipment / Mobile Station, terminal equipment.

EPC: Abbreviation for Evolved Packet Core, and means a core network supporting a Long Term Evolution (LTE) network. UMTS evolved network

EPS: An abbreviation for Evolved Packet System, which means a mobile communication system including a terminal, an access network including LTE, and an EPC.

PDN (Public Data Network): Independent network where the server that provides the service is located

PDN connection: Connection from the terminal to the PDN, that is, association between the terminal represented by an IP address and the PDN expressed as an APN (access point name) (connection)

PDN-GW (Packet Data Network Gateway): Network node of EPS network that performs UE IP address allocation, Packet screening & filtering, Charging data collection

Serving GW (Serving Gateway): Network node of EPS network performing Mobility anchor, Packet routing, Idle mode packet buffering, Triggering MME to page UE

PCRF (Policy and Charging Rule Function): Node of EPS network that performs policy decision to apply differentiated QoS and charging policy dynamically according to service flow

APN (Access Point Name): A name of an access point managed in a network, which is provided to a UE. That is, a string that refers to or distinguishes a PDN. In order to connect to the requested service or network (PDN), the P-GW goes through the name. A predefined name (string) in the network to find this P-GW (example) internet.mnc012.mcc345.gprs

Tunnel Endpoint Identifier (TEID): End point ID of a tunnel established between nodes in a network, and is set for each section in bearer units of each UE.

NodeB: Base station of the UMTS network, which is installed outdoors, and the cell coverage size corresponds to a macro cell.

eNodeB: Base station of EPS (Evolved Packet System) is installed outdoors, the cell coverage size corresponds to a macro cell.

(e) NodeB: A term referring to NodeB and eNodeB.

MME: Abbreviation for Mobility Management Entity, which controls each entity in EPS to provide session and mobility for the UE.

Session: A session is a channel for data transmission. The unit may be a PDN, a bearer, or an IP flow unit. The difference in each unit can be divided into the entire target network unit (APN or PDN unit), the QoS classification unit (Bearer unit), and the destination IP address unit as defined in 3GPP.

PDN connection (connection): A connection from the terminal to the PDN, that is, the association (connection) between the terminal represented by the IP address and the PDN represented by the APN. This means an inter-entity connection (terminal-PDN GW) in the core network so that a session can be established.

UE Context: Context information of UE used to manage UE in the network, ie Context Information composed of UE id, mobility (current location, etc.), session attributes (QoS, priority, etc.)

OMA DM (Open Mobile Alliance Device Management) is a protocol designed to manage mobile devices such as mobile phones, PDAs, portable computers, etc., and includes device configuration, firmware upgrade, and error report. Perform a function

OAM (Operation Administration and Maintenance): OAM is a group of network management functions that provides network fault indication, performance information, and data and diagnostic functions.

NAS configuration MO (Management Object): A MO (Management Object) used to configure the UE with parameters associated with NAS Function.

The following describes in detail the first disclosure and the second disclosure, which are the disclosures herein.

Specifically, the first and second disclosures herein are directed to providing a scheme for handling paging at an entity (eg, MME) that is in charge of a control plane in a mobile communication network.

First, the first disclosure of this specification describes that the entity receives a downlink data notification (hereinafter referred to as DDN) (message) from a network node (eg, S-GW) and then confirms downlink data notification (hereinafter referred to as DDN ACK) ( Downlink containing information (e.g., Cause Value) indicating Temporally Reject, if successful retransmission or re-selection of the entity (e.g., relocation of the MME) has been successfully sent. A method of transmitting a link data notification rejection (hereinafter, DDN rejection) (message) to the network node is disclosed.

Next, the second disclosure of the present specification provides information indicating a temporary rejection when the entity recognizes the reassignment of the entity after successfully transmitting the DDN ACK (message) after receiving the DDN (message) from the network node ( For example, a method of transmitting a DDN ACK (message) including a Cause Value back to the network node is disclosed.

For reference, to distinguish two DDN ACKs, the first DDN ACK may be a first DDN ACK, and a DDN ACK including information indicating a temporary rejection may be referred to as a second DDN ACK.

< 본 명세서의 제1 개시 ><First disclosure of the present specification>

Hereinafter, a first disclosure of the present specification will be described in detail with reference to FIGS. 8 to 9.

Specifically, with respect to the first disclosure of the present specification, the paging processing method and the context request before transmission of paging when the Old MME 510a receives the context request after transmitting the paging and recognizes the MME relocation. The description will be made by dividing into a paging processing method in the case of receiving MME relocation and receiving MME relocation.

I. 제1-1 방안: 페이징 송신 후 MME 재배정이 인지된 경우I. Option 1-1: Recognition of MME Relocation After Paging Transmission

As described above, the first-first scheme provides a paging processing scheme when the Old MME 510a receives a context request after transmitting paging and recognizes MME reselection or relocation.

도 8은 본 명세서의 제1 개시에 따른 페이징 송신 후 MME 재배정이 인지된 경우에 있어서의 페이징 처리 방안을 나타내는 예시도이다.8 is an exemplary diagram illustrating a paging processing scheme in the case where MME relocation is recognized after paging transmission according to the first disclosure of the present specification.

Referring to FIG. 8, the paging processing scheme according to the first-first scheme may be performed in the following order (steps 1 to 7 below).

1. First, when there is downlink data to be delivered to the UE 100 by the S-GW 520, a downlink data notification (DDN) message may be transmitted to the Old MME 510a.

2. The Old MME 510a may successfully transmit (Cause: Successful) a downlink data notification acknowledgment (DDN ACK) message after receiving the DDN message.

3. Thereafter, the Old MME 510a may perform a paging process to the UE 100 through the Old eNodeB 200a.

4. At this time, the Old MME 510a may receive a Kentext Request message from the new MME 510b due to MME relocation due to the movement of the UE 100 during the paging process.

5. Accordingly, the Old MME 510a may detect Inter-MME / SGSN Mobility by receiving a context request from the New MME 510b after receiving a DDN message and transmitting a DDN ACK.

6. In this case, the Old MME 510a stops the paging process it is performing and sends a downlink data rejection (DDN Reject: DDN failure indication) to the S-GW 520.

At this time, the Old MME 510a adds a "temporally reject" as a cause value and sends the DDN rejection message, so that the S-GW 520 sends the packet data of the UE 100. Do not drop, but allow buffering for some time.

In this case, when the S-GW 520 receives a bearer modification request from the New MME 510b within a predetermined time and transmits the DDN back to the New MME 510b, the New MME 510b receives the downlink packet. An initial context setup procedure is performed to configure S1-U for data transmission.

7. At this time, the old MME 510a may transmit a paging cancellation message to stop the paging transmission to the old eNodeB 200a requesting the paging transmission.

As a result, unnecessary repetitive paging resources may be prevented when repeated paging transmission is required at the base station due to coverage enhancement.

Steps 6 to 7 described above may be performed regardless of the order.

II. 제1-2 방안: 페이징 송신 전 MME 재배정이 인지된 경우II. Method 1-2: MME Relocation Before Paging Transmission

As described above, the 1-2 scheme provides a paging processing scheme when the Old MME 510a receives a context request and recognizes MME reselection or relocation (MME relocation) before transmitting the paging. .

도 9는 본 명세서의 제1 개시에 따른 페이징 송신 전 MME 재배정이 인지된 경우에 있어서의 페이징 처리 방안을 나타내는 예시도이다.9 is an exemplary diagram illustrating a paging processing scheme in the case where MME re-arrangement before paging transmission is recognized according to the first disclosure of the present specification.

Referring to FIG. 9, the paging processing scheme according to the 1-2 scheme may be performed in the following order (steps 1 to 5 below).

2. The Old MME 510a may successfully transmit a Downlink Data Notification Acknowledgment (DDN ACK) message after receiving the DDN message.

3. The Old MME 510a may receive a Kentext Request message from the new MME 510b with MME relocation due to the movement of the UE 100 before transmitting the paging after transmitting the DDN ACK.

4. Finally, the Old MME 510a may detect the Inter-MME / SGSN Mobility by receiving the context request from the New MME 510b after receiving the DDN message and transmitting the DDN ACK.

5. Therefore, even when the Old MME 510a detects Inter-MME / SGSN Mobility by receiving a context request from the New MME 510b before performing the paging process, cause information (Cause value) By adding a "temporally reject" to send a DDN rejection message, the S-GW 520 can be buffered for a certain time without dropping the packet data of the UE (100).

In addition, according to the method 1-2, since the MME mobility is detected before the paging process is performed, an unnecessary paging process is not performed.

< 본 명세서의 제2 개시 ><2nd disclosure of the present specification>

Hereinafter, a second disclosure of the present specification will be described in detail with reference to FIGS. 10 to 11.

Specifically, with respect to the second disclosure of the present specification, the paging processing method and the context request before transmitting the paging when the Old MME 510a receives the context request after transmitting the paging to recognize the MME relocation. The description will be made by dividing into a paging processing method in the case of receiving MME relocation and receiving MME relocation.

I. 제2-1 방안: 페이징 송신 후 MME 재배정이 인지된 경우I. SECTION 2-1: MME Reassignment Recognized After Paging Transmission

As described above, the 2-1 scheme provides a paging processing scheme in the case where the old MME 510a receives a context request after transmitting paging to recognize the MME relocation.

도 10은 본 명세서의 제2 개시에 따른 페이징 송신 후 MME 재배정이 인지된 경우에 있어서의 페이징 처리 방안을 나타내는 예시도이다.FIG. 10 is an exemplary diagram illustrating a paging processing scheme when MME relocation is recognized after paging transmission according to the second disclosure of the present specification.

Referring to FIG. 10, the paging processing scheme according to the first-first scheme may be performed in the following order (steps 1 to 7 below).

6. In this case, the Old MME 510a stops the paging process it is performing and sends a downlink data notification acknowledgment (DDN ACK) back to the S-GW 520.

Hereinafter, to distinguish the DDN ACK in step 2 and the DDN ACK in step 6, the DDN ACK in step 2 is referred to as the first DDN ACK, and the DDN ACK in step 6 is referred to as the second DDN ACK. Will be explained.

At this time, the Old MME 510a adds a "temporally reject" as a cause value and sends the second DDN ACK message, so that the S-GW 520 sends a packet of the UE 100. Allows buffering for some time without dropping data.

That is, the S-GW 520 may receive an error even if the S-GW 520 receives the second DDN ACK again with the cause value “temporally rejected” after the successful reception of the first DDN ACK after one DDN transmission. The packet data is buffered for a specific time (for example, guard time) without being recognized as an error).

Steps 6 to 7 described above may be performed regardless of the order.

II. 제2-2 방안: 페이징 송신 전 MME 재배정이 인지된 경우II. Method 2-2: MME reallocation is recognized before paging transmission

As described above, the second-2 scheme provides a paging processing scheme in the case where the old MME 510a receives a context request and recognizes an MME relocation before transmitting the paging.

도 11은 본 명세서의 제2 개시에 따른 페이징 송신 전 MME 재배정이 인지된 경우에 있어서의 페이징 처리 방안을 나타내는 예시도이다.FIG. 11 is an exemplary diagram illustrating a paging processing scheme in a case where MME relocation before paging transmission is recognized according to a second disclosure of the present specification.

Referring to FIG. 11, the paging processing scheme according to the method 2-2 may be performed in the following order (steps 1 to 5 below).

2. The Old MME 510a may successfully transmit a first DDN ACK message, which is a downlink data notification acknowledgment message, after receiving the DDN message.

5. Therefore, even when the Old MME 510a detects Inter-MME / SGSN Mobility by receiving a context request from the New MME 510b before performing the paging process, cause information (Cause value) By adding a "temporally reject" to the second DDN ACK message can be sent, so that the S-GW 520 can be buffered for a certain time without dropping the packet data of the UE (100).

That is, the S-GW 520 considers the normal operation when the cause value of the second DDN ACK is temporarily rejected even when the DDN ACK is received twice, and drops the packet data for a predetermined time. I never do that.

In addition, according to the method 2-2, since the MME mobility is detected before the paging process is performed, an unnecessary paging process is not performed.

< 본 명세서의 추가적 개시 >Additional disclosures herein

Hereinafter, as an additional disclosure of the present specification, if the Old MME 510a successfully transmits the DDN ACK to the S-GW 520 and then does not transmit the DDN rejection message when the MME mobility is detected, the S- A method of causing the GW 520 to buffer downlink data is described.

Specifically, when the UE 100 is in the ECM-IDLE state, when the DDN message is transmitted, a network triggered service request operation triggered by the network is performed.

A further disclosure of the present disclosure is that the UE 100 receives a context request from the New MME 510b after the Old MME 510a receives a DDN message from the S-GW 520 and successfully transmits a DDN ACK for it. If the UE recognizes the inter-MME movement operation (when the UE 100 performs a TAU at the MME boundary region and the serving MME is changed), even if paging is not successfully transmitted to the UE 100 (old MME ( 510a already recognizes that the UE 100 cannot receive paging). In step 5, the UE 100 proposes a method not to send a DDN rejection or failure (Downlink Data Notification Reject / Failure).

In this case, the S-GW 520 does not discard the packet, and when the S-GW 520 receives a bearer modification request from the New MME 510b, the S-GW 520 sends the DDN back to the New MME 510b. And transmit downlink packet data again.

According to a further disclosure of the present specification, the following may be added in step 5 of section 5.3.4 of the standard document 3GPP TS 23.401 related to the service request procedure disclosed in FIG. 7.

-If the MME receives no response from the UE because the Tracking Area Update procedure with MME change or the Routing Area Update procedure is in progress, it shall not send the Downlink Data Notification Reject message to the Serving GW. Similarly, if the SGSN receives no response from the UE because the Routing Area Update procedure with SGSN change or the Tracking Area Update procedure is in progress, it shall not send the Downlink Data Notification Reject message to the Serving GW.

도 12는 UE, eNodeB, MME 간의 인터페이스와 프로토콜을 나타낸 예시도이다.12 is an exemplary diagram illustrating an interface and a protocol between a UE, an eNodeB, and an MME.

As illustrated in FIG. 12, messages transmitted and received between the UE 100 and the eNodeB 200 are messages based on a Radio Resource Control (RRC) protocol. The messages transmitted and received between the eNodeB 200 and the MME 510 are messages based on S1-AP (S1 Application Protocol). The messages transmitted and received between the UE 100 and the MME 510 are messages based on a non-access stratum (NAS) protocol. The messages by the NAS protocol are transmitted by encapsulating the messages by the RRC protocol and the S1-AP message, respectively.

The contents described so far can be implemented in hardware. This will be described with reference to FIG. 18.

도 13은 본 발명의 실시예에 따른 UE(100) 및 MME/SGSN(510)의 구성 블록도이다.13 is a block diagram illustrating a configuration of a UE 100 and an MME / SGSN 510 according to an embodiment of the present invention.

As shown in FIG. 13, the UE 100 includes a storage means 101, a controller 102, and a transceiver 103. The MME 510 includes a storage means 511, a controller 512, and a transceiver 513. Similarly, the S-GW 520 includes a storage means 521, a controller 522, and a transceiver 523.

The storage means 101, 511, 521 store the method according to the disclosures herein.

The

controllers

102, 512, and 522 control the storage means 101, 511, and 521 and the

transceivers

103, 513, and 523. Specifically, the

controllers

102, 512, 522 execute the methods stored in the storage means 101, 511, 521, respectively. The

controllers

102, 512, and 522 transmit the aforementioned signals through the

transceivers

103, 513, and 523.

In the above description of the preferred embodiments of the present invention by way of example, the scope of the present invention is not limited only to these specific embodiments, the present invention is in various forms within the scope of the spirit and claims of the present invention Can be modified, changed, or improved.

Claims

A method of processing paging at an entity in charge of a control plane in a mobile communication network,

Receiving a downlink data notification (DDN) message from a network node;

Sending a first DDN ACK message to the network node;

If a context request message for a terminal is received from another entity in charge of a control plane after the DDN message is received, transmitting a second DDN ACK message to the network node.

The second DDN ACK message is,

And information indicating Temporally Reject.
The method of claim 1, wherein the context request message is received before performing a paging process to the terminal.

Wherein the paging process is not performed.
The method of claim 1, wherein the context request message is received after performing a paging process.

Sending a paging cancellation message indicating to cancel the paging process to the base station requested paging.
The method of claim 1, wherein the network node,

Buffering packet data when the second DDN ACK message is received.
The method of claim 4, wherein the network node,

Buffering the packet data until a Guard Timer expires.
The method of claim 4, wherein the network node,

If a Bearer Change Request is received from the other entity, transmitting a DDN message for transmitting the packet data to the other entity.
In the entity responsible for the control plane in the mobile communication network,

A transceiver for receiving a downlink data notification (DDN) message from a network node;

When a first DDN ACK message is transmitted to the network node and a context request message is received from the other entity in charge of a control plane after the DDN message is received, a second DDN is transmitted to the network node. A controller for controlling the transceiver to transmit an ACK message,

The second DDN ACK message is,

An entity comprising information indicating Temporally Reject.
The method of claim 7, wherein the context request message is received before performing a paging process to the terminal.

The paging process is not performed.
The method of claim 7, wherein the controller,

And when the context request message is received after the paging process is performed, transmitting a paging cancel message indicating the cancellation of the paging process to a base station requested for paging.
The method of claim 7, wherein the network node,

When the second DDN ACK message is received, buffering the packet data.
The method of claim 10, wherein the network node,

And buffer the packet data until a Guard Timer expires.
The method of claim 10, wherein the network node,

And if a Bearer Change Request is received from the other entity, sending a DDN message for transmitting the packet data to the other entity.