KR20160140262A - Method and apparatus for transmitting uplink data in a wireless system - Google Patents

Abstract

The present invention relates to a method for transmitting uplink data (UL data) in a wireless communication system supporting a low latency service, comprising the steps of: performing an initial attach procedure between a terminal and a network; And performing a service request procedure for performing uplink transmission of the low delay service between the UE and the network, wherein performing the service request procedure comprises: receiving a Service Management Entity (SME) And transmitting the control information used for generating uplink data of the low-delay service to the base station.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a method and apparatus for transmitting uplink data in a wireless communication system,

The present invention relates to a wireless communication system, and more particularly, to a method for transmitting uplink data in a wireless communication system supporting low latency communication (ultra-low latency communication) and a device supporting the same .

The mobile communication system has been developed to provide voice service while ensuring the user 's activity. However, in the mobile communication system, not only the voice but also the data service are extended. At present, due to the increase of the explosive traffic, there is a shortage of resources and users require higher speed service, have.

The requirements of the next-generation mobile communication system largely depend on the acceptance of explosive data traffic, the dramatic increase in the rate per user, the acceptance of a significantly increased number of connected devices, very low end-to-end latency, Should be able to. For this purpose, a dual connectivity, a massive multiple input multiple output (MIMO), an in-band full duplex, a non-orthogonal multiple access (NOMA) wideband support, and device networking.

In particular, in the case of 5G mobile communication, the perceived transmission rate, the maximum transmission rate, the maximum transmission rate, the transmission delay, the density of the terminal, the energy efficiency, the frequency efficiency, and the system capacity per area are considered as the core performance indexes.

Particularly, in the 5G mobile communication system, a low latency is demanded as a main feature different from the existing 4G mobile communication system.

This is to support various services such as smart grid, inter-vehicle communication, virtual reality, etc., which are considered to be used in the 5G mobile communication system, and these services generally require very low latency.

Therefore, there is a problem that it is difficult to support the corresponding services as the transmission delay time of the existing mobile communication system.

In the existing 4G mobile communication system, research has been carried out to improve the maximum data rate of the mobile terminal. Recently, researches for satisfying a low transmission delay demand have been conducted variously in the research for the 5G mobile communication system.

In the existing LTE / LTE-A communication technology, when the UE in the RRC_Idle state performs uplink transmission, it must perform the RRC connection procedure and transit to the RRC_Connected state.

However, in the RRC connection procedure, a control message is transmitted and received between the UE and the BS at least 10 times, resulting in a delay time of at least 50 ms.

Therefore, the RRC connection procedure becomes a bottleneck to satisfy the low delay requirement required in the 5G mobile communication technology.

In particular, in a service such as smart grid and inter-vehicle communication expected to be a low-delay service in the 5G mobile communication technology, it is expected that the terminal is likely to be in the RRC_Idle state in the uplink transmission while requiring a low transmission delay time. It becomes a big problem in achieving the low delay requirement of the corresponding service.

The RRC protocol is a protocol existing between a mobile station and a base station in order to exchange basic control information for a mobile station to access a mobile communication system in an LTE / LTE-A mobile communication technology.

A terminal exchanges necessary information with a base station to establish an RRC connection in order to perform communication. In this case, the terminal is defined as being in the RRC_Connected state.

However, if there is no communication between the subscriber station and the base station for a certain period of time in order to manage the power usage of the subscriber station, the corresponding subscriber is released and the subscriber station transitions to the RRC_Idle state, and maintains the RRC_Idle state until the uplink or downlink transmission occurs to the subscriber station do.

In the existing LTE / LTE-A communication technology, a UE entering the RRC_Idle state must perform an RRC connection again to transmit data, and it takes about 50 ms to perform RRC connection and data transmission.

In the inter-vehicle communication, smart grid communication, and interrupt message of the IoT device, it is difficult to apply the existing communication technology because it can not predict the generation time of the packet and requires a low delay time.

In addition, since the RRC connection procedure requires at least 9 RRC message exchanges between the UE and the BS, performing RRC connection procedure every time to transmit small data such as sensor information results in inefficient use of resources in terms of signaling overhead do.

Therefore, in order to meet the requirements of the above-mentioned services and efficiently use the resources, it is necessary to reduce the overhead and delay time required for the transmission by simplifying the RRC connection procedure for the uplink transmission.

Accordingly, an object of the present invention is to provide a method for acquiring a low delay time and a low signaling overhead by enabling a UE to transmit an uplink packet through a radio resource obtained through a single random access procedure without RRC connection .

It is another object of the present invention to provide a method for maintaining uplink security while having a small delay time and a transmission overhead while allowing an uplink transmission without an RRC connection when an uplink packet is generated in an RRC_Idle state.

To this end, it is an object to distinguish destinations of data to be transmitted according to a service used by a terminal and newly define an entity for managing the destinations in the EPC.

In addition, a method of transmitting a predefined type of data to a destination by transmitting a control message including the simplified data and the terminal's identity to the corresponding entity using the resource acquired through the random access of the terminal in the RRC_Idle state The purpose is to provide.

It is another object of the present invention to provide a method of reducing a delay time while reducing an overhead required for transmission compared to existing technologies by performing uplink transmission without establishing an RRC connection using the above-described method.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, unless further departing from the spirit and scope of the invention as defined by the appended claims. It will be possible.

The present invention relates to a method for transmitting uplink data (UL data) in a wireless communication system supporting a low latency service, comprising the steps of: performing an initial attach procedure between a terminal and a network; And performing a service request procedure for performing uplink transmission of the low delay service between the UE and the network, wherein performing the service request procedure comprises: receiving a Service Management Entity (SME) And transmitting the control information used for generating uplink data of the low-delay service to the base station, wherein the control information includes terminal identification information indicating the identity of the terminal, A response indicator indicating whether a response to the uplink transmission is received, a packet indicator indicating a data packet to be transmitted by the terminal, or destination information indicating a destination of the data packet, And at least one of them.

Further, the present invention further includes the step of the terminal performing a reconfiguration procedure with the network to reset or update security information and / or service information associated with the uplink transmission of the low-delay service .

In addition, the present invention is characterized by further comprising performing a detach procedure for terminating the connection between the terminal and the network.

The performing of the initial attach procedure may further include performing an RRC connection establishment procedure between the terminal and the network; Performing an authentication procedure for performing authentication on the terminal and the service; Performing a security setup procedure to obtain security and integrity related to uplink transmission of the low delay service; And performing a service information acquisition procedure for the terminal to acquire information on the low-delay service.

In this specification, the step of performing the authentication procedure includes: obtaining a service ID of a low-delay service to be used by the MS from a home subscriber server (MSS) by an MME (Mobility Management Entity); And transmitting, by the MME, a service authentication request message for requesting service authentication to the SME, wherein the service authentication request message includes an International Mobile Subscriber Identity (IMSI) of the terminal, And a service ID of a low-delay service to be used.

Also, the step of performing the security setup procedure in this specification includes the steps of: the MME transmits a security key request message including algorithm information to be used for security key generation to the SME; Generating a second secret key using a first secret key shared by the SME in advance with the terminal and algorithm information included in the secret key request message; Sending, by the SME, the generated second security key and the identifier of the first security key to the MME; Transmitting a security mode command message including an identifier of a second security key and an identifier of the first security key received from the SME to the MME; Performing an integrity check based on the received security mode command message; And transmitting the security mode complete message including the second security key to the SME when the integrity check is successful.

이고, 상기 제 2 보안 키는 SME-MAC인 것을 특징으로 한다.Also, in this specification, the first security key

And the second security key is an SME-MAC.

The step of performing the service request procedure includes performing a random access procedure between the subscriber station and the base station to allocate uplink resources for transmitting the control information. And generating the uplink data of the low-delay service based on the control information, and transmitting the uplink data of the low-delay service to the destination by the SME.

In addition, the present invention is characterized in that the SME further includes transmitting a response indicating whether the uplink data transmission of the low-latency service is successful to the terminal.

In addition, the data packet indicator and the destination information are encrypted through a security key obtained in the initial access procedure.

In addition, the reconfiguration procedure in this specification includes a step in which the UE transmits a service reconfiguration request message to the SME; Transmitting a security reconfiguration request message instructing the SME to perform security setting again to the MME; And performing the service information acquisition procedure by the terminal to acquire and update low-delay service related information.

The reconfiguration procedure may further include receiving a service reconfiguration request message from the SME indicating that the UE needs to be reconfigured; And transmitting the service reconfiguration response message to the SME in response to the service re-establishment request message.

Also, in the present invention, the step of performing the detach procedure may include transmitting the detach request message including the identification information of the terminal and the identifier of the first secret key and the first secret key to the SME step; Backing up a security context based on the received revocation request message; Receiving a detach accept message informing the terminal of the acceptance of the revocation from the MME; The SME terminating the service registration context of the terminal; And transmitting, from the SME to the MME, a delete context response indicating that the service registration context of the terminal has been successfully terminated.

In the present invention, performing the detach procedure includes transmitting a detach request message from the SME to the MME; The terminal receiving the revocation request message from the MME; Deleting contexts related to uplink transmission security of the low delay service; Transmitting a release acknowledgment message indicating termination acceptance to the MME; Sending, by the MME, a delete context request message instructing deletion of a low delay service context of the UE to the SME based on the received revocation acceptance message; And transmitting a delete context response message from the SME to the MME indicating that the low-latency service context of the UE has been successfully terminated.

In this specification, the terminal and the SME have LSM (Low Latency Service Management) -Registered state and LSM-Deregistered state.

The present invention has an effect that a terminal can acquire a low delay time and a low signaling overhead by transmitting an uplink packet through a radio resource obtained through a single random access procedure without RRC connection.

In addition, the present invention has an effect of maintaining uplink security while maintaining a small delay time and a transmission overhead while allowing the UE to perform uplink transmission without RRC connection when an uplink packet occurs in the RRC_Idle state.

In addition, the present invention has an effect that a control message including the simplified data and the identity of the UE can be delivered to the corresponding entity by using the resource acquired through the random access by the UE in the RRC_Idle state.

The effects obtained in the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the following description .

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the technical features of the invention.
1 is a diagram illustrating an example of an EPS (Evolved Packet System) related to an LTE system to which the present invention can be applied.
2 shows a wireless communication system to which the present invention is applied.
3 is a block diagram illustrating an example of a functional split between an E-UTRAN and an EPC to which the present invention can be applied.
4A is a block diagram illustrating an example of a radio protocol architecture for a user plane to which the technical features of the present disclosure may be applied.
4B is a block diagram illustrating an example of a wireless protocol structure for a control plane to which the technical features of the present disclosure can be applied.
5 is a diagram illustrating an example of a physical channel structure to which the present invention can be applied.
6 is a diagram for explaining an operation procedure of a terminal and a base station in a contention-based random access procedure.
7 is a flowchart illustrating a terminal operation in an RRC idle state to which the present invention can be applied.
8 is a flowchart illustrating a procedure for establishing an RRC connection to which the present invention can be applied.
9 is a flowchart illustrating an RRC connection reset process to which the present invention can be applied.
10 is a diagram illustrating an example of an RRC connection re-establishment procedure to which the present invention can be applied.
11 is a diagram illustrating an example of a transition process between the LSM-state and the EMM-state proposed in the present specification.
12 is a flowchart illustrating an example of an initial access procedure of a communication method for low delay uplink transmission proposed in the present specification.
13 is a flowchart illustrating an example of a service request procedure of a communication method for low delay uplink transmission proposed in the present specification.
FIGS. 14 and 15 are flowcharts illustrating an example of a reconfiguration procedure of a communication method for low-delay uplink transmission proposed in the present specification.
16 and 17 are flowcharts illustrating an example of a cancellation procedure of a communication method for low-delay uplink transmission proposed in the present specification.
18 illustrates a block diagram of a wireless communication device to which the methods proposed herein may be applied.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following detailed description, together with the accompanying drawings, is intended to illustrate exemplary embodiments of the invention and is not intended to represent the only embodiments in which the invention may be practiced. The following detailed description includes specific details in order to provide a thorough understanding of the present invention. However, those skilled in the art will appreciate that the present invention may be practiced without these specific details.

In some instances, well-known structures and devices may be omitted or may be shown in block diagram form, centering on the core functionality of each structure and device, to avoid obscuring the concepts of the present invention.

In this specification, a base station has a meaning as a terminal node of a network that directly communicates with a terminal. The specific operation described herein as performed by the base station may be performed by an upper node of the base station, as the case may be. That is, it is apparent that various operations performed for communication with a terminal in a network composed of a plurality of network nodes including a base station can be performed by a network node other than the base station or the base station. A base station (BS) is a fixed station, a Node B, an evolved NodeB (eNB), a base transceiver system (BTS), an access point (AP), a MeNB (Macro eNB) Secondary eNB) or the like.

Also, a 'terminal' may be fixed or mobile and may be a mobile station (UE), a mobile station (MS), a user terminal (UT), a mobile subscriber station (MSS), a subscriber station (SS) Advanced Mobile Station (WT), Wireless Terminal (WT), Machine-Type Communication (MTC), Machine-to-Machine (M2M), and Device-to-Device (D2D) devices.

Hereinafter, a downlink (DL) means communication from a base station to a terminal, and an uplink (UL) means communication from a terminal to a base station. In the downlink, the transmitter may be part of the base station, and the receiver may be part of the terminal. In the uplink, the transmitter may be part of the terminal and the receiver may be part of the base station.

The specific terminology used in the following description is provided to aid understanding of the present invention, and the use of such specific terminology may be changed into other forms without departing from the technical idea of the present invention.

The following techniques may be used in various wireless communication systems such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC- (non-orthogonal multiple access), and the like. CDMA can be implemented with radio technology such as universal terrestrial radio access (UTRA) or CDMA2000. TDMA can be implemented with wireless technologies such as global system for mobile communications (GSM) / general packet radio service (GPRS) / enhanced data rates for GSM evolution (EDGE). OFDMA can be implemented with wireless technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and evolved UTRA (E-UTRA). UTRA is part of the universal mobile telecommunications system (UMTS). 3GPP (3rd Generation Partnership Project) LTE (Long Term Evolution) is part of E-UMTS (evolved UMTS) using E-UTRA, adopting OFDMA in downlink and SC-FDMA in uplink. LTE-A (advanced) is the evolution of 3GPP LTE.

1 is a diagram illustrating an example of an EPS (Evolved Packet System) related to an LTE system to which the present invention can be applied.

The LTE system aims to provide seamless Internet Protocol connectivity between a user terminal (UE) and a packet data network (PDN), without interfering with the end-user's application usage on the go . The LTE system completes the evolution of wireless access through Evolved Universal Terrestrial Radio Access Network (E-UTRAN), which defines a radio protocol architecture between a user terminal and a base station, which is an Evolved Packet Core (EPC) network But also through non-wireless evolution by the inclusion of System Architecture Evolution (SAE). LTE and SAE include the Evolved Packet System (EPS).

EPS uses the concept of EPS bearers to route IP traffic from a gateway to a user terminal within a PDN. The bearer is an IP packet flow having a QoS (Quality of Service) between the gateway and the user terminal. The E-UTRAN and EPC together set up or release the bearer required by the application.

The EPC, also called the core network (CN), controls the UE and manages the bearer configuration.

1, a node (logical or physical node) of the SAE EPC includes an MME (Mobility Management Entity) 30, a PDN-GW or a P-GW (PDN gateway) 50, an S-GW Serving Gateway 40, Policy and Charging Rules Function (PCRF) 60, Home Subscriber Server (HSS) 70, and the like.

The MME 30 is a control node that handles the signaling between the UE and the CN. The protocol exchanged between the UE and the CN is known as the Non-Access Stratum (NAS) protocol. Examples of functions supported by the MME 30 include functions related to bearer management operated by a session management layer in the NAS protocol, including setting up, managing, and releasing bearers, And is operated by a connection layer or a mobility management layer in the NAS protocol layer, including establishment of connection and security between UEs.

The S-GW 40 serves as a local mobility anchor for data bearers when the UE moves between base stations (eNodeBs). All user IP packets are transmitted via the S-GW 40. The S-GW 40 may also be configured to temporarily store the downlink data while the UE is in an idle state known as the ECM-IDLE state and the MME initiates paging of the UE to re- Maintains information related to the bearer when buffering. It also acts as a mobility anchor for inter-working with other 3GPP technologies such as General Packet Radio Service (GRPS) and Universal Mobile Telecommunications System (UMTS).

The P-GW 50 performs IP address allocation for the UE and performs flow-based charging according to QoS enforcement and rules from the PCRF 60. P-GW 50 performs QoS enforcement for Guaranteed Bit Rate (GBR) bearers. It also acts as a mobility anchor for interworking with non-3GPP technologies such as CDMA2000 and WiMAX networks.

The PCRF 60 performs policy control decision-making and performs flow-based charging.

The HSS 70 is also referred to as an HLR (Home Location Register) and includes SAE subscription data including information on an EPS-subscribed QoS profile and access control for roaming. It also includes information about the PDN to which the user is connected. This information can be maintained in the form of an APN (Access Point Name), which is a label based on a DNS (Domain Name System), an identification that describes the access point to the PDN or the PDN address indicating the subscribed IP address Technique.

As shown in FIG. 1, various interfaces such as S1-U, S1-MME, S5 / S8, S11, S6a, Gx, Rx and SG may be defined between EPS network elements.

Hereinafter, the concept of mobility management (MM) and the mobility management (MM) back-off timer will be described in detail. Mobility Management (MM) is a procedure for reducing overhead on the E-UTRAN and processing in the UE.

When mobility management (MM) is applied, all information related to the UE in the access network can be released during the period of data inactivation. The MME may maintain information related to the UE context and the set bearer during the Idle interval.

The UE can inform the network about the new location each time it leaves the current TA (Tracking Area) so that the network can contact the UE in the ECM-IDLE state. This procedure may be referred to as a " Tracking Area Update ", which may be referred to as a " Routing Area Update " in a universal terrestrial radio access network (UTRAN) or a GSM EDGE radio access network (GERAN) system. The MME performs the function of tracking the user's location while the UE is in the ECM-IDLE state.

If there is downlink data to be delivered to the UE in the ECM-IDLE state, the MME sends the paging message to all base stations (eNodeBs) on the registered tracking area (TA) of the UE.

The base station then starts paging for the UE on a radio interface. As the paging message is received, it performs a procedure that causes the UE's state to transition to the ECM-CONNECTED state. This procedure can be referred to as a " Service Request Procedure ". Accordingly, information related to the UE is generated in the E-UTRAN, and all the bearers are re-established. The MME performs the function of resetting the radio bearer and updating the UE context on the base station.

When the mobility management (MM) procedure described above is performed, a mobility management (MM) back-off timer may be additionally used. Specifically, the UE may send a TAU (Tracking Area Update) to update the TA, and the MME may reject the TAU request due to core network congestion. In this case, Time value. Upon receiving the corresponding time value, the UE may activate the MM backoff timer.

2 shows a wireless communication system to which the present invention is applied.

This may be referred to as Evolved-UMTS Terrestrial Radio Access Network (E-UTRAN) or Long Term Evolution (LTE) / LTE-A system.

The E-UTRAN includes a base station (BS) 20 that provides a user plane (UE) with a control plane and a user plane.

The base stations 20 may be interconnected via an X2 interface. The base station 20 is connected to an S-GW (Serving Gateway) through an EPC (Evolved Packet Core) through an S1 interface, more specifically, through an MME (Mobility Management Entity) and an S1-U through an S1-MME.

EPC consists of MME, S-GW and P-GW (Packet Data Network-Gateway). The MME has information on the access information of the terminal or the capability of the terminal, and this information is mainly used for managing the mobility of the terminal. The S-GW is a gateway having an E-UTRAN as an end point, and the P-GW is a gateway having a PDN as an end point.

The layers of the radio interface protocol between the UE and the network are classified into L1 (first layer), L1 (second layer), and the like based on the lower three layers of the Open System Interconnection (OSI) A physical layer belonging to a first layer provides an information transfer service using a physical channel, and a physical layer (physical layer) An RRC (Radio Resource Control) layer located at Layer 3 controls the radio resources between the UE and the network. To this end, the RRC layer exchanges RRC messages between the UE and the BS.

3 is a block diagram illustrating an example of a functional split between an E-UTRAN and an EPC to which the present invention can be applied.

Referring to FIG. 3, the hatched block represents a radio protocol layer, and the empty block represents a functional entity of a control plane.

The base station performs the following functions. (1) radio resource management such as radio bearer control, radio admission control, connection mobility control, and dynamic resource allocation to a terminal, (RRM) function, (2) Internet Protocol (IP) header compression and encryption of user data streams, (3) routing of user plane data to the S-GW, (4) Scheduling and transmission, (5) scheduling and transmission of broadcast information, and (6) measurement and measurement reporting setup for mobility and scheduling.

The MME performs the following functions. (2) security control, (3) idle state mobility control, (4) SAE bearer control, (5) NAS (Non-Access) Stratum signaling ciphering and integrity protection.

The S-GW performs the following functions. (1) termination of user plane packets for paging, and (2) user plane switching to support terminal mobility.

4A shows an example of a radio protocol architecture for a user plane to which the technical features of the present invention can be applied, and FIG. 4B shows an example of a control plane FIG. 2 is a block diagram illustrating an example of a wireless protocol structure for a wireless network.

The user plane is a protocol stack for transmitting user data, and the control plane is a protocol stack for transmitting control signals.

4A and 4B, a physical layer (PHY) provides an information transfer service to an upper layer using a physical channel. The physical layer is connected to a MAC (Medium Access Control) layer, which is an upper layer, through a transport channel. Data is transferred between the MAC layer and the physical layer through the transport channel. The transport channel is classified according to how the data is transmitted through the air interface.

Data moves between different physical layers, i. E., Between the transmitter and the physical layer of the receiver, over the physical channel. The physical channel can be modulated by an Orthogonal Frequency Division Multiplexing (OFDM) scheme, and uses time and frequency as radio resources.

The function of the MAC layer is to perform mapping / demultiplexing ('/') between a logical channel and a transport channel and a transport block provided as a physical channel over a transport channel of a MAC SDU (service data unit) Includes both the concepts of 'or' and 'and'). The MAC layer provides a service to a Radio Link Control (RLC) layer through a logical channel.

The function of the RLC layer includes concatenation, segmentation and reassembly of the RLC SDUs. The RLC layer includes a Transparent Mode (TM), an Unacknowledged Mode (UM), and an Acknowledged Mode (RB) in order to guarantee various QoSs required by a radio bearer (RB) , And AM). AM RLC provides error correction via automatic repeat request (ARQ).

The Radio Resource Control (RRC) layer is defined only in the control plane. The RRC layer is responsible for the control of logical channels, transport channels and physical channels in connection with the configuration, re-configuration and release of radio bearers. RB means a logical path provided by a first layer (PHY layer) and a second layer (MAC layer, RLC layer, PDCP layer) for data transmission between a UE and a network.

The functions of the Packet Data Convergence Protocol (PDCP) layer in the user plane include transmission of user data, header compression and ciphering. The functions of the Packet Data Convergence Protocol (PDCP) layer in the control plane include transmission of control plane data and encryption / integrity protection.

The setting 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 an operation method. RB can be divided into SRB (Signaling RB) and DRB (Data RB). The SRB is used as a path for transmitting the RRC message in the control plane, and the DRB is used as a path for transmitting the user data in the user plane.

When an RRC connection is established between the RRC layer of the UE and the RRC layer of the E-UTRAN, the UE is in the RRC connected state, and if not, the UE is in the RRC idle state.

The downlink transmission channel for transmitting data from the network to the terminal includes a BCH (Broadcast Channel) for transmitting system information and a downlink SCH (Shared Channel) for transmitting user traffic or control messages. In case of a traffic or control message of a downlink multicast or broadcast service, it may be transmitted through a downlink SCH, or may be transmitted via a separate downlink MCH (Multicast Channel). Meanwhile, the uplink transmission channel for transmitting data from the UE to the network includes a random access channel (RACH) for transmitting an initial control message and an uplink SCH (Shared Channel) for transmitting user traffic or control messages.

A logical channel mapped to a transport channel is a broadcast control channel (BCCH), a paging control channel (PCCH), a common control channel (CCCH), a multicast control channel (MCCH), a multicast traffic Channel).

A physical channel is composed of several OFDM symbols in the time domain and a plurality of sub-carriers in the frequency domain. One sub-frame is composed of a plurality of OFDM symbols in the time domain. A resource block is a resource allocation unit, and is composed of a plurality of OFDM symbols and a plurality of sub-carriers. In addition, each subframe can use specific subcarriers of specific OFDM symbols (e.g., first OFDM symbol) of a corresponding subframe for a physical downlink control channel (PDCCH), i.e., an L1 / L2 control channel. The TTI (Transmission Time Interval) is the unit time of the subframe transmission.

5 is a diagram illustrating an example of a physical channel structure to which the present invention can be applied.

Referring to FIG. 5, a subframe includes two slots in the time domain. A maximum of 3 OFDM symbols preceding a first slot in a subframe are control regions to which control channels are allocated, and the remaining OFDM symbols are data regions to which a physical downlink shared channel (PDSCH) is allocated.

The downlink control channels used in the 3GPP LTE are a Physical Control Format Indicator Channel (PCFICH), a Physical Downlink Control Channel (PDCCH), and a Physical Hybrid-ARQ Indicator Channel (PHICH). The PCFICH transmitted in the first OFDM symbol of the subframe carries information on the number of OFDM symbols (i.e., the size of the control region) used for transmission of the control channels in the subframe. The control information transmitted through the PDCCH is referred to as downlink control information (DCI). DCI indicates uplink resource allocation information, downlink resource allocation information, and uplink transmission power control commands for certain UE groups. The PHICH carries an ACK (Acknowledgment) / NACK (Not-Acknowledgment) signal for an uplink HARQ (Hybrid Automatic Repeat Request). That is, the ACK / NACK signal for the uplink data transmitted by the UE is transmitted on the PHICH.

6 is a diagram for explaining an operation procedure of a terminal and a base station in a contention-based random access procedure.

(1) transmission of the first message

First, the UE randomly selects one random access preamble from a set of random access preambles indicated through system information or a handover command, and transmits a PRACH (Physical RACH) capable of transmitting the random access preamble, Resources can be selected and transmitted (S610).

(2) Receiving the second message

The method of receiving the random access response information is similar to that in the non-contention based random access procedure. That is, after transmitting the random access preamble as in step S610, the terminal attempts to receive its random access response in the random access response reception window indicated by the system information or the handover command, The PDSCH is received through the RNTI information (S620). (UL Grant), Temporary C-RNTI (Temporary C-RNTI), and Timing Advance Command (TAC).

(3) Third message transmission

When the terminal receives a random access response valid to itself, it processes the information included in the random access response, respectively. That is, the UE applies the TAC and stores the temporary C-RNTI. In addition, data (i.e., the third message) is transmitted to the base station using UL acknowledgment (S630). The third message should include the identifier of the terminal. In the contention-based random access procedure, the base station can not determine which UEs perform the random access procedure, and it is necessary to identify the UE in order to resolve the collision later.

Two methods have been discussed as a way to include the terminal identifier. In the first method, if the UE has already received a valid cell identifier allocated in the cell before the random access procedure, the UE transmits its cell identifier through the UL transmission signal corresponding to the UL grant. On the other hand, if a valid cell identifier is not allocated before the random access procedure, the UE transmits its own unique identifier (for example, S-TMSI or random ID). Generally, the unique identifier is longer than the cell identifier. If the UE has transmitted data corresponding to the UL acknowledgment, it starts a contention resolution timer.

(4) Receiving the fourth message

After the UE transmits data including its own identifier through the UL acknowledgment included in the random access response, it waits for an instruction from the base station to resolve the collision. That is, the PDCCH is attempted to receive a specific message (S640). Two methods have been discussed in the method of receiving the PDCCH. As described above, when a third message transmitted in response to the UL acknowledgment is transmitted using a cell identifier, the UE attempts to receive a PDCCH using its cell identifier, and if the identifier is a unique identifier , It is possible to attempt to receive the PDCCH using the temporary C-RNTI included in the random access response. Thereafter, in the former case, if the PDCCH is received through its cell identifier before the conflict resolution timer expires, the UE determines that the random access procedure has been normally performed, and terminates the random access procedure. In the latter case, if the PDCCH is received through the temporary C-RNTI before expiration of the collision resolution timer, the PDSCH confirms data delivered by the PDSCH indicated by the PDCCH. If the unique identifier is included in the contents of the data, the terminal normally determines that the random access procedure has been performed and terminates the random access procedure.

Hereinafter, the RRC state (RRC state) and the RRC connection method of the UE will be described in detail.

The RRC state refers to whether or not the RRC layer of the UE is a logical connection with the RRC layer of the E-UTRAN. If the RRC layer is connected, the RRC connection state is referred to as the RRC idle state. Since the RRC-connected terminal has an RRC connection, the E-UTRAN can grasp the existence of the corresponding terminal on a cell-by-cell basis, thereby effectively controlling the terminal.

On the other hand, the UEs in the RRC idle state can not be grasped by the E-UTRAN and are managed by the CN (core network) in units of a tracking area (Tracking Area) larger than the cell. That is, the UEs in the RRC idle state are only detected on the basis of a large area, and must move to the RRC connection state in order to receive normal mobile communication services such as voice and data.

When the user turns on the terminal for the first time, the terminal searches for the appropriate cell first and then stays in the RRC idle state in the corresponding cell. The UE in the RRC idle state establishes the RRC connection with the E-UTRAN through the RRC connection procedure when the UE needs to establish the RRC connection, and transitions to the RRC connection state. There are a number of cases where the UE in the RRC idle state needs to make an RRC connection. For example, if uplink data transmission is required due to a user's call attempt or the like, or a paging message is received from the E-UTRAN And transmission of a response message to the received message.

The non-access stratum (NAS) layer located at the top of the RRC layer performs functions such as session management and mobility management.

In order to manage the mobility of the terminal in the NAS layer, two states of EMM-REGISTERED (EPS Mobility Management-REGISTERED) and EMM-DEREGISTERED are defined, and these two states are applied to the terminal and the MME. The initial terminal is in the EMM-DEREGISTERED state, and the terminal performs a process of registering with the network through an initial attach procedure to access the network. When the Attach procedure is successfully performed, the UE and the MME enter the EMM-REGISTERED state.

In order to manage the signaling connection between the terminal and the EPC, two states of ECM (EPS Connection Management) -IDLE state and ECM-CONNECTED state are defined, and these states are applied to the terminal and the MME. When the UE in the ECM-IDLE state establishes the RRC connection with the E-UTRAN, the UE enters the ECM-CONNECTED state.

The MME in the ECM-IDLE state enters the ECM-CONNECTED state when it makes an S1 connection with the E-UTRAN. When the UE is in the ECM-IDLE state, the E-UTRAN does not have context information of the UE. Therefore, the terminal in the ECM-IDLE state performs terminal-based mobility-related procedures such as cell selection or cell reselection without receiving commands from the network. On the other hand, when the terminal is in the ECM-CONNECTED state, the mobility of the terminal is managed by the command of the network. If the location of the terminal differs from the location known by the network in the ECM-IDLE state, the terminal notifies the network of the location of the terminal through a Tracking Area Update procedure.

The following describes the system information.

The system information includes essential information that the terminal needs to know in order to access the base station. Therefore, the terminal must receive all the system information before connecting to the base station, and always have the latest system information. Since the system information is information that must be known by all terminals in a cell, the base station periodically transmits the system information.

According to Section 5.2.2 of 3GPP TS 36.331 V8.7.0 (2009-09) "Radio Resource Control (RRC), Protocol specification (Release 8)", the system information includes MIB (Master Information Block), SB (Scheduling Block) , And SIB (System Information Block). The MIB allows the UE to know the physical configuration of the cell, for example, the bandwidth. The SB informs the transmission information of the SIBs, for example, the transmission period. An SIB is a collection of related system information. For example, some SIBs only contain information of neighboring cells, and some SIBs only contain information of uplink radio channels used by the UE.

7 is a flowchart illustrating a terminal operation in an RRC idle state to which the present invention can be applied.

FIG. 7 shows a procedure in which a terminal with an initial power on is registered in a network via a cell selection process, and then a cell is selected if necessary.

Referring to FIG. 7, the MS selects a radio access technology (RAT) for communicating with a public land mobile network (PLMN), which is a network to which the MS desires to receive services (S710). Information on the PLMN and the RAT may be selected by a user of the UE or may be stored in a universal subscriber identity module (USIM).

The terminal selects a cell having the largest value among the cells having the measured signal strength or quality higher than a specific value (Cell Selection) (S720). This may be referred to as an initial cell selection in which a terminal that is powered on performs cell selection. The cell selection procedure will be described later in detail. After the cell selection, the terminal receives the system information periodically transmitted by the base station. The above-mentioned specific value refers to a value defined in the system in order to guarantee the quality of a physical signal in data transmission / reception. Therefore, the value may vary depending on the applied RAT.

If the terminal needs to register the network, the terminal performs a network registration procedure (S730). The terminal registers its information (eg, IMSI) to receive a service (eg, Paging) from the network. The terminal does not register in the network to be connected every time the cell is selected, but when the information of the network received from the system information (for example, Tracking Area Identity (TAI) do.

The terminal performs cell reselection based on the service environment provided in the cell or the environment of the terminal (S740). If the strength or quality of the signal measured from the serving base station is lower than the value measured from the base station of the adjacent cell, the terminal selects one of the other cells providing better signal characteristics than the base station cell connected to the terminal do. This process is called cell re-selection by distinguishing the initial cell selection from the initial cell selection in step 2. At this time, a time constraint is set in order to prevent the cell from being reselected frequently according to the change of the signal characteristics. The cell reselection procedure will be described later in detail.

8 is a flowchart illustrating a procedure for establishing an RRC connection to which the present invention can be applied.

The MS sends an RRC Connection Request message to the network requesting an RRC connection (S810). The network sends an RRC Connection Setup message in response to the RRC connection request (S820). After receiving the RRC connection setup message, the UE enters the RRC connection mode.

The MS sends an RRC Connection Setup Complete message to the network to confirm successful completion of the RRC connection establishment in operation S830.

9 is a flowchart illustrating an RRC connection reset process to which the present invention can be applied.

RRC connection reconfiguration is used to modify the RRC connection. This is used to establish / modify / release RB, perform handover, and setup / modify / release measurements.

The network sends an RRC Connection Reconfiguration message for modifying the RRC connection to the terminal (S910). In response to the RRC connection re-establishment, the MS sends an RRC Connection Reconfiguration Complete message to the network (S920), which is used to confirm successful completion of the RRC connection re-establishment.

10 is a diagram illustrating an example of an RRC connection re-establishment procedure to which the present invention can be applied.

Referring to FIG. 10, the UE stops using all radio bearers except SRB 0 (Signaling Radio Bearer # 0) and initializes various sub-layers of the AS (Access Stratum) (S1010). In addition, each of the sub-layers and the physical layer is set as a default configuration. During this process, the terminal maintains the RRC connection state.

The UE performs a cell selection procedure to perform the RRC connection re-establishment procedure (S1020). During the RRC connection re-establishment procedure, the cell selection procedure may be performed in the same manner as the cell selection procedure performed by the UE in the RRC idle state even though the UE remains in the RRC connection state.

After performing the cell selection procedure, the UE checks system information of the corresponding cell and determines whether the corresponding cell is a suitable cell (S 1030). If it is determined that the selected cell is an appropriate E-UTRAN cell, the UE transmits an RRC connection reestablishment request message to the cell (S1040).

On the other hand, if it is determined through the cell selection procedure for performing the RRC connection re-establishment procedure that the selected cell is a cell using another RAT other than E-UTRAN, the RRC connection re-establishment procedure is stopped, and the UE enters the RRC idle state Enter (S1050).

The UE can be configured to complete the cell validation within a limited time through the cell selection procedure and the system information reception of the selected cell. In order to do this, the UE can start the timer by starting the RRC connection re-establishment procedure. The timer can be stopped if it is determined that the terminal has selected a suitable cell. If the timer expires, the terminal may assume that the RRC connection re-establishment procedure has failed and enter the RRC idle state. This timer is referred to below as a radio link failure timer. LTE Specification In TS 36.331, a timer named T311 can be used as a radio link failure timer. The UE can acquire the set value of this timer from the system information of the serving cell.

Upon receiving the RRC connection re-establishment request message from the terminal and accepting the request, the cell transmits an RRC connection reestablishment message to the terminal.

Upon receiving the RRC connection re-establishment message from the cell, the UE reconfigures the PDCP sublayer and the RLC sublayer for SRB1. Also, various key values related to the security setting are recalculated, and the PDCP sublayer responsible for security is reconfigured with newly calculated security key values.

Accordingly, the UE-cell SRB 1 is opened and the RRC control message can be exchanged. The MS completes the resumption of the SRB 1 and transmits an RRC connection reestablishment complete message indicating that the RRC connection re-establishment procedure to the cell has been completed (S 1060).

On the other hand, if the UE receives the RRC connection re-establishment request message and does not accept the request, the cell transmits an RRC connection re-establishment reject message to the UE.

If the RRC connection re-establishment procedure is successfully performed, the cell and the UE perform the RRC connection re-establishment procedure. Through this, the UE recovers the state before performing the RRC connection re-establishment procedure, and ensures the continuity of the service to the maximum.

Hereinafter, a method for performing uplink transmission without a RRC connection procedure by a terminal according to the present invention will be described in detail with reference to related drawings.

In the following description, the UE considers the situation of performing uplink communication with the BS.

The terminal described herein has one of the RRC idle state and the RRC_Connected state in order to perform communication with the base station.

In the following description, the RRC_Idle state is referred to as a dormant state (or idle state), and the RRC_Connected state is referred to as an RRC connected state.

In this specification, when a packet transmitted in a low latency service is defined in advance, a terminal in a dormant state does not perform an RRC connection procedure with a base station, and transmits a radio resource acquired through a random access procedure An indicator of a packet to be transmitted and a destination information of a packet to be transmitted to the base station by performing uplink transmission related to a low delay service by using the uplink and downlink Provides a method for reducing time.

In this specification, a new entity SME (Service Management Entity) is defined in the EPC (Evolved Packet Core), a method of transmitting uplink data by one random access using the SME, a method of transmitting LSM Low-latency Service Management) state, and a signaling procedure for managing the LSM state.

All the low-delay services described in this specification are regarded as using the uplink transmission method of the terminal proposed in the present specification.

SME ( S ervice M anagement E ntity)

The uplink transmission of the UE proposed in the present specification is performed using an EPC entity called a 'SME (service management entity)' that newly defines the uplink transmission.

The function of the SME can be defined as follows.

The type of packet transmitted in the low-delay service, the indicator of the corresponding packet, the destination of the packet, the user authentication key,

Performing user authentication based on uplink transmission information of the terminal and acquiring security for the uplink

Generates a data packet based on the transmission information of the terminal and transmits it to the destination requested by the terminal

First, the first function of the SME will be described.

First, the SME manages the type of packet transmitted in the low-delay service, the indicator of the corresponding packet, the destination of the packet, the user authentication key, and the charging method.

In order for the UE to perform uplink transmission related to the low-delay service, information on the user authentication key, packet type, and the like is needed.

Therefore, the SME manages the information on the user authentication key, the packet type, etc., confirms the service information used by the corresponding terminal through the control message received at the initial connection of the terminal, To the corresponding terminal.

Here, since there may be a plurality of low-delay services, the SME must manage information on a plurality of low-delay services.

Secondly, the SME performs authentication of the UE and performs the function of obtaining security for the UL transmission.

In the existing LTE / LTE-A communication technology, an AS (access stratum) security setup is performed through an RRC connection procedure, and security and data integrity between the BS and the UE are obtained through the AS security setup.

However, in the case of the method proposed in this specification, since the UE in the idle state does not perform the RRC connection procedure in the process of performing the uplink transmission, in the conventional method, the security and integrity of the uplink data to be transmitted Can not.

Accordingly, the present invention provides a method for obtaining security and data integrity in uplink transmission of a terminal through SME.

Thirdly, the SME receives the indicator of the packet transmitted from the terminal and the destination information of the packet, thereby generating a packet corresponding to the indicator of the packet and transmitting the generated packet to the destination.

Since the SME manages the packet information of the low-delay service as shown in the first function of the SME, the SME can generate the packet (to be transmitted to the request destination of the terminal) using the information of the packet transmitted from the terminal .

In addition, this specification newly defines a low-latency service management (LSM) state in order to efficiently exchange information between the terminal and the SME and manage the current state.

The newly defined LSM-state can be classified into two states: (1) LSM-Registered state and (2) LSM-Deregistered state.

That is, a terminal supporting (or using) a low-delay service may have the LSM-state state defined above.

Each LSM-state (LSM-Registered state and LSM-Deregistered state) represents the information exchange state between the terminal and the SME.

In the LSM-Registered state, terminal information and security information for uplink transmission are shared between the terminal and the SME, and terminal information is also shared between the SME and the MME.

Accordingly, when the UE is in the LSM-Registered state and the EMM-Registered state, it is possible to perform the low delay uplink transmission proposed in the present specification.

The EMM (EPS Mobility Management) -Registered state indicates that the UE is attached to the network and has an IP address and an EPS bearer is set.

The LSM-Deregistered state refers to a state in which information of the UE and information for security of the UL transmission are not shared between the UE and the SME.

The MS can have any one of the following four states according to the LSM-state and the EMM-state.

State 1 (1110): EMM-Deregistered and LSM-Deregistered

State 2 (1120): EMM-Deregistered and LSM-Registered

State 3 (1130): EMM-Registered and LSM-Registered

State 4 (1140): EMM-Registered and LSM-Deregistered

11 is a diagram illustrating an example of a transition process between the LSM-state and the EMM-state proposed in the present specification.

Referring to FIG. 11, the four states will be described in more detail.

Status 1 (EMM-Deregistered and LSM-Deregistered) indicates when the user has joined the network and has not turned on the terminal at all, or a long time has passed since the user turned off the terminal.

In state 2 (EMM-Deregistered and LSM-Registered), the EMM connection with the network is released by the user when the user turns off the terminal, or the terminal information for the low-delay UL transmission is left in the network Respectively.

Here, when the state 2 continues for a predetermined time or more, the state 2 transitions to the state 1. [

In state 3 (EMM-Registered and LSM-Registered), information for low-delay uplink transmission is shared between the UE and the SME, and the UE is attached to the network. Indicates a state in which delayed uplink transmission can be performed.

State 4 (EMM-Registered and LSM-Deregistered) indicates a state in which the UE in State 3 fails in user authentication during the low-delay UL transmission or the security information is not shared or expired between the UE and the SME.

In order to transition from state 4 to state 3, the terminal must perform a reconfiguration process.

Hereinafter, a communication method for low delay uplink transmission proposed in the present specification will be described.

The communication method for low delay uplink transmission proposed in this specification can be roughly divided into (1) an initial attach procedure, (2) a service request procedure, (3) a reconfiguration procedure, and (4) And a detach procedure.

Each of the procedures (1) to (4) is performed when the terminal performs initial access to the network, when LSM state transition is required, when low-delay UL transmission is performed, ) Is required.

Each procedure will be described in more detail with reference to FIG. 12 to FIG.

Early connect ( I nitial attach ) step

12 is a flowchart illustrating an example of an initial access procedure of a communication method for low delay uplink transmission proposed in the present specification.

12A and 12B correspond to a series of processes for performing the initial connection procedure, which are divided for convenience of description and convenience of drawing.

The initial attach procedure is a process in which a terminal in an EMM-Deregistered state and an LSM-Deregistered state accesses a network for the first time, transmits a network access request (Attach Request) to the network (or network) to be.

12, the initial attach procedure includes (1) UE ID acquisition S1210, (2) Authentication S1220, (3) Security setup S1230, and (4) Service information acquisition S1240 It can be divided into four stages.

First, the UE ID acquisition step, which is the first step of the initial attach procedure, will be described.

The UE ID acquisition step S1210 is a procedure for acquiring an International Mobile Subscriber Identity (IMSI) through an Attach Request message in the same manner as the RRC connection procedure of the existing LTE / LTE-A communication technology.

The UE performs the same procedure as the existing RRC connection procedure in order to connect to the network, and therefore, a specific description of the procedure will be referred to in the foregoing.

After the UE ID acquisition step, the UE transitions to the EMM-Registered and LSM-Deregistered states.

Next, the authentication step as the second step of the initial attach procedure will be described (S1220).

The authentication step is a step of acquiring an authentication vector through signaling between the MME and the HSS and performing a subscriber authentication and may be divided into a network authentication procedure S1221 and a service authentication procedure S1222 .

The Network authentication procedure is a process of authenticating whether the terminal is actually a terminal that can use the network.

At this time, the network authentication procedure is the same as the network authentication procedure in the existing LTE / LTE-A communication technology, but the terminal using the low-delay service acquires the authentication vector from the HSS for the service authentication process, Service ID 1210 of the low-delay service to be used.

When mutual authentication is completed between the terminal and the MME, the MME performs a service authentication process by transmitting a service authentication request message to the SME.

The service authentication request message includes an IMSI of the MS and a service ID 1220 of a service to be used by the MS acquired from the HSS.

The SME informs the MME that the IMSI and the service ID of the terminal acquired by the MME from the terminal through the service authentication response message are the same information as the information registered in the SME.

Next, the security setup step S1230, which is the third step of the initial attach procedure, will be described.

The security setup step refers to a step in which the UE exchanges information to acquire security and integrity while performing low-delay uplink transmission.

The Security Setup step basically has a similar procedure to the NAS Security Setup process of the existing LTE / LTE-A communication technology, so the difference will be mainly described below.

At this stage, information that the terminal and the SME share with each other in order to generate the same security key is needed.

라는 동일한 보안 키를 부여하는 방법을 제공한다.Accordingly, in the present specification, in order to generate a corresponding security key, when the UE registers in the low-delay service, the USIM of the UE and the SME of the network

Quot; and " the same "

Here, the security setup step may be roughly divided into a security preparation procedure S1231 and a security setup complete procedure S1232.

In the security preparation procedure, the MME transmits a Security Key Request message including algorithm information to be used in the security key generation to the SME.

In this case, the algorithm used for the security key generation may be the same algorithm used in the NAS security setup.

(1230)을 이용하여 상기 보안 키 요청 메시지에 포함된 알고리즘으로 보안 키 SME-MAC을 생성하고,

의 식별자인

(1240)와 함께 MME로 전달한다.The SME that has received the security key request message transmits the security key request message

Generates a security key SME-MAC using an algorithm included in the security key request message using the security key request message 1230,

Is the identifier of

(1240) to the MME.

(1260) 및 NAS security setup을 위한 정보를 보안 모드 명령(Security mode command) 메시지를 통해 단말로 전달한다.In the Security Setup Complete procedure, the MME receives the SME-MAC 1250,

(1260) and information for NAS security setup to a terminal through a security mode command message.

Upon receiving the security mode command message, the terminal generates XNAS-MAC and XSME-MAC in the same manner as NAS-MAC and SME-MAC through the algorithm included in the security mode command message.

Then, the UE performs an integrity check by checking whether the generated XNAS-MAC and XSME-MAC have the same values as the NAS-MAC and the SME-MAC.

Thereafter, if the integrity check is successful, the MS transmits a NAS-MAC and an SME-MAC 1270 to the MME through a security mode complete message to indicate that the integrity check is successful.

Then, the MME transmits the received SME-MAC to the SME to notify that the integrity check is successful.

In the authentication step and the security setup step, when the user authentication information exists in the network, the UE transmits NAS-MAC and SME-MAC to the MME in the UE ID acquisition step, and the received NAS-MAC and SME- If the SME has the same NAS-MAC and SME-MAC (i.e., integrity check is successful), the procedures may be omitted.

Next, the service information acquisition procedure (S1240) which is the fourth step of the initial attach procedure will be described.

The Service information acquisition procedure refers to a step in which the UE acquires information on the low-delay service.

After the security setup with the terminal is completed, the SME registers the terminal with the service and transmits a service information message to the terminal.

The service information message may be transmitted from the SME to the mobile station when the mobile station has not received the information about the service or a long time has elapsed since the information on the service was acquired.

In addition, the service information message includes information necessary for uplink transmission in a low-delay service used by the UE.

The necessary information included in the service information message may include not only information necessary for transmission such as an identifier list of predefined data, a service policy, a timer length for updating service information, and information selected arbitrarily by a service provider.

After the initial attach procedure, the UE transitions to the EMM-Registered and LSM-Registered states to be able to perform the low-delay UL transmission.

service request (Service request) step

13 is a flowchart illustrating an example of a service request procedure of a communication method for low delay uplink transmission proposed in the present specification.

The service request procedure is a procedure in which a UE successfully performing an initial attach procedure performs a low-delay UL transmission.

Here, if the MS transmits a service request message to the BS, the BS transmits the service request message to the SME so that the SME can actually transmit data to the destination.

In this procedure, it is assumed that the terminal is in the LSM-Registered and EMM-Registered state and in the idle state.

The Service request procedure includes (1) a random access procedure S1310, (2) a service message forwarding procedure S1320, (3) a packet delivery procedure S1330, and (4) a response message procedure (optional) (S1340).

If the (4) response message procedure is omitted, the Service request procedure can be roughly classified into three steps.

First, the Random access step (S1310), which is the first step of the service request procedure, will be described.

The random access step refers to a process in which the UE performs random access with the Node B for uplink transmission.

The UE waits for a RACH cycle as in the existing LTE / LTE-A communication technology and transmits a random access preamble to a corresponding RACH to the Node B, and the Node B transmits a random access response to the UE in response to the RACH preamble. send.

The random access response includes uplink resource information that the MS can transmit to the BS the next control message.

Next, the service message forwarding step (S1320), which is the second step of the service request procedure, will be described.

The Service message forwarding step is a step in which the MS transmits a service message to the BS through an uplink resource obtained through random access and the BS forwards the service message to the SME.

Here, the MS transmits at least one of its identity, a service ID, an acknowledgment of uplink transmission, an indicator of a packet to be transmitted, or destination information to the BS using uplink resources obtained through random access (S1321).

Here, the indicator of the packet to be transmitted by the terminal and the destination information are encrypted through the security key acquired in the initial attach procedure and transmitted to the base station.

On the other hand, in the case of the identity of the terminal, the service ID, and whether the response to the UL transmission is received, it is transmitted without being encrypted through the security key acquired in the initial attach procedure. This is because the base station must transmit the service message to the SME using the corresponding information (identity, service ID, whether or not to receive the response to the uplink transmission) of the terminal.

Then, the BS receiving the service message from the MS confirms the identity of the MS, the type of the service, whether a response to the UL transmission is received, and transmits the service message to the SME of the corresponding service.

If the terminal needs to receive a response to the uplink transmission, the base station transmits a service response to the service message to the terminal so that the terminal can receive a response to the uplink transmission in the future And transmits the resource information (S1322).

Here, if the UE does not need to interact with the destination after transmitting a message such as notification of an accident situation, the UE does not need to receive a response to the UL transmission.

Next, the packet delivery step (S1330), which is the third step of the service request procedure, will be described.

The packet delivery step is a process in which an SME generates an actual packet using a service message transmitted from a base station and transmits the generated packet to a destination.

The SME performs an integrity check and a decryption process with a security key corresponding to the terminal identity in the received service message.

The security key corresponding to the terminal identity means a security key obtained by the SME in the security setup step of the initial attach procedure.

Here, the success of the integrity check means that the terminal transmitting the service message is an authenticated terminal.

Thereafter, when the integrity check and deciphering are successful, the SME generates a packet using the packet indicator and the destination of the service message, and then transmits the generated packet to the destination.

Next, a response message step (S1340) which is the fourth step of the service request procedure will be described.

The response message step refers to a step in which the SME transmits a response message for uplink transmission.

The SME generates a response message to be transmitted to the UE according to whether the uplink transmission of the UE is successful or not, and transmits the generated response message to the UE in step S1341.

The generated response message includes information on the success or failure of the uplink transmission and information on the cause of the failure.

The UE may generate a service message again, perform a re-authentication process, or transition to an LSM-Deregistered state depending on the cause of the failure.

Also, when the uplink transmission of the UE has failed several times, the SME can transmit a detach request message.

However, the step of transmitting the revocation request message may not be performed according to the type of service used by the terminal and the SME.

reset (Reconfiguration) step

FIGS. 14 and 15 are flowcharts illustrating an example of a reconfiguration procedure of a communication method for low-delay uplink transmission proposed in the present specification.

The reconfiguration procedure refers to the procedure used for resetting or updating related information associated with low delay services and low delay uplink transmissions.

If the terminal receives a response message including a reset request due to an unsuccessful integrity verification performed on the Service message and the terminal receives a reset request from the SME, the security information and the service information of the terminal and the SME may expire And may be performed when updating is required.

The reconfiguration procedure reconfigures the security information between the UE and the SME by performing the security setup and the service information acquisition of the initial attach procedure again by the UE and the SME, And obtaining and updating information from the SME.

Since the UE performing the low-delay UL transmission is in a dormant state, there are two methods of requesting reconfiguration to the base station through the random access or the reconfiguration through the paging of the base station in order to exchange information. .

Therefore, the Reconfiguration procedure is divided into two parts: (1) a UE-initiated reconfiguration procedure initiated by the UE, and (2) a SME-initiated reconfiguration procedure initiated by the SME, Can be divided into cases.

FIG. 14 is a flowchart illustrating an example of a reconfiguration procedure initiated by a terminal, and FIG. 15 is a flowchart illustrating an example of a reconfiguration procedure initiated by an SME.

First, the UE-initiated reconfiguration procedure will be described with reference to FIG.

The UE-initiated reconfiguration procedure may be performed when the UE desires to update its own security information and service information.

The first step of the UE-initiated reconfiguration procedure is a reconfiguration request step (S1410) in which the UE acquires uplink resources from the base station by performing random access with the base station, and uses the acquired uplink resources And transmits a service reconfiguration request to the SME.

The second step of the UE-initiated reconfiguration procedure is a security reconfiguration step S1420 in which the SME sends a security reconfiguration request to the MME to perform a security setup again .

The security setup is the same as the security setup in the initial attach procedure.

The third step of the UE-initiated reconfiguration procedure is a service information acquisition (S 1430) step in which the UE acquires and updates the service related information again.

The service information acquisition step is the same as the service information acquisition step in the initial attach procedure.

Next, the SME-initiated reconfiguration procedure will be described with reference to FIG.

The SME-initiated reconfiguration procedure can be performed when the service information is changed and needs to be updated or when the integrity check of the service message fails while the terminal is performing the service request procedure.

In step S1520 and step S1530, the SME-initiated reconfiguration procedure (the reconfiguration request step in step S1520) is performed in the UE-initiated reconfiguration procedure (step S1420) And a service information acquisition (SIA) step S1430.

That is, the reconfiguration request step (S1510), which is the first step of the SME-initiated reconfiguration procedure, transmits a service reconfiguration request message informing that the SME needs reconfiguration to the terminal.

If the SME can send a response message for the integrity check to the SS when the integrity check of the SS has failed and the SME needs to perform reconfiguration, the SME transmits a Service reconfiguration request message to the SS through the response message for the integrity check. Lt; / RTI >

If the reconfiguration procedure is required due to the change of the service information other than the failure of the integrity check or the failure of the integrity check, since the terminal is in the idle state and the terminal receives the Service reconfiguration request message from the SME Paging to the terminal is required.

Accordingly, in this case, the SME transmits a Service reconfiguration request message and information of the UE to the MME.

Thereafter, the MME transmits paging to the MS to wake up the MS, and transmits a Service reconfiguration request message to the MS.

The paging and Service reconfiguration request message can be simultaneously transmitted to the UE.

The MS receives the Service reconfiguration request message and transmits a Service reconfiguration response signal in response to the Service reconfiguration request message.

The security reconfiguration step and the service information acquisition step are the same as the UE-initiated reconfiguration procedure, so a detailed description will be omitted.

Termination ( Detach ) step

16 and 17 are flowcharts illustrating an example of a cancellation procedure of a communication method for low-delay uplink transmission proposed in the present specification.

Fig. 16 shows an example of a detach procedure initiated by the terminal, and Fig. 17 shows an example of a detach procedure initiated by the SME.

Detach procedure is a procedure in which a terminal disconnects a connection with a network. When a terminal is powered off and the terminal is no longer using a service requiring low-delay uplink transmission, Or when the use of the terminal's service is to be stopped.

Through the Detach procedure, the UE terminates the connection with the service and the network, and transitions to the EMM-Deregistered and the LSM-Deregistered state, and the UE can no longer perform the low-delay UL transmission.

The detach procedure for disconnecting the network can utilize the procedure of the existing LTE / LTE-A communication technology. Hereinafter, a procedure for terminating a connection with a service will be described.

The detach procedure can be classified into (1) a UE-initiated detach procedure initiated by the UE and (2) a SME-initiated detach procedure initiated by the SME, depending on the subject initiating the procedure.

Initially, a UE-initiated detach procedure initiated by the UE will be described with reference to FIG.

The UE-initiated detach procedure may be used when the terminal is powered off or when it is determined that the terminal itself will no longer use the service.

The first step of the UE-initiated detach procedure is a detach triggering step (S1610) wherein the UE acquires an uplink resource by performing random access and transmits the uplink resource to the SME And a detach request is transmitted.

및

(1610)를 포함한다.At this time, the detach request includes identification information of the terminal,

And

(1610).

(1610)값을 기반으로 보안 컨텍스트(security context)를 백업한다.Wherein the SME receives a Detach request from the terminal,

And backs up the security context based on the value of the security context 1610.

를 제외한 정보를 MME로 전달하고, 상기 MME는 상기 detach request를 수신한 후

값을 기반으로 security context를 백업한다.Also, the SME sends a Detach request

To the MME, and the MME receives the detach request

Backs up the security context based on the value.

The backed-up security information can be used again when the terminal attempts to attach the network to the network.

Upon completion of the backup of the security information, the MME transmits a Detach Accept message to the terminal.

The Detach Accept message may not be delivered depending on the cause of the detach.

For example, when the terminal is powered off, the Detach Accept message may not be transmitted.

The second step of the UE-initiated detach procedure is a UE context termination step (S1620). The SME terminates the service registration context of the UE in the low-delay service used by the UE, Thereby preventing the low-delay service from being used.

After terminating the service registration context of the UE, the SME transmits a Delete context response to the MME indicating that the service registration context of the UE has been successfully terminated.

Next, a SME-initiated detach procedure will be described with reference to FIG.

The SME-initiated detach procedure refers to a process in which a UE attempts to transmit a low-delay uplink but detaches the UE from the network due to continued service authentication failure.

That is, the terminal attempts to initial attach again after the detach procedure.

The first step of the SME-initiated detach procedure is a detach triggering step (S1710), which transmits a detach request to the terminal.

If it is set to use an authentication response message of a service request procedure, the SME transmits a detach request message to the terminal through the authentication response message.

However, if the authentication response is set not to be transmitted, paging may be required to transmit a detach request message to the terminal.

In this case, the SME transmits a Detach request to the MME, the MME receives the Detach request, and transmits a Detach request to the terminal through paging to the terminal.

The terminal that receives the detach request from the SME or MME backs up the context related to the NAS security.

Here, the MME also backs up the context associated with the NAS security.

The UE deletes the context related to the security of the uplink transmission in the low delay service and transmits a Detach Accept message in response to the Detach request.

The second step of the SME-initiated detach procedure is a UE context termination step (S1720), in which the SME deletes all contexts of the UE.

When the MME receives a Detach Accept message from the terminal, the MME transmits a Delete Context Request message to the SME to delete all low-delay service related contexts of the terminal.

When receiving the Delete Context request message, the SME terminates all contexts of the UE.

Since the terminal has been detached due to the continued service authentication failure, the SME needs to cancel all service related contexts for the terminal in order to attempt initial attach in the initial state.

After terminating all the contexts of the UE, the SME transmits a Delete context response to the MME indicating that the low-delay service related context of the UE has been successfully terminated.

Hereinafter, an uplink transmission method for the low-delay service proposed in the present specification will be summarized briefly.

The present invention provides methods for reducing delay time and signaling overhead that may occur in the process of performing uplink transmission in a RRC_Idle state (or idle state) using a low delay service.

In this specification, a new entity called 'SME' is defined in the EPC in this specification, and a method for managing information for uplink transmission such as a packet type and a destination to be transmitted according to a service used by the terminal is provided by the SME.

By using the SME, the UE transmits information including its identity, an indicator of a packet to be transmitted, and a destination in a single message to an uplink resource obtained through random access, It is possible to perform uplink transmission with a delay time and a small overhead.

To this end, the present invention provides a LSM-state for managing user information between an SME and a terminal, a management method thereof, a method for performing low-delay uplink transmission using SME information, and a signaling procedure therefor.

Also, in this specification, in order to acquire security and integrity of data in a process of performing low-delay uplink transmission, there is a method of mutual authentication between a terminal and an SME when the terminal is connected to a network, And provided a method to guarantee performance integrity.

example Invention To be applied Number there is Device Normal

18 illustrates a block diagram of a wireless communication device to which the methods proposed herein may be applied.

Referring to FIG. 18, a wireless communication system includes a base station 1810 and a plurality of terminals 1820 located in a base station 1810 area.

The base station 1810 includes a processor 1811, a memory 1812, and a radio frequency unit 1813. The processor 1811 implements the functions, procedures, and / or methods suggested earlier in FIGS. 1-17. The layers of the air interface protocol may be implemented by the processor 1811. [ The memory 1812 is coupled to the processor 1811 to store various information for driving the processor 1811. The RF unit 1813 is connected to the processor 1811 to transmit and / or receive a radio signal.

The terminal 1820 includes a processor 1821, a memory 1822, and an RF section 1823. The processor 1821 implements the functions, processes and / or methods suggested in Figs. 1-17 above. The layers of the air interface protocol may be implemented by the processor 1821. The memory 1822 is coupled to the processor 1821 to store various information for driving the processor 1821. RF section 1823 is coupled to processor 1821 to transmit and / or receive wireless signals.

The memories 1812 and 1822 may be internal or external to the processors 1811 and 1821 and may be coupled to the processors 1811 and 1821 in various well known means.

Also, the base station 1810 and / or the terminal 1820 may have a single antenna or multiple antennas.

The embodiments described above are those in which the elements and features of the present invention are combined in a predetermined form. Each component or feature shall be considered optional unless otherwise expressly stated. Each component or feature may be implemented in a form that is not combined with other components or features. It is also possible to construct embodiments of the present invention by combining some of the elements and / or features. The order of the operations described in the embodiments of the present invention may be changed. Some configurations or features of certain embodiments may be included in other embodiments, or may be replaced with corresponding configurations or features of other embodiments. It is clear that the claims that are not expressly cited in the claims may be combined to form an embodiment or be included in a new claim by an amendment after the application.

Embodiments in accordance with the present invention may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. In the case of hardware implementation, an embodiment of the present invention may include one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs) field programmable gate arrays, processors, controllers, microcontrollers, microprocessors, and the like.

In the case of an implementation by firmware or software, an embodiment of the present invention may be implemented in the form of a module, a procedure, a function, or the like which performs the functions or operations described above. The software code can be stored in memory and driven by the processor. The memory is located inside or outside the processor and can exchange data with the processor by various means already known.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the essential characteristics thereof. Accordingly, the foregoing detailed description is to be considered in all respects illustrative and not restrictive. The scope of the present invention should be determined by rational interpretation of the appended claims, and all changes within the scope of equivalents of the present invention are included in the scope of the present invention.

Although the method for uplink data transmission and reception in the wireless communication system of the present invention has been described with reference to an example applied to the 3GPP LTE / LTE-A system, it can be applied to various wireless communication systems other than the 3GPP LTE / LTE-A system .

10: Terminal
20: Base station

Claims (15)

A method for transmitting uplink data (UL data) in a wireless communication system supporting a low latency service,
Performing an initial attach procedure between the terminal and the network; And
Performing a service request procedure for uplink transmission of a low delay service between the UE and the network,
The step of performing the service request procedure comprises:
And transmitting the control information used for generating uplink data of the low-delay service to the base station in the Service Management Entity (SME)
The control information includes terminal identification information indicating the identity of the terminal, a service ID indicating a type of the low delay service, response reception information indicating whether or not a response to the uplink transmission is received, A packet indicator indicating a packet, or destination information indicating a destination of the data packet. The method according to claim 1,
Further comprising the step of the terminal performing a reconfiguration procedure with the network to reset or update security information and / or service information associated with the uplink transmission of the low-latency service. The method according to claim 1,
Further comprising the step of performing a detach procedure for terminating the connection between the terminal and the network. The method according to claim 1,
The step of performing the initial attach procedure comprises:
Performing an RRC connection establishment procedure between the terminal and the network;
Performing an authentication procedure for performing authentication on the terminal and the service;
Performing a security setup procedure to obtain security and integrity related to uplink transmission of the low delay service; And
And performing a service information acquisition procedure for the terminal to obtain low-latency service information. 5. The method of claim 4,
Wherein the performing the authentication procedure comprises:
Obtaining a service ID of a low-delay service to be used by the MS from a home subscriber server (MSS) by an MME (Mobility Management Entity); And
The MME sending a service authentication request message for requesting service authentication to the SME,
Wherein the service authentication request message includes an International Mobile Subscriber Identity (IMSI) of the UE and a service ID of a low-delay service to be used by the UE. 5. The method of claim 4,
The step of performing the security setting procedure includes:
The MME sending a security key request message including algorithm information to be used in the security key generation to the SME;
Generating a second secret key using a first secret key shared by the SME in advance with the terminal and algorithm information included in the secret key request message;
Sending, by the SME, the generated second security key and the identifier of the first security key to the MME;
Transmitting a security mode command message including an identifier of a second security key and an identifier of the first security key received from the SME to the MME;
Performing an integrity check based on the received security mode command message; And
And transmitting the security mode complete message including the second security key to the SME if the integrity check is successful. The method according to claim 6,
The first security key

And the second security key is an SME-MAC. The method according to claim 1,
The step of performing the service request procedure comprises:
Performing a random access procedure between the subscriber station and the base station to allocate uplink resources for transmitting the control information; And
The SME generates uplink data of the low-delay service based on the control information, and transmits the uplink data of the low-delay service to the destination. 9. The method of claim 8,
Further comprising the step of the SME transmitting a response indicating whether the uplink data transmission of the low-delay service is successful to the terminal. The method according to claim 1,
Wherein the data packet indicator and destination information are encrypted through a secret key obtained in the initial access procedure. 3. The method of claim 2,
The reconfiguration procedure comprises:
The MS transmitting a service reconfiguration request message to the SME;
Transmitting a security reconfiguration request message instructing the SME to perform security setting again to the MME; And
And performing the service information acquisition procedure with the network to reacquire and update the low delay service related information. 3. The method of claim 2,
The reconfiguration procedure comprises:
Receiving a service reconfiguration request message from the SME indicating that the terminal needs to be reconfigured; And
And the UE transmitting a service reconfiguration response message to the SME in response to the service re-establishment request message. The method of claim 3,
The step of performing the detach procedure comprises:
Transmitting the detach request message including the identification information of the terminal and the identifier of the first secret key and the first secret key to the SME;
Backing up a security context based on the received revocation request message;
Receiving a detach accept message informing the terminal of the acceptance of the revocation from the MME;
The SME terminating the service registration context of the terminal; And
And sending a Delete Context Response from the SME to the MME indicating that the service registration context of the terminal has been successfully terminated. The method of claim 3,
The step of performing the detach procedure comprises:
Sending a detach request message from the SME to the MME;
The terminal receiving the revocation request message from the MME;
Deleting contexts related to uplink transmission security of the low delay service;
Transmitting a release acknowledgment message indicating termination acceptance to the MME;
Sending, by the MME, a delete context request message instructing deletion of a low delay service context of the UE to the SME based on the received revocation acceptance message; And
And sending a Delete Context Response message from the SME to the MME indicating that the low latency service context of the terminal has been successfully terminated. The method according to claim 1,
Wherein the terminal and the SME have a Low Latency Service Management (LSM) -Registered state and an LSM-Deregistered state.

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