KR20140058366A - Method of device to device discovery and apparatus thereof - Google Patents

Abstract

Disclosed are a method of device-to-device (D2D) discovery and an apparatus thereof. A restricted discovery method includes receiving a discovery identifier of a discovery terminal from a D2D server; performing an authorization procedure for performing the restricted discovery of an application located in the discovery terminal with the D2D server; and obtaining terminal information of a terminal to be discovered as a counterpart terminal with which performs the restricted discovery from the D2D server when the authorization is completed. Therefore, the restricted discovery can be performed efficiently.

Description

[0001] METHOD OF DEVICE TO DEVICE DISCOVERY AND APPARATUS THEREOF [0002]

The present invention relates to an inter-terminal discovery technique, and more particularly, to a communication method and apparatus for efficiently performing inter-terminal discovery.

In a cellular communication environment, a general method by which terminals transmit and receive data is through a base station. That is, when there is data to be transmitted to the second terminal, the first terminal transmits the data to the first base station to which the first terminal belongs. The first base station transmits the data received from the first terminal to the second base station to which the second terminal belongs through the core network. Finally, the second base station transmits the data received from the first base station to the second terminal. Here, the first base station and the second base station may be the same base station or different base stations.

Meanwhile, device to device communication (D2D) means that terminals communicate directly without going through a base station. That is, the first terminal can directly communicate with the second terminal without going through the base station to transmit / receive data.

End-to-end discovery means that nearby terminals or services are discovered using a direct link between terminals, similar to direct communication between terminals.

SUMMARY OF THE INVENTION An object of the present invention is to provide a limited discovery method for efficiently performing near-end discovery.

Another object of the present invention is to provide a method for activating limited discovery in order to efficiently perform inter-terminal discovery.

Another object of the present invention is to provide a limited discovery inactivation method for efficiently performing inter-terminal discovery in close proximity.

According to another aspect of the present invention, there is provided a limited discovery method, comprising: receiving a discovery identifier of a search terminal from a D2D server; performing an authentication procedure for performing limited discovery of an application located in the search terminal, And acquiring, from the D2D server, pause terminal information that is a counterpart terminal to perform limited discovery when authentication of the application is completed.

Here, the discovery ID may indicate that the search terminal supports limited discovery.

The step of performing the authentication procedure with the D2D server comprises the steps of: transmitting to the D2D server an authentication request message requesting authentication for restricted discovery of an application located at the search terminal; And receiving an authentication response message that is a response to the request message.

Here, the authentication request message may include a search terminal ID and an application ID.

The step of acquiring the searched terminal information from the D2D server may include transmitting the searched terminal information request message to the D2D server, receiving the searched terminal information request message from the D2D server, Receiving the information response message, and updating the paired terminal list based on the paired terminal information included in the paired terminal information response message.

Here, the sought-after-terminal information request message may include a target terminal ID, an operation flag, and the application ID to be searched.

Here, the action flag may indicate a consent request or an agreement release request for limited discovery.

Here, the searched terminal information response message may include response information on the paired terminal ID and limited discovery agreement.

Here, if the response to the limited discovery agreement is consent, the piconceived terminal ID may be added to the paired search terminal list.

According to another aspect of the present invention, there is provided a method for activating restricted discovery of a piconeting terminal, the method comprising: transmitting a limited discovery activation request message to a D2D server; Receiving a radio resource information used for limited discovery through a base station interfaced with the D2D server when discovery is activated, receiving a limited discovery activation response message from the D2D server in response to the limited discovery activation request message And performing limited discovery with the called terminal through radio resources indicated by the radio resource information.

The limited discovery activation request message may include a discovery type, a discovery state, an application identifier of the search terminal, and a search terminal ID.

Here, the limited discovery activation response message may include a discovery ID of the search terminal and a discovery ID of the search terminal.

Here, if the limited discovery activation response message is received, the search terminal may transition to a restricted discovery activation state.

Here, when receiving the limited discovery activation request message, the D2D server may allocate radio resources used for limited discovery to the paired search terminal.

Here, when the allocation of radio resources used for restricted discovery to the p-th search terminal is completed, the D2D server can set the discovery ID of the search terminal and the discovery ID of the p-th search terminal.

Here, the message transmitted between the search terminal and the D2D server may be transmitted through the mobile management entity.

According to another aspect of the present invention, there is provided a method of inactivating limited discovery of a piconeting terminal, the method comprising: transmitting a limited discovery inactivation request message for disabling limited discovery of a piconeting terminal to a D2D server; Receiving a limited discovery disable response message, which is a response to the restricted discovery disable request message, from the D2D server when the restricted discovery is disabled, receiving a notification of release of radio resources allocated for restricted discovery from the base station interfaced with the D2D server Receiving, and transitioning to an idle state.

Here, when receiving the limited discovery inactivation request message, the D2D server may release the radio resources allocated to the paired terminals for limited discovery.

Here, when the radio resources allocated to the p-th search terminal are completely released, the server can release the discovery ID set for the p-th search terminal.

Here, when the radio resource allocated to the search terminal is completed, the server D2D may release the discovery ID set for the search terminal.

According to the present invention, limited discovery can be effectively performed.

1 is a conceptual diagram showing an operation scenario related to D2D discovery.
2 is a conceptual diagram illustrating a shared spectrum operation scheme for D2D discovery and communication.
3 is a conceptual diagram illustrating a dedicated spectrum scheme shared by a number of operators for D2D discovery and communication.
4 is a conceptual diagram showing a functional structure for D2D discovery.
5 is a conceptual diagram showing an LTE network structure for D2D discovery.
6 is a conceptual diagram showing a functional structure of a user terminal for D2D discovery when the DMF operates as a function of a control plane.
7 is a conceptual diagram showing a protocol interworking structure for D2D discovery when the D2D server operates as a function of a control plane.
8 is a conceptual diagram showing the functional structure of a user terminal for D2D discovery when the DMF operates as a function of a user plane.
9 is a conceptual diagram showing a protocol interworking structure for D2D discovery when the D2D server operates as a function of a user plane.
10 is a conceptual diagram illustrating a channel mapping for a D2D discovery message transmission / reception procedure.
11 is a conceptual diagram showing D2D discovery transmission and reception states.
12 is a flowchart showing an authentication procedure of the limited discovery application using the control plane function.
13 is a flowchart showing an authentication procedure of the limited discovery application using the user plane function.
FIG. 14 is a flowchart illustrating a limited discovery agreement and dissolution agreement procedure using the control plane function.
FIG. 15 is a flowchart illustrating a limited discovery agreement and dissolution agreement procedure using the user plane function.
FIG. 16 is a flowchart showing an activation procedure (S200 to S210) of a limited discovery service using a control plane.
FIG. 17 is a flowchart showing a procedure of activating the limited discovery service (S211 to S228) using the control plane.
FIG. 18 is a flowchart showing the inactivation procedures (S250 to S261) of the limited discovery service using the control plane.
FIG. 19 is a flowchart showing the inactivation procedures (S261 to S273) of the limited discovery service using the control plane.
20 is a flowchart showing a procedure of activating the limited discovery service using the user plane (S300 to S313).
FIG. 21 is a flowchart showing a procedure of activating the limited discovery service (S314 to S326) using the user plane.
22 is a flowchart showing a procedure for deactivating the limited discovery service using the user plane.
23 is a flowchart showing a discovery event and a discovery information reporting procedure using a control plane.
24 is a flowchart illustrating a discovery event and a discovery information reporting procedure using a user plane.
25 is a flowchart showing discovery setup information exchange procedures (S500 to S514) between D2D servers for limited discovery using the control plane function.
FIG. 26 is a flow illustrating a discovery setup information exchange procedure (S515 to S533) between D2D servers for limited discovery using the control plane function.
FIG. 27 is a flowchart showing discovery setup information exchange procedures (S600 to S610) between D2D servers for limited discovery using the user plane function.
FIG. 28 is a flow illustrating a discovery setup information exchange procedure (S611 to S623) between D2D servers for limited discovery using a user plane function.
29 is a conceptual diagram showing an embodiment (globally unique discovery ID) of a discovery message configuration for limited discovery.
30 is a conceptual diagram showing another embodiment (locally unique discovery ID) of discovery message configuration for limited discovery.
31 is a conceptual diagram showing a definition of a protocol message for D2D discovery.
32 is a conceptual diagram showing the definition of another protocol message for D2D discovery.
33 is a conceptual diagram showing a parameter definition of a protocol message for D2D discovery.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail.

It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be interpreted in an ideal or overly formal sense unless explicitly defined in the present application Do not.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In order to facilitate the understanding of the present invention, the same reference numerals are used for the same constituent elements in the drawings and redundant explanations for the same constituent elements are omitted.

Throughout the specification, the network can be, for example, a wireless Internet such as WiFi (Wireless Fidelity), a WiBro (Wireless Broadband Internet) or a WiMax (World Interoperability for Microwave Access) A 3G mobile communication network such as a Wideband Code Division Multiple Access (WCDMA) or CDMA2000, a High Speed Downlink Packet Access (HSDPA) or a High Speed Uplink Packet Access (HSUPA) A 3.5G mobile communication network, a 4G mobile communication network such as an LTE (Long Term Evolution) network or an LTE-Advanced network, and a 5G mobile communication network.

Throughout the specification, the communication network may include, for example, a 2G mobile communication network such as GSM (Global System for Mobile communication), CDMA (Code Division Multiple Access), wireless Internet such as WiFi (Wireless Fidelity), WiBro (3G) mobile communication network such as WCDMA (Wideband Code Division Multiple Access) or CDMA2000, HSDPA (High Speed Downlink Packet Access) or HSUPA (High Speed Downlink Packet Access) Speed uplink packet access), 4G mobile communication network such as LTE (Long Term Evolution) network or LTE-Advanced network, etc.).

A mobile station, a mobile station, a subscriber station, a portable subscriber station, a user equipment, an access terminal, And may include all or some of the functions of a terminal, a mobile station, a mobile terminal, a subscriber station, a mobile subscriber station, a user equipment, an access terminal, and the like.

Here, a desktop computer, a laptop computer, a tablet PC, a wireless phone, a mobile phone, a smart phone, an e- a book reader, a portable multimedia player (PMP), a portable game machine, a navigation device, a digital camera, a digital multimedia broadcasting (DMB) player, a digital audio recorder, A digital picture recorder, a digital picture player, a digital video recorder, a digital video player, or the like can be used.

Device-to-device communication (D2D) Discovery refers to a procedure for discovering a nearby terminal / service based on a signal received by a specific terminal using radio resources. For this purpose, terminals / services that desire to be discovered by a nearby terminal / service can transmit a predefined message using radio resources set for D2D discovery, and a terminal desiring to discover neighboring terminals can transmit such a radio resource Lt; RTI ID = 0.0 > a < / RTI > discovery message.

The scope of D2D discovery can be broadly categorized as service level discovery and terminal level discovery. Discovery at the service level means discovery of services provided by peripheral terminals, and terminal level discovery means discovery of identifiers (ID) of peripheral terminals.

The D2D discovery described in the present invention includes both service level discovery and terminal level discovery. In addition, a terminal that desires to be discovered by neighboring terminals is defined as a discoverable UE, and a terminal that desires to discover neighboring terminals is defined as a discovery UE.

The D2D discovery function can be classified as a commercial use case and a public safety use case, and the requirements related to the D2D discovery are as follows.

● D2D discovery requirements for commercial use cases

- restricted discovery

· Discovery performed only when there is agreement of the terminal to be found

Examples: social networking service (SNS), evolved packet system (EPS), proximity service (ProSe) discovery

- Open discovery

Discovery without the consent of the terminal to be discovered

· Example: advertising services, mobile games

- Discovery capability

· Ability to discovery other nearby terminals

· Ability to be disbursed to other nearby terminals

- Discovery with subscribers of other land mobile networks (PLMNs)

Discovery between terminals belonging to different PLMNs

- Discovery with roaming subscribers

· Discovery of terminals roaming in other networks

● D2D discovery requirements for public safety use cases

- Discovery within network coverage

Discovery of terminals located within operator network coverage

- Discovery beyond network coverage

· Discovery of terminals located outside the network of operators

In addition, the requirements for authorization and charging for D2D discovery are as follows.

● Approval

- Approval of discovery operations for each terminal

- Approval of the terminal to be discovered by other terminals

- Approval of the terminal that discovers other terminals

● Charging

- Ability for the terminal to be discovered.

- Ability to discovery other terminals

- Event for discovery of terminal

Meanwhile, the main requirements presented in the direct communication between terminals (i.e., direct discovery wireless aspects) are as follows.

● Overseeing the D2D discovery process

- Supervision by network operators

- For scenarios beyond network coverage, supervision by specific terminals

● Spectral aspects

- LTE frequency division duplex (FDD) and LTE (time division duplex) operation

- Private spectrum shared by multiple operators

- Shared spectrum operations

1 is a conceptual diagram showing an operation scenario related to D2D discovery.

Referring to FIG. 1, the D2D discovery-related operational scenarios include inter-operator discovery scenarios, intra-cell discovery scenarios, inter-cell discovery scenarios, discovery for roaming terminals, Scenarios and the like.

Spectrum usage schemes for D2D discovery and communication can be categorized into a shared spectrum mode of operation and a dedicated spectrum mode shared by multiple operators.

2 is a conceptual diagram illustrating a shared spectrum operation scheme for D2D discovery and communication.

Referring to FIG. 2, the features of the shared spectrum operation scheme are as follows.

Perform D2D discovery using a portion of the cellular spectrum allocated to each mobile carrier network

- share the same carrier with cellular communication, or use a separate carrier for D2D discovery and communication

● D2D discovery setup and control, authentication and billing for D2D discovery, and D2D discovery procedures are through each operator network

In the case of the shared spectrum operation method, in order to perform discovery of UEs subscribed to other service provider networks, the UE transmits configuration information of D2D discovery radio resources used in other networks as well as a system information block (SIB) ≪ / RTI > The pSearch terminal can transmit the discovery message through the frequency spectrum of the subscriber. The search terminal may receive at least one discovery message through its own or other business spectrum and may perform the D2D discovery procedure based on the received discovery message.

In order to perform D2D discovery between terminals subscribed to different service provider networks, the UE must be equipped with a receiver capable of receiving network signals of other service providers. Otherwise, the discovery radio resources allocated to each service provider network must be orthogonal in time do. In addition, the carrier networks may support D2D discovery among terminals subscribed to other carrier networks by exchanging D2D discovery radio resource configuration information.

3 is a conceptual diagram illustrating a dedicated spectrum scheme shared by a number of operators for D2D discovery and communication.

Referring to FIG. 3, a dedicated spectrum scheme shared by a plurality of operators is as follows.

● Performs D2D discovery using independent spectrum shared by multiple mobile operators for D2D discovery and communication

● D2D discovery setup and control, authentication and billing procedures for D2D discovery are through the cellular spectrum

When a plurality of operators share a common spectrum for D2D discovery and communication, the UE can receive configuration information of D2D discovery radio resources used in a common spectrum through the SIB from the subscribed network have. The pSearch terminal can transmit the discovery message through a common spectrum. The search terminal may receive at least one discovery message on the same spectrum (i.e., a common spectrum) and may perform the D2D discovery procedure based on the received discovery message.

At this time, each terminal must be equipped with a receiver capable of receiving signals through a common spectrum, and the carrier networks must share radio resource configuration information of a common D2D discovery spectrum.

In order to satisfy the D2D discovery related requirements described above, the LTE system defines an additional functional entity for D2D discovery and uses it to provide a D2D discovery feature. To this end, the present invention introduces a D2D server and a dicovery management function (DMF), which are functional objects and functional modules for managing the D2D discovery function.

4 is a conceptual diagram showing a functional structure for D2D discovery.

Referring to FIG. 4, the D2D server is a functional entity located in an LTE network for a discovery service. The DMF is a functional module that is located in the terminal and manages the discovery function in conjunction with the D2D server.

The D2D server can perform generation and issuance of a discovery ID, storage of information related to discovery of a terminal, information exchange for D2D discovery among mobile communication providers, and interworking procedures between existing LTE functional entities. The D2D server is a functional entity that performs control functions for D2D discovery and can exist as an independent functional entity of the LTE network. Also, one mobile communication company can provide the D2D discovery service using at least one D2D server. In addition, the interface between the D2D servers can be provided for the discovery service between providers, and the D2D server can exchange configuration information related to the discovery using this interface.

The present invention considers that the D2D server exists as one independent functional entity and each mobile communication provider provides a D2D discovery service using one logical D2D server.

5 is a conceptual diagram showing an LTE network structure for D2D discovery.

Referring to FIG. 5, the D2D server can work with other functional entities (e.g., HSS, PDN GW) of the LTE network using additional reference points such as Sxx or Gyy.

The DMF located in the terminal can store the discovery related information, and can perform the D2D discovery procedure in conjunction with the LTE protocol function and the D2D discovery application in which the D2D discovery related function is added. Similar to the D2D server described above, the DMF may be included in an existing protocol function of the UE or may exist as an independent function. In the present invention, it is assumed that the DMF exists as a function independent of the terminal.

In the present invention, the DMF and the D2D server can operate with a control plane function or a user plane function. When the DMF and D2D servers operate with the control plane function, the functions of the DMF and D2D servers are included in the NAS (non-access stratum) protocol or NAS protocol and operate in conjunction with the control plane protocol of the LTE function node. When the DMF and D2D servers operate with the user plane function, the DMF and D2D servers are located at the application level and exchange control information related to D2D discovery through the user plane.

6 is a conceptual diagram showing a functional structure of a user terminal for D2D discovery when the DMF operates as a function of a control plane.

Referring to FIG. 6, the RRC +, MAC +, and PHY + layers of the protocol stack for D2D discovery may include additional functions for D2D discovery.

7 is a conceptual diagram showing a protocol interworking structure for D2D discovery when the D2D server operates as a function of a control plane.

Referring to FIG. 7, the NAS layer of the UE interworks with the NAS layer of an MME (mobility management entity), and the GTP-C layer of the MME includes a D2D server (HPLMN) Discovery mngt. Layer, and discovery mngt. Of the D2D server (HPLMN). The layer is the discovery mngt. Of the D2D server (VPLMN). Layer.

8 is a conceptual diagram showing the functional structure of a user terminal for D2D discovery when the DMF operates as a function of a user plane.

Referring to FIG. 8, the RRC +, MAC +, and PHY + layers of the protocol stack for D2D discovery may include additional functions for D2D discovery.

9 is a conceptual diagram showing a protocol interworking structure for D2D discovery when the D2D server operates as a function of a user plane.

Referring to FIG. 9, the application layer of the UE includes a discovery mngt. Of the D2D server HPLMN. Layer, and discovery mngt. Of the D2D server (HPLMN). The layer is the discovery mngt. Of the D2D server (VPLMN). Layer.

10 is a conceptual diagram illustrating a channel mapping for a D2D discovery message transmission / reception procedure.

Referring to FIG. 10, a newly defined DDCH (device discovery channel), a DCH (discovery channel), and a PDCH (physical discovery channel) can be used for transmitting / receiving a discovery message between terminals.

When the DMF operates as a function of the control plane, the control protocol procedure for D2D discovery can utilize the existing hierarchical structure and uplink / downlink channels of the LTE system. That is, a dedicated control channel (DCCH), a downlink-shared channel (DL-SCH), and a physical downlink shared channel (PDSCH) on the downlink may be used, and a DCCH, an uplink- (physical uplink shared channel).

When the DMF operates as a user plane function, the control protocol procedure for D2D discovery can utilize the existing hierarchical structure and uplink / downlink channels of the LTE system. That is, a dedicated traffic channel (DTCH), a DL-SCH, and a PDSCH on the downlink may be used, and a DTCH, UL-SCH, and PUSCH on the uplink may be used.

In addition to the D2D server and DMF described above, a mobile communication service provider can provide a discovery interface server and a discovery application for joining, registering, and setting up a user's D2D discovery service. The Discovery Interface Server and the Discovery Application refer to functional entities and terminal applications located outside the business network provided by each business entity for D2D discovery. The Discovery Interface Server and the Discovery Application are one operating method provided by the mobile communication provider for providing the Discovery Service.

The D2D server and DMF can manage the state associated with D2D discovery.

11 is a conceptual diagram showing D2D discovery transmission and reception states.

Referring to FIG. 11, an idle state refers to a state in which a procedure related to D2D discovery is not performed, and a discovery state refers to a state in which a discovery message for D2D discovery is received. The 'discoverable' state refers to a state in which a discovery message for D2D discovery is transmitted, and the 'discovery and discovery' state refers to a state in which a discovery message is transmitted and received for D2D discovery.

limited( restricted ) Discovery

The limited discovery procedure is a procedure for discovery of a terminal based on mutual agreement between the search terminal and the search terminal. For this purpose, the terminal can perform procedures such as generating and issuing limited discovery information, limited discovery application authentication, limited discovery agreement and disassociation of the terminal to be searched, and perform procedures for limited discovery. The limited discovery procedure refers to a procedure of transmitting and receiving a discovery message and recognizing the corresponding terminal using the received discovery message. The terminal having completed the discovery procedure reports information acquired through the discovery procedure and events related to the discovery Can be performed.

In performing the limited discovery procedure described above, terminals managed by different providers or different D2D servers may perform a limited discovery procedure including an interworking procedure between D2D servers.

In the following, the operation procedure will be described by dividing the case where D2D discovery operates as the function of the control plane and the case of operating as the function of the user plane.

Each functional entity for limited discovery can perform the following functions.

◈ D2D Server (Network)

* function

- Creating and Issuing Discovery ID

- Third party application authentication

- Discovery information management (terminal ID, discovery ID, discovery range class)

- Discovery configuration information management (Discovery type, Discovery status)

- Manage terminal IDs that agree to limited discovery service

- Limited discovery information interworking with other D2D servers

- Information management

- Perform protocol procedures for D2D discovery in conjunction with DMF

- Interworking with LTE network function entities (eg MME, eNB, HSS (home subscriber server)) (authentication, billing)

* Storage information

- Terminal ID, Discovery ID, Discovery Range Class

- Discovery type, Discovery status

- list of terminal IDs that have agreed to the limited discovery service

- Discovery information reported as a result of D2D discovery

- 3rd party application contract information

◈ DMF (Terminal)

* function

- Save and manage your own Discovery ID

- Terminal ID management (terminal ID, discovery ID)

- 3rd party application authentication support

- Generation and transmission of limited discovery messages

- Receiving and interpreting limited discovery messages

- Reporting ID and billing information recognized through D2D discovery process

- Perform protocol procedures for D2D discovery in conjunction with D2D server

- Interworking with Discovery related application and LTE terminal protocol

* Storage information

- Your own Discovery ID assigned at the time of Discovery request

- Discovery ID of the searchable terminal allocated at the time of discovery request

- List of searchable terminals

Generate and issue limited discovery information

The limited discovery information generation and issuance process may include a process of generating and issuing a discovery ID for a limited discovery service by the mobile communication service provider and a process of storing the discovery ID by the terminal.

Discovery ID generation and issuance for limited discovery may be performed at the time of opening or when the terminal is required (for example, when a D2D discovery service is requested or a D2D discovery service is requested). In performing such a procedure, the D2D server can issue the discovery ID of the subscribed terminal, and can store and manage the discovery ID and the terminal ID of the terminal. The terminal can store the discovery ID issued by the mobile communication service provider.

The Discovery ID issued according to the above procedure is an ID that can not be recognized as a specific user, and can be used in transmission of limited discovery information. In addition, open discovery and limited discovery services can share the same discovery ID.

● Classification of limited discovery ID generation and issuance type

- When the user terminal subscribes (opens) to a specific mobile communication carrier, it is created and issued by the D2D server

- If the user terminal subscribes to the D2D discovery service or requests the D2D discovery service, it is created and issued by the D2D server.

The terminal can subscribe to the limited discovery service according to the user's request. That is, the user can access the discovery interface server of the mobile communication company through the application of the terminal or the PC, and can subscribe to the limited discovery service or cancel the subscription.

In the operation procedure described above, a description has been given of a method in which a D2D server generates and issues a discovery ID when a terminal subscribes to a D2D discovery service and requests a discovery service. However, when the user terminal subscribes (opens) to a specific mobile communication service provider, the D2D server may generate and issue the discovery ID.

Limited Discovery application  certification

Limited discovery application authentication refers to an authentication procedure performed by applications located in a terminal to utilize a limited discovery feature. This authentication procedure refers to an authentication procedure for a specific application developed by a third party developer to use limited discovery functionality. To this end, the third party developer must enter into a contract with the mobile operator in advance to use the limited discovery functionality of the application. The authentication procedure for using a limited discovery service of a specific application may be performed only when the application is first used or whenever an application is executed according to the setting of the provider network.

A case where the terminal exists in a network to which the terminal belongs and a case where the terminal exists in a roaming business network can be considered in the authentication procedure. In case of existing in the roaming business network, the authentication procedure can be performed through interworking between D2D servers.

12 is a flowchart showing an authentication procedure of the limited discovery application using the control plane function.

12, the first terminal 10 can transmit an authentication request message (APP_DISCOVERY_FEATURES_REQ) to the MME 40 (S100), and the MME 40 transmits the authentication request message received from the first terminal 10 To the first D2D server 60 (S101). The authentication request message is a message for requesting authentication for use of the limited discovery service of the application, and may include an application ID (app. Id), first terminal ID information, and the like.

The first D2D server 60 may perform approval / authentication of the application based on the information included in the authentication request message (S102). After the approval / authentication of the application is completed, the first D2D server 60 may transmit an authentication response message (APP_DISCOVERY_FEATURES_RSP) including the approval / authentication result information to the MME 40 (S103). The MME 40 may transmit the authentication response message received from the first D2D server 60 to the first terminal 10 (S104). The authentication response message means an authentication response message for use of the limited discovery service of the application, and may include result, cause information, and the like.

13 is a flowchart showing an authentication procedure of the limited discovery application using the user plane function.

Referring to FIG. 13, the first terminal 10 may transmit an authentication request message (APP_DISCOVERY_FEATURES_REQ) to the first D2D server 60 (S110). The authentication request message refers to a message for requesting authentication for use of the limited discovery service of the application, and may include an application ID, first terminal ID information, and the like. The first D2D server 60 can perform approval / authentication for the application based on the information included in the authentication request message (S111). After the approval / authentication of the application is completed, the first D2D server 60 may transmit an authentication response message (APP_DISCOVERY_FEATURES_RSP) including the approval / authentication result information to the first terminal 10 (S112). The authentication response message means an authentication response message for use of the limited discovery service of the application, and may include a result, cause information, and the like.

Consent and Release of Limited Discovery

The procedure of consent and release of limited discovery means a procedure for obtaining mutual consent or canceling consent of the terminals for limited discovery service. For a limited discovery agreement procedure, the Discovery application can perform the consent procedure for the limited discovery service at the application level, and then instruct the DMF a limited discovery agreement procedure with the other terminal.

The DMF, directed to perform the limited discovery agreement procedure, may send a consent request message to the D2D server, including an ID of the target terminal seeking the consent request and an action flag (set or clear). The D2D server can transmit the agreement request message received from the DMF to the target terminal, and can receive the response message for the agreement request message from the target terminal.

In the limited discovery agreement and agreement release procedures, the motion flag is set to set when the motion is requested, and the motion flag is set to clear when motion is requested. When receiving a response message to the consent request message from the target terminal, the D2D server can update the list of piconet search terminals when the target terminal accepts the consent request based on the information included in the response message, Message to the DMF of the search terminal. The DMF of the search terminal requesting the consent of the limited discovery and releasing the agreement can update the list of the search terminals based on the response message to the consent request message.

FIG. 14 is a flowchart illustrating a limited discovery agreement and dissolution agreement procedure using the control plane function.

14, the first terminal 10 (i.e., the search terminal) can transmit a discoverable ID request message (DISCOVERABLE_ID_REQ) to the MME 40 (S120), and the MME 40 transmits the ID request message To the first D2D server 60 (S121). The searchable ID request message refers to a message requesting the addition of a search term list and may include a target terminal ID (i.e., a second terminal ID), an operation flag, application ID information, have.

The first D2D server 60 may transmit the invitation request message INVITE_REQ for the limited discovery agreement to the MME 40 in step S122 and the MME 40 transmits the invitation request message received from the first D2D server 60 To the second terminal 20 which is the target terminal (S123). The invitation request message is a request message used to add a terminal to the piconeting terminal list, and may include a first terminal ID, an operation flag, a target terminal ID, application ID information, and the like.

The second terminal 20 may decide to consent or cancel the limited discovery based on the received invitation request message and may transmit the invitation response message INVITE_RSP including the determined result information to the MME 40 ). The MME 40 may transmit the invitation response message received from the second terminal 20 to the first D2D server 60 (S125). The invitation response message means a response message used to add a terminal to the piconeting terminal list, and may include a result, cause information, and the like. On the other hand, the second terminal 20 can update the piconeting terminal list based on the determined result information (that is, consent or release of the limited discovery) (S126).

The first D2D server 60 can generate an ID response message (DISCOVERABLE_ID_RSP) that can be searched based on the information included in the invitation response message received from the second terminal 20 and transmits a searchable ID response message to the MME 40 (S127). The MME 40 may transmit the searchable ID response message received from the first D2D server 60 to the first terminal 10 (S128). The searchable ID response message means a response message for adding a terminal to the piconeting terminal list, and may include a result, cause, target terminal ID information, and the like.

On the other hand, the first D2D server 60 can update the p searching terminal list based on the information included in the searchable ID response message (S129) The search terminal terminal can update the search terminal terminal based on the information (S130).

FIG. 15 is a flowchart illustrating a limited discovery agreement and dissolution agreement procedure using the user plane function.

Referring to FIG. 15, the first terminal 10 (i.e., the search terminal) may transmit a searchable ID request message (DISCOVERABLE_ID_REQ) to the first D2D server 60 (S140). The searchable ID request message refers to a message requesting the addition of the piconet terminal list, and may include a target terminal ID (i.e., a second terminal ID), an operation flag, application ID information, and the like.

The first D2D server 60 may transmit the invitation request message (INVITE_REQ) for the limited discovery agreement to the second terminal 20 which is the target terminal (S141). The invitation request message is a request message used to add a terminal to the piconeting terminal list, and may include a first terminal ID, an operation flag, a target terminal ID, application ID information, and the like.

The second terminal 20 may decide to consent or cancel the limited discovery based on the received invitation request message and may transmit the invitation response message INVITE_RSP including the determined result information to the first D2D server 60 (S142). The invitation response message means a response message used to add a terminal to the piconeting terminal list, and may include a result, cause information, and the like. On the other hand, the second terminal 20 can update the piconeting terminal list based on the determined result information (that is, consent or release of the limited discovery) (S143).

The first D2D server 60 can generate an ID response message (DISCOVERABLE_ID_RSP) that can be searched based on the information included in the invitation response message received from the second terminal 20, (S144). The searchable ID response message means a response message for adding a terminal to the piconeting terminal list, and may include a result, cause, target terminal ID information, and the like.

On the other hand, the first D2D server 60 can update the piconeting terminal list based on the information included in the searchable ID response message (S145) The search terminal terminal can update the search terminal index based on the information (S146).

Limited discovery service for a specific terminal

A limited discovery service for a particular terminal means limited discovery that discovers a user specified terminal. This procedure starts when the application requests discovery for a specific terminal, and the discovery service can be performed for a certain period of time through an operation mode setting or the like until the discovery release request by the application is requested. In addition, not only the terminal requesting the discovery but also the terminal to be subjected to the discovery can discovery (i.e., confirm that the terminal is nearby) through this procedure.

Limited discovery services can use the control plane or the user plane, and each case will be described below.

Limited discovery with control plane

(Activation / deactivation) for the limited discovery service using the control plane. When providing the D2D discovery service using the control plane, the DMF of the terminal can operate in conjunction with the D2D server through eNB / MME, S-GW (serving gateway) / P-GW (packet data network-gateway) have. Here, a terminal to which a specific terminal is to be disassociated is defined as a first terminal (i.e., a search terminal), and a discovery target terminal is defined as a second terminal (i.e., a search terminal). In addition, the procedure described below assumes that both the first terminal and the second terminal start in an idle state.

FIG. 16 is a flowchart showing a procedure for activating a limited discovery service (S200 to S210) using a control plane, and FIG. 17 is a flowchart showing a procedure for activating a limited discovery service (S211 to S228) using a control plane.

Referring to FIG. 16 and FIG. 17, a procedure of activating the limited discovery service using the control plane is as follows.

The DMF of the first terminal 10 sends an ACTIVATE DISCOVERY REQUEST message including information of a discovery type, a discovery state, a second terminal ID, an application ID, and the like to the MME (Step S200). When the MME 40 receives the discovery activation message for the specific terminal from the first terminal 10, the MME 40 can determine whether to perform the discovery of the requested first terminal 10 and the second terminal 20 (S201). That is, the MME 40 can determine whether to perform the discovery by using the serving cell, location information, etc. of the first terminal 10 and the second terminal 20. If it is possible to perform the discovery, the MME 40 may transmit an activation request message for the limited discovery service to the first D2D server 60 (S202).

When receiving the discovery activation request message from the MME 40, the first D2D server 60 can confirm whether the limited discovery service agreement between the first terminal 10 and the second terminal 20 is acceptable. If there is no mutual agreement for the limited discovery service, a peer invitation procedure may be performed between the first D2D server 60 and the second terminal 20 (S203). If there is mutual agreement for limited discovery, the first D2D server 60 does not perform the peer invitation procedure.

After performing the above procedure, the first D2D server 60 may transmit a discovery request message (REQ DISCOVERY ACTIVATION) to the MME 40 to which the second terminal 20 belongs (S204). The MME 40 may transmit the received discovery request message to the DMF of the second terminal 20 (S205). The discovery request message may include a discovery type, a discovery state, a cause, a first terminal ID, an application ID (app id) information, and the like.

Upon receiving the discovery request message, the DMF of the second terminal 20 can perform a response procedure for the discovery request. If the network accepts the indicated discovery, the DMF of the second terminal 20 may send an ACTIVATE DISCOVERY REQ message to the MME 40 (S206). The MME 40 may transmit the received discovery activation request message to the first D2D server 60 (S207). On the other hand, if the network does not accept the indicated discovery, the DMF of the second terminal 20 may send a Discovery Activation Request Reject message containing the cause code to the MME 40. The MME 40 may transmit the received discovery activation request rejection message to the first D2D server 60. [

When receiving the discovery activation request message from the second terminal 20, the first D2D server 60 may perform the discovery resource setting procedure to be used by the second terminal 20. For setting the discovery resource, the first D2D server 60 may transmit a discovery resource setting request message (DISCOVERY_SETUP_REQ) to the MME 40 (S208). The MME 40 having received the discovery resource setting request message can instruct the eNB 30 to allocate a discovery channel (S209). The discovery resource setting request message may include a second terminal ID, discovery state information, and the like.

When receiving a discovery channel allocation request from the MME 40, the radio resource control function of the eNB 30 may perform the discovery channel allocation procedure together with the second terminal 20 (S210). The discovery channel allocation procedure performed by the eNB 30 for the second terminal 20 includes a process of measuring the reception characteristics of the discovery channels set by the second terminal 20 by the second terminal 20, Selecting the discovery candidate channel (s) to transmit the discovery message based on the received reception characteristics and reporting the selected discovery candidate channel to the eNB 30 and transmitting the discovery candidate channel (s) to the second terminal 20 (20) based on the discovery candidate channel ) May specify a radio resource to use.

After completing the discovery channel allocation request procedure, the eNB 30 may transmit a discovery resource setting response message (DISCOVERY_SETUP_RSP) including the result of discovery channel allocation, cause information, etc. to the MME 40 (S211). The MME 40 may transmit the received discovery resource setting response message to the first D2D server 60 (S212).

The first D2D server 60 may set a discovery ID for the first terminal 10 and the second terminal 20 (S213). The first D2D server 60 may transmit a limited discovery activation response message including the discovery ID of the first terminal 10 and the discovery ID information of the second terminal 20 to the MME 40 (S214). The MME 40 may transmit the received limited discovery activation response message to the DMF of the second terminal 20 (S215). Upon receiving the limited Discovery Activation Response message, the DMF of the second terminal 20 may transition to a 'discoverable & discovery' state (S216) and then initiate a discovery message transmission / reception procedure (S225 , S226, S227).

After the discovery activation procedure of the second terminal 20 is completed, the first D2D server 60 may perform the discovery resource setting procedure and the discovery channel allocation procedure for the first terminal 10 (S217, S218, S219 , S220, S221). The discovery resource setting procedure and the discovery channel allocation procedure for the first terminal 10 may be the same as the discovery resource setting procedure and the discovery channel allocation procedure for the second terminal 20 described above.

Thereafter, the first D2D server 60 may transmit a limited discovery activation response message including the discovery ID of the first terminal 10 and the discovery ID of the second terminal 20 to the MME 40 (S222) . The MME 40 may transmit the received limited discovery activation response message to the first terminal 10 (S223).

When the limited discovery activation response message is received, the first terminal 10 can transition to the 'searchable & search' state (S224) and then perform a discovery message transmission / reception procedure (S225, S227, S228 ).

That is, the DMF of the terminal (the first terminal 10 or the second terminal 20) transited to the " searchable & search " state can receive the discovery message by searching for the set radio resource, It is possible to check whether the discovery ID corresponds to the discovery ID received by the above procedure. If the discovery ID included in the discovery message corresponds to the discovery ID received by the above procedure, the terminal's DMF may transmit limited discovery indication information to the application. On the other hand, if the discovery ID included in the discovery message does not correspond to the discovery ID received by the above procedure, the DMF of the terminal can discard the discovery message.

FIG. 18 is a flowchart showing the inactivation procedures (S250 to S261) of the limited discovery service using the control plane, and FIG. 19 is a flowchart showing the inactivation procedures (S261 to S273) of the limited discovery service using the control plane.

Referring to FIGS. 18 and 19, the procedure of disabling limited discovery using the control plane is as follows.

The DMF of the first terminal 10 may transmit a DEACTIVATE DISCOVERY REQ message to the MME 40 in order to deactivate the limited discovery service using the control plane at step S250. The MME 40 may transmit the discovery inactivation request message received from the first terminal 10 to the first D2D server 60 (S251). The first D2D server 60 may request the second terminal 20 to perform a discovery disable request based on the discovery inactivation request message S252 and S253 and the second terminal 20 transmits a discovery inactivation request In step S254, a discovery disable request message (DEACTIVATE DISCOVERY REQ) to the first D2D server 60 (S254, S255). Here, the message transmission between the second terminal 20 and the first D2D server 60 can be performed through the MME 40.

Thereafter, the first D2D server 60 may perform the release procedure of the radio resources allocated to the second terminal 20 for deactivating the limited discovery service of the second terminal 20. That is, the first D2D server 60 may transmit a discovery release request message (DISCOVERY_RELEASE_REQ) requesting release of the radio resource to the MME 40 (S256). The MME 40 may transmit the discovery release request message received from the first D2D server 60 to the eNB 30 (S257). The discovery release request message may include a terminal ID, discovery state information, and the like. The eNB 30 may perform the radio resource release procedure with the second terminal 20 based on the information included in the discovery release request message (S258, S259).

When the release of the radio resource is completed, the eNB 30 may transmit a discovery release response message (DISCOVERY_RELEASE_RSP) to the MME 40 (S260). The MME 40 may transmit the discovery release response message received from the eNB 30 to the first D2D server 60 (S261). The discovery release response message means a response message to the radio resource disassembly request, and may include a result of radio resource release, cause information, and the like.

When the radio resource release procedure is completed, the first D2D server 60 can release the discovery ID assigned for the second terminal 20 (S262). After the above procedure is completed, the first D2D server 60 transmits a discovery disable response message (DEACTIVATE DISCOVERY RSP) to the second terminal 20 in response to the discovery disable request message received from the second terminal 20 (S263). The discovery inactivation response message means a response message to the discovery inactivation request, and may include a result of discovery inactivation, cause information, and the like. On the other hand, when receiving the discovery inactivation response message from the first D2D server 60, the second terminal 20 can transition to the idle state (S264). That is, the second terminal stops sending / receiving the discovery message.

After completing the process of deactivating the limited discovery service for the second terminal 20, the first D2D server 60 can perform the release of the radio resource allocated to the first terminal 10 for sending / receiving the discovery message (S265, S266, S267, S268, S269). Here, the procedure for releasing the radio resources allocated to the first terminal 10 may be the same as the procedure for releasing the radio resources allocated to the second terminal 20 described above.

The first D2D server 60 transmits a Discovery Disable Response message in response to the discovery disabling request message received from the first terminal 10 when the radio resource allocated to the first terminal 10 is released, RSP) to the MME 40 (S270). The MME 40 may transmit a discovery inactivation response message to the first terminal 10 (S271). Thereafter, the first D2D server 60 can unset the discovery ID assigned for the first terminal 10 (S272). On the other hand, when receiving the discovery inactivation response message from the first D2D server 60, the first terminal 10 can transition to the idle state (S273). That is, the first terminal stops sending and receiving the discovery message.

Limited discovery with user plane

The following describes the operation procedure (enable / disable) for the limited discovery service using the user plane. When providing the D2D discovery service using the user plane, the DMF of the terminal operates in cooperation with the D2D server through the eNB, the S-GW / P-GW, and uses the IP layer protocol. Here, a terminal to which a specific terminal is to be disassociated is defined as a first terminal (i.e., a search terminal), and a discovery target terminal is defined as a second terminal (i.e., a search terminal). In addition, the procedure described below assumes that both the first terminal and the second terminal start in an idle state.

FIG. 20 is a flowchart showing a procedure for activating a limited discovery service (S300 to S313) using a user plane, and FIG. 21 is a flowchart showing a procedure for activating a limited discovery service (S314 to S326) using a user plane.

20 and 21, the procedure for activating the limited discovery service using the user plane is the same as the procedure for activating the limited discovery service using the control plane (see FIGS. 16 and 17) except for the following differences.

● Delivery of Discovery Protocol messages between D2D server and D2D server

- use function nodes included in the user plane

- Discovery control message based on IP packet

● Discovery feasibility estimation

- The D2D server receiving the Discovery Request message requests the MME, and the MME performs the discovery possibility estimation procedure of the type presented in the limited discovery using the control plane, and then responds to the D2D server

22 is a flowchart showing a procedure for deactivating the limited discovery service using the user plane.

Referring to FIG. 22, the procedure for deactivating the limited discovery service using the user plane is the same as the procedure for deactivating the discovery service using the control plane (see FIGS. 18 and 19) except for the following differences.

● Delivery of Discovery Protocol messages between D2D server and D2D server

- use function nodes included in the user plane

- Discovery control message based on IP packet

blind( blind Limited discovery service

The blind discovery service means that discovery is performed on all terminals that have agreed to the discovery without specifying a specific terminal. The blind discovery procedure is started when the application requests blind discovery, and the blind discovery service can be performed for a certain period of time through the operation mode setting, or until the discovery release request of the application is requested.

The blind discovery service activation procedure starts when the application of the first terminal (i.e., search terminal) delivers a blind discovery request, i.e., a discovery service request of the terminals that have agreed to mutual discovery with the DMF. The DMF, which is requested to the blind discovery service, can transmit the discovery activation request message including the information of the discovery type and the discovery state to the D2D server.

Upon receiving the discovery activation request message from the first terminal, the D2D server can perform the authentication procedure of the first terminal requesting the blind discovery, and then determine which of the target terminals to participate in the discovery. That is, since the D2D server stores the list of terminal IDs agreed to the discovery with the first terminal, the D2D server can detect a terminal having a possibility of being close to the first terminal using the terminal ID list. The D2D server checks the serving cell of the corresponding terminal when the terminal is in the RRC_CONNECTED state and transitions the terminals located in the same tracking area of the corresponding terminal to the RRC_CONNECTED state when the terminal is in the RRC_IDLE state, do. The D2D server can assign a discovery ID to other terminals (second terminal to Nth terminal) that are likely to be close to the first terminal as well as the first terminal.

After completing the above procedure, the D2D server may first perform a discovery transmission channel allocation procedure of the first terminal. Next, the D2D server can perform the discovery channel allocation and the discovery channel information transfer procedure of the first terminal in cooperation with the LTE function (function +) of the eNB and the corresponding terminal, for the second terminal to the Nth terminal. The D2D server may transmit the discovery ID of the first terminal and the terminal ID of the first terminal to the DMF, and then activate the transmission / reception of the discovery message.

After completing the above process, the D2D server transmits the channel information of the second terminal through the Nth terminal to the LTE function (function +) of the first terminal or the discovery ID and the terminal IDs of the second terminal through the Nth terminal, DMF of the discovery message, and can activate the transmission / reception of the discovery message.

When the above-described procedure is completed, all the first to Nth terminals transit to the " searchable & search " state. Accordingly, the first terminal can attempt to receive the discovery message from the second terminal through the Nth terminal through the discovery channel for the known second terminal through the Nth terminal. If the first terminal successfully receives the discovery message, Can be notified to the application. Similarly, the second terminal through the Nth terminal may attempt to receive the discovery message from the first terminal through the discovery channel for the known first terminal, and if the reception of the discovery message is successful, Can notify.

The blind discovery service deactivation procedure can be initiated by an application. That is, when receiving a request to stop the blind discovery service from the application, the DMF can transmit a discovery disable request message to the D2D server, and the D2D server receiving the discovery disable request cancels discovery channel allocation and reception disconnection for the first to Nth terminals To the corresponding eNB and perform necessary procedures with the corresponding terminal. The D2D server can request discovery inactivation to the DMFs of the second to the Nth terminals and receive the response to the discovery inactivation from the DMFs of the second to Nth terminals. Finally, the D2D server may transmit a response message for discovery disabling to the DMF of the first terminal.

Report limited discovery events and discovery information

The limited discovery event and the discovery information reporting procedure refer to a process of reporting to the D2D server the event that occurs when performing the D2D discovery procedure and the information obtained through the D2D discovery procedure. Discovery event reporting is a procedure in which a terminal that has transmitted a discovery message and a terminal that has received the discovery message transmit the event to the D2D server, and the discovery information report is a procedure to report information of the discovered neighboring terminal to the D2D server.

This information can be used to manage the billing and proximity of the terminal for D2D discovery. The information obtained through the limited discovery event and the discovery information reporting procedure can be used as a priori information for future direct communication and mode selection (direct communication or communication via a network entity).

The limited discovery event and the discovery information reporting procedure described above can take into account the types of the search terminal and the piconceived terminal existing in the same provider network and those existing in different provider networks. In particular, when the search terminal and the p-th search terminal exist in different service providers' networks, the above-described procedure can be performed through the inter-operation procedure between the D2D servers.

23 is a flowchart showing a discovery event and a discovery information reporting procedure using a control plane.

Referring to FIG. 23, the first terminal 10 may transmit a discovery event report message (DISCOVERY_EVENT_REPORT) to the MME 40 (S400). The MME 40 may transmit the discovery event report message received from the terminal to the first D2D server 60 (S401). The discovery event report message may include an event type, paired search terminal ID information, and the like.

The first D2D server 60 may update the discovery information based on the received discovery event report message (S402), and may access the billing function to manage the billing for the discovery (S403).

24 is a flowchart illustrating a discovery event and a discovery information reporting procedure using a user plane.

Referring to FIG. 24, the first terminal 10 may transmit a discovery event report message (DISCOVERY_EVENT_REPORT) to the first D2D server 60 (S410). The discovery event report message may include an event type, paired search terminal ID information, and the like.

The first D2D server 60 may update the discovery information based on the received discovery event report message (S411), and may access the billing function to manage the billing for the discovery (S412).

D2D  Exchange information about server-to-server discovery

The D2D discovery configuration information exchange procedure between D2D servers is an information exchange procedure that enables a discovery procedure between terminals managed by different D2D servers. In particular, this procedure enables discovery procedures between terminals subscribed to different carriers. This procedure includes a procedure for transmitting spectrum information for limited discovery and allocation information of radio resources managed by a D2D server of each provider and a procedure for transparently transmitting a protocol message for limited discovery as described above . The information and procedures exchanged between D2D servers for open discovery are as follows.

● Spectrum & Wireless resource setting information

- Spectrum-related information for limited discovery, discovery resource setting information of the cell managed by the D2D server is transmitted to the partner D2D server

● Application authorization procedures

Encapsulate the protocol message for the application authentication procedure described in the 'limited discovery application authentication' and exchange it with the other D2D server

● Discovery and Disassociation

- encapsulate the protocol message for the searchable terminal list acquisition procedure described in the 'limited discovery agreement and release agreement' and exchange it with the relative D2D server

● Discovery ID acquisition procedure

Encapsulates a protocol message for securing the discovery ID of the terminal to be searched and described in the 'limited discovery service for a specific terminal', exchanges it with the other D2D server

● Discovery Activation Procedure

- encapsulate the protocol message for the limited discovery activation procedure described in 'limited discovery service for a specific terminal' and 'blind limited discovery service' and exchange it with a relative D2D server

● Discovery disabling procedure

- encapsulate the protocol message for the restricted discovery inactivation procedure described in the 'limited discovery service for a specific terminal' and 'the blind limited discovery service' and exchange it with a relative D2D server

● Discovery Information Reporting Procedures

Encapsulate the protocol message for the limited discovery reporting procedure described in the 'Limited Discovery Event and Discovery Information Reporting' section and exchange it with the relative D2D server

FIG. 25 is a flowchart illustrating a discovery setup information exchange procedure (S500 to S514) between D2D servers for limited discovery using the control plane function, FIG. 26 illustrates a discovery setup procedure between D2D servers for limited discovery using a control plane function Information exchange procedures (S515 to S533).

Referring to FIGS. 25 and 26, the first D2D server 60 may transmit a resource setting information request message (RESOURCE_CONFIG_INFO_REQ) to the eNB / MME 50 in the wireless setting exchange procedure (S500). The eNB / MME 50 may transmit a resource setup information response message (RESOURCE_CONFIG_INFO_RSP) to the first D2D server 60 in response to the resource setup information request message (S501). The resource setting information request message may include cell ID information and the like, and the resource setting information response message may include radio resource setting information and the like. The first D2D server 60 may transmit a discovery information message (DISCOVERY_INFO_XFER) to the second D2D server 70 (S502). The discovery information message may include radio resource setting information and the like.

In the application approval procedure, the first D2D server 60 may send an application discovery feature request message (APP_DISCOVERY_FEATURE_REQ) to the second D2D server 70 (S503). The second D2D server 70 may transmit an application discovery feature response message (APP_DISCOVERY_FEATURE_RSP) to the first D2D server 60 in response to the application discovery feature request message (S504). The application discovery feature request message is a message for requesting authentication of the application using the discovery, and may include an application ID, terminal ID information, and the like. The application discovery feature response message means a response message to the application use request for discovery use authentication, and may include a result, cause information, and the like.

In the discovery agreement process, the first D2D server 60 may transmit the invitation request message (INVITE_REQ) to the second D2D server 70 (S505). The second D2D server 70 may transmit the invitation request message received from the first D2D server 10 to the eNB / MME 50 in step S506 and the eNB / To the first terminal 10 (S507). The first terminal 10 may send an invite response message INVITE_RSP to the eNB / MME 50 in response to the invitation request message (S508), and the eNB / MME 50 transmits the invite response message to the second D2D server (S509).

Thereafter, the second D2D server 70 may transmit an invitation response message to the first D2D server 60 in response to the invitation request message received from the first D2D server 60 (S510). The first D2D server 60 may transmit the invitation completion message INVITE_COMPLETE to the second D2D server 70 in response to the invitation response message (S511). The second D2D server 70 may transmit the invitation completion message to the first terminal 10 (S512).

Here, the invitation request message refers to a request message used for adding the piconeting terminal list, and may include a target terminal ID, application ID information, and the like. The invitation response message means a response message used for adding the search term list, and may include a result, cause information, and the like. The invitation completion message means a completion message used for adding the piconnection search terminal list, and may include the discovery ID information of the source terminal.

In the discovery ID acquisition procedure, the first D2D server 60 can transmit a discovery ID request message (DISCOVERY_ID_REQ) to the second D2D server 70 (S513), and the second D2D server 70 transmits the discovery ID request message The D2D server 60 may transmit the discovery ID response message to the first D2D server 60 (S514).

Here, the discovery ID request message refers to a message requesting a discovery ID for a specific terminal, and may include terminal ID information and the like. The discovery ID response message means a response message to a discovery ID request of a specific terminal, and may include a result, cause, discovery ID information, and the like.

In the activation discovery request procedure, the first D2D server 60 may transmit a discovery activation request message (REQUEST_DISCOVERY_ACTIVATION) to the second D2D server 70 (S515). The second D2D server 70 may transmit the discovery activation request message received from the first D2D server 60 to the eNB / MME 50 (S516), and the eNB / MME 50 transmits the discovery activation request message to the second D2D server 70 To the first terminal 10 (S517). The first terminal 10 may send an ACTIVATE_DISCOVERY_REQ message to the eNB / MME 50 in response to the discovery activation request message in step S518. The eNB / MME 50 transmits the ACTIVATE_DISCOVERY_REQ message to the first terminal 10, To the second D2D server 70 (S519).

Thereafter, the second D2D server 70 may send an activation discovery request message to the first D2D server 60 (S520), and the first D2D server 60 transmits an activation discovery response in response to the activation discovery request message Message (ACTIVATE_DISCOVERY_RSP) to the second D2D server 70 (S521). When receiving the activation discovery response message from the first D2D server 60, the second D2D server 70 may transmit an activation discovery response message to the eNB / MME 50 (S522). The eNB / MME 50 may transmit the activation discovery response message received from the second D2D server 70 to the first terminal 10 (S523).

Here, the discovery activation request message means a discovery activation request message starting from the network and may include a cause, a discovery type, a discovery state, a range class (for a search terminal), a reception mode (for a search terminal) . The activation discovery request message is a message requesting activation of the D2D discovery. The activation discovery request message may include a discovery type, a discovery state, a target terminal ID, a permission flag, a reception mode, a range class information, and the like. The activation discovery response message means a response message to the D2D discovery activation request, and may include a result, cause, target discovery ID information, and the like.

In the deactivation discovery request procedure, the first D2D server 60 may transmit a discovery disable request message (REQUEST_DISCOVERY_DEACTIVATION) to the second D2D server 70 (S524). The second D2D server 70 may transmit the discovery inactivation request message received from the first D2D server 60 to the eNB / MME 50 at step S525 and the eNB / MME 50 transmits the discovery inactivation request message to the second D2D server 70 To the first terminal 10 (S526). The first terminal 10 may send a discovery discovery request message DEACTIVATE_DISCOVERY_REQ to the eNB / MME 50 in step S527 in response to the discovery disabling request message. The eNB / To the second D2D server 70 (S528).

Thereafter, the second D2D server 70 may send a deactivation discovery request message to the first D2D server 60 (S529), and the first D2D server 60 transmits a deactivation discovery request message in response to the deactivation discovery request message Message (DEACTIVATE_DISCOVERY_RSP) to the second D2D server 70 (S530). When receiving the deactivation discovery response message from the first D2D server 60, the second D2D server 70 may transmit a deactivation discovery response message to the eNB / MME 50 (S531). The eNB / MME 50 may transmit an inactivated discovery response message received from the second D2D server 70 to the first terminal 10 (S532).

Here, the discovery disabling request message is a message requesting disabling D2D discovery starting from the network, and may include cause information and the like. Deactivation The discovery request message refers to a message requesting disabling D2D discovery. The deactivation discovery response message means a response message to the D2D discovery deactivation request, and may include the result, cause information, and the like.

In the discovery information reporting procedure, the first D2D server 60 may send a discovery event report message (DISCOVERY_EVENT_REPORT) to the second D2D server 70 (S533). Here, the discovery event report message refers to a D2D discovery related event and an information report message, and may include an event type, a discovered terminal ID information, and the like.

FIG. 27 is a flowchart illustrating discovery setup information exchange procedures (S600 to S610) between D2D servers for limited discovery using a user plane function, FIG. 28 is a flowchart illustrating a discovery setup procedure between D2D servers for limited discovery using a user plane function Information exchange procedures (S611 to S623).

27 and 28, the wireless setting exchange procedure, the application approval procedure, the discovery ID acquisition procedure, and the discovery information reporting procedure are the same as those shown in FIG. 25 and FIG.

The discovery agreement procedure, the active discovery request procedure and the inactivation discovery request procedure are the same as those shown in FIG. 25 (a), except that a message transmitted between the first terminal 10 and the second D2D server 70 does not pass through the eNB / MME 50 And the procedure shown in Fig.

D2D  Configuring Information for Discovery

D2D discovery information for limited discovery refers to information transmitted and received when performing limited discovery procedures. The D2D discovery information for limited discovery may include a discovery ID that can point to a particular terminal (i.e., UE), and these information should be any information that is not a security issue when exposed. In addition, if the terminal has mapping information between the received discovery information and the terminal ID, the terminal must be able to recognize a specific terminal subscribed to its own network or another network using mapping information, To be able to access a specific terminal.

The D2D discovery information is allocated by a DME present in the network, and the information can be acquired through the opening of the terminal as described above.

The D2D discovery message for limited discovery may include a delimiter, a discovery ID, and an application ID. The delimiter may indicate the type of D2D discovery information. The discovery ID is information for recognizing the terminal that transmitted the D2D discovery information, and has a mapping relationship of 1: 1 with the terminal ID. The application ID can be used to transmit the application ID requesting the discovery service. If a discovery message for limited discovery and a discovery message for open discovery have different lengths, then the reserved field of the limited discovery message is not used.

The delimiter included in the D2D discovery message for limited discovery may have a length of 2 bits, which can be defined as follows.

● 00

  - limited D2D discovery information

● 01

  - Open D2D Discovery Information

● 10

  - Public Safety Information

● 11

  - spare field

The discovery ID included in the limited D2D discovery message can be used to obtain the ID of the corresponding terminal. When the terminal receives the discovery message, it can obtain the terminal ID by recognizing the terminal by comparing the discovery ID included in the discovery message with the list of piconeting terminals stored therein.

The discovery ID may be defined as a globally unique ID, or it may be defined as a locally unique ID. Each case has the following characteristics.

● Globally unique ID

- It is globally unique, so you do not have to change ID even if the terminal moves area

● Locally unique ID

  - ID change is required when the search terminal is out of the designated area

- Information needs to be changed each time the discovery ID of the terminal included in the search terminal list is changed.

29 is a conceptual diagram showing an embodiment (globally unique discovery ID) of a discovery message configuration for limited discovery.

29, the device discovery message has a total size of 16 bytes and may include discovery type information, a discovery ID, and an application ID. The discovery type information may have a size of 2 bits. The Discovery ID may have a size of 64 bits and may include a mobile country code (MCC), a mobile network code (MNC), and the like, similar to the configuration of an international mobile subscriber identity (IMSI) And a mobile identifier (ID). The application ID may have a size of 62 bits.

30 is a conceptual diagram showing another embodiment (locally unique discovery ID) of discovery message configuration for limited discovery.

Referring to FIG. 30, the device discovery message has a total size of 16 bytes, and may include discovery type information, a discovery ID, and an application ID. The discovery type information may have a size of 2 bits. The Discovery ID may have a size of 56 bits or 68 bits and may have a configuration similar to a globally unique temporary UE identity (GUTI) used in conventional LTE. That is, the Discovery ID is hierarchical, including mobile country code (MCC), mobile network code (MNC), MME group ID, MME code and MME temporary mobile subscriber identity (M- , Or may be configured in a hierarchical form including an MME group ID, an MME code, and an M-TMSI (or temporary ID). The application ID may have a size of 70 bits or 58 bits.

FIG. 31 is a conceptual diagram showing a definition of a protocol message for D2D discovery, and FIG. 32 is a conceptual diagram showing a definition of another protocol message for D2D discovery. Referring to FIG. 31 and FIG. 32, the protocol message refers to the protocol message shown in FIG. 12 to FIG.

33 is a conceptual diagram showing a parameter definition of a protocol message for D2D discovery. Referring to FIG. 33, definitions of parameters of a protocol message can be known.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. It will be possible.

10:
20:
30: eNB
40: MME
50: eNB / MME
60: the first D2D server
70: the second D2D server

Claims (20)

Discovery A method for restricted discovery in a terminal, the method comprising:
Receiving a discovery identifier (ID) of the search terminal from a device-to-device communication (D2D) server;
Performing an authentication procedure for limited discovery of an application located at the search terminal with the D2D server; And
Acquiring from the D2D server discoverable terminal information that is an opponent terminal to perform limited discovery when authentication of the application is completed. The method according to claim 1,
Wherein the discovery ID indicates that the search terminal supports limited discovery. The method according to claim 1,
Wherein performing the authentication procedure with the D2D server comprises:
Transmitting, to the D2D server, an authentication request message requesting authentication for restricted discovery of an application located at the search terminal; And
And receiving an authentication response message from the D2D server, the authentication response message being a response to the authentication request message. The method of claim 3,
Wherein the authentication request message includes a search terminal ID and an application ID. The method according to claim 1,
The step of acquiring the searched terminal information from the D2D server comprises:
Transmitting a search request message to the D2D server;
Receiving a paging terminal information response message that is a response to the paging terminal information request message from the D2D server; And
And updating the piconet terminal list based on the piconet terminal information included in the piconalt terminal information response message. The method of claim 5,
Wherein the sought-after-terminal information request message includes a target terminal ID to be searched, an operation flag, and the application ID. The method of claim 6,
Wherein the action flag indicates a consent request or a consent release request for limited discovery. The method of claim 5,
Wherein the paired search terminal information response message includes response information for a paired search terminal ID and limited discovery agreement. The method of claim 8,
And if the response to the limited discovery agreement is a consent, the piconceived terminal ID is added to the paired search terminal list. Discovery A method for activating restricted discovery in a terminal, the method comprising:
Transmitting a limited discovery activation request message to a device-to-device communication (D2D) server to activate limited discovery of a discoverable terminal;
Receiving radio resource information used for limited discovery through a base station interfaced with the D2D server when restricted discovery of the paired terminals is activated;
Receiving a limited discovery activation response message which is a response to the limited discovery activation request message from the D2D server; And
And performing limited discovery with the called terminal through a radio resource indicated by the radio resource information. The method of claim 10,
Wherein the limited discovery activation request message includes a discovery type, a discovery state, an application identifier of the search terminal, and a search termination ID. The method of claim 10,
Wherein the limited discovery activation response message includes a discovery ID of the search terminal and a discovery ID of the sought terminal. The method of claim 10,
And when the limited discovery activation response message is received, the search terminal transits to a limited discovery activation state. The method of claim 10,
And when the limited discovery activation request message is received, the D2D server allocates radio resources used for limited discovery to the p-th search terminal. 15. The method of claim 14,
Wherein the D2D server sets a discovery ID of the search terminal and a discovery ID of the search terminal when the allocation of the radio resources used for limited discovery to the p-th search terminal is completed. The method of claim 10,
Wherein the message transmitted between the search terminal and the D2D server is transmitted through a mobile management entity (MME). Discovery A method for disabling restricted discovery in a terminal, the method comprising:
Transmitting a limited discovery disable request message to a device-to-device communication (D2D) server for disabling limited discovery of the discoverable terminal;
Receiving a release of radio resources allocated for restricted discovery from a base station associated with the D2D server when limited discovery of the paired terminals is deactivated;
Receiving a limited discovery disable response message from the D2D server, the limited discovery disable response message being a response to the limited discovery disable request message; And
And transitioning to an idle state. 18. The method of claim 17,
And upon receiving the limited discovery disable request message, the D2D server releases radio resources allocated to the paired terminals for limited discovery. 19. The method of claim 18,
Wherein when the radio resources allocated to the paired search terminals are released, the server releases the discovery ID set for the paired terminals in the D2D. 18. The method of claim 17,
And when the radio resource allocated to the search terminal is released, the server releases the discovery ID set for the search terminal.

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