KR20100086632A - Method and apparatus for setupingpeer to peer communication in wireless communication system - Google Patents

Abstract

PURPOSE: A system and a device for setting and synchronizing P2P communication in a mobile communication system are provided to maintain synchronization between two terminals which are equal during P2P communication and sets connection for effective P2P communication. CONSTITUTION: A controller(830) compares cell including a source node and a destination node. If the source and a destination node is in a same cell, P2P resource allocator(833) assigns P2P request resource to the sources node and the destination node. A mode selector(831) measures measured reception power level of the source node and considers the measured reception power level to determine capacity of P2P communication between the source node and the destination node.

Description

METHOD AND APPARATUS FOR SETUPING PEER TO PEER COMMUNICATION IN WIRELESS COMMUNICATION SYSTEM}

The present invention relates to P2P communication in a mobile communication system, and more particularly, to a method and apparatus for P2P communication establishment and synchronization based on a base station centralized control framework.

Next-generation networks require support for peer-to-peer communication, in which users generate and transmit traffic directly to each other. Due to the characteristics of the P2P communication, there are many advantages such as high flexibility, high reliability, high data rate, space reuse of resources, and avoidance of traffic bottleneck at the base station.

The terminal uses a separate frequency band other than the frequency band allocated to the mobile communication system for general P2P communication. In addition, a separate RF transceiver is used to process other frequency band signals. For example, infrared wireless communication (IrDA) or Bluetooth (Bluetooth) communication is used for P2P communication. However, when the P2P communication and the mobile communication use the same frequency band, if the interference problem is solved using an efficient resource management scheme, it is possible to flexibly adjust each transmission band to expect improved bandwidth efficiency.

On the other hand, P2P communication using the frequency band allocated to the mobile communication system without using a separate RF transceiver for P2P communication has been studied.

In order to perform P2P communication using the frequency band allocated to the mobile communication system, a criterion for determining whether P2P communication is possible in the mobile communication system and determining whether to perform P2P communication or point-to-multi-point communication is provided. need. In addition, there is a need for synchronization between two terminals performing P2P communication.

An object of the present invention is to provide a method and apparatus for establishing P2P communication in a mobile communication system.

Another object of the present invention is to provide a synchronization method and apparatus for P2P communication in a mobile communication system.

According to a first aspect of the present invention for achieving the above objects, in a method for establishing and synchronizing peer-to-peer communication in a mobile communication system, after establishing a first connection between a base station and a source node, the base station and the destination Establishing a second connection between the nodes, checking whether the source node and the destination node are in the same cell by using the IP addresses of the source node and the destination node, and the source node and the destination node Determining whether peer-to-peer (P2P) communication is possible between the source node and the destination node when in the same cell, and when the P2P communication is possible, after establishing a first P2P connection with the source node, And establishing a second P2P connection with the destination node.

According to a second aspect of the present invention for achieving the above objects, in a method for operating a base station for peer-to-peer communication configuration and synchronization in a mobile communication system, after establishing a first connection with a source node, a destination node and a first node may be used. Establishing a second connection, checking whether the source node and the destination node are in the same cell, and when the source node and the destination node are in the same cell, the peer-to-peer request resource; Allocating to a source node and the destination node, receiving a measured received power level of the source node from the destination node, and considering the measured received power level of the source node, the source node and the destination. And determining whether P2P communication between nodes is possible.

According to a third aspect of the present invention for achieving the above objects, in a method for operating a source node for peer-to-peer communication establishment and synchronization in a mobile communication system, a process of establishing a first connection with a base station, and from the base station And a process of receiving a peer-to_peer (P2P) request resource, and transmitting a preamble at a predetermined power by using the P2P request resource.

According to a fourth aspect of the present invention for achieving the above objects, a method for operating a source node for peer-to-peer communication configuration and synchronization in a mobile communication system, the method comprising: establishing a first connection with a base station; And a process of receiving a peer-to_peer (P2P) request resource, and transmitting a preamble at a predetermined power by using the P2P request resource.

According to a fifth aspect of the present invention for achieving the above objects, a system for establishing and synchronizing peer-to-peer communication in a mobile communication system, comprising: a source node for establishing a first connection with a base station; A destination terminal for establishing a connection, a gateway for confirming whether the source node and the destination node are in the same cell by using IP addresses of the source node and the destination node, and the source node and the destination node in the same cell In this case, it is determined whether peer-to-peer (P2P) communication is possible between the source node and the destination node, and when the P2P communication is possible, after establishing a first P2P connection with the source node, the destination node and the second node are established. It characterized in that it comprises a base station for establishing a P2P connection.

According to a sixth aspect of the present invention for achieving the above objects, in a base station for peer-to-peer communication establishment and synchronization in a mobile communication system, after establishing a first connection with a source node, a second connection with a destination node A control unit for checking whether the source node and the destination node are in the same cell, and a peer-to-peer (P2P) request resource when the source node and the destination node are in the same cell. A P2P resource allocation unit for allocating a destination node, a measured reception power level of the source node from the destination node, and considering the measured reception power level of the source node, a P2P between the source node and the destination node; And a mode selection unit for determining whether communication is possible.

According to a seventh aspect of the present invention for achieving the above objects, a source terminal device for peer-to-peer communication setting and synchronization in a mobile communication system, comprising: a control unit for establishing a first connection with a base station, and a P2P from the base station; (Peer-to_Peer) includes a P2P control unit that is allocated a request resource and transmits a preamble at a predetermined power by using the P2P request resource.

According to an eighth aspect of the present invention for achieving the above objects, a destination terminal device for peer-to-peer communication setting and synchronization in a mobile communication system, the control unit for establishing a second connection with the base station, and the P2P from the base station (Peer-to_Peer) receiving a request resource, receiving power measurement unit for measuring the preamble signal strength transmitted by the source node using the P2P request resource, and reporting the measured preamble signal strength to the base station It characterized in that it comprises a P2P control unit.

As described above, by proposing P2P communication based on the centralized control of the base station in the mobile communication system, it is possible to maintain synchronization between two comparable terminals during P2P communication and to perform connection setup for efficient P2P communication. Can be. In addition, the present invention allows for a P2P link measurement, and a mechanism for P2P adaptive modulation. Furthermore, after the network components (base station and ASN_GW) automatically recognize the possibility of P2P communication, the P2P communication mode or PMP communication mode can be efficiently selected based on the channel state, overhead, and the like.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, detailed descriptions of related known functions or configurations will be omitted when it is determined that the detailed description may unnecessarily obscure the subject matter of the present invention. The following terms are defined in consideration of the functions of the present invention, and may be changed according to the intentions or customs of the user, the operator, and the like. Therefore, the definition should be made based on the contents throughout the specification.

Hereinafter, a method and apparatus for establishing and synchronizing peer-to-peer communication in a mobile communication system will be described.

In the following description, peer-to-peer direct communication of a base station centralized control based on a broadband wireless communication system (e.g., Institute of Electrical and Electronics Engineers (IEEE) 802.16) is referred to as "P2P DC" Will be described by way of example. In particular, it mainly deals with scenarios in which source and destination nodes exist in the same cell. For example, in a network that performs a particular task, such as a campus network, a corporate network, or a military or public safety network, employees are grouped in groups and within the group. Perform communication.

In order to deal with efficient P2P DC based on the base station centralized control structure, the present invention addresses two important issues. The first is the system's ability to recognize the availability of P2P communication. If P2P communication is possible, the system must also be able to determine the communication mode that can efficiently communicate in either P2P or Point-to-Multi-Point (PMP) communication mode (traditional data transmission through the base station). . Another issue is peer synchronization that performs P2P communication. In other words, we will cover the mechanism for performing and maintaining time synchronization between two comparable terminals.

1 is a schematic block diagram of a broadband wireless communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the broadband wireless communication system includes an access service network gate (ASN_GW) 100, a base station (BS) 110, and a mobile station (MS) 112 and 114.

The ASN_GW 100 is also called a base station control station or an access control router (ACR), and controls the terminals 112 and 114 and the base station 110 and routes IP packets. The ASN_GW 100 checks an IP address of a source node (called a terminal to transmit a packet) and a destination node (called a terminal to receive a packet) of a packet transmitted from the base station 110 and the source node. It informs the base station whether the destination node is in the same cell or in a different cell.

The base station 110 is also called a RAS (Radio Access Station) and performs transmission and reception with the terminals 112 and 114 through a wireless interface at a wired network end. The base station 110 also determines whether the source node and the destination node can perform P2P communication in the same cell and allocates the corresponding P2P resource.

The terminals 112 and 114 are devices used by subscribers to receive portable Internet service and voice service. The terminals 112 and 114 may be laptops, desktop computers, mobile communication terminals, or the like.

Meanwhile, in the base station centralized control P2P DC environment, paths for data and control traffic are physically separated. In other words, the traffic path is between two terminals communicating with each other, while the path for the control signal is between the terminal and the base station.

By using the P2P DC of the base station centralized control method, problems such as P2P traffic scheduling and management suitable for distributed control operation (eg, contention-based P2P operation) can be easily solved. In addition, through P2P communication of the base station centralized control method, QoS guarantee, efficient resource allocation, and efficient parallel P2P communication (spatial reuse of resources) can be performed.

In a normal PMP operation, the source node 112 transmits a packet to the serving base station 110 to send, and to determine the location of the destination node 114, the base station 110 sends the packet to the corresponding ASN_GW 100. Send them.

Since the destination node 114 and the source node 112 are in the same cell, the ASN_GW 100 sends the packets back to the base station 110 to forward the packet to the destination node 114. This procedure causes more delay and consumes more network resources than P2P communication, in which the source node can send packets directly to the destination node, especially when the two nodes are close to each other and the same radio resource is reusable.

In the present invention, this procedure allows the ASN_GW 100 and the base station 110 to automatically identify the opportunity to send packets in the P2P communication mode. Furthermore, in the present invention, the base station 110 provides a mechanism for efficiently determining the P2P mode or the PMP mode according to the performance expected from the operation of the two communication modes (P2P / PMP). The present invention also provides a method for further improving performance of P2P communication. In particular, in a P2P communication, one node transmits a long preamble for synchronization between two nodes and for P2P channel measurement. The base station 110 may select an optimal modulation code for P2P communication according to the P2P channel state, and switch to operate from the P2P mode to the PMP mode if the P2P channel state is bad.

In the present invention, a frame structure based on the viewpoint of the base station centralized control is proposed.

2 illustrates a frame structure according to a base station centralized control method according to an embodiment of the present invention.

Referring to FIG. 2, a frame is divided into a downlink subframe and an uplink subframe, and a downlink subframe indicates a preamble, a DL_MAP indicating a downlink burst position, and an uplink burst position. UL_MAP, downlink bursts # 1 to #n, and the uplink subframe includes uplink bursts # 1 to #m, a long preamble, and an area for at least one P2P communication.

In the present invention, in order to support P2P communication, a frame structure in which a dedicated P2P region is defined at the end of the uplink subframe is proposed. The amount of resources allocated to the P2P region is determined by the base station scheduler and known through the UL_MAP message. In each P2P area, a source node and a destination node are used for P2P communication as a pair, and are composed of a long preamble and a data area. The long preamble is used for synchronization between comparable terminals. The base station must allocate resources to the source node during the long preamble transmission. The destination node may adjust synchronization with the source node by detecting the long preamble transmitted by the source node. In addition, the long preamble interval and modulation is fixed or known to all terminals.

In FIG. 2, all subchannels are allocated to one P2P communication pair. However, according to an implementation, the base station may divide the subchannels into at least one P2P communication pair.

3 is a flowchart for setting and synchronizing for P2P communication in a mobile communication system according to an exemplary embodiment of the present invention.

In FIG. 3, it is assumed that the source node has been allocated Basic CID1 (BCID1) from the base station in the network entry process, and the destination node has been allocated BCID2 from the base station in the network entry process. The BCID is an identifier assigned by the base station during the network entry process of the terminal and used to distinguish the terminal in the cell.

Referring to FIG. 3, the base station and the source node perform connection establishment according to a predetermined procedure in step 300, and in step 302, the source node transmits a data packet to the base station. In other words, the source node establishes a service flow and receives a Transport Connection ID (TCID) 1 from the base station through a DSA (Dynamic Service Add) request / response message exchange with the base station. The service flow is represented by the source IP address, the destination IP address, the source port number, and the destination port number of the packet, and the TCID is assigned by the base station for each service flow. In FIG. 3, the source node uses TCID1 when transmitting a data packet for the service flow to the base station.

Thereafter, when the source node transmits the packet to the destination node through the base station, the base station forwards the packet having the TCID1 received from the source node to ASN_GW in step 304.

On the other hand, when receiving a packet from the base station, the ASN_GW checks the IP address of the source node and the destination node in the IP datagram portion of the packet, so that the source node and the destination node exist in the same base station or not. It can be checked whether they exist in different base stations.

If the source node and the destination node are not in the same base station, the ASN_GW sets the P2P indication flag value to 0 to forward the packet to the destination ASN_GW or the destination base station (not shown in FIG. 3). Thereafter, the destination base station establishes a connection with the destination node through a DSA-REQ / RSP message exchange, and forwards the packet to the destination node (not shown in FIG. 3).

On the other hand, if the source node and the destination node are in the same base station and there is no connection establishment for the service flow between the base station and the destination node, the ASN_GW sends a connection establishment request for the service flow in step 306 to the base station. Send to. In this case, the base station and the destination node establish a connection to the service flow through the DSA-REQ / RSP message exchange in step 308. After the connection between the base station and the destination node for the service flow and TCID2 have been allocated, the ASN_GW forwards the packet of the service flow to the base station using TCID2 with additional information necessary for establishing P2P communication. The additional information required for the P2P communication setting includes a value set to P2P indication flag = 1 and TCID1 information allocated for the service flow between the source node and the base station node.

That is, if the source node and the destination node are in the same base station, the ASN_GW forwards the packet received from the base station to the base station in step 310. In this case, the ASN_GW indicates by setting the P2P indication flag to 1 that the source node and the destination node are in the same base station.

Thereafter, the base station transmits the packet to the destination node using the TCID2 in a traditional PMP communication mode in step 312.

In step 320, the base station determines that the source node and the destination node are present in the cell area of the mobile station (P2P indication flag = 1), and whether the source node and the destination node are adjacent to each other to enable P2P communication. Judge.

To this end, the base station first allocates resources for P2P request message transmission through the P2P_REQ_Zone IE (Table 1) in step 322.

Syntax Size (bit) Note P2P_REQ_Zone IE () {  Extended-2 UIUC 4 TBA; Shall be set to one of the available (reserved) Extended-2 UIUC  Length 8 Length in bytes of the below data fields  Source BCID 16 BCID of the P2P_REQ sender  Destination BCID 16 BCID of the P2P_REQ receiver  OFDMA symbol offset 8 Indicate starting point of P2P_REQ based on time  Duration 6 Indicate Duration of P2P_REQ based on time  Padding 6 Padding to byte; Shall be set to 0 }

The P2P_REQ_Zone IE includes BCIDs of the source node and the destination node, an OFDMA symbol offset indicating a start point of a P2P request resource on a time axis, a duration information indicating a section of a P2P request resource on a time axis, and included in a UL_MAP message. do. Here, BCID1 of the source node and BCID2 of the destination node are derived from TCID1 and TCID2 provided by the ASN_GW. For the service flow, BCID1 of the source node capable of P2P communication is found using TCID1 information, and BCID2 of the destination node is found using TCID2 information.

Here, TCID1 used to find BCID1 of the source node for the service flow is indicated by a field newly defined in a MAC header, and TCID2 used to find BCID2 of the destination node for the service flow is a data packet MAC header. It is indicated by the CID field of.

Thereafter, in step 324, the source node transmits a P2P_REQ message such as a long preamble to the destination node through a resource indicated by the OFDMA symbol offset and duration information specified in the P2P_REQ_Zone IE at a predetermined transmission power.

In step 326, the destination node newly defined P2P_REQ_indicator message including measured received power of the long preamble received from the source node, BCID1 of the source node (known by P2P_REQ_Zone IE), and BCID2 information of the destination node. Report to the base station through (Table 2). The report message is transmitted by a traditional PMP UL transmission scheme.

Syntax Size (bit) Note P2P_REQ_Indicator message format ()  Management message type 8 TBA; Shall be set to one of the available (reserved) MAC management message type  Source BCID 16 BCID of the source node who transmits preamble  Destination BCID 16 BCID of the reporter (destination node)  RSSI 8 Signal strength of the received preamble }

The P2P_REQ_indicator message includes BCID of the source node, BCID of the destination node, Received Signal Strength Indication (RSSI) information of the preamble, and the like.

Thereafter, after receiving the reception power measurement report from the destination node in step 330, the base station determines whether to switch to the P2P communication mode or maintain the existing PMP communication mode using the received power measurement report. Here, in order to select the PMP / P2P communication mode, the base station may compare the channel state and overhead associated with the P2P communication and the PMP communication and determine the overhead. The parameter used in the Marking Algorithm is the received power of the reported long preamble (used to calculate the channel state between the source node and the destination node), the preamble size (overhead in P2P communication). , PMP channel state (channel state between base station and source node, channel state between base station and destination node) and the like. Based on the parameter, the base station should select an operation mode (PMP or P2P communication mode) that provides better expected performance. Here, the decision marking algorithm is an implementation issue and will not be described in detail in the present invention.

If the PMP communication mode operation is selected (when the comparable terminals are not within a certain range of each other or the P2P communication mode does not have the expected performance better than the PMP communication mode), the base station is configured with the source node and the already established for the service flow. Communication continues using the PMP connection with the destination node (not shown in FIG. 3).

On the other hand, when the P2P communication mode operation is selected (when the comparable terminals are in a certain range with each other and the performance of the P2P communication mode is better than that of the PMP communication mode), the base station is divided into two equal terminals (the source node and the destination node). In order to establish a P2P connection for the service flow (step 330), a P2P_DSA-REQ / RSP message is exchanged between the base station and the source node in step 332, and the P2P_DSA between the base station and the destination node in step 334. -Exchange REQ / RSP messages. The P2P_DSA-REQ message transmitted by the base station to the source node includes TCID1 for the service flow and P2P_TCID for the service flow. Through this, the source node can transmit traffic of the service flow from the base station to the base station or the destination node through a resource allocated as TCID1 or P2P_TCID. In addition, the P2P_DSA_REQ message transmitted by the base station to the destination node includes a TCID2 for the service flow and a P2P_TCID for the service flow. In this way, the destination node can receive the traffic of the service flow from the base station or the source node through the resources allocated to the TCID2 or P2P_TCID from the base station.

Here, due to the base station centralized control frame structure, the P2P_DSA-REQ / RSP message and also other control messages cannot be transmitted directly between comparable terminals.

That is, all control messages such as bandwidth requests or channel measurements are sent to the base station, and only data packets are sent directly from the source node to the destination node (from the destination node to the source node) in a P2P communication mode.

After establishing a P2P connection between the source node and the destination node (330), the base station allocates resources for P2P communication through the P2P_zone IE (see Table 3 below) in step 340.

Syntax Size (bit) Note P2P_Zone IE () {  Extended-2 UIUC 4 TBA; Shall be set to one of the available (reserved) Extended-2 UIUC  Length 8 Length in bytes of the below data fields P2P_TCID 16 Transport CID of P2P connection OFDMA symbol offset 8 Indicate starting point of P2P Zone based on time Duration 6 Indicate duration of P2P Zone based on time  Long preamble flag One Set to 1 if preamble is included at the beginning of P2P Zone (transmitted by source)
Set to 0 to omit preamble in P2P Zone UIUC 4 Repetition Coding Indication 2 Padding Var Padding to byte; Shall be set to 0 }

The P2P_zone IE is a long preamble flag indicating whether a resource start point (OFDMA symbol offset) of a resource for P2P communication based on a P2P_TCID value and a time axis, a resource duration for a P2P communication based on a time axis, and whether to use a long preamble are used. Information and the like.

The message formats of Tables 1, 2, and 3 may be one example. The message format may be changed according to implementation.

Thereafter, the source node directly transmits traffic of the service flow corresponding to P2P_TCID to the destination node through the allocated P2P resource, without passing through the base station. In addition, the destination node operates in a reception mode to receive traffic of the service flow corresponding to P2P_TCID directly from the source node without passing through a base station through an allocated P2P resource.

4 is a flowchart illustrating an operation of a base station for setting and synchronizing for P2P communication in a mobile communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 4, the base station performs a first PMP connection setup and packet transmission in step 400. The first PMP connection establishment means a PMP connection establishment between a source node and the base station.

In step 402, the base station determines whether the source node and the destination node are in the same base station through the "P2P indication flag" setting value sent by the ASN_GW.

If the source node and the destination node are not in the same base station, the base station proceeds to step 418 to perform a second PMP connection setup. The second PMP connection establishment means a PMP connection establishment between the destination node and the base station.

In step 420, the base station transmits the packet through the PMP communication mode. That is, according to the conventional predefined procedure, the packet is transmitted to the destination node through the destination base station.

On the other hand, when the source node and the destination node is in the same base station, the base station proceeds to step 404 to establish a second PMP connection with the destination node and transmits the packet.

In step 406, the base station allocates a P2P request resource through a P2P_REQ_Zone IE (see Table 1).

In step 408, the base station reports the received power of the source node through the P2P_REQ_Indicator message from the destination node, and determines whether to switch to the P2P communication mode or maintain the PMP communication mode based on the report in step 410. .

Thereafter, when the base station selects the P2P communication mode in step 412, the base station proceeds to step 414 to establish a P2P connection between the source node and the destination node.

In step 416, the base station allocates resources for P2P communication through P2P_Zone_IE.

Thereafter, the base station terminates the procedure of the present invention,

5 is a flowchart illustrating an operation of a source node for setting and synchronizing for P2P communication in a mobile communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 5, in step 500, the source node performs a first PMP connection establishment with a base station and transmits a packet.

Thereafter, when the P2P request resource is allocated from the base station through the P2P_REQ_Zone IE in step 502, the source node proceeds to step 504 and transmits a long preamble through a resource region allocated with a predetermined power.

After that, when the source node is selected as the P2P communication mode by the base station in step 506, the source node proceeds to step 508 to perform P2P connection establishment with the base station and to allocate resources for P2P communication to perform P2P communication with the destination node. To perform.

On the other hand, when the P2P communication mode is not selected by the base station in step 506 (that is, when the PMP communication mode is selected), the previously set PMP communication mode is maintained and the P2P request resource is checked in step 502.

The source node then terminates the procedure of the present invention.

6 is a flowchart illustrating an operation of a destination node for setting and synchronizing for P2P communication in a mobile communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 6, the destination node performs a second PMP connection establishment with the base station in step 600 and receives a packet.

Thereafter, when the P2P request resource is allocated from the base station through the P2P_REQ_Zone IE in step 602, the destination node proceeds to step 604 to measure the reception power of the long preamble transmitted by the source node.

Thereafter, the destination node reports the received power measured in step 606 to the base station through a P2P_REQ_Indicator message.

Then, when the destination node is selected as the P2P communication mode by the base station in step 608, the process proceeds to step 610 to establish a P2P connection with the base station and receives a resource for P2P communication to perform P2P communication with the source node. To perform.

On the other hand, when the P2P communication mode is not selected by the base station in step 608 (that is, when the PMP communication mode is selected), the previously set PMP communication mode is maintained and the P2P request resource is checked in step 602.

The destination node then terminates the procedure of the present invention.

7 shows an example for a P2P request transmission and detection scheme according to the present invention.

Referring to FIG. 7, the source node identifies and transmits a location for long preamble transmission through UL_MAP information, and the destination node detects a long preamble transmitted by the source node through UL_MAP information.

8 illustrates a base station apparatus for setting and synchronizing for P2P communication in a mobile communication system according to an embodiment of the present invention.

Referring to FIG. 8, the base station includes an RF processor 800, an OFDM demodulator 810, a message processor 820, a controller 830, a message generator 840, an OFDM modulator 850, and an RF processor 860. It is configured to include.

The RF processor 800 converts a radio frequency (RF) signal received through an antenna into a baseband analog signal. The OFDM demodulator 810 converts an analog signal from the RF processor 800 into sample data and outputs the sample data. The sample data is converted into data of a frequency domain by fast Fourier transform (FFT), and data of subcarriers to be actually received are selected and output from the data of the frequency domain. The OFDM demodulator 810 demodulates and decodes data according to a predetermined modulation level (MCS level) and outputs the data to the message processor 820.

The message processor 820 decomposes the control message input from the OFDM demodulator 830 and provides the result to the controller 830. The message processor 820 decomposes the P2P_REQ_indicator message including the received power information of the source node from the destination node.

The controller 830 performs corresponding processing on the information provided from the message processor 820, and provides the result to the message generator 840. That is, the controller 830 receives information necessary for performing general mobile communication protocol processing through the base station from the corresponding component of the physical layer, or generates a control signal to the corresponding component of the physical layer.

In addition, the controller 830 controls PMP connection establishment with a source node and a destination node, and controls P2P communication. To this end, the controller 830 includes a mode selection unit 831, a P2P resource allocating unit 833, and a P2P connection setting unit 835.

The mode selector 831 determines whether to switch to a P2P communication mode or maintain an existing PMP communication mode based on the P2P_REQ_indicator message information. Here, when selecting the PMP / P2P communication mode, the mode selector 831 may compare the channel state and overhead associated with the P2P communication and the PMP communication and determine the overhead. The parameter used in the mode decision marking algorithm is used to calculate the received power of the reported long preamble (used to calculate the channel state between the source node and the destination node), the preamble size (overhead in P2P communication). ), PMP channel state (channel state between base station and source node, channel state between base station and destination node). Based on the parameter, the base station should select an operation mode (PMP or P2P communication mode) that provides better expected performance. Here, the mode decision marking algorithm is an implementation issue and will not be described in detail in the present invention.

When the PMP communication mode operation is selected by the mode selection unit 831, the control unit 830 continues the operation in the traditional PMP communication mode using a PMP connection established between the source node and the destination node. .

When the P2P connection setting unit 835 selects the P2P communication mode operation by the mode selection unit 831, the base station establishes a P2P connection between two equal terminals (the source node and the destination node). The P2P_DSA-REQ / RSP message is exchanged between the base station and the source node and the P2P_DSA-REQ / RSP message is exchanged between the base station and the destination node.

The P2P resource allocation unit 833 allocates a P2P request resource and a P2P communication resource when the source node and the destination node are in the same base station. To this end, information for configuring P2P_REQ_Zone IE and P2P_Zone IE is provided to the message generator 840.

The P2P connection establishment unit 835 performs P2P connection establishment with the source node and the destination node, respectively, according to a predetermined procedure. In other words, through the P2P_DSA_REQ / RSP message exchange with the source node and the destination node, the service flow is set and P2P_TCID is allocated.

The message generator 840 generates a message with various types of information provided from the controller 830 and outputs the message to the OFMD modulator 850 of the physical layer. For example, the message generator 840 generates a P2P_REQ_Zone IE for allocating a P2P request resource and a P2P_Zone IE for allocating a P2P region.

The OFMD modulator 850 codes and modulates data from the message generator 840 according to a predetermined modulation level (MCS level). The modulated data is subjected to Inverse Fast Fourier Transform (IFFT) to output sample data (OFDM symbols). The sample data is converted into an analog signal and output to the RF processor 860. The RF processor 860 converts the analog signal into a radio frequency (RF) signal and transmits the same through an antenna.

9 illustrates a terminal device for P2P communication connection between terminals in a mobile communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 9, the terminal includes an RF processor 900, an OFDM demodulator 902, a message processor 904, a controller 906, a message generator 908, an OFDM modulator 910, and an RF processor 912. The P2P controller 916 and the reception power measurement unit 914 are configured.

The RF processor 900, the OFDM demodulator 902, the message processor 904, the message generator 908, the OFDM modulator 910, and the RF processor 912 are registered in FIG. 8. The same reference numerals will be used to refer to FIG. 8.

The controller 906 performs overall control of the terminal. For example, it controls the PMP connection establishment with the base station. In addition to the present invention, when receiving a P2P request resource (P2P_REQ_Zone IE) from the base station as a source node, by generating a long preamble at a predetermined power to the transmitting end (the message generator 908, OFDM modulator 910, And transmits the data through the RF processor 912. The measured preamble signal strength of the source node is transmitted to the base station.

The P2P control unit 916 controls P2P connection establishment with a base station, receives a resource (P2P_Zone_IE) for P2P communication from the base station, and controls P2P communication.

The reception power measuring unit 914 measures the preamble signal of the source node and provides the control unit 906 when operating as a destination node.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the scope of the following claims, but also by the equivalents of the claims.

1 is a schematic configuration diagram of a broadband wireless communication system according to an embodiment of the present invention;

2 is a frame structure according to a base station centralized control method according to an embodiment of the present invention;

3 is a flowchart for setting and synchronizing for P2P communication in a mobile communication system according to an embodiment of the present invention;

4 is a flowchart illustrating a base station for setting and synchronizing for P2P communication in a mobile communication system according to an embodiment of the present invention;

5 is an operation flowchart of a source node for configuration and synchronization for P2P communication in a mobile communication system according to an embodiment of the present invention;

6 is an operation flowchart of a destination node for setting and synchronization for P2P communication in a mobile communication system according to an embodiment of the present invention;

7 is a diagram for a P2P request transmission and detection scheme according to the present invention;

8 is a base station apparatus for setting and synchronization for P2P communication in a mobile communication system according to an embodiment of the present invention;

9 is a terminal device for setting and synchronization for P2P communication in a mobile communication system according to an embodiment of the present invention.

Claims (26)

In the method for peer-to-peer communication setting and synchronization in a mobile communication system, After establishing a first connection between the base station and the source node, establishing a second connection between the base station and the destination node; Checking whether the source node and the destination node are in the same cell by using the IP addresses of the source node and the destination node; Determining whether peer-to-peer (P2P) communication is possible between the source node and the destination node when the source node and the destination node are in the same cell; And when the P2P communication is possible, after establishing a first P2P connection with the source node, establishing a second P2P connection with the destination node. The method of claim 1, And after the P2P connection is established, performing P2P communication by using a resource for P2P communication. The method of claim 1, The process of determining whether peer-to-peer communication between the source node and the destination node is possible, Allocating the P2P request resource to the source node and the destination node by the base station; Transmitting, by the destination node, the source node to the destination node by using the P2P request resource; And measuring the signal strength of the preamble of the source node and reporting the signal strength to the base station. A method of operating a base station for peer-to-peer communication configuration and synchronization in a mobile communication system, After establishing a first connection with the source node, establishing a second connection with the destination node, Checking whether the source node and the destination node are in the same cell; Allocating a peer-to-peer request resource to the source node and the destination node when the source node and the destination node are in the same cell; Receiving the measured received power level of the source node from the destination node; Determining whether P2P communication is possible between the source node and the destination node in consideration of the measured reception power level of the source node. The method of claim 4, wherein When P2P communication is possible between the source node and the destination node, establishing a P2P connection with the source node and the destination node, respectively; And allocating resources for P2P communication between the source node and the destination node. The method of claim 4, wherein And maintaining a point-to-multi-point communication mode when the P2P communication between the source node and the destination node is not possible. The method of claim 4, wherein When establishing a first connection with the source node and establishing a second connection with the destination node, the first node may be distinguished by a first TCID (Transport Connection ID) for the first connection and a second TCID for the second connection. How to feature. The method of claim 4, wherein The step of checking whether the source node and the destination node are in the same cell is confirmed through a "P2P Indication flag" value received from the gateway. The method of claim 4, wherein In order to determine whether the P2P communication is possible, the size of the preamble, the channel state between the base station and the source node and the channel state between the base station and the destination node is considered. A method of operating a source node for peer to peer communication setup and synchronization in a mobile communication system, Establishing a first connection with the base station, Receiving a peer-to-peer request resource from the base station; Using the P2P request resource, transmitting a preamble at a predetermined power. The method of claim 10, Performing P2P connection establishment with the base station; Receiving a resource for P2P communication from the base station; And performing P2P communication with a destination node by using the allocated P2P communication resource. A method for operating a destination node for peer to peer communication setup and synchronization in a mobile communication system, Establishing a second connection with the base station, Receiving a peer-to-peer request resource from the base station; Measuring a preamble signal strength transmitted by a source node using the P2P request resource; Reporting the measured preamble signal strength to the base station. The method of claim 12, Performing P2P connection establishment with the base station; Receiving a resource for P2P communication from the base station; And performing P2P communication with a source node by using the allocated P2P communication resource. In the system for peer-to-peer communication setting and synchronization in a mobile communication system, A source node establishing a first connection with a base station, a destination terminal establishing a second connection with the station, A gateway for checking whether the source node and the destination node are in the same cell by using the IP addresses of the source node and the destination node; When the source node and the destination node is in the same cell, it is determined whether peer-to-peer communication is possible between the source node and the destination node, And a base station configured to establish a second P2P connection with the destination node after establishing a first P2P connection with the source node when the P2P communication is possible. 15. The method of claim 14, The source node and the destination node After establishing a P2P connection with the base station, a system for performing P2P communication using resources for P2P communication. 15. The method of claim 14, The base station comprises: Allocate the P2P request resource to the source node and the destination node, The source node transmits a preamble to the destination node using the P2P request resource, And reporting the signal strength of the preamble of the source node. A base station for peer to peer communication setup and synchronization in a mobile communication system, After establishing a first connection with the source node, establish a second connection with the destination node, A controller for confirming whether the source node and the destination node are in the same cell; A P2P resource allocation unit for allocating a peer-to-peer request resource to the source node and the destination node when the source node and the destination node are in the same cell; And a mode selection unit configured to receive the measured reception power level of the source node from the destination node, and determine whether P2P communication between the source node and the destination node is possible in consideration of the measured reception power level of the source node. Device characterized in that. The method of claim 17, When the P2P communication between the source node and the destination node is possible, further comprising a P2P connection setting unit for establishing a P2P connection with the source node and the destination node, respectively, And the P2P resource allocation unit allocates resources for P2P communication between the source node and the destination node. The method of claim 17, The control unit And maintain a point-to-multi-point (PMP) communication mode when P2P communication between the source node and the destination node is not possible. The method of claim 17, When establishing a first connection with the source node and establishing a second connection with the destination node, the first node may be distinguished by a first TCID (Transport Connection ID) for the first connection and a second TCID for the second connection. Characterized in that the device. The method of claim 17, The control unit The step of confirming whether the source node and the destination node is in the same cell is confirmed by the "P2P Indication flag" value received from the gateway. The method of claim 17, In order to determine whether the P2P communication is possible, the size of the preamble, the channel state between the base station and the source node and the channel state between the base station and the destination node is considered. A source terminal device for peer to peer communication setting and synchronization in a mobile communication system, A control unit for establishing a first connection with the base station, And a P2P controller configured to receive a peer-to-peer request resource from the base station and to transmit a preamble at a predetermined power using the P2P request resource. 24. The method of claim 23, Performing P2P connection establishment with the base station; Receiving a resource for P2P communication from the base station; And performing P2P communication with a destination node by using the allocated P2P communication resource. A destination terminal device for peer-to-peer communication configuration and synchronization in a mobile communication system, A control unit for establishing a second connection with the base station, Receiving a peer-to-peer request resource from the base station; A reception power measurement unit measuring a preamble signal strength transmitted by a source node using the P2P request resource; And a P2P controller for reporting the measured preamble signal strength to the base station. The method of claim 12, P2P controller Perform a P2P connection with the base station, Receiving resources for P2P communication from the base station, And perform P2P communication with a source node by using the allocated P2P communication resource.

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