KR20090062435A - Resource allocation method and system for direct communication between terminals in mobile communication system - Google Patents

Abstract

The present invention relates to a method and apparatus for allocating resources for direct communication between terminals in a mobile communication system. The present invention relates to a method for allocating resources for a terminal for direct communication (Peer to Peer) between terminals in a mobile communication system. Receiving a communication terminal and mobile communication resource allocation information; scanning the presence / absence of a neighboring P2P communication terminal and a neighboring mobile communication terminal using the resource allocation information; and transmitting the scan result to the base station for P2P communication. There is an advantage that can efficiently allocate resources for P2P communication, including the process of requesting resources, and the process of receiving P2P communication resource allocation information for the resource request.

Description

Resource allocation method and system for direct communication between terminals in mobile communication system {METHOD AND SYSTEM FOR ALLOCATING RESOURCE PEER TO PEER COMUNUCATION IN WIRELESS COMMUNICATION SYSTEM}

The present invention relates to peer to peer (P2P) communication, and more particularly, to a method and system for allocating resources for P2P communication by base station control in a mobile communication system.

In a mobile communication system, a calling terminal always makes a call with the called terminal through a mobile communication network regardless of the distance from the called terminal to make a call with another terminal. That is, regardless of the distance between the calling terminal and the called terminal, the connection is made with the called terminal via a base station, an exchange station, or the like that constitutes a mobile communication system. However, if the distance between the calling terminal and the called terminal is very close, it may be more reasonable to communicate directly without relaying the base station. Here, direct communication between terminals without going through the relay of the base station will be referred to as direct communication between terminals (Peer-to-Peer: hereinafter referred to as "P2P") communication.

When a terminal supporting dual-mode performs P2P communication, the dual mode terminal is a module that provides a wireless personal area network (WPAN) function of the IEEE 802.15 standard or an IEEE 802.11 standard such as a wireless LAN. Along with the module, mobile communication functions such as existing Code Division Multiple Access (CDMA) and Global System for Mobile Communications (GSM) can be simultaneously performed. That is, several standardization modules are applied to one terminal, and major specifications such as respective operating frequencies are configured in such a manner that they are mounted independently of each other. Standards such as WLAN of IEEE 802.11 or WPAN of IEEE 802.15 are configured to operate in unlicensed band. In particular, in case of WLAN, the purpose of development is not for communication between two adjacent terminals. In order to establish a P2P connection, the P2P communication must be configured through an optional ad-hoc mode.

In case of non-dual mode (i.e., performing only mobile communication functions such as CDMA and GSM), if the terminal sees P2P communication, Winner proposes a standard technology to use P2P communication in the mobile communication system. have. One master device manages all slave devices, and this master device may be a base station or another device that supports network management.

1 illustrates a frame structure for P2P communication in a mobile communication system according to the prior art.

Referring to FIG. 1, there is a CTP (Control Period) 100 portion for sending and receiving a control message, and is composed of a CAP (Contention Access Period) 102 and a TDMA scheme that can be accessed in a competitive manner by the other half. It consists of a guaranteed access period (GAP) 104 that can use the allocated resources. The CTP 100 includes a beacon 110, a downlink command 120, an uplink command 130, and the like.

In the case of a dual mode terminal, two or more modules need to be applied to a single terminal, which may result in complicated implementation and a terminal cost increase. In addition, since the two systems are not cross-optimized in terms of performance, using both communication modes at the same time may limit the system performance.

In case of P2P communication of Winner, a separate device manages several P2P user groups, and there is a contention-based frame, so it is not possible to guarantee QoS (Quality Of Service) of P2P terminals. In addition, since separate frequency resources for P2P communication are divided, there is a disadvantage in that the efficiency of resource use is lower than that of using the same resource, which is the proposed scheme in common.

An apparatus and method for efficiently reusing resources for P2P communication under the initiative of a base station are proposed to solve the above problems.

According to a first aspect of the present invention for achieving the above object, in a mobile communication system in the method of allocating a terminal for a peer-to-peer (P2P) terminal directly from the base station to the P2P communication terminal and mobile communication resource allocation Receiving information, scanning the presence or absence of a neighboring P2P communication terminal and a neighboring mobile communication terminal using the resource allocation information, transmitting the scan result to the base station, requesting a P2P communication resource, and And receiving the P2P communication resource allocation information for the resource request.

According to a second aspect of the present invention for achieving the above object, in the resource allocation method of the base station for the peer-to-peer (P2P) communication in the mobile communication system, the spatial resources when the P2P resource allocation request from the terminal And allocating the resource in consideration of reuse, and transmitting the resource allocation information.

According to a third aspect of the present invention for achieving the above object, in a method for allocating a resource for peer-to-peer (P2P) communication in a mobile communication system, a base station allocates a P2P communication terminal and a mobile communication resource. Receiving information, scanning the presence / absence of a neighboring P2P communication terminal and a neighboring mobile communication terminal using the resource allocation information, transmitting the scan result to the base station to request P2P communication resources, and And updating the resource allocation information in consideration of spatial resource reuse according to the scan result, and transmitting the updated resource request information.

According to a fourth aspect of the present invention for achieving the above object, in a mobile communication system for allocating resources for peer-to-peer (P2P) communication, receiving resource allocation information from a base station, the resource allocation Resource allocation information by scanning the presence / absence of neighboring P2P communication terminals and neighboring mobile communication terminals using the information, transmitting the scan result to the base station, and requesting resources, and reusing spatial resources according to the scan results. It is characterized in that it comprises a base station for updating the, and transmits the updated resource request information.

As described above, by allocating P2P communication resources under base station control in the mobile communication system, there is an advantage in that resources for P2P communication can be efficiently allocated. In addition, in the case of P2P communication located in the outer cell, since interference by adjacent cells is considered, QoS can be guaranteed for mobile communication terminals and P2P communication terminals located in the cell boundary area.

Hereinafter, preferred 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 well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

Hereinafter, a method and apparatus for allocating resources for peer-to-peer communication by base station control in a mobile communication system will be described. In the following description, a terminal wanting P2P communication among two terminals performing P2P communication is referred to as a master terminal and a counterpart terminal is referred to as a slave terminal.

2 is a flowchart illustrating resource allocation for P2P communication in a mobile communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 2, in step 200, the master terminal is periodically provided with resource allocation information from the serving base station and neighbor base stations. The reason for this is to reduce interference between P2P terminals outside the cell and mobile communication terminals (ie, terminals in cells of neighboring base stations) by receiving resource allocation information from neighboring base stations.

In step 202, the master terminal analyzes the resource allocation information and scans neighboring terminals in its vicinity (not shown in FIG. 2). Through the scanning, it is possible to check the presence or absence of adjacent terminals for P2P communication and uplink communication.

In step 204, the master terminal transmits a spatial reuse information message to the serving base station to request a resource with the scan result to the serving base station.

Thereafter, the serving base station exchanges resource allocation information with neighboring base stations in step 206. The serving base station may exchange resource allocation information with neighboring base stations so that the same resource is not allocated to terminals that perform P2P communication in the vicinity of the neighbor cell. Interference from the neighboring cells will be described in detail later.

Thereafter, the serving base station allocates resources with reference to the scan result sent from the master terminal in step 208 and provides updated resource allocation information to the master terminal.

Thereafter, the resource allocation procedure of the present invention is terminated.

3 is an example for resource allocation for P2P communication in a base station according to an embodiment of the present invention.

Referring to FIG. 3, the terminal 303 is a terminal for P2P communication with the terminal 305, and the terminal 307 and the terminal 309 are terminals that are in P2P communication with each other around the terminal 305. The terminal 311 and the terminal 313 are located far from the terminal 305 to perform P2P communication with each other. Similarly, the terminal 317 and the terminal 319 are located far from the terminal 305. P2P communication with each other. The terminal 315 is a terminal for mobile communication through the base station 301 at a long distance, and the terminal 316 is a terminal for mobile communication through the base station 301 at a short distance.

At this time, when the resource information allocated to the terminals 307 to 319 is broadcast from the base station 301, the master terminal 303 to perform P2P communication with the terminal 305 uses the resource allocation information (MAP information 300 )) To scan the terminals 307 to 319. When the terminal 303 scans, other terminals 311 to 319 other than the terminals 307 and 309 will not be searched. The location of the P2P communication resource region and the mobile communication resource region can be known through the MAP information. That is, by performing scanning on the allocated resource region, the terminal 303 may know which terminals are located from its vicinity.

When the base station 301 allocates resources for the new P2P communication, the base station 301 does not overlap with the resource regions of the mobile communication terminals 315 and 316 in use in the cell by using the scan result reported by the master terminal 303. Allocate resources. In order to prevent interference with existing users, radio resources are allocated so as not to overlap with neighboring P2P terminals 307, 309, 311, 313, 317, and 319 specified by the scan information of the terminals of the new P2P communication. Then, one portion of the resources of the existing P2P communication not present in the neighbor terminal list of the new P2P terminals 303 to 305 is allocated to the new P2P communication for spatial reuse 304. In this case, the radio resources are allocated to the P2P terminal 307, 309, 311, 313, 317, 319 or the effect of the interference from the mobile communication terminals 315 to 316 at the new P2P communication. .

Referring to FIG. 3, the terminal 317 and the terminal 319 receive P2P resources 304 to perform P2P communication, and the terminal 307 and the terminal 309 receive P2P resources 306 to perform P2P communication. In addition, the terminal 311 and the terminal 313 receives the P2P resource 302 to perform P2P communication. Here, the base station 301 may allocate the P2P resources 302 and 304 or the new P2P resources that can be spatially reused for the resources requested by the master terminal 303.

In addition, the base station 301 performs scheduling while considering a mobile communication user and a P2P user who has made a resource allocation request at the same time. Therefore, if the base station 301 first allocates resources to the P2P communication connection to satisfy the QoS (Quality Of Service) for P2P communication with a delay sensitive service, the corresponding P2P communication is guaranteed with QoS. Can be. Here, when the base station 301 informs the P2P terminals of resource allocation information, the base station 301 performs the same method as the existing mobile communication. That is, it transmits the resource allocation information of the other mobile communication user together with the resource allocation information message format used in the mobile communication.

4 illustrates an operation sequence of a master terminal for P2P communication according to an embodiment of the present invention.

Referring to FIG. 4, when the master terminal performs P2P communication in step 400, the master terminal proceeds to step 402 to determine a counterpart terminal for P2P communication. For example, when a master terminal broadcasts a P2P request message, neighboring terminals receive and respond to a P2P request message. In this case, the terminal may select a P2P counterpart terminal if necessary by making a list of candidate terminals capable of P2P communication with reference to the response message. According to the implementation, the scanning result may be viewed and determined in operation 406 to determine the counterpart terminal of the P2P communication.

In step 404, the master terminal receives the first resource allocation information from the serving base station and neighbor base stations. Through the first resource allocation information, it can be seen how the base station uses resources for mobile communication and resources for P2P communication with respect to terminals in its cell.

In step 406, the master terminal analyzes the first resource allocation information to search for neighboring P2P communication terminals and uplink communication terminals. Through the scanning, the master terminal can know which terminals are communicating in the vicinity.

In step 408, the terminal requests P2P resource allocation from the serving base station through an existing cellular resource allocation process. Resource allocation used in existing mobile communication is included, but additional information necessary for P2P resource allocation is transmitted together. For example, this is a resource request for P2P communication, and a list of other P2P connections and mobile communication resource areas where spatial resource reuse is not possible.

Thereafter, the terminal receives second resource allocation information from the serving base station in step 410. The second resource allocation information is information in which a serving base station allocates resources by grouping terminals capable of reusing spatial resources, and the master terminal can know what resources it should use for P2P communication.

Thereafter, the terminal performs P2P communication with the counterpart terminal (slave terminal) with the allocated resources in step 412, and when the P2P communication ends in step 414, the terminal transmits a message indicating that the P2P communication is terminated in step 416. Terminate the connection.

Thereafter, the P2P communication procedure of the present invention is terminated.

Here, an operation of scanning adjacent P2P communication terminals and mobile communication terminals for increasing resource utilization will be described.

Since P2P communication terminals can sufficiently communicate with low power, they often reuse resources spatially within the same cell. Therefore, the P2P communication terminal performs scanning before the resource request in order to confirm whether the resource is spatially reused. Through this, the P2P resource area and the mobile communication resource area used in the corresponding cell can reuse spatial resources. In addition, in the case of new P2P terminals located outside the cell, since the mobile communication terminals of the neighboring cell will act as a significant interference to the P2P communication using the corresponding resource, the presence of the mobile communication terminal of the neighboring cell also needs to be scanned. Signal-to-Interference-plus-Noise-Ratio (SINR) measurement for scanning will be described in FIG.

5 illustrates an operation sequence of a base station for P2P communication according to an embodiment of the present invention.

Referring to FIG. 5, the base station broadcasts resource allocation information through a broadcast channel in step 500. The resource allocation information includes information on resources allocated for mobile communication and P2P communication by terminals currently in a cell of a base station.

Thereafter, the base station determines whether the P2P terminal requests the P2P resource in step 502, and if there is no P2P resource request, the base station proceeds to step 500 and periodically broadcasts resource allocation information.

If there is a P2P resource request, the base station proceeds to step 504 and allocates P2P resources with reference to the scan result. For detailed resource allocation, see FIG. 3 above.

Thereafter, the base station proceeds to step 506 and transmits a resource allocation possible confirmation message.

Thereafter, the base station proceeds to step 500 when the P2P termination message is not received in step 508 and proceeds to step 510 when receiving the P2P termination message, and transmits a P2P termination confirmation message to the corresponding terminal.

Thereafter, the P2P communication procedure of the present invention is terminated.

6 is a flowchart illustrating a signal-to-noise ratio measurement when scanning for P2P communication according to an exemplary embodiment of the present invention.

Referring to FIG. 6, the master terminal determines the 600 transmission power size, and identifies the P2P communication resource region and the mobile communication resource region using resource allocation information from the base station in step 602.

In step 604, the master terminal measures the interference measurement on the P2P communication resource region and the mobile communication resource region.

In step 606, the master terminal calculates an SINR between terminals in the P2P communication resource region and the mobile communication resource region based on the ratio of the transmission power magnitude of the master terminal and the measured interference size.

Thereafter, the master terminal compares the SINR measured in step 608 with a preset threshold and determines that the terminal is adjacent if the threshold is greater than or equal to the preset threshold.

In step 610, the master terminal transmits a spatial reuse information message including a neighbor terminal list as a result of the scan to the base station.

Since the resources allocated to the mobile communication terminal fluctuate and the mobility of the P2P communication terminals may change due to the influence of interference from the mobile communication terminals of neighboring P2P communication terminals or neighboring cells, the scanning process is performed periodically. If a change occurs in the scan result, the master terminal reports to the base station.

Thereafter, the SINR measurement process of the present invention is terminated.

A resource allocation method for solving the interference problem between the P2P terminal and the cellular terminals outside the cell will be described in detail.

In the case of P2P communication in the cell inner region, the influence of interference from neighboring cells is small, but in order to perform P2P communication in the cell outer region, the influence of the interference from terminals communicating in the neighboring cell may be increased. Such interference can be classified into two types, one of which is interference between adjacent P2P terminals located in different cells, and the other of which is interference between P2P terminals located in different cells and mobile communication terminals.

First, in the case of interference between P2P communication terminals, the above-described scanning process may be performed on adjacent cells to solve the problem. In order to scan P2P communication terminals located in the neighbor cell, P2P resource allocation information of the neighbor cell must be received. As a method for this, first, there is a method in which a master terminal directly synchronizes with a neighbor cell and directly receives broadcasted P2P resource allocation information. In another method, when the P2P resource allocation information of the neighbor cell cannot be normally received, the corresponding base station transmits the P2P resource allocation information of the neighbor base station to the master terminal of the P2P communication instead. As described above, when the master terminal receives the P2P resource allocation information, the SINR of the P2P resource region is measured and the P2P communication terminals adjacent to the corresponding resource region are recorded in the list as in the scanning process. This scan process is performed periodically even after the P2P communication configuration is completed. When the scanning process is completed, the master terminal transmits a scan result and neighbor cell ID information to the corresponding base station and performs a resource allocation request.

When the base station allocates resources, the base station independently manages P2P communications located inside the cell and P2P communications located outside the cell. For P2P communication outside the cell, before the P2P resource allocation, the serving base station assigns the resources allocated to the neighboring P2P terminal by the neighboring base station to the corresponding P2P communication based on the neighbor P2P terminal list of the neighbor cell received from the P2P master terminal. The control message is transmitted to the neighboring base station so as not to overlap with the resource. The neighboring base station receiving the message does not allocate the reported P2P resource region to the P2P terminal determined to be the mobile communication terminal or the neighboring terminal, thereby preventing interference caused by the P2P terminal of the corresponding cell or the cellular terminal of the neighboring cell. On the other hand, in consideration of the mobility of the terminal or the flexibility of resource allocation to the uplink terminal, the base station continues to report the scanning result periodically transmitted by the master terminal of the P2P communication, and the neighboring P2P communication terminal is P2P resources for reasons such as information change or scheduling Whenever the area needs to be changed, a control message for a new P2P resource allocation may be transmitted to a neighboring base station to prevent interference with P2P terminals outside the cell.

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 frame structure for P2P communication in a mobile communication system according to the prior art

2 is a flowchart illustrating resource allocation for P2P communication in a mobile communication system according to an embodiment of the present invention;

3 is an exemplary diagram for resource allocation for P2P communication in a base station according to an embodiment of the present invention;

4 is an operation flowchart of a master terminal for P2P communication according to an embodiment of the present invention;

5 is an operation flowchart of a base station for P2P communication according to an embodiment of the present invention;

6 is a signal to noise ratio measurement flowchart when scanning for P2P communication according to an embodiment of the present invention.

Claims (25)

In a method of allocating resources of a terminal for peer to peer (P2P) communication in a mobile communication system, Receiving a P2P communication terminal and mobile communication resource allocation information from a base station; Scanning the presence / absence of a neighboring P2P communication terminal and a neighboring mobile communication terminal using the resource allocation information; Requesting a P2P communication resource by transmitting the scan result to the base station; And receiving the P2P communication resource allocation information for the resource request. The method of claim 1, And performing P2P communication with a counterpart terminal according to the updated resource request information. The method of claim 2, And transmitting a P2P communication termination message when the P2P communication ends. The method of claim 1, And determining a counterpart terminal for the P2P communication. The method of claim 1, And a signal-to-interference-plus-noise-ratio (SINR) for a P2P communication resource region and a mobile communication resource region during the scanning process. In the resource allocation method of the base station for the direct communication (peer to peer: peer-to-peer) in a mobile communication system, Allocating resources in consideration of spatial resource reuse when requesting P2P resource allocation from a terminal; Resource allocation method comprising the step of transmitting the resource allocation information. The method of claim 6, Resource allocation method further comprising the step of periodically broadcasting the resource allocation information. The method of claim 6, And receiving a P2P termination confirmation message upon receiving the P2P termination message. The method of claim 6, In the process of allocating resources in consideration of spatial resource reuse, the resource areas are allocated not to be overlapped among terminals that are not allowed to be reused spatially, and the resource areas are repeatedly allocated between terminals capable of reusing spatial resources. Resource allocation method. The method of claim 6, And scheduling the mobile communication terminals and the P2P communication terminals at the same time when requesting the P2P resource allocation from the terminal. The method of claim 6, And after exchanging the resource in consideration of the reuse of the spatial resources, exchanging the resource allocation information with an adjacent station. In the resource allocation method for the direct communication (Peer to Peer: P2P) in the mobile communication system, Receiving a P2P communication terminal and mobile communication resource allocation information from a base station; Scanning the presence / absence of a neighboring P2P communication terminal and a neighboring mobile communication terminal using the resource allocation information; Requesting a P2P communication resource by transmitting the scan result to the base station; Updating resource allocation information in consideration of spatial resource reuse according to the scan result; And transmitting the updated resource request information. The method of claim 12, And performing P2P communication with a counterpart terminal according to the updated resource request information. The method of claim 13, And transmitting a P2P communication termination message when the P2P communication ends. The method of claim 12, And determining a counterpart terminal for the P2P communication. The method of claim 12, Resource allocation method further comprising the step of periodically broadcasting the resource allocation information. The method of claim 12, In the process of allocating resources in consideration of spatial resource reuse, the resource areas are allocated not to be overlapped among terminals that are not allowed to be reused spatially, and the resource areas are repeatedly allocated between terminals capable of reusing spatial resources. Resource allocation method. The method of claim 12, And after exchanging the resource in consideration of the reuse of the spatial resources, exchanging the resource allocation information with an adjacent station. In a mobile communication system for allocating resources for peer-to-peer (P2P) communication, Receiving a P2P communication terminal and mobile communication resource allocation information from the base station, using the resource allocation information to scan the presence or absence of the adjacent P2P communication terminal and the adjacent mobile communication terminal, and transmits the scan result to the base station to request resources A master terminal, And a base station for updating the resource allocation information in consideration of spatial resource reuse according to the scan result and transmitting the updated resource request information. The method of claim 19, And a peer-to-peer communication with the counterpart terminal according to the updated resource request information. The method of claim 20, The master terminal transmits a P2P communication termination message when the P2P communication ends. The method of claim 19, The master resource allocation system, characterized in that for determining the counterpart terminal to the P2P communication. The method of claim 19, And the base station periodically broadcasts the resource allocation information. The method of claim 19, The base station is a resource allocation system, characterized in that the resource area is allocated so as not to overlap between the terminals that are not allowed to use spatial resource reuse, and the resource area is overlappingly allocated between the terminals capable of spatial resource reuse. The method of claim 19, And allocating resources in consideration of reuse of the spatial resources, and exchanging the resource allocation information with an adjacent station.

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