KR102103469B1 - Communicating method of terminal and station for direct communication link between terminals - Google Patents

Abstract

Disclosed is a communication method of a terminal and a communication method of a base station for a direct communication link between terminals. The base station schedules the reference terminal to transmit the ranging code, and schedules the target terminal to receive the ranging code. The reference terminal measures the ranging code received from the target terminal, and transmits the ranging code measurement result to the base station. And the base station selects a terminal to form a direct communication link with the reference terminal from the target terminal based on the ranging code measurement result.

Description

COMMUNICATING METHOD OF TERMINAL AND STATION FOR DIRECT COMMUNICATION LINK BETWEEN TERMINALS

The present invention relates to a communication method of a terminal and a communication method of a base station for establishing and utilizing a direct communication link between terminals.

In order to support a proximity-based service in a mobile communication system, a method of forming and communicating a direct communication link between terminals has been proposed. In particular, a direct communication link between terminals is discussed in IEEE 802.16n, IEEE 802.16.1a and 3GPPP Direct Communication.

When both terminals are present in the access area of the base station and within the communication area between each other, a direct communication link between the terminals is formed to exchange data between the terminals. Under the frame structure of the infrastructure communication (that is, cellular communication) between the base station and the terminal, some of the resources for cellular communication are used by terminals utilizing a direct communication link between terminals. As a radio communication resource for a direct communication link between terminals, some resources of an uplink in an infrastructure communication (cellular communication) frame are allocated, and base stations and terminals participating in the infrastructure communication do not use the resources allocated to the direct communication link between terminals. . In this allocated resource, terminals perform a direct communication link between terminals as a direct communication link protocol and procedure.

Existing proposed methods deal with methods of performing communication using a direct link between terminals, but the development of a search method of an adjacent terminal to determine whether a direct communication link between terminals is possible is insufficient.

The problem to be solved by the present invention is to provide a method of searching for an adjacent terminal in order to establish a direct communication link between terminals.

Another problem to be solved by the present invention is to provide a method for continuously monitoring the quality of a corresponding direct communication link when a direct communication link exists between terminals.

Another problem to be solved by the present invention is to provide a method for detecting a terminal forming a direct communication link between terminals when it is out of the range of a base station.

According to an embodiment of the present invention, a communication method of a base station for controlling a direct communication link between terminals is provided. The communication method comprises: selecting a first terminal as a reference terminal to form the direct communication link; selecting a second terminal as a candidate terminal to form the direct communication link with the first terminal; Scheduling the first terminal so that the first terminal transmits the first ranging code, scheduling the second terminal so that the second terminal receives the first ranging code, and the second terminal Receiving the first information measured by using the first ranging code received from the first terminal, from the second terminal, and using the first information, the first terminal of the second terminal And selecting a third terminal to form the direct communication link.

The communication method may include scheduling the first terminal so that the first terminal periodically transmits a second ranging code, and allowing the third terminal to periodically receive the second ranging code. 3 may further include the step of scheduling the terminal.

The communication method may include receiving, from the third terminal, second information measured using the second ranging code periodically received by the third terminal from the first terminal, and receiving the second information. The method may further include determining whether the direct communication link is lost or quality.

In the periodic communication method, when the second ranging code is not received from the first terminal, determining that the first terminal has lost coverage, and the second information is not received from the third terminal. If not, it may further include the step of determining that the third terminal is lost coverage.

The scheduling of the first terminal may include transmitting a ranging command message to the first terminal, wherein the ranging command message includes a field in which transmission information of the first ranging code is set. It can contain.

The scheduling of the second terminal may include transmitting a ranging command message to the second terminal, wherein the ranging command message includes a field in which reception information of the first ranging code is set. It can contain.

Scheduling the first terminal to periodically transmit the second ranging code may include transmitting a ranging command message to the first terminal, wherein the ranging command message is the second lane It may include a field indicating the transmission period of the gong code, and a field indicating the transmission duration of the second ranging code.

The scheduling of the third terminal may include transmitting a ranging command message to the third terminal, wherein the ranging command message is a field indicating a reception period of the second ranging code, and the A field indicating the reception duration of the second ranging code may be included.

Receiving the first information from the second terminal may include receiving a ranging response message from the second terminal, and the ranging response message may include a field indicating the first information. You can.

According to another embodiment of the present invention, a communication method of a terminal serving as a reference for forming a direct communication link between terminals is provided. The communication method comprises: scheduling by a base station to transmit a first ranging code, transmitting the first ranging code to a target terminal that is a candidate to form the direct communication link with the terminal, and the target The method may include forming a direct communication link with a selection terminal selected based on a measurement result of the first ranging code measured by the target terminal among terminals.

The communication method may further include the step of being scheduled by the base station to periodically transmit a second ranging code, and periodically transmitting the second ranging code to the selected terminal.

When the base station fails to receive the second ranging code, it may be determined that the terminal has lost coverage.

The step of being scheduled by the base station may include receiving a ranging command message from the base station, and the ranging command message may include a field in which transmission information of the first ranging code is set. have.

The step of being scheduled by the base station to transmit the second ranging code may include receiving a ranging command message from the base station, wherein the ranging command message is a transmission cycle of the second ranging code And a field indicating a transmission duration of the second ranging code.

According to another embodiment of the present invention, a communication method of a base station for controlling a direct communication link between terminals is provided. The communication method may include selecting a first terminal as a reference for forming the direct communication, selecting a second terminal as a candidate for forming the direct communication link with the first terminal, and the second terminal. Transmitting a first ranging command message to the second terminal to transmit a first ranging code, and a second ranging command to the first terminal so that the first terminal receives the first ranging code Transmitting a message, receiving the first information measured by the first terminal using the first ranging code received from the second terminal, receiving the first information from the first terminal, and using the first information Accordingly, a step of selecting a third terminal to form the direct communication link with the first terminal among the second terminals may be included.

The communication method may include transmitting a third ranging command message to the first terminal so that the first terminal periodically receives the second ranging code, and the third terminal transmits the second ranging code. To periodically transmit, the method may further include transmitting a fourth ranging command message to the third terminal.

The communication method may include receiving, from the first terminal, second information measured by using the second ranging code periodically received by the first terminal from the third terminal, and receiving the second information. The method may further include determining whether the direct communication link is lost or quality.

The first ranging command message may include a field in which transmission information of the first ranging code is set, and the second ranging command message is a field in which reception information of the first ranging code is set. The third ranging command message may include a field indicating a reception period of the second ranging code, and a field indicating a reception duration of the second ranging code, and the fourth The ranging command message may include a field indicating a transmission period of the second ranging code and a field indicating a transmission duration of the second ranging code.

In the communication method, when the second information is not received from the first terminal, determining that the first terminal has lost coverage, and when the second ranging code is not received from the third terminal And, it may further include the step of determining that the third terminal has lost coverage.

According to an embodiment of the present invention, a base station may search for terminals capable of forming a direct communication link between terminals, and through this, proximity-based services may be provided through a direct communication link.

According to an embodiment of the present invention, the base station can periodically acquire the quality information of the direct communication link between the terminals, and can quickly recognize when the terminal forming the direct communication link leaves the area of the base station. In addition, since the base station can quickly recognize the loss of the direct communication link and the loss of coverage, the procedure of restoring the direct communication link or restoring the service can be quickly performed.

1 is a view showing a mobile communication system for a direct communication link between terminals according to an embodiment of the present invention.
2 is a diagram illustrating a procedure for searching a terminal for forming a direct communication link between terminals according to an embodiment of the present invention.
3 is a diagram illustrating a procedure for searching a terminal for forming a direct communication link between terminals according to another embodiment of the present invention.
4 is a diagram illustrating a case in which a direct communication link is used to provide an adjacency-based service.
FIG. 5 is a diagram illustrating a case in which a direct communication link is used to recover the loss of the reference terminal 200A.
6 is a diagram illustrating a procedure for monitoring the quality of a direct communication link between terminals according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains may easily practice. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. In addition, in order to clearly describe the present invention in the drawings, parts irrelevant to the description are omitted, and like reference numerals are assigned to similar parts throughout the specification.

Throughout the specification, a terminal is a mobile terminal (MT), a mobile station (MS), an advanced mobile station (AMS), or a high reliability mobile station (HR-MS). , Subscriber station (SS), portable subscriber station (PSS), access terminal (access terminal, AT), may also refer to user equipment (user equipment, UE), etc., MT, AMS, HR -It may include all or part of functions such as MS, SS, PSS, AT, and UE.

In addition, the base station (base station, BS) is an advanced base station (advanced base station, ABS), high reliability base station (HR-BS), node B (node B), advanced node B (evolved node B), eNodeB), access point (AP), radio access station (RAS), base transceiver station (BTS), mobile multihop relay (MMR) -BS, repeater serving as a base station (relay) station, RS), a high reliability relay station serving as a base station (high reliability relay station, HR-RS), etc., ABS, Node B, eNodeB, AP, RAS, BTS, MMR-BS, RS, HR -It may include all or part of functions such as RS.

Now, a communication method of a terminal and a communication method of a base station for a direct communication link between terminals according to an embodiment of the present invention will be described in detail with reference to the drawings.

A communication method of a terminal and a communication method of a base station for establishing a direct communication link between terminals according to an embodiment of the present invention largely include a procedure for searching a terminal for forming a direct communication link between terminals, a terminal for forming a direct communication link between terminals It is divided into a procedure for selecting, a procedure for monitoring the quality of a direct communication link between terminals, and a procedure for detecting loss of coverage of a terminal forming a direct communication link. Each of these procedures is described below.

First, referring to FIGS. 1 and 2, a procedure for searching a terminal for forming a direct communication link between terminals according to an embodiment of the present invention will be described.

1 is a view showing a mobile communication system for a direct communication link between terminals according to an embodiment of the present invention.

As shown in FIG. 1, a mobile communication system according to an embodiment of the present invention includes a base station 100 and terminals 200A and 200B in a coverage area of the base station 100. In FIG. 1, 200A is a reference terminal (hereinafter referred to as a reference terminal) for a direct communication link between terminals, and 200B is a candidate terminal (hereinafter referred to as a target) to form a direct communication link with the reference terminal 200A. (Target) terminal). Here, it is assumed that the reference terminal 200A is determined in advance by communication between the reference terminal 200A and the base station 100.

In order to search for the reference terminal 200A and the target terminal 200B, the base station 100 may schedule the reference terminal 200A to transmit a ranging code in a specific resource, and the target terminal 200B lanes in the corresponding resource It can be scheduled to receive a gong code. At this time, the target terminal 200B receiving the ranging code may be all terminals in the cell, and the base station 100 may randomly select terminals adjacent to the reference terminal 200A as the target terminal 200B. . When the base station 100 schedules transmission and reception of a ranging code in this way, since the same resource can be designated to all target terminals 200B, broadcast can be used. Through this, a search procedure can be performed with a small number of message transmissions.

2 is a diagram illustrating a procedure for searching a terminal for forming a direct communication link between terminals according to an embodiment of the present invention.

When the base station 100 schedules the transmission of the ranging code of the reference terminal 200A and the reception of the ranging code of the target terminal 200B, a ranging command message (AAI-HR-RNG-CMD, Advanced Air Interface-High Reliability -Ranging-Command) is used, and it can be replaced with other messages depending on the purpose.

First, the base station 100 transmits a ranging command message (AAI-HR-RNG-CMD) to the reference terminal 200A (S210), through which the reference terminal 200A is scheduled to transmit a ranging code. The ranging command message (AAI-HR-RNG-CMD) includes an Action field, a Frame field, an Index field, a Subframe Index field, and a Dedicated Ranging Code Index field. Here, the Action field is used to indicate that the transmission or reception of the ranging code is for scheduling. Accordingly, the Action field of the ranging command message (AAI-HR-RNG-CMD) transmitted to the reference terminal 200A is set to ranging code transmission, through which the reference terminal 200A is ranging It is scheduled to send the code. The Frame field and the Subframe field are used to indicate the location of the resource for transmission of the ranging code, and the Dedicated Ranging Code Index is used to specify the ranging code to be transmitted by the reference terminal 200A.

The base station 100 transmits a ranging command message (AAI-HR-RNG-CMD) to the target terminal 200B (S220), through which the target terminal 200B is scheduled to receive the ranging code. That is, the reception of the ranging code of the target terminal 200B is also scheduled by the ranging command message (AAI-HR-RNG-CMD). The ranging request message (AAI-HR-RNG-CMD) transmitted to the target terminal 200B may include an Action field, a Frame Index field, and a Subframe Index field. The Action field of the ranging command message (AAI-HR-RNG-CMD) is set to ranging code reception, through which the target terminal 200B is scheduled to receive the ranging code.

In addition, the ranging command message (AAI-HR-RNG-CMD) received by the target terminal 200B may include a Dedicated Ranging Code Index field in some cases. When the Dedicated Ranging Code Index field is included in the ranging command message (AAI-HR-RNG-CMD), the target terminal 200B receives the measurement result of the ranging code to the base station 100 only when the designated code is received. Inform. If the Dedicated Ranging Code Index field is not included in the ranging command message (AAI-HR-RNG-CMD), the target terminal 200B notifies the base station 100 of the measurement results of all ranging codes received.

As described above, when the reference terminal 200A is scheduled to transmit the ranging code and the target terminal 200B is scheduled to receive the ranging code by the ranging command message (AAI-HR-RNG-CMD), the reference terminal (200A) transmits a ranging code (Ranging code) to the target terminal (200B) (S230).

When the target terminal 200B receives the ranging code transmitted by the reference terminal 200A, the reception result (that is, the ranging code measurement result) is displayed as a ranging response message (AAI-HR-RNG-REP, Advanced Air Interface) -High Reliability-Ranging-Reply) to inform the base station 100 (S240). The ranging response message (AAI-HR-RNG-REP) used to inform the result of receiving the ranging code includes the Frame Index field, Subframe Index field, Dedicated Ranging Code Index field, SINR field, Time Offset field, and frequency And an offset (Frequency Offset) field. Here, the Frame Index field and the Subframe Index field indicate the location of the resource that has received the ranging code, and the Dedicated Ranging Code Index field is used to identify the received ranging code. In addition, the SINR field, the time offset field and the frequency offset field are used to indicate the measurement result of the received ranging code.

2, the base station 100 schedules the transmission or reception of the ranging code, and the target terminal 200B informs the base station 100 of the ranging code measurement result. Through this, the base station 100 can know the information of the target terminal 200B capable of forming a link with the reference terminal 200A.

3 is a diagram illustrating a procedure for searching a terminal for forming a direct communication link between terminals according to another embodiment of the present invention.

Unlike the embodiment of FIG. 2, the base station 100 schedules the reference terminal 200A to receive a ranging code through at least one resource and uses a different resource or a different code index to the target terminal 200B. It can be scheduled to transmit a ranging code.

As shown in FIG. 3, the base station 100 transmits a ranging command message (AAI-HR-RNG-CMD) to the reference terminal 200A and an Action field of the ranging command message (AAI-HR-RNG-CMD) Is set to Ranging code reception (S310).

And the base station 100 transmits a ranging command message (AAI-HR-RNG-CMD) to the target terminal 200B, and an Action field of the ranging command message (AAI-HR-RNG-CMD) transmits a transmission code (Ranging code transmission) (S320). At this time, when there are multiple target terminals 200B, different resources or different code indexes are allocated to each target terminal 200B. Accordingly, the base station 100 may transmit a ranging command command message (AAI-HR-RNG-CMD) to each target terminal 200B.

By these steps S310 and S320, the reference terminal 200A is scheduled to receive the ranging code, and the target terminal 200B is scheduled to transmit the ranging code.

Next, each target terminal 200B transmits a ranging code to the reference terminal 200A using different resources or different code indexes (S330).

The reference terminal 200A measures the ranging code received from the target terminal 200B and transmits the measurement result to the base station 100 through a ranging response message (AAI-HR-RNG-REP) (S340). According to this embodiment of the present invention, even if the reference terminal 200A receives the ranging code from each target terminal 200B, the base station via the ranging response message (AAI-HR-RNG-REP) It is possible to transmit at (100).

2 or 3, after the base station 100 receives the ranging measurement result, the base station 100 performs a procedure of selecting a terminal to form a direct communication link between terminals. The base station 100 selects a target terminal to form a direct communication link with the reference terminal 200A among the target terminals 200B, and the selected target terminal is hereinafter referred to as a 'selected terminal 200B'.

4 is a diagram illustrating a case in which a direct communication link is used to provide an adjacency-based service.

The base station 100 may classify a service that can be provided through a direct communication link with the reference terminal 200A using the received ranging measurement result. In addition, the base station 100 may select the selected terminal 200B 'from the target terminal 200B so that the reference terminal 200A can provide a specific service, such as a social network service with an adjacent terminal, using a direct communication link. have.

There are various methods for the base station 100 to select a service to be provided using a direct communication link among the services of the reference terminal 200A. First, a method using a direct communication link between terminals for all services may be applied. Second, a method using a direct communication link may be applied when radio resources can be saved.

Meanwhile, a direct communication link may be used to recover the reference terminal 200A when the reference terminal 200A is lost from the base station 100 as shown in FIG. 5, as well as when providing an adjacent base service through a direct communication link. have.

FIG. 5 is a diagram illustrating a case in which a direct communication link is used to recover the loss of the reference terminal 200A.

The base station 100 can select a selection terminal 200B 'to replace the reference terminal 200A from among the target terminals 200B adjacent to the reference terminal 200A, and the selection terminal 200B' is the reference terminal 200A It can perform the function of relaying data.

Various criteria may also be applied to the method in which the base station 100 selects the selection terminal 200B 'to configure the alternative path of the reference terminal 200A. For example, a method of selecting a terminal having the best link quality with the reference terminal 200A as the selection terminal 200B 'may be applied. A method of selecting a terminal having the best link quality with the base station 100 as the selection terminal 200B 'may be applied. In addition, a method of selecting a terminal having both good link quality with the reference terminal 200A and the base station 100 as a selection terminal 200B 'may be applied.

After the base station 100A selects the selection terminal 200B 'to form a direct communication link with the reference terminal 200A, a procedure for monitoring the quality of the direct communication link is performed. That is, the base station 100A can periodically monitor the link quality between the reference terminal 200A and the selection terminal 200B '. Hereinafter, this will be described in detail.

6 is a diagram illustrating a procedure for monitoring the quality of a direct communication link between terminals according to an embodiment of the present invention.

In order to monitor the direct communication link between the reference terminal 200A and the selection terminal 200B ', the base station 100A periodically transmits a ranging code to the reference terminal 200A and periodically to the selection terminal 200B'. Schedule reception of the ranging code.

The transmission of the periodic ranging code of the reference terminal 200A and the reception of the periodic ranging code of the selected terminal 200B 'are also scheduled through the ranging command message (AAI-HR-RNG-CMD) described in FIG. 2 above. do.

As shown in FIG. 6, the base station 100 transmits a ranging command message (AAI-HR-RNG-CMD) to the reference terminal 200A (S610), and the ranging command message (to the selected terminal 200B ') AAI-HR-RNG-CMD) is transmitted (S620). In the ranging command message (AAI-HR-RNG-CMD) transmitted to the reference terminal 200A, an Action field is set to ranging code transmission, and a ranging command transmitted to the selected terminal 200B ' In the message (AAI-HR-RNG-CMD), the Action field is set to ranging code reception. In addition, a period field and a duration field are additionally set in the ranging command message (AAI-HR-RNG-CMD).

The period of transmission or reception of the ranging code may be set through the Period field of the ranging command message (AAI-HR-RNG-CMD). The base station sets the value of the period field of the ranging command message (AAI-HR-RNG-CMD) to a non-zero value (that is, a fixed period). The reference terminal 200A receiving the ranging command message (AAI-HR-RNG-CMD) having such a fixed period periodically transmits the ranging code from the transmission time of the first ranging code (S630). In addition, the selection terminal 200B 'that has received the ranging command message (AAI-HR-RNG-CMD) having a fixed periodicity periodically receives the ranging code from the time at which the first ranging code is received.

On the other hand, the duration of transmission or reception of the ranging code may be set through the duration field of the ranging command message (AAI-HR-RNG-CMD). If the duration field is not 0, the reference terminal 200A stops the ranging code transmission operation after performing the ranging code transmission operation for a time corresponding to the set period multiplied by the duration field value. do. In addition, the selection terminal 200B 'also performs a ranging code reception operation for a time corresponding to the product of a set period multiplied by a duration field value, and then stops the ranging code reception operation. On the other hand, even when the reference terminal 200A receives an instruction to stop the transmission of the periodic ranging code from the base station 100, the ranging code transmission operation is stopped, and the selected terminal 200B 'also performs a periodic lane from the base station 100. The ranging code transmission operation is also stopped even when a command to stop the transmission of the gong code is received.

The selection terminal 200B 'measures the ranging code received from the reference terminal 200A, and informs the base station 100 of the measurement result through the ranging response message (AAI-HR-RNG-REP) (640). The base station 100 may determine whether or not the direct communication link is lost and the quality through the ranging code measurement result received from the selection terminal 200B '. When the base station 100 recognizes the loss of the direct communication link, the base station 100 starts an operation of notifying the loss of the link to the reference terminal 200A and the selection node 200B ', or recovers the loss of the direct communication link. You can start the process.

On the other hand, in contrast to the case of Figure 6, the base station 100 can schedule the monitoring of the direct communication link. That is, similar to the case of FIG. 3, the base station 100 may schedule the periodic reception of the ranging code to the reference terminal 200A and the periodic transmission of the ranging code to the selected terminal 200B '. . In this case, the selection terminal 200B 'transmits the ranging code to the reference terminal 200A, and the reference terminal 200A transmits the measurement result of the ranging code through the ranging response message (AAI-HR-RNG-REP). Inform the base station 100.

When the base station 100 forms a direct communication link or one of two terminals (that is, a reference terminal and a selection terminal) that will form a direct communication link, a case in which the terminal is outside the transmission range of the base station 100 is called loss of coverage. Hereinafter, a method for detecting such loss of coverage will be described.

 When the reference terminal 200A periodically transmits the ranging code as shown in FIG. 6, the base station 100 can also receive the ranging code transmitted by the reference terminal 200A. If the base station does not receive this ranging code, it may be determined that the reference terminal 200A has lost coverage.

Also, as shown in FIG. 6, the selection terminal 200B 'periodically transmits the measurement result of the ranging code to the base station 100. Accordingly, if the ranging response message (AAI-HR-RNG-REP) is not received, the base station 100 may determine that the selection terminal 200B 'has lost coverage.

Meanwhile, as described above, the base station 100 may schedule the periodic reception of the ranging code to the reference terminal 200A and the periodic transmission of the ranging code to the selected terminal 200B '. In this case, the base station 100 may determine that the selection terminal 200B 'has lost coverage when the ranging code transmitted by the selection terminal 200B' is not received. In addition, when the ranging response message (AAI-HR-RNG-REP) transmitted by the reference terminal 200A is not received, the base station 100 may determine that the reference terminal 200A has lost coverage.

Table 1 below is a diagram showing each field description (AAI-HR-RNG-CMD message field description) of the ranging command message described above.

Field Size  ( bits ) Value / Description Condition Frame Identifier 4 Frame which contains the ranging channel. The frame identifier is the 4 least significant bits of the frame num-ber. Subframe Index 3 Indicates the subframe index of the allocated ranging opportunity. Action 2 Indicates the purpose of this message
0b00: Ranging code transmission
0b01: Ranging code reception
0b10: Terminate periodic ranging code transmission or reception
0b11: Reserved if (Action == 0b00) { Period 4 Indicates the period of periodic ranging:
Bits 0-3: If bit 0-3 represent the binary representation of the integer N, then the Period = 2 ^ (N + 1) [Superframes] Shall be present when this message is unicast Duration 8 Indicates the duration of periodic ranging
0: Stop the periodic ranging code transmission when it receive the suspension command
1-255: Stop the periodic ranging code transmission after this value of periods Shall be present when this message is unicast Dedicated ranging code index 5 Indicates the index of dedicated rang-ing code. Transmit power level 5 Unsigned integer from 0 to 31 in units of 1 dBm, where 0b00000 = 0dBm and 0b11111 = 31dBm Reversed action offset 4 Indicates the reversed action
0: No reversed action
1-15: Number of frames between the transmit and reception frames If (Reversed action offset! = 0) { Reporting mode One Indicates if the report mode is exclu-sive or triggered by threshold.
0b0: exclusive reporting
0b1: triggered-based reporting if (Reporting mode == 0b1) { SINR threshold 4 Indicates the SINR threshold for the ranging signal above which report should be made by receiving station. The 4 bit value from 0b0000 to 0b1111 represent values among {-9, -8.5, -8, -7.5, -7, -6.5, -6, -5.5, -5, -4.5, -4, -3.5, -3 , -2.5, -2, -1.5} dB } // end of Reporting mode } // end of Reversed action offset } // end of Action } elseif (Action = 0b01) { Period 4 Indicates the period of periodic ranging:
Bits 0-3: If bit 0-3 represent the binary representation of the integer N, then the Period = 2 ^ (N + 1) [Superframes] Shall be present when this message is unicast Duration 8 Indicates the duration of periodic ranging
0: Stop the periodic ranging code transmission when it receive the suspension command
1-255: Stop the periodic ranging code transmission after this value of periods Shall be present when this message is unicast Reversed action offset 4 Indicates the reversed action
0: No reversed action
1-15: Number of frames between the transmit and reception frames Reporting mode One Indicates if the report mode is exclu-sive or triggered by threshold.
0b0: exclusive reporting
0b1: triggered-based reporting if (Reporting mode == 0b1) { SINR threshold 4 Indicates the SINR threshold for the ranging signal above which report should be made by receiving station. The 4 bit value from 0b0000 to 0b1111 represent values among {-9, -8.5, -8, -7.5, -7, -6.5, -6, -5.5, -5, -4.5, -4, -3.5, -3 , -2.5, -2, -1.5} dB } // end of Reporting mode If (Reversed action offset! = 0) { Dedicated ranging code index 5 Indicates the index of dedicated rang-ing code. Transmit power level 5 Unsigned integer from 0 to 31 in units of 1 dBm, where 0b00000 = 0dBm and 0b11111 = 31dBm } else { Dedicated ranging code index 5 Indicates the index of dedicated rang-ing code. Optional } // end of Reversed action offset }

Table 2 below is a diagram showing each field description (AAI-HR-RNG-REP message field description) of the ranging response message described above.

Field Size  ( bits ) Value / Description Condition For ( i = 0; i <Number of ranging codes to be reported; i ++) { Frame Identifier 4 Frame which contains the ranging channel. The frame identifier is the 4 least significant bits of the frame number. Subframe Index 3 Indicates the subframe index of the allocated ranging opportunity. Received ranging code index 5 Indicates the index of dedicated ranging code received in this ranging opportunity Received SINR 4 Indicates the received SINR of the ranging code. The 4 bit value from 0b0000 to 0b1111 represent values among {-9, -8.5, -8, -7.5, -7, -6.5, -6, -5.5, -5, -4.5, -4, -3.5, -3 , -2.5, -2, -1.5} dB Timing offset 15 Time offset, in units of F _s , of the received ranging signal, with respect to the frame timing of the HR-MS.

MSB 1 bit represents the sign of the value. That is, the value is negative (-) if the MSB = 0b1, and the value is positive (+) if the MSB = 0b0. LSB 14 bits represent timing offset correction value of [1 ·· 16384] that corresponds to 0x0000 ~ 0x3FFF, respectively.
Optional Frequency offset 9 Frequency offset, in units of
2% of the subcarrier spacing (f), of the received ranging signal, with respect to the frequency of the HR-MS.

MSB 1 bit represents the sign of the value. That is, the value is negative (-) if the MSB = 0b1, and the value is positive (+) if the MSB = 0b0. LSB 8 bits represent frequency offset correction value of [1..256] that corresponds to 0x00 ~ 0xFF, respectively Optional }

Although the embodiments of the present invention have been described in detail above, the scope of rights of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims (19)

A communication method of a base station that controls a direct communication link between terminals,
Scheduling the first terminal to transmit the first ranging code by the first terminal by sending a first ranging command message to the first terminal,
Scheduling the second terminal so that the second terminal receives the first ranging code by sending a second ranging command message to the second terminal, and
And receiving, by the second terminal, first information measured using the first ranging code received by the second terminal from the first terminal,
The first and second ranging command messages include an action field indicating whether each ranging command message is for transmission or reception of a ranging code, and a dedicated ranging code field for the first ranging code. , The action field of the first ranging command message indicates transmission of the first ranging code, and the action field of the second ranging command message indicates reception of the first ranging code
Method of communication. According to claim 1,
Scheduling the first terminal so that the first terminal periodically transmits a second ranging code, and
And scheduling the third terminal so that the third terminal periodically receives the second ranging code,
The third terminal is a communication method selected from the second terminal, the terminal selected to form the direct communication link with the first terminal. According to claim 2,
Receiving, by the third terminal, second information measured using the second ranging code periodically received by the third terminal from the first terminal, and
And determining whether the direct communication link is lost or quality using the second information. According to claim 3,
And when the second ranging code is not received from the first terminal, determining that the first terminal has lost coverage. delete delete According to claim 2,
Scheduling the first terminal to periodically transmit the second ranging code includes transmitting a third ranging command message to the first terminal,
The third ranging command message includes a field indicating a transmission period of the second ranging code and a field indicating a transmission duration of the second ranging code. According to claim 2,
The scheduling of the third terminal includes transmitting a third ranging command message to the third terminal,
The third ranging command message includes a field indicating a reception period of the second ranging code, and a field indicating a reception duration of the second ranging code. According to claim 1,
The receiving of the first information from the second terminal includes receiving a ranging response message from the second terminal,
The ranging response message includes a field indicating the first information. As a communication method of the terminal as a reference for forming a direct communication link between the terminals,
Receiving a first ranging command message from a base station to transmit a first ranging code,
Transmitting the first ranging code to a target terminal that is a candidate to form the direct communication link with the terminal, and
And forming a direct communication link with a selection terminal selected based on a measurement result of the first ranging code measured by the target terminal among the target terminals,
The target terminal receives a second command message from the base station to receive the first ranging code,
The first and second ranging command messages include an action field indicating whether each ranging command message is for transmission or reception of a ranging code, and a dedicated ranging code field for the first ranging code. , The action field of the first ranging command message indicates transmission of the first ranging code, and the action field of the second ranging command message indicates reception of the first ranging code
Method of communication. The method of claim 10,
Scheduled by the base station to periodically transmit a second ranging code, and
And transmitting the second ranging code periodically to the selection terminal. The method of claim 11,
If the base station fails to receive the second ranging code, the communication method is determined as the terminal is lost coverage. delete The method of claim 11,
The step of being scheduled by the base station to transmit the second ranging code includes receiving a third ranging command message from the base station,
The third ranging command message includes a field indicating a transmission period of the second ranging code and a field indicating a transmission duration of the second ranging code. A communication method of a base station that controls a direct communication link between terminals,
Selecting a first terminal as a reference for forming the direct communication,
Selecting a second terminal that is a candidate for forming the direct communication link with the first terminal,
Transmitting a first ranging command message to the second terminal so that the second terminal transmits a first ranging code,
Transmitting a second ranging command message to the first terminal so that the first terminal receives the first ranging code,
Receiving, by the first terminal, first information measured by using the first ranging code received from the second terminal by the first terminal, and
And selecting a third terminal to form the direct communication link with the first terminal among the second terminals using the first information.
The first and second ranging command messages include an action field indicating whether each ranging command message is for transmission or reception of a ranging code, and a dedicated ranging code field for the first ranging code. , The action field of the first ranging command message indicates transmission of the first ranging code, and the action field of the second ranging command message indicates reception of the first ranging code
Method of communication. The method of claim 15,
Transmitting a third ranging command message to the first terminal so that the first terminal periodically receives the second ranging code, and
And transmitting a fourth ranging command message to the third terminal so that the third terminal periodically transmits the second ranging code. The method of claim 16,
Receiving, by the first terminal, second information measured using the second ranging code periodically received by the first terminal from the third terminal, and
And determining whether the direct communication link is lost or quality using the second information. The method of claim 16,
The third ranging command message includes a field indicating a reception period of the second ranging code, and a field indicating a reception duration of the second ranging code,
The fourth ranging command message includes a field indicating a transmission period of the second ranging code and a field indicating a transmission duration of the second ranging code. The method of claim 17,
If the second information is not received from the first terminal, determining that the first terminal has lost coverage, and
And if the second ranging code is not received from the third terminal, determining that the third terminal has lost coverage.

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