KR20090089985A - Apparatus and method for processing call for mobiles out of cell coverage based on point-to-point communication - Google Patents

Abstract

An apparatus and a method for processing a call about a terminal outside of a cell coverage by requesting a call based on peer-to-peer communications are provided to supply a call service to the terminal outside the call coverage by replaying a neighboring terminal to the base station. A broadcast message is not received from a base station for a certain time and recognizes the terminal of the cell coverage outside the terminal(503). When the house request event is generated, help signal is transmitted from the terminal to neighboring terminals in order to request the relay about the call(513). When the response message about help signal is received, the terminal sets up the neighboring terminal transmitting the response message direct(517).

Description

Apparatus and method for processing calls to terminals out of cell coverage based on point-to-point communication {APPARATUS AND METHOD FOR PROCESSING CALL FOR MOBILES OUT OF CELL COVERAGE BASED ON POINT-TO-POINT COMMUNICATION}

The present invention relates to call processing, and more particularly, to an apparatus and method for processing a call to a terminal out of cell coverage based on P2P communication.

Referring to a call scenario in an existing cellular system, a terminal in cell coverage may set up a call by transmitting a call request message to a base station, except when a shadow area is generated in a cell due to a terminal out of cell coverage or a natural disaster. Call setup is not supported for terminals in the created shadow area.

Ad hoc technology is basically a technology that enables direct communication between terminals without the help of a base station. Therefore, when the ad hoc technology is introduced, terminals outside the cell coverage may perform direct communication between terminals without the help of a base station. In this case, the call must reach the backbone network through the base station. Therefore, in order to support a call service for the terminal outside the cell coverage, an ad hoc connection with the terminal within the cell coverage is required.

However, while the terminal in the conventional ad hoc system is always ready for the ad hoc connection request of the other terminal, the terminal in cell coverage in the existing cellular system is communicating with the base station or broadcasting (broadcasting) of the base station Since the information is received, it is difficult to receive the ad hoc connection request message of the neighboring terminal. Due to this limitation, there is a problem that it is difficult to support a call service for a terminal out of cell coverage only by introducing an existing ad hoc technology.

Accordingly, an object of the present invention is to provide an apparatus and method for processing a call to a terminal out of cell coverage based on P2P communication.

Another object of the present invention is to provide a call service to the terminal outside the cell coverage, when the terminal outside the cell coverage requests the call, the neighboring terminal that can communicate with the base station detects the relay and relays to the base station; And providing a method.

Another object of the present invention is to provide a broadcast message error based help signal transmission method and a downlink channel quality indicator (CQI) distortion based help signal transmission method.

Another object of the present invention is to provide a help signal transmission scheme for minimizing power consumption of a call request terminal and minimizing degradation of cellular system performance by a help signal.

Another object of the present invention is to provide a method for transmitting a help signal by gradually setting a helpable signal reception region through a transmission power control.

According to an embodiment of the present invention to achieve the above object, a call processing method of the terminal, when a call request event occurs, to transmit a helping (helping) signal to the surrounding terminals to request the relay for the call And establishing a direct transmission connection with a neighboring terminal that has transmitted the response message when a response message to the helping signal is received.

According to an embodiment of the present invention to achieve the above object, a call processing device of the terminal, when a call request event occurs, to transmit a helping signal to the surrounding terminals to request the relay for the call And means for establishing a direct transmission connection with a neighboring terminal which transmitted the response message when a response message to the helping signal is received.

According to an embodiment of the present invention to achieve the above object, a call processing method of the terminal, the terminal, when the call request event occurs, help (helping) to the neighboring terminals to request the relay for the call Transmitting a signal, transmitting a response message to the terminal by a neighboring terminal that recognizes the help signal, and establishing a direct transmission connection between the terminal and the neighboring terminal transmitting the response message. It is characterized by.

According to an embodiment of the present invention to achieve the above object, a call processing device of the terminal, when a call request event occurs, to transmit a helping signal to the surrounding terminals to request the relay for the call When a response message for the help signal is received, the terminal establishes a direct transmission connection with the neighboring terminal that transmitted the response message, and when the help signal is detected, the terminal transmits the help signal. And a peripheral terminal for transmitting a message and establishing a direct transmission connection with the terminal.

According to the present invention, when a terminal out of cell coverage requests a call based on P2P communication, a neighboring terminal capable of communicating with the base station detects this and relays it to the base station. There is an advantage in that the service can be provided. That is, the present invention has the effect of extending the coverage of the call service, which has a great meaning in that the success of the action for the accident, such as a lifesaving, is determined depending on the availability of the call service when an accident occurs. That is, by enabling the call service in the event of an accident according to the present invention can contribute to reducing the scale of damage of life or property. In addition, the present invention allows the terminal out of cell coverage to perform the call setup with the optimized power, thereby bringing the effect of extending the life of the call requesting terminal. In addition, the present invention has the advantage of minimizing the degradation of the system performance because it minimizes the interference to the neighboring terminal compared to the conventional scheme.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted.

Hereinafter, the present invention is an apparatus and method for processing a call for a terminal outside the cell coverage based on P2P communication, in particular, when the terminal outside the cell coverage requests a call, the neighboring terminal that can communicate with the base station detects it and the base station By relaying, a method in which a terminal outside the cell coverage may be provided with a call service will be described.

1 is a diagram illustrating a network for call processing of a terminal out of cell coverage based on P2P communication according to the present invention.

As shown, the network for the call processing, the terminal (100-1, 100-4), and the terminal (100-1, 100-4) to receive a call service at a location where direct communication with the base station 110 is not possible The terminal 100-2, 100-3 in the cell coverage 101 capable of direct communication with the base station 110 while being within a distance capable of direct communication with the base station 110, and a base station 110 providing the call service do. In the present invention, the terminals 100-1 and 100-4 that exist at locations where direct communication with the base station 110 is not possible will be collectively referred to as 'terminals out of cell coverage'. That is, the terminal outside the cell coverage is a failure of the repeater in the shaded area 102 even if the terminal 100-1 without the base station 110 exists within a predetermined level or less, or the base station 110 close in distance exists. This means that the terminal 100-4 in a state in which communication with the base station 110 is impossible.

2 is a signal flow diagram illustrating a method for processing a call to a terminal out of cell coverage based on P2P communication according to an embodiment of the present invention.

Referring to FIG. 2, the base station 210 periodically transmits a broadcast message to terminals within cell coverage. In this case, a terminal in cell coverage capable of directly communicating with the base station 210 may receive a broadcast message transmitted by the base station 210, but a terminal outside cell coverage may receive a broadcast message transmitted by the base station 210. Cannot be received. Accordingly, the terminal that has not received the broadcast message transmitted by the base station 210 for a predetermined time may recognize that the terminal is out of cell coverage in which direct communication with the base station 210 is impossible. In FIG. 2, the first terminal 200-1 and the fourth terminal 200-4 are terminals outside the cell coverage, and the second terminal 200-2 and the third terminal 200-3 are the cell coverage. Assume that it is an internal terminal. In this case, a call processing process when the first terminal 200-1, which is a terminal outside the cell coverage, requests a call is as follows.

First, in step 201, the first terminal 200-1 outside the cell coverage detects the occurrence of a call request event according to a user's call request, and in step 203, a low power signal for a help signal for a call relay to a neighboring terminal. To send. Here, the help signal is transmitted in a help signal transmission interval, and in the present invention, as the help signal transmission method, a broadcast message error based help signal transmission method and a downlink channel quality indicator (hereinafter referred to as 'CQI') We propose a method of transmitting a distortion-based help signal, which will be described in detail later with reference to FIGS. 3 and 4.

In this case, the second terminal 200-2 and the third terminal 200-3 within the cell coverage recognize the help signal in steps 205 and 207, respectively, and the first terminal (211 and 213). 200-1) to send a response message. Here, the response message is transmitted in a section in which the help signal is not transmitted, so that the first terminal 200-1 can receive it. In addition, the response message is information for direct communication between the first terminal 200-1 and the second terminal 200-2 (eg, a preamble number, timing, and frame synchronization information to be used for communication). And relay terminal information (eg, ID information of the relay terminal). In contrast, the fourth terminal 200-4 outside the cell coverage does not recognize the help signal in step 209.

After receiving the response message, the first terminal 200-1 stops the transmission of the help signal, and in step 215, one of the terminals 200-2 and 200-3 that transmitted the response message ( 200-2) is selected as the relay terminal, and then an ACK message is transmitted, and then the terminal enters the direct transmission mode. At this time, the second terminal 200-2 receiving the ACK message also recognizes that it is selected as a relay terminal through the ACK message, and enters a direct transmission mode between the terminals. In this case, the first terminal 200-1 and the second terminal 200-2 perform a connection setting method in a direct transmission mode between terminals to establish a direct transmission connection between terminals, thereby directly transmitting data packets between terminals. Allows you to send and receive In step 217, the second terminal 200-2 sets up a call for relaying with the relay station 210 to relay a call data packet to the base station 210, and in step 219, the second terminal 200-2. 200-1), a message indicating a successful call setup is transmitted.

When all connections are established in this manner, the first terminal 200-1 transmits a call data packet to the second terminal 200-2 in step 221, and the second terminal 200-2 transmits the call. The data packet is relayed to the base station 210. On the contrary, when a call data packet occurs from the base station 210, the base station 210 transmits a call data packet to the second terminal 200-2, and the second terminal 200-2 sends the call. The data packet is relayed to the first terminal 200-1.

3 and 4 are diagrams illustrating a method for transmitting a help signal according to an embodiment of the present invention, which shows a method for transmitting a broadcast message error based help signal and a method for transmitting a downlink CQI distortion based help signal, respectively.

First, referring to FIG. 3, a method of transmitting a broadcast message error-based help signal is described. All terminals in idle mode or uplink / downlink communication include resource allocation information or base station related information from a base station. You will receive a broadcasting message. Accordingly, when a call requesting terminal provides an interference signal using a help signal so that an error occurs when the terminals receive and decode the broadcasting message, the terminals detect a decoding error of the broadcasting message. Therefore, it can be recognized that the interference signal from the surrounding help signal is being received.

On the other hand, if the call requesting terminal simply generates an interference signal, the terminals are signal-to-noise due to whether the error is caused by the helped signal when the broadcasting message decoding error is detected, or simply by signal attenuation or interference from an adjacent cell. And whether the error is caused by a decrease in the Signal to Interference and Noise Ratio (hereinafter referred to as 'SINR').

Therefore, if the call requesting terminal repeatedly transmits a help signal during the N _s1 frame period and does not transmit the help signal during the N _s2 frame period, the terminals receive broadcasting information in which an error occurs during the N _s1 frame period. And receive broadcasting information without error during the N _s2 frame period, and it is possible to detect the surrounding help signal while observing this phenomenon. That is, the help signal is made to have the same pattern as the Morse code, so that the error occurrence pattern of the broadcast message may be different from the simple reduction of the SINR, thereby making it possible to detect the surrounding help signal.

3 illustrates an example of a case where N _s1 = N _s2 = 2. In the cellular system, a frame structure includes a section for transmitting the broadcasting message and a section for transmitting uplink / downlink data. In this case, the call requesting terminal transmits the help signal during two frame periods and repeatedly does not transmit the help signal during the two frame periods so that the terminal within the cell coverage can detect its own help signal.

Next, referring to FIG. 4, a method of transmitting a downlink CQI distortion-based help signal is performed. The cellular terminal always monitors a downlink channel state, and quantizes the monitored channel state in a downlink CQI form. Will be saved. In this case, the UE may determine that the state of the channel is good when the CQI is high, and may determine that the state of the channel is not good when the CQI is low.

This channel condition is time-varying, and it is rare for certain subchannels to keep CQI low for a long time. Accordingly, when the call requesting terminal transmits an interference signal for a specific subchannel for a predetermined time, the neighboring terminal recognizes that the downlink CQI is continuously low only for the specific subchannel, thereby receiving the interference signal due to the surrounding help signal. can do.

On the other hand, in order to more clearly distinguish the case where the downlink CQI of a particular subchannel is kept low and the help signal is transmitted in the absence of the help signal, the call requesting terminal selects the subchannel transmitting the help signal. Hopping can be performed. If the hopping pattern for the call is known in advance, the neighboring terminal may detect the help signal of the surrounding by confirming that the hopping pattern of the subchannel having the low downlink CQI matches the previously promised pattern. Using this approach reduces the probability of falsely detecting the helped signal compared to transmitting a help signal only for a specific subchannel without hopping.

As described above, the broadcast message error-based help signal transmission method is a method of transmitting a help signal in a time pattern, and the downlink CQI distortion-based help signal transmission method is a method of transmitting a help signal in a frequency pattern.

5 is a flowchart illustrating a procedure of a method for processing a call to a terminal out of cell coverage based on P2P communication according to an embodiment of the present invention. 5 is a call processing method using a broadcast message error based help signal transmission method as a help signal transmission method according to the present invention.

Referring to FIG. 5, the terminal determines whether a call request event is generated according to a call request of a user in step 501, and when the occurrence of the call request event is detected, the terminal itself displays a cell in step 503. Check whether the terminal is out of coverage. Here, whether the terminal itself is a terminal out of cell coverage can be recognized according to whether or not the broadcast message transmitted by the base station is received, and if the broadcast message has not been received for a predetermined time, the terminal itself is It may be recognized that the terminal is out of cell coverage where direct communication with the base station is impossible.

In step 503, when the terminal itself is a terminal out of cell coverage where direct communication with the base station is not possible, the terminal establishes a call with the base station through the relay of a neighboring terminal capable of direct communication with the base station, Search for a neighboring terminal capable of relaying, and transmit a help signal for requesting relaying of the call to the found neighboring terminal.

Meanwhile, in performing the operation of the present invention, it is necessary to minimize the power consumption which is very important for the call requesting terminal and to minimize the degradation of the cellular system performance by the help signal. Accordingly, the present invention proposes a method of transmitting a help signal by performing transmission power and subchannel number control and gradually setting a helpable signal reception region through the transmission power control.

In this case, if the distance R affecting the help signal is specified, the transmission power Pt and the number of subchannels N corresponding thereto must satisfy the following Equation 1.

Here, the PER _th means an error probability of a target broadcast message (eg, MAP) and has a value close to one. The P _max means the maximum transmission power in a call situation, and the N _max means the maximum number of subchannels that the terminal can transmit simultaneously. P (Pt, N, R) is a broadcast message error probability of a terminal at a distance R, which may be expressed as a function of the transmission power Pt and the number of subchannels N to transmit. Specifically, it is shown in Equation 2 below.

Here, S denotes SINR, Pr denotes a signal strength estimation value of a broadcasting message received by a neighboring terminal from a base station, and M denotes an estimated noise amount of the neighboring terminal. The I (Pt, N, R) is an average interference estimation value received by a terminal receiving a help signal from a distance of R when the transmission power is Pt and the number of subchannels is N. A path loss model and N It can be calculated by the power allocation scheme for the two subchannels.

Here, in order to transmit the help signal in a manner of gradually setting a helpable signal reception region through the transmission power control, the terminal has an error probability of a target broadcast message (eg, MAP) at a predetermined level or more in step 505. The target SINR S _th is determined as the SINR, and an initial value for the distance R at which the help signal is affected is determined in step 507. Thereafter, the terminal proceeds to step 509 where the SINR of the terminal separated by an R distance is equal to the S _th. The amount of interference I is determined to be equal to or less, and in step 511, the transmission power Pt and the number of subchannels N for satisfying the determined interference amount I are determined. A helper signal for call relay is transmitted to a remote terminal. Here, the help signal is transmitted at low power for a predetermined time in the help signal transmission period.

In step 515, the terminal determines whether a response message for the help signal is received from the terminal in the neighboring cell coverage for a predetermined time. In this case, the response message is transmitted in a section in which no help signal is transmitted so that the terminal can receive the information, for example, information for performing direct communication with the terminal (eg, a preamble number, timing, and Frame synchronization information) and relay terminal information (eg, ID information of the relay terminal).

When the response message is received, the terminal stops transmitting the help signal in step 517, selects a terminal within cell coverage that has transmitted the response message as a relay terminal, and transmits an ACK message, and directly transmits between terminals. By setting the direct transmission connection between the terminals by performing the connection setup method in the above, the message to inform the success of the call setup with the base station for the relay from the terminal in the cell coverage after the direct transmission and reception of data packets between the terminals thereafter Receive Here, when there are a plurality of terminals in cell coverage that simultaneously transmit the response message, one terminal is selected as a relay terminal and the ACK message is transmitted. When all connections are established as described above, the terminal transmits a call data packet to the relay terminal within the cell coverage in step 519. At this time, the call data packet is transmitted to the base station by the relay terminal.

On the other hand, when the response message is not received, the terminal updates the R in step 521 and then returns to step 509 to repeat the following steps. At this time, the R can be updated by adding a predetermined value to the R. As described above, transmission of the help signal may be attempted several times while increasing R, and thus, the call request terminal may minimize power consumption due to the help signal transmission because the relay terminal may be found as close as possible. However, it may not generate unnecessary interference to the terminal that exists at a greater distance than this.

On the other hand, in step 503, when the terminal itself is a terminal in cell coverage capable of direct communication with the base station, the terminal performs a direct call setup process with the base station to establish a call, and through the set call Send and receive call data packets with the base station.

Thereafter, the terminal terminates the algorithm according to the present invention.

Meanwhile, in the call processing method of FIG. 5, another help signal transmission method according to the present invention, a downlink CQI distortion-based help signal transmission method, may be applied. In this case, the CQI may be used instead of the SINR. That is, the maximum CQI value determined as the distortion caused by the help signal is determined as the target CQI S _th , and the amount of interference is determined so that the CQI of the UE separated by the R distance is equal to or less than S _th . In this case, since a help signal is transmitted to a specific subchannel, it is not necessary to determine the number of subchannels.

Meanwhile, in the present invention, a terminal subject to a relay request corresponds to all terminals except for a terminal in a sleep mode to save power consumption. That is, the relay request target terminal, a terminal that may only receive broadcasting information from the base station in idle mode, a terminal directly exchanging data packets with other neighboring terminals in direct communication mode, and the base / An active mode terminal having a downlink connection is possible. Among them, the terminal to which the relay request is made may be given priority to a terminal that is directly exchanging data packets with another neighboring terminal in a direct communication mode. If the first terminal is searched for the existence and the corresponding terminal is not found, the terminal may be receiving only broadcasting information from the base station in idle mode, or the active mode has an uplink / downlink connection with the base station. It is possible to search for the existence of the terminal.

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 diagram illustrating a network for call processing of a terminal out of cell coverage based on P2P communication according to the present invention;

2 is a signal flow diagram illustrating a method for processing a call to a terminal out of cell coverage based on P2P communication according to an embodiment of the present invention;

3 and 4 illustrate a help signal transmission method according to an embodiment of the present invention, and

5 is a flowchart illustrating a procedure of a method for processing a call to a terminal out of cell coverage based on P2P communication according to an embodiment of the present invention.

Claims (56)

In the call processing method of the terminal, When a call request event occurs, transmitting a helping signal to neighboring terminals in order to request a relay for a call; And when a response message for the help signal is received, establishing a direct transmission connection with a neighboring terminal that has transmitted the response message. The method of claim 1, The terminal is characterized in that the terminal out of cell coverage. The method of claim 2, And when the broadcast message transmitted by the base station is not received for a predetermined time, recognizing that the terminal itself is a terminal out of cell coverage incapable of direct communication with the base station. The method of claim 2, The terminal outside the cell coverage is a terminal in which a base station capable of direct communication within a distance of a predetermined level or less exists, or a terminal in a state where communication with the base station is impossible because it is located in a shadow area even if a base station close to the distance exists. How to.  The method of claim 1, When the response message for the help signal is received, stopping the transmission of the help signal and transmitting a confirmation message to the neighboring terminal which transmitted the response message. The method of claim 1, And transmitting a call data packet to the neighboring terminal when a message indicating successful call establishment with the base station is received from the neighboring terminal. The method of claim 1, The neighboring terminal transmitting the response message is characterized in that the terminal capable of direct communication with the base station. The method of claim 1, The response message may include at least one of information for performing direct communication with the terminal and information about the neighboring terminal. The method of claim 1, The help signal is transmitted in the help signal transmission interval, and the response message is characterized in that it is received in the period that does not transmit the help signal. The method of claim 1, wherein the help signal is, And providing interference so that a decoding error occurs when the neighboring terminals decode the broadcasting message, thereby indicating the existence of the terminal. The method of claim 10, wherein the help signal is And transmitting at a predetermined time period. The method of claim 1, wherein the help signal is, And providing a interference to keep a channel quality indicator (CQI) of the neighboring terminals low for a certain time for a specific subchannel, thereby indicating the presence of the terminal itself. The method of claim 12, wherein the help signal is, And transmitting only for the specific subchannel. The method of claim 13, wherein the help signal is: And is transmitted in a previously promised subchannel hopping pattern. The method of claim 1, wherein the help signal is, And transmitting and setting the helpable signal reception area gradually wider through the transmission power control. The method of claim 15, wherein the help signal transmission process, Determining a target signal-to-interference and noise ratio (SINR), Designating an initial value for a distance that the helped signal affects, Determining an amount of interference so that the SINR of the neighboring UE separated by the distance is equal to or less than the target SINR; Determining transmission power and the number of subchannels so as to satisfy the determined interference amount; And transmitting the help signal to a neighboring terminal separated by the distance using the determined transmission power and the number of subchannels. The method of claim 16, When the response message for the help signal is not received, updating the helped signal distance to a larger value, and then repeating the help signal transmission process. The method of claim 15, wherein the help signal transmission process, Determining a target channel quality indicator (CQI), Designating an initial value for a distance that the helped signal affects, Determining an interference amount such that a CQI of a neighboring UE separated by the distance is equal to or less than the target CQI; Determining transmission power to satisfy the determined interference amount; And transmitting the help signal to a neighboring terminal separated by the distance by using the determined transmission power. The method of claim 18, When the response message for the help signal is not received, updating the helped signal distance to a larger value, and then repeating the help signal transmission process. The method of claim 1, wherein the peripheral terminal, A terminal that may be receiving only broadcasting information from a base station in idle mode, a terminal directly exchanging data packets with another neighboring terminal in direct communication mode, and an active node having an uplink / downlink connection with the base station Method characterized in that one of the terminal of the mode. In the call processing apparatus of the terminal, Means for transmitting a helping signal to neighboring terminals to request a relay for a call when a call request event occurs; Means for establishing a direct transmission connection with a peripheral terminal that transmitted the response message when a response message to the helping signal is received. The method of claim 21, And the terminal is a terminal out of cell coverage. The method of claim 22, And when the broadcast message transmitted by the base station is not received for a predetermined time period, the terminal further recognizes that the terminal is a terminal out of cell coverage incapable of direct communication with the base station. The method of claim 22, The terminal outside the cell coverage is a terminal in which a base station capable of direct communication within a distance of a predetermined level or less exists, or a terminal in a state where communication with the base station is impossible because it is located in a shadow area even if a base station close to the distance exists. Device.  The method of claim 21, And receiving a response message for the help signal, and stopping the transmission of the help signal and transmitting a confirmation message to the neighboring terminal that transmitted the response message. The method of claim 21, And receiving a call data packet to the neighboring terminal when a message indicating successful call establishment with the base station is received from the neighboring terminal. The method of claim 21, The peripheral terminal transmitting the response message is characterized in that the terminal capable of direct communication with the base station. The method of claim 21, The response message may include at least one of information for performing direct communication with the terminal and information about the neighboring terminal. The method of claim 21, The help signal is transmitted in the help signal transmission section, the response message is characterized in that the device is received in the section not transmitting the help signal. The method of claim 21, wherein the help signal is: And providing a signal to inform the existence of the terminal by providing interference so that a decoding error occurs when the neighboring terminals decode the broadcasting message. The method of claim 30, wherein the help signal is Device for transmitting in a predetermined pattern of time periods. The method of claim 21, wherein the help signal is: And a signal for indicating an existence of the terminal by providing interference so that a channel quality indicator (CQI) of the neighboring terminals is kept low for a certain time for a specific subchannel. 33. The method of claim 32, wherein the help signal is And transmit only for the specific subchannel. The method of claim 33, wherein the help signal is And transmit in a previously promised subchannel hopping pattern. The method of claim 21, wherein the help signal is: The apparatus characterized in that for transmitting while gradually setting the helpable signal receiving region through the transmission power control. The method of claim 35, wherein the help signal transmission means, Means for determining a target signal to interference and noise ratio (SINR), Means for specifying an initial value for the distance at which the help signal is affected; Means for determining an amount of interference so that the SINR of the neighboring terminal separated by the distance is equal to or less than the target SINR; Means for determining a transmission power and the number of subchannels so as to satisfy the determined interference amount; And means for transmitting the help signal to a neighboring terminal separated by the distance using the determined transmission power and the number of subchannels. The method of claim 36, Means for updating the distance the helped signal affects to a larger value when a response message to the helped signal is not received. The method of claim 35, wherein the help signal transmission means, Means for determining a target channel quality indicator (CQI); Means for specifying an initial value for the distance at which the help signal is affected; Means for determining an amount of interference such that a CQI of a neighboring terminal separated by the distance is equal to or less than the target CQI; Means for determining transmit power to satisfy the determined amount of interference; Means for transmitting the help signal to a neighboring terminal separated by the distance using the determined transmit power. The method of claim 38, Means for updating the distance the helped signal affects to a larger value when a response message to the helped signal is not received. The method of claim 21, wherein the peripheral terminal, A terminal that may be receiving only broadcasting information from a base station in idle mode, a terminal directly exchanging data packets with another neighboring terminal in direct communication mode, and an active node having an uplink / downlink connection with the base station Apparatus characterized in that one of the terminal of the mode. In the call processing method of the terminal, When the terminal, when the call request event occurs, transmitting a helping signal to the neighboring terminal to request a relay for the call, Transmitting a response message from the neighboring terminal to the terminal after recognizing the help signal; And establishing, by the terminal and the neighboring terminal which has transmitted the response message, a direct transmission connection. 42. The method of claim 41 wherein The terminal is a terminal that does not have a base station capable of direct communication within a distance of a predetermined level or less, or a terminal which is located in a shadow area and cannot communicate with the base station even if a base station close to a distance exists, and transmits the response message. One peripheral terminal is characterized in that the terminal capable of direct communication with the base station. 42. The method of claim 41 wherein Setting up a call with a base station for relaying the call, and transmitting a message indicating a successful call setup to the terminal; Transmitting, by the terminal, a call data packet to the neighboring terminal upon receiving the call setup success notification message; The neighboring terminal further comprises the step of transmitting a call data packet from the terminal to the base station. 42. The method of claim 41 wherein The response message may include at least one of information for performing direct communication with the terminal and information about the neighboring terminal. 42. The method of claim 41 wherein The help signal is transmitted in the help signal transmission interval, and the response message is characterized in that it is received in the period that does not transmit the help signal. 42. The method of claim 41 wherein the help signal is: And providing interference so that a decoding error occurs when the neighboring terminals decode the broadcasting message, and transmitting the signal at a predetermined pattern of time periods as a signal for indicating the existence of the terminal. 42. The method of claim 41 wherein the help signal is: Provides interference so that a channel quality indicator (CQI) of the neighboring terminals is kept low for a certain time for a specific subchannel, and transmits only for the specific subchannel as a signal for indicating the existence of the terminal itself. Characterized in that the method. 42. The method of claim 41 wherein the help signal is: And transmitting and setting the helpable signal reception area gradually wider through the transmission power control. In the call processing apparatus of the terminal, When a call request event occurs, a helping signal is transmitted to neighboring terminals to request a relay for a call, and when a response message for the helping signal is received, the neighboring terminal has transmitted the response message. A terminal for establishing a direct transport connection, And a peripheral terminal for transmitting a response message to the terminal that has transmitted the helping signal and establishing a direct transmission connection with the terminal when the helping signal is detected. The method of claim 49, The terminal is a terminal that does not have a base station capable of direct communication within a distance of a predetermined level or less, or a terminal which is located in a shadow area and cannot communicate with the base station even if a base station close to a distance exists, and transmits the response message. One peripheral terminal is a device characterized in that the terminal capable of direct communication with the base station. The method of claim 49, The neighboring terminal establishes a call with the base station for relaying the call, transmits a message indicating a successful call setup to the terminal, and then transmits a call data packet from the terminal to the base station, The terminal may transmit a call data packet to the neighboring terminal according to the reception of the call setup success notification message. The method of claim 49, The response message may include at least one of information for performing direct communication with the terminal and information about the neighboring terminal. The method of claim 49, The help signal is transmitted in the help signal transmission section, the response message is characterized in that the device is received in the section not transmitting the help signal. The method of claim 49, wherein the help signal is: And providing interference to generate a decoding error when the neighboring terminals decode the broadcasting message, and transmit the signal as a signal for notifying the existence of the terminal, in a predetermined pattern of time periods. The method of claim 49, wherein the help signal is: Provides interference so that a channel quality indicator (CQI) of the neighboring terminals is kept low for a certain time for a specific subchannel, and transmits only for the specific subchannel as a signal for indicating the existence of the terminal itself. Device characterized in that. The method of claim 49, wherein the help signal is: The apparatus characterized in that for transmitting while gradually setting the helpable signal receiving region through the transmission power control.

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