KR100725770B1 - Apparatus and method for scanning in a multi-hop relay broadband wireless access communication system - Google Patents

Abstract

The present invention relates to an apparatus and method for scanning in a cellular communication system using a multi-hop relay scheme. In the scanning method according to the present invention, the terminal transmits a scan request message requesting scanning to the base station through the relay station, and the scan response message including information necessary for the base station to scan the terminal through the relay station; And transmitting, by the base station, a scan notification message informing of the scanning of the terminal to the relay station. As described above, the present invention can provide the MSS with the same service and function as the case of communicating using the direct link with the base station through the relay station.

Relay communication system, relay station, scanning

Description

Apparatus and method for scanning in a broadband wireless access communication system using a multi-hop relay method {APPARATUS AND METHOD FOR SCANNING IN A MULTI-HOP RELAY BROADBAND WIRELESS ACCESS COMMUNICATION SYSTEM}

1 is a diagram schematically showing the structure of a general IEEE 802.16e communication system.

2 is a diagram illustrating a signaling procedure between an MSS and a base station for performing a scanning operation in a broadband wireless access communication system according to the prior art.

3 is a diagram schematically illustrating a structure of a broadband wireless communication system using a multi-hop relay scheme according to the present invention.

4 is a diagram illustrating a signal flow between a terminal, a relay station, and a base station for performing a scanning operation in a broadband wireless communication system using a multi-hop relay scheme according to the first embodiment of the present invention.

5 is a diagram illustrating an operation procedure of a relay station in a broadband wireless communication system using a multi-hop relay scheme according to the first embodiment of the present invention.

6 is a diagram illustrating an operation procedure of a base station in a broadband wireless communication system using a multi-hop relay scheme according to the first embodiment of the present invention.

7 is a diagram illustrating a signal flow between a terminal, a relay station, and a base station for performing a scanning operation in a broadband wireless communication system using a multi-hop relay method according to the second embodiment of the present invention.

8 is a diagram illustrating an operation procedure of a relay station in a broadband wireless communication system using a multi-hop relay scheme according to a second embodiment of the present invention.

9 is a diagram illustrating an operation procedure of a base station in a broadband wireless communication system using a multi-hop relay scheme according to a second embodiment of the present invention.

10 is a diagram illustrating a signal flow between a terminal, a relay station, and a base station for performing a scanning operation in a broadband wireless communication system using a multi-hop relay scheme according to a third embodiment of the present invention.

FIG. 11 is a diagram illustrating a signal flow between a terminal, a relay station, and a base station for performing a scanning operation in a broadband wireless communication system using a multi-hop relay scheme according to a fourth embodiment of the present invention.

12 is a diagram illustrating an operation procedure of a relay station in a broadband wireless communication system using a multi-hop relay scheme according to the third and fourth embodiments of the present invention.

13 is a diagram illustrating an operation procedure of a base station in a broadband wireless communication system using a multi-hop relay scheme according to the third and fourth embodiments of the present invention.

14 is a diagram illustrating a scanning operation procedure of a terminal in a broadband wireless communication system using a multi-hop relay method according to an embodiment of the present invention.

15 is a block diagram of a MSS (or relay station or base station) according to an embodiment of the present invention.

The present invention relates to a broadband wireless access communication system using a multi-hop relay scheme, and more particularly, to an apparatus and a method for scanning in a broadband wireless access communication system using a multi-hop relay scheme.

In the 4th Generation (hereinafter, referred to as '4G') communication system, users of services having various quality of service (hereinafter referred to as 'QoS') having a transmission rate of about 100 Mbps are used. Active research is underway to provide them. In particular, in 4G communication systems, broadband wireless such as a wireless local area network (hereinafter, referred to as a 'LAN') system and a wireless metropolitan area network (hereinafter, referred to as a 'MAN') system are used. Research is being actively conducted to support high-speed services in a form of guaranteeing mobility and quality of service (BoS) in a broadband wireless access (BWA) communication system. (Institute of Electrical and Electronics Engineers) 802.16a communication system and IEEE 802.16e communication system.

The IEEE 802.16a communication system and the IEEE 802.16e communication system are orthogonal frequency division multiplexing (OFDM) for supporting a broadband transmission network on a physical channel of the wireless MAN system. Or OFDM) orthogonal frequency division multiple access (OFDMA) scheme. The IEEE 802.16a communication system is a system currently considering only a single cell structure and a state in which a subscriber station (SS) (hereinafter referred to as SS) is fixed, that is, no consideration of mobility of the SS is considered. . In contrast, the IEEE 802.16e communication system is a system considering the mobility of the SS in the IEEE 802.16a communication system, and the SS having the mobility is referred to as a mobile subscriber station (MSS). It will be called.

1 is a diagram schematically illustrating a structure of a general IEEE 802.16e communication system.

Referring to FIG. 1, the IEEE 802.16e communication system has a multi-cell structure, that is, a base station (BS) 110 having a cell 100 and a cell 150 and managing the cell 100. And a base station 140 that manages the cell 150 and a plurality of MSSs 111, 113, 130, 151, and 153. Signal transmission and reception between the base stations 110 and 140 and the MSSs 111, 113, 130, 151 and 153 is performed using the OFDM / OFDMA scheme. However, among the MSSs 111, 113, 130, 151, and 153, the MSS 130 exists in a boundary region of the cell 100 and the cell 150, that is, a handover region. That is, when the MSS 130 moves to the cell 150 managed by the base station 140 while transmitting and receiving a signal with the base station 110, the serving BS is transferred from the base station 110. The base station 140 is changed.

2 illustrates a signaling procedure between an MSS and a base station for performing a scanning operation in a broadband wireless access communication system according to the prior art.

Referring to FIG. 2, the MSS 210 first communicates with the serving base station 230 in step 211. As such, during communication with the serving base station 230, the MSS 210 determines whether scanning for neighboring base stations and pilot channel signals transmitted from the serving base station 230 is required. If it is determined that scanning is necessary, the MSS 210 sends a mobile subscriber station scan request (MOB_SCN-REQ) to the serving base station 230 (MOB_SCN-REQ) in step 213. Send a message. The MOB_SCN-REQ message structure is as shown in Table 1 below.

Syntax Size (bits) Notes MOB_SCN-REQ_format () {   Management Message Type = 54 8 -   Scan duration 8 units are in frames   Interleaving interval 8 units are frames   Scan iteration 8 in frames   N_Recommended_BS 8 Number of neighboring BS to be scanned   for (i = 0; i <N_Recommended_BS; i ++) {     Recommended BS_ID 48 BS Identifier   } }

As shown in Table 1, the MOB_SCN-REQ message includes a plurality of Information Element (IE), that is, a "Management Message Type" indicating the type of message to be transmitted, and scanning of pilot signals transmitted from the neighbor base stations. "Scan duration" representing the desired scan interval, "Scan Iteration" representing the number of scanning if the scanning operation is repeated periodically, "Interleaving interval" representing the time interval between each scanning operation if the scanning operation is repeated, and scanning &Quot; Recommended_BS_ID " representing each base station to be desired.

On the other hand, the serving base station 230 receiving the MOB_SCN-REQ message includes the scanning information for the MSS 210 in step 215, and the mobile subscriber station scan response (MOB_SCN-RSP: Mobile Scanning) where the scanning interval is not 0 Interval Allocation Response, hereinafter referred to as 'MOB_SCN-RSP' message, is transmitted to the MSS 210.

Here, the MOB_SCN-RSP message structure is as shown in Table 2 below.

Syntax Size (bits) Notes MOB_SCN-RSP_format () {   Management Message Type = 55 8 -   Scan duration 8 units are in frames. When Scan duration is set to zero, no scanning parameters are specified in the message. When MOB_SCN-RSP is sent in response to MOB_SCN-REQ, setting Scan duration to zero denies MOB_SCN-REQ.   Report mode 2 0b00: no report 0b01: periodic report 0b10: event triggered report 0b11: reserved; shall be set to zero   reserved 6 shall be set to zero   Report period 8 Available when the value of Report mode is set to 0b01. Report period in frames.   Report metric 8 Bitmap indicating metrics on which the corresponding triggers are based: Bit 0: BS CINR mean Bit 1: BS RSSI mean Bit 2: Relative delay Bit 3: BS RTD BIt 4-7: reserved; shall be set to zero   if (Scan duration! = 0) {     Start frame 4 -     reserved 4 shall be set to zero     Interleaving interval 8 duration in frames     Scan iteration 8 -     N_Recommended_BS 8 Number of neighboring BS to be scanned     for (i = 0; i <N_Recommended_BS; i ++) {       Recommended BS_ID 48 BS Identifier     }   } }

As shown in Table 2, the MOB_SCN-RSP message includes a plurality of IEs, that is, a message type (Management Message Type) transmitted, a scan duration in which the MSS performs scanning, and a scan result reporting method. (report mode), the scan report period to be applied when the scan result reporting method is the periodic result report, the information to be reported as the scan result (report metric), and the start point of the scan operation (start frame) ), A scan iteration when performing periodic scanning, an interleaving interval between every scan, and each base station information (Recommended BS_ID) to perform scanning. The scan interval, when the value is 0, indicates that the scanning request of the MSS has been rejected. The information to be reported as the scan result is received signal strength indicator (RSSI), delay (in addition to the carrier to interference and noise ratio (CINR). relative delay), round trip delay (RTD), and the like.

Upon receiving the MOB_SCN-RSP message including the scanning information, the MSS 210 receives a pilot channel corresponding to the parameters included in the MOB_SCN-RSP message for neighboring base stations and the serving base station 230 in step 217. Scan the signals.

Meanwhile, the serving base station 230 stops data transmission to the MSS 210 while the MSS 210 performs scanning corresponding to the parameters included in the MOB_SCN-RSP message in step 219. Buffer the data for 210.

After the scanning of the pilot channel signals received from the neighbor base stations and the serving base station 230 is completed, the MSS 210 reports the mobile subscriber station scan (MOB_SCN-REP: Mobile Scanning Result Report) to inform the scan result in step 221. In the following description, a &quot; MOB_SCN-REP &quot; message is transmitted to the serving base station 230.

The MOB_SCN-REP message structure is as shown in Table 3 below.

Syntax Size (bits) Notes MOB_SCN-REP_format () {   Management Message Type = 60 8 -   Report mode One 0: Event-triggered report 1: Periodic report   reserved 7 shall be set to zero   Report Metric 8 Bitmap indicating presence of certain metrics: Bit 0: BS CINR mean Bit 1: BS RSSI mean Bit 2: Relative delay Bit 3: BS RTD Bit 4-7: reserved; shall be set to zero   N_BS 8 Number of BS to be scanned   for (i = 0; i <N_BS; i ++) {     BS_ID 48 BS Identifier     Scanning result 8 this field contains the scanning result corresponding to Report metric (CIRN / RSSI / Relative delay / RTD / etc.)   } }

As shown in Table 3, the MOB_SCN-REP message is reported by a plurality of IEs, that is, a message type (Management Message Type) transmitted, a method in which the MSS reports a scanning result, and a scan result. Information to be reported (Report Metric), each base station information (BS_ID) that the MSS has performed scanning, and scanning result information (Scanning result) for each base station. The scan result information is included in the MOB_SCN-REP message according to whether there is information to be reported as the scan result, and the scan result information includes RSSI (Received Signal Strength Indication) and delay in addition to a carrier to interference and noise ratio (CINR). (relative delay) and round trip delay (RTD).

In the general IEEE 802.16e communication system, signaling is transmitted and received through a direct link between the fixed base station and the MSS, as shown in FIG. However, in the IEEE 802.16e communication system, since the location of the base station is fixed, the flexibility of the wireless network configuration is low, and thus, it is difficult to provide an efficient communication service in a wireless environment in which the traffic distribution and the call demand change are severe.

In order to overcome this drawback, a multi-hop relay data transfer scheme can be applied to a general cellular wireless communication system such as the 802.16e communication system using a fixed relay station, a mobile relay station, or general MSS. have. Therefore, the wireless communication system using the multi-hop relay method can quickly reconfigure the network in response to changes in the communication environment, it is possible to operate the entire wireless network more efficiently. A wireless communication system using the multi-hop relay scheme can expand a cell service area and increase system capacity. That is, when the channel state between the base station and the MSS is poor, a relay station may be installed between the base station and the MSS to configure a multi-hop relay path through the relay station, thereby providing the MSS with a better channel state. In addition, by using the multi-hop relay scheme in a cell boundary region having a poor channel state from a base station, it is possible to provide a faster data channel and expand a cell service area.

3 is a diagram schematically illustrating a structure of a wireless communication system using a multi-hop relay scheme.

Referring to FIG. 3, the multi-hop relay wireless communication system provides a base station 310 and a plurality of MSSs 311, 313, 331, and 333, and a multi-hop relay path between the base station and the MSS. It is composed of a relay station (Relay Station) (320). Signal transmission and reception between the base station 310 and the relay station 320 and the MSSs 311, 313, 331, and 333 is performed using the OFDM / OFDMA scheme. The base station 310 manages the cell 300, and the MSSs 311 and 313 and the relay station 320 included in the cell 300 area may directly transmit and receive a signal with the base station 310. However, MSSs 331 and 333 present in the area 330 outside the cell 300 may not directly transmit / receive signals with the base station 310. Accordingly, the relay station 320 manages the area 330 and relays a signal between the base station 310 and the MSSs 331 and 333, which cannot directly transmit and receive a signal as described above, and the MSSs 331 and 333 A signal may be transmitted and received with the base station 310 through the relay station 320.

In the wireless communication system using the multi-hop relay method through the relay station as described above, the MSS may communicate with the base station through the relay station or establish a direct link with the base station. Therefore, even in a wireless communication system using a multi-hop relay method, the services and functions provided in the existing wireless communication system should be equally applied.

Typically, in the case of a broadband wireless access communication system using a multi-hop relay scheme, the target of communication in the MSS is extended to the base station and the repeater. Therefore, the MSS must include not only the neighbor base stations but also the neighbor relay stations in the scanning for smooth communication. do. Since the conventional system does not consider the multi-hop relay scheme, the scanning scheme considering the relay station has not been proposed. Accordingly, there is a need to define a signaling procedure for scanning MSS in a multi-hop relay radio access communication system.

Accordingly, an object of the present invention is to provide an apparatus and method for transmitting and receiving a signal required for scanning by a terminal through a relay station in a broadband wireless access communication system using a multi-hop relay scheme.

Another object of the present invention is to provide an apparatus and method for transmitting and receiving a signal required between a relay station and a base station in order to support scanning of a terminal in a broadband wireless access communication system using a multi-hop relay scheme.

According to an aspect of the present invention for achieving the above object, in a communication method of a relay station in a cellular communication system using a multi-hop relay method, transmitting a scan request message received from a terminal to a base station; And transmitting a scan response message including information necessary for scanning of the terminal received from the base station to the terminal.

According to another aspect of the present invention, in a communication method of a relay station in a cellular communication system using a multi-hop relay method, when a scan request message is received from a terminal, the information of the terminal is received by using information of the scan request message. And determining a scan schedule, and transmitting a scan response message including the determined scan schedule information to the terminal.

According to still another aspect of the present invention, a scanning method in a cellular communication system using a multi-hop relay method, the terminal transmits a scan request message requesting scanning to the base station through the relay station, the base station is the terminal; And transmitting a scan response message including information necessary for scanning to the terminal through the relay station, and transmitting, by the base station, a scan notification message informing of the scanning of the terminal to the relay station. .

According to still another aspect of the present invention, in a cellular communication system using a multi-hop relay method, a scanning method includes: transmitting, by a terminal, a scan request message to a relay station requesting scanning; And transmitting a scan response message including necessary information to the terminal, and transmitting a scan notification message to the base station by the relay station to notify the terminal of the scanning performance.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that in the following description, only parts necessary for understanding the operation according to the present invention will be described, and descriptions of other parts will be omitted so as not to distract from the gist of the present invention.

According to the present invention, a mobile subscriber station (MSS) is referred to as a serving BS in a broadband wireless access (BWA) communication system using a multi-hop relay method. A signaling procedure for scanning a neighboring relay station including a neighboring base station and a serving relay station is proposed.

The broadband wireless access communication system using the multi-hop relay method is, for example, orthogonal frequency division multiplexing (OFDM) and orthogonal frequency division multiple access (OFDMA). Frequency division multiple access, hereinafter referred to as &quot; OFDMA. &Quot; In the broadband wireless access communication system using the multi-hop relay method, since the OFDM / OFDMA method is used, high-speed data transmission is possible by transmitting a physical channel signal using a plurality of sub-carriers. It can support MSS mobility by supporting multi-cell structure.

In addition, the relay station of the broadband wireless access communication system using the multi-hop relay scheme may be a fixed node or a mobile node, or may be a specific system installed by a base station. That is, any node having the above characteristics may be selected as a relay station through a relay station capability negotiation procedure with the base station according to a predefined criterion for cell area expansion of the base station.

In the following description, a broadband wireless access communication system is described as an example, but the present invention may be equally applicable to a cellular-based communication system using a multi-hop relay method.

4 illustrates a signal flow between a terminal, a relay station, and a base station for a scanning operation in a broadband wireless communication system using a multi-hop relay method according to the first embodiment of the present invention.

Referring to FIG. 4, first, the MSS 410 communicates with the relay station 440 in step 411, and the relay station 440 communicates with the base station 450 in step 413. That is, the MSS 410 and the base station 450 do not directly transmit and receive a signal, and perform communication through a signal relayed by the relay station 440.

When it is determined that scanning during communication is performed through the relay station 440 as described above, the MSS 410 is adjacent to the neighboring base station including the serving base station 450 and the serving relay station 440 in step 415. A scan request (MOB_SCN-REQ) message is transmitted to the relay station 440 requesting scanning of pilot channel signals transmitted from the relay stations. Herein, the scan request (MOB_SCN-REQ) message structure according to the present invention is shown in Table 4 below.

Syntax Size (bits) Notes MOB_SCN-REQ_format () {   Management Message Type = 54 8 -   Scan duration 8 units are in frames   Interleaving interval 8 units are frames   Scan iteration 8 in frames   N_Recommended 8 Number of neighboring RS or BS to be scanned   for (i = 0; i <N_Recommended; i ++) {     Recommended Node_ID 48 BS Identifier or RS Identifier   } }

As shown in Table 4, the scan request (MOB_SCN-REQ) message according to the present invention includes a plurality of information elements (IEs), that is, a message type (Management Message Type) indicating the type of a message to be transmitted, Scan duration indicating a scan period for which pilot channel signals transmitted from base stations and neighboring relay stations are desired to be scanned, and scan iterations indicating the number of repetitions of scanning performed when the scanning operation is periodically repeated. And an interleaving interval indicating a time interval between scanning operations when the scanning operation is repeated, and node identifiers indicating the base stations and relay stations desired to be scanned. Since the point of request is not directly related to the present invention, the detailed description thereof will be omitted here. do.

In step 417, the RS 440 receives the scan request (MOB_SCN-REQ) message and relays the scan request message received from the MSS 410 to the base station 450. After receiving the scan request (MOB_SCN-REQ) message, the base station 450 includes information necessary for the scanning operation of the MSS 410 in step 419, and the scan response in which the scanning interval is not zero (MOB_SCN-RSP). Send a message to the relay station 440.

Here, the scan response (MOB_SCN-RSP) message structure according to the present invention is as shown in Table 5 below.

Syntax Size (bits) Notes MOB_SCN-RSP_format () {   Management Message Type = 55 8 -   Scan duration 8 units are in frames. When Scan duration is set to zero, no scanning parameters are specified in the message. When MOB_SCN-RSP is sent in response to MOB_SCN-REQ, setting Scan duration to zero denies MOB_SCN-REQ.   Report mode 2 0b00: no report 0b01: periodic report 0b10: event triggered report 0b11: reserved; shall be set to zero   reserved 6 shall be set to zero   Report period 8 Available when the value of Report mode is set to 0b01. Report period in frames.   Report metric 8 Bitmap indicating metrics on which the corresponding triggers are based: Bit 0: CINR mean Bit 1: RSSI mean Bit 2: Relative delay Bit 3: RTD BIt 4-7: reserved; shall be set to zero   if (Scan duration! = 0) {     Start frame 4 -     reserved 4 shall be set to zero     Interleaving interval 8 duration in frames     Scan iteration 8 -     N_Recommended 8 Number of neighboring BS or RS to be scanned     for (i = 0; i <N_Recommended; i ++) {       Recommended Node_ID 48 BS Identifier or RS Identifier     }   } }

As shown in Table 5, the scan response (MOB_SCN-RSP) message according to the present invention is a plurality of IEs, that is, a message type (Management Message Type) indicating the type of the message to be transmitted, and the MSS performs the scanning Scan duration, scan mode reporting mode (Report Mode), scan result reporting period (Periodic report), scan report period (report period), and information to be reported as scan results (Report Metric) ), The start frame of the scanning operation, the scan iteration when performing the periodic scanning, the interleaving interval between the scanning operations when the scanning operation is repeated, and the base station to be scanned. And Node IDs indicating relay stations. The scan interval, when the value is 0, indicates that the scanning request of the MSS has been rejected, and the information to be reported as the scan result is received signal strength indication (RSSI), delay (in addition to the carrier to interference and noise ratio (CINR)). relative delay (RTD), round trip delay (RTD), and so on.

The relay station 440 receiving the scan response (MOB_SCN-RSP) message including the scanning information relays the scan response (MOB_SCN-RSP) message to the MSS 410 in step 421. Upon receiving the scanning response (MOB_SCN-RSP) message, the MSS 410 pilot channel corresponding to the parameters included in the scan response (MOB_SCN-RSP) message for neighboring base stations and neighboring relay stations in step 423. Perform scanning of the signals.

In step 425, the base station 450 stops transmitting data to the MSS 410 while the MSS 410 performs scanning corresponding to the parameters included in the scan response (MOB_SCN-RSP) message. do. In this case, the base station 450 may buffer data to the MSS 410.

After completing scanning of the pilot channel signals received from the neighbor base stations and the neighbor relay stations, the MSS 410 sends a scan report (MOB_SCN-REP) message including a scan result to the relay station (step 427). 440).

Here, the scan report (MOB_SCN-REP) message structure according to the present invention is as shown in Table 6 below.

Syntax Size (bits) Notes MOB_SCN-REP_format () {   Management Message Type = 60 8 -   Report mode One 0: Event-triggered report 1: Periodic report   reserved 7 shall be set to zero   Report Metric 8 Bitmap indicating presence of certain metrics: Bit 0: CINR mean Bit 1: RSSI mean Bit 2: Relative delay Bit 3: RTD Bit 4-7: reserved; shall be set to zero   N_Node 8 Number of RS or BS to be scanned   for (i = 0; i <N_Node; i ++) {     Node_ID 48 BS Identifier or RS Identifier     Scanning result 8 this field contains the scanning result corresponding to Report metric (CIRN / RSSI / Relative delay / RTD / etc.)   } }

As shown in Table 6, the scan report (MOB_SCN-REP) message according to the present invention includes a plurality of IEs, that is, a message type (Management Message Type) indicating a type of a message to be transmitted, and the MSS reports a scanning result Report mode indicating how to do it, Report Metrics indicating the kind of information to be reported as scanning result, Node information (Node_ID) which MSS has scanned, Scanning result for each node (Scanning result). The scanning result may be RSSI, relative delay, RTD (round trip delay), etc. in addition to the CINR according to the report metric value.

Meanwhile, the RS 440 relays the scan report (MOB_SCN-REP) message to the BS 450 in step 429, and the BS 450 recognizes the end of the scan of the MSS 410 in step 431. Meanwhile, the MSS 410 transmits the buffered data of the MSS 410 instead of transmitting it while scanning.

Alternatively, when the MSS 410 terminates scanning earlier than the scan schedule determined in steps 415 to 421 and transmits any uplink data, the RS 440 and the base station 450 may use the MSS ( By receiving the uplink data of the 410, it is possible to recognize the end of scanning of the MSS (410).

Meanwhile, in FIG. 4, the relay station 440 performs the scanning operation of the MSS 410 and the scanning result information from the scanning control messages of Tables 4 to 6 exchanged between the MSS 410 and the base station 450. It is assumed that can be identified.

Referring to the operation of the relay station and the base station corresponding to FIG. 4 as follows.

5 is a flowchart illustrating an operation procedure of a relay station in a broadband wireless communication system using a multi-hop relay scheme according to the first embodiment of the present invention.

Referring to FIG. 5, the RS 440 first receives a scan request (MOB_SCN-REQ) message from the MSS 410 in step 511 and transmits the scan request message to the base station 450 in step 513. do. Subsequently, the RS 440 receives a scan response (MOB_SCN-RSP) message, which is a response to the scan request message of the MSS 410, from the BS 450 in step 515, and sends the MSS 410 to the MSS 410 in step 517. Deliver the scan response message. Since the RS 440 may read a scan request message and a scan response message exchanged between the MSS 410 and the base station 450, the RS 440 may know whether the MSS 410 performs scanning and scanning schedule information. .

When the scan response message transmitted to the MSS 410 does not include scan performance rejection information, that is, when the MSS 410 performs scanning, the RS 440 proceeds to step 519 and waits. Perform In step 523, the RS 440 recognizes the end of the scan of the MSS by receiving a scan report (MOB_SCN-REP) message or any uplink data that reports a scan result from the MSS 410. In step 523, the RS 440 transmits the scan report message or any uplink data to the BS 450.

If the scan response message transmitted to the MSS 410 includes scan performance rejection information, the RS 440 recognizes that the scanning of the MSS 410 has been rejected and continues with the MSS 410 and the BS. (450) Relay communication between.

6 is a flowchart illustrating an operation procedure of a base station in a broadband wireless communication system using a multi-hop relay method according to the first embodiment of the present invention.

Referring to FIG. 6, in step 611, the base station 450 receives a scan request (MOB_SCN-REQ) message of the MSS 410 from the relay station 440 to obtain scan request information of the MSS 410. In step 613, the base station 450 determines the scan schedule of the MSS 410 using the scan request information.

When the scan schedule for the MSS 410 is determined, the base station 450 transmits a scan response (MOB_SCN-RSP) message including the determined scan schedule information to the RS 440 in step 615. As such, when the scanning is not rejected with respect to the MSS 410, the base station 450 proceeds to step 617 to perform a standby state. If scanning of the MSS 410 is denied, communication with the MSS 410 is continued using the relay of the RS 440.

During the standby state, the base station 450 checks whether a scan report (MOB_SCN-REP) message or any uplink data of the MSS 410 is received from the relay station 440 in step 619. At this time, upon receiving the scan report message or any uplink data, the base station 450 recognizes the scan termination and the scan result of the MSS 410 and resumes communication with the MSS 410.

4 to 6 illustrate an example in which a relay station can decode a scanning control message exchanged between an MSS and a base station.

Next, an embodiment of a case where a control message exchanged between the MSS and the base station cannot be decoded by the relay station will be described. When the relay station cannot recognize the scanning control message exchanged between the MSS and the base station, the base station may inform the relay station of the scanning operation performance information and the scanning result information of the MSS through separate signaling.

FIG. 7 illustrates a signal flow between a terminal, a relay station, and a base station for a scanning operation in a broadband wireless communication system using a multi-hop relay scheme according to a second embodiment of the present invention.

Referring to FIG. 7, first, the MSS 710 communicates with the relay station 740 in step 711, and the relay station 740 communicates with the base station 750 in step 713. That is, the MSS 710 and the base station 750 do not directly transmit and receive signals, and perform communication through a signal relayed by the relay station 740.

If it is determined that scanning during communication is necessary through the relay station 740 as described above, the MSS 7101 may determine the neighboring base stations including the serving base station 750 and the adjacent relay station 740 including the serving relay station 740 in step 715. A scan request (MOB_SCN-REQ) message of Table 4 is transmitted to the relay station 740 requesting scanning of pilot channel signals transmitted from the relay stations. The relay station 740 that has received the scan request (MOB_SCN-REQ) message relays the scan request (MOB_SCN-REQ) message received from the MSS 710 to the base station 750 in step 717. The base station 750 receiving the scan request (MOB_SCN-REQ) message includes information necessary for the scanning operation of the MSS 710 in step 719, and the scan response of Table 5 in which the scanning interval is not zero (0). MOB_SCN-RSP) message to the relay station 740. The RS 740 receiving the scan response (MOB_SCN-RSP) message including the scanning information relays the scan response (MOB_SCN-RSP) message to the MSS 710 in step 721.

On the other hand, the base station 750 transmitting the scan response (MOB_SCN-RSP) message to allow the scanning of the MSS 710, the terminal scan notification for notifying the scanning of the MSS 710 in step 723 (scan-notify) Send a message to the relay station 740.

Here, the terminal scan-notify message according to the present invention is as shown in Table 7 below.

Syntax Notes SCAN-NOTIFY_format () {   MS ID MS's identifier   Scan duration units are in frames. Time duration when MS performs scanning   Start frame first scanning interval start time   Interleaving interval duration in frames The period interleaved between scanning intervals when MS shall perform normal operation   Scan iteration The number of iterating scanning interval }

As shown in Table 7, the terminal scan notification message according to the present invention includes a plurality of IEs, a terminal identifier (MS ID) for scanning, a scan duration for scanning by the MSS, and a scanning. The start frame includes a start frame, a scan iteration when performing periodic scanning, an interleaving interval between scan operations, and the like.

On the other hand, the MSS 710 receiving the scan response (MOB_SCN-RSP) message is pilot corresponding to the parameters included in the scan response (MOB_SCN-RSP) message for neighboring base stations and neighboring relay stations in step 725. Perform scanning of channel signals. In step 727, the base station 750 stops transmitting data to the MSS 710 while the MSS 710 performs scanning corresponding to the parameters included in the scan response (MOB_SCN-RSP) message. . In this case, the base station 750 may buffer data transmitted to the MSS 710.

After completing scanning of the pilot channel signals received from the neighbor base stations and the neighbor relay stations, the MSS 710 transmits a scan report (MOB_SCN-REP) message including a scanning result to the relay station (729). 740. The relay station 740 relays the scan report (MOB_SCN-REP) message to the base station 750 in step 731. Thereafter, the base station 750 recognizes the end of the scan of the MSS 710 by the scan report message in step 733, and the end of the scan of the MSS 710 and the scan result information of the MSS 710 in step 733. A terminal scan result (scan-result) message to inform the relay station 740 is transmitted.

Here, the terminal scan result (scan-result) message according to the present invention is as shown in Table 8 below.

Syntax Notes SCAN-RESULT_format () {   MS ID MS's identifier   Report Metric Bitmap indicating presence of certain metrics: Bit 0: no scan result Bit 1: CINR mean Bit 2: RSSI mean Bit 3: Relative delay Bit 4-: RTD Bit 5-: reserved. shall be set to zero note) Bit 0 = 1 indicates that this message does not contain MS's scanning result. When Bit 0 is set to 1, the remaining bits in this field shall be set to 0. Also the remaining field in this message shall be discarded.   N_Node Number of RS or BS to be scanned   for (i = 0; i <N_Node; i ++) {     Node_ID BS Identifier or RS Identifier     Scanning result this field contains the scanning result corresponding to Report metric (CIRN / RSSI / Relative delay / RTD / etc.)   } }

As shown in Table 8, the terminal scan result message according to the present invention includes a plurality of IEs, a terminal identifier (MS ID) that terminates scanning, whether the MSS includes a scan result, and a scan result of the MSS. If included, a report metric indicating a type of information to be reported as a scan result, node information (Node_ID) that the MSS has scanned, and a scanning result for each node are included. The scanning result may be RSSI, relative delay, RTD (round trip delay), etc. in addition to the CINR according to the report metric value.

In addition, in step 735, the base station 750 transmits data of the MSS 710 buffered instead of transmitting while the MSS 710 performs scanning.

Meanwhile, when the MSS 710 finishes scanning earlier than the scanning schedule determined in steps 715 to 721 and transmits any uplink data, the base station 750 transmits uplink data of the MSS 710. The end of scan of the MSS 710 may be recognized by receiving. In this case, the base station 750 transmits the terminal scan result message to the relay station 740 to inform the end of the scan of the MSS 710.

The operations of the relay station and the base station corresponding to FIG. 7 are as follows.

8 is a flowchart illustrating an operation procedure of a relay station in a broadband wireless communication system using a multi-hop relay scheme according to a second embodiment of the present invention.

Referring to FIG. 8, the RS 740 first receives a scan request (MOB_SCN-REQ) message from the MSS 710 in step 811 and transmits the scan request message to the base station 750 in step 813. do. In step 815, the RS 740 receives a scan response (MOB_SCN-RSP) message from the base station 750 in response to the scan request message, and in step 817 receives the scan response (MOB_SCN-RSP) message. Send to MSS 710. In this process, the relay station 740 cannot recognize the scanning of the MSS 710 because the relay station 740 cannot decrypt the message exchanged between the MSS 710 and the base station 750.

Accordingly, the RS 740 checks whether a SCAN-NOTIFY message is received from the BS 750 to inform the MSS 710 of scanning in step 819. If the terminal scan notification message is not received, the RS 740 proceeds to step 821 to continuously relay data exchanged between the MSS 710 and the base station. If the terminal scan notification message is received, the RS 740 recognizes that the MSS 710 performs scanning according to the scanning schedule in step 823 and proceeds to the standby state.

Subsequently, the RS 740 receives a scan report (MOB_SCN-REP) message or random uplink data that reports scan results from the MSS 710 in step 825, and receives the received scan report (MOB_SCN) in step 827. -REP) relays the message or the uplink data to the base station 750. In this process, the relay station 740 cannot recognize the end of scanning of the MSS 710 because the relay station 740 cannot decrypt the message exchanged between the MSS 710 and the base station 750.

Accordingly, the RS 740 receives the terminal scan result (SCAN-RESULT) message including the scan end and scan result information of the MSS 710 from the BS 750 in step 829. Recognize the completion of scanning.

9 illustrates an operation procedure of a base station in a broadband wireless communication system using a multi-hop relay scheme according to a second embodiment of the present invention.

Referring to FIG. 9, the base station 750 first receives a scan request (MOB_SCN-REQ) message of the MSS 710 from the relay station 740 in step 911 to obtain scan request information of the MSS 710. In step 913, the base station 750 determines the scan schedule of the MSS 710 using the scan request information.

When the scan schedule for the MSS 710 is determined, the base station 750 checks whether scanning of the MSS 710 is allowed in step 915. If the scanning of the MSS 710 is not allowed, the base station 750 proceeds to step 917 and transmits a scan response (MOB_SCN-RSP) message including scan rejection information of the MSS 710 to the RS. 740.

If scanning of the MSS 710 is allowed, the base station 750 proceeds to step 919 and the RS 740 sends a scan response (MOB_SCN-RSP) message including scan schedule information of the MSS 710. To send. In this case, since the RS 740 cannot decrypt the scan response message transmitted to the MSS 710, the RS 740 should transmit a message indicating the scanning performed by the MSS 710 to the RS 740.

Accordingly, the base station 750 transmits a terminal scan notification (SCAN-NOTIFY) message to the relay station 740 to notify the scanning of the MSS 710 in step 921, and proceeds to step 923 to perform a standby state. do. In this case, data transmission to the MSS 710 may be stopped and data transmitted to the MSS 710 may be buffered.

During the standby state, the base station 750 checks whether a scan report (MOB_SCN-REP) message or any uplink data of the MSS 710 is received from the relay station 740 in step 925. At this time, upon receiving the scan report message or any uplink data, the base station 750 recognizes the scan termination and the scan result of the MSS 710 and resumes communication with the MSS 710.

In step 927, the base station 750 transmits a terminal scan end (SCAN-RESULT) message to the relay station 740 to inform the end of the scan and the scan result of the MSS 710.

In the above-described first and second embodiments of the present invention, the MSSs 410 and 710 describe a scanning operation by a UE request that starts by transmitting a scan request (MOB_SCN-REQ) message. Of course, the same applies to the scanning operation by the base station request which starts by transmitting a scan response (MOB_SCN-RSP) message to the terminal without receiving the scan request message.

On the other hand, if the MSS to which the MSS directly communicates can control and schedule the scanning of the MSS by processing the scan request (MOB_SCN-REQ) message and the scan response (MOB_SCN-RSP) message, The information necessary for negotiating a scanning operation does not have to be delivered to the base station not directly communicating with the MSS. The details are as follows.

FIG. 10 illustrates a signal flow between an MSS, a relay station, and a base station for performing a scanning operation of an MSS in a broadband wireless communication system using a multi-hop relay scheme according to a third embodiment of the present invention.

Referring to FIG. 10, first, the MSS 1010 communicates with the relay station 1040 in step 1011, and the relay station 1040 communicates with the base station 1050 in step 1013. That is, the MSS 1010 and the base station 1050 do not directly transmit and receive signals, and perform communication through a signal relayed by the relay station 1040.

If it is determined that scanning during communication is performed through the relay station 1040 as described above, the MSS 1010 may include adjacent base stations including the serving base station 1050 and adjacent relay stations including the serving relay station 1040 in step 1015. Transmits a scan request (MOB_SCN-REQ) message of Table 4 to the RS 1040 requesting scanning of the pilot channel signals transmitted from the APs.

The relay station 1040 receiving the scan request (MOB_SCN-REQ) message determines the scan schedule of the MSS 1010 in step 1017, and sends a scan response message including the determined scan schedule information to the MSS 1010. send. That is, the scan response (MOB_SCN-RSP) message of Table 5 including information necessary for the scanning operation of the MSS 1010 and the scanning interval is not 0 is transmitted to the MSS 1010. In the present invention, it is assumed that the relay station knows the neighbor base stations and the information of the neighboring relay stations in advance through the neighbor base station list broadcasted by the base station. Then, the MSS 1010 receiving the scan response (MOB_SCN-RSP) message pilots corresponding to the parameters included in the scan response (MOB_SCN-RSP) message for neighboring base stations and neighboring relay stations in step 1019. Perform scanning of channel signals.

Meanwhile, in step 1021, the RS 1040 stops transmitting data to the MSS 1010 while the MSS 1010 performs scanning corresponding to the parameters included in the scan response (MOB_SCN-RSP) message. . In this case, the RS 1040 may buffer data transmitted to the MSS 1010. In addition, in order to stop data transmission from the base station 1050 to the MSS 510 while the MSS 1010 performs a scanning operation, the RS 1040 transmits a scan notification message to the BS 1050 in step 1023. MOB_SCN-INF: Mobile Scanning Inform (hereinafter referred to as MOB_SCN-INF) to inform the base station 1050 of the scanning of the MSS 1010.

 Here, the scan notification (MOB_SCN-INF) message structure according to the present invention is as shown in Table 9 below.

Syntax Notes MOB_SCN-INF_Format () {   Management Message Type = TBD To be determined N_MS Number of MSS to perform scanning   For (i = 0; i <N_MS; i ++) {     MSS ID Identifier of MSS     Scan duration Duration (in units of frames) where the MSS may perform scanning for available BS / RS.     Start frame Measured from the frame in which this message was received.     Interleaving interval     Scan iteration     Reserved Shall be set to zero   } }

As shown in Table 9, the scan notification (MOB_SCN-INF) message according to the present invention includes a plurality of IEs, that is, a message type (Management Message Type) indicating the type of a message to be transmitted, MSS information for performing scanning, And time related parameter information that the MSS applies to scanning neighbor base stations and neighbor relay stations. In addition, since one or more MSSs may perform scanning at the same time, information of these MSSs may be included together in one scan notification (MOB_SCN-INF) message. Meanwhile, the time-related parameter information includes a scan duration indicating a scan period in which the MSS performs scanning, a start frame indicating a start time of the scanning operation of the MSS, and periodically repeating the scanning operation. In this case, the method may include a scan iteration indicating a scanning repetition frequency and an interleaving interval indicating a time interval between scanning operations when the scanning operation is repeated. As another example, the scan notification (MOB_SCN-INF) message may not include the time-related parameter information as described above, or may include additional information other than the above-mentioned time-related parameters or delete some information of the time-related parameters. Of course it can. In addition, since a detailed operation of the system according to time-related parameter information included in the scan notification (MOB_SCN-INF) message is not directly related to the present invention, a detailed description thereof will be omitted.

Meanwhile, in step 1025, the base station 1050 receiving the scan notification (MOB_SCN-INF) message informs the relay station 1040 that the scan notification (MOB_SCN-INF) message has been received. INFACK: Mobile Scanning Inform Acknowledgement (hereinafter referred to as MOB_SCN-INFACK)) is transmitted to the relay station 540.

Here, the scan notification response (MOB_SCN-INFACK) message structure according to the present invention is as shown in Table 10 below.

Syntax Size (bits) Notes MOB_SCN-INFACK_Format () {   Management Message Type = TBD 8 To be determined N_MS 8 Number of MSS to perform scanning   For (i = 0; i <N_MS; i ++) {     MSS ID 48 Identifier of MSS   } }

As shown in Table 10, the scan notification response (MOB_SCN-INFACK) message according to the present invention includes a plurality of IEs, that is, a message type (Management Message Type) indicating the type of a message to be transmitted, and the scan notification (MOB_SCN-). INF) includes MSS information to perform scanning included in the message.

In step 1027, the base station 1050 that recognizes the scanning of the MSS 1010 stops data transmission to the MSS 1010 and buffers the data to the MSS 1010. After completing the scanning of the pilot channel signals received from the neighbor base stations and the neighbor relay stations, the MSS 1010 scans the scan report (MOB_SCN-REP) of Table 6 including the scan result in step 1029. ) Transmits a message to the relay station 1040.

Then, the relay station 1040 relays the scan report (MOB_SCN-REP) message received in step 1031 to the base station 1050. In this case, the relay station 1040 reports the scan result of the MSS 1010 to the base station 1050 is configured in a message format between the relay station and the base station. For example, the message may include a content of the scan report (MOB_SCN-REP) message of Table 6, and may be a scan-result message of the terminal of Table 8 as another example.

The RS 1040 transmits the buffered data to the MSS 1010 without transmitting the MSS 1010 while scanning in step 1033. Meanwhile, the base station 1050 receiving the scan report message recognizes the end of the scan of the MSS 1010 in step 1035, while the MSS 1010 buffers the MSS 1010 without transmitting it while performing the scanning. The data of 1010 is transmitted.

Alternatively, when the MSS 1010 finishes scanning earlier than the scanning execution time determined in the scan negotiation procedure of steps 1015 to 1017, the MSS 1010 may resume communication by transmitting arbitrary uplink data. In this case, the RS 1040 may recognize the end of the scan of the MSS 1010 through any uplink data received from the MSS 1010. In this case, the relay station 1040 relays the uplink data to the base station 1050, and the base station 1050 receives the uplink data to recognize the end of the scan of the MSS 1010.

The third embodiment of the present invention described above has described the scanning operation by the MSS request started by the MSS 1010 transmitting the scan request (MOB_SCN-REQ) message, but the base station 1050 is the scan request Of course, the present invention can also be applied to a scanning operation by a base station request, which starts by transmitting the scan response message to the MSS 1010 without receiving a message. In addition, the relay station 1040 may also be applied to a scanning operation by a relay station request that starts by transmitting the scan response (MOB_SCN-RSP) message to the MSS 1010 without receiving the scan request (MOB_SCN-REQ) message. Of course it can. At this time, the scanning operation procedure by the request for the relay station 1040 corresponds to the remaining procedure except for step 1015 of FIG. 10.

On the other hand, if the MSS does not report the scanning result after the scanning is completed, the base station that does not communicate directly with the MSS does not know the end of the scan of the MSS, so a method for notifying the end of the scan from the relay station to the base station is necessary. Do. The details are as follows.

FIG. 11 illustrates a signal flow between an MSS, a relay station, and a base station for performing a scanning operation of an MSS in a broadband wireless communication system using a multi-hop relay scheme according to the fourth embodiment of the present invention.

Referring to FIG. 11, first, the MSS 1110 communicates with the relay station 1140 in step 1111, and the relay station 1140 communicates with the base station 1150 in step 1113. That is, the MSS 1110 and the base station 1150 do not directly transmit and receive a signal, and perform communication through a signal relayed by the relay station 1140.

When it is determined that scanning during communication is performed through the relay station 1140 as described above, the MSS 1110 may transmit pilots transmitted from neighboring base stations including a serving base station and adjacent relay stations including a serving relay station in step 1115. The scan request (MOB_SCN-REQ) message of Table 4 requesting scanning of channel signals is transmitted to the relay station 1140.

The relay station 1140 that has received the scan request (MOB_SCN-REQ) message includes information necessary for the scanning operation of the MSS 1110 in step 1117, and the scan response of Table 5 in which the scanning interval is not 0. A (MOB_SCN-RSP) message is transmitted to the MSS 1110. Upon receiving the scan response (MOB_SCN-RSP) message, the MSS 1110 corresponds to a pilot channel corresponding to the parameters included in the scan response (MOB_SCN-RSP) message for neighboring base stations and neighboring relay stations in step 1119. Perform scanning of the signals.

Meanwhile, the RS 1140 stops transmitting data to the MSS 1110 while the MSS 1110 performs scanning corresponding to the parameters included in the scan response (MOB_SCN-RSP) message in step 1121. . In this case, the RS 1140 may buffer data transmitted to the MSS 1110.

In addition, in order to stop data transmission from the base station 1150 to the MSS 1110 while the MSS 1110 performs the scanning operation, the RS 1140 transmits the information to the base station 1150 in step 1123. Sends the Scan Notification (MOB_SCN-INF) message. The base station 1150 receiving the scan notification (MOB_SCN-INF) message recognizes the scanning of the MSS 1110 in step 1125 and informs the relay station 1140 that the MOB_SCN-INF message has been received. The scan notification response (MOB_SCN-INFACK) message shown in Table 10 is transmitted. In addition, the base station 1150 stops data transmission to the MSS 1110 and buffers the data to the MSS 1110 while the MSS 1110 performs scanning in step 1127.

After completing the scanning of the pilot channel signals received from the neighbor base stations and the neighbor relay stations, the MSS 1110 determines whether to report a scan result in step 1129, and immediately if it is determined not to report. Communication with the relay station 1140 is resumed. Here, the resumption of communication with the relay station 1140 may include a periodic ranging procedure or an uplink bandwidth request procedure, and the detailed description thereof will be omitted since the procedures are not directly related to the present invention.

Meanwhile, when the MSS 1110 resumes communication with the RS 1140 but does not transmit a MOB_SCN-REP message, the RS 1140 recognizes that the MSS 1110 has completed scanning in step 1131. In order to inform the base station 1150 of this, a scan end (MOB_SCN-FIN: Mobile Scanning Finish, hereinafter 'MOB_SCN-FIN') message is transmitted to the base station 1150. The RS 1140 transmits the buffered data to the MSS 1110 without transmitting the MSS 1110 while scanning in step 1133.

Here, the scan termination (MOB_SCN-FIN) message structure according to the present invention is as shown in Table 11 below.

Syntax Notes MOB_SCN-FIN_Format () {   Management Message Type = TBD To be determined N_MS Number of MSS to finish scanning operation   For (i = 0; i <N_MS; i ++) {     MSS ID Identifier of MSS   } }

As shown in Table 11, the scan completion (MOB_SCN-FIN) message according to the present invention includes a plurality of IEs, that is, a message type (Management Message Type) indicating the type of a message to be transmitted, and MSS information that has completed scanning. It includes. The scan end (MOB_SCN-FIN message) may include information on a plurality of MSSs that have completed the scan operation.

The base station 1150 receiving the scan termination (MOB_SCN-FIN) message recognizes the end of the scan of the MSS 1110 in step 1135 and buffers the MSS 1110 without transmitting it while performing the scanning. Data to the MSS 1110 is transmitted.

Meanwhile, in step 1131, the terminal scan result (scan-result) in addition to the scan termination (MOB_SCN-FIN) message of Table 11 as a message transmitted between the relay station and the base station to inform the end of the scan of the MSS. Of course, messages can be used.

In the third and fourth embodiments of the present invention described above, the MSS 1010 and 1110 describe the scanning operation by the MSS request, which starts by sending the scan request (MOB_SCN-REQ) message. 1040 and 1140 may also be applied to a scanning operation by a relay station request that is initiated by transmitting the scan response (MOB_SCN-RSP) message to the MSS 1010 and 1110 without receiving the scan request (MOB_SCN-REQ) message. Of course. In this case, the scanning operation procedure according to the request of the relay station 1110 corresponds to a procedure other than step 1115 of FIG. 11.

Hereinafter, operations of the relay station and the base station corresponding to FIGS. 10 and 11 will be described.

12 is a flowchart illustrating an operation procedure of a relay station in a broadband wireless communication system using a multi-hop relay scheme according to the third and fourth embodiments of the present invention.

Referring to FIG. 12, first, the RS receives a scan request (MOB_SCN-REQ) message requesting scanning from the MSS in step 1211, and scan response (MOB_SCN) including information necessary for scanning of the MSS in step 1213. -RSP) message to the MSS.

The relay station stops transmitting data to the MSS and buffers the data to the MSS while the MSS performs scanning. In step 1215, the RS transmits a scan notification (MOB_SCN-INF) message to the serving base station to notify the scanning of the MSS.

In step 1217, the RS checks whether a scan notification response (MOB_SCN-INFACK) message, which is a response to the scan notification message, is received from the base station. If the scan notification response message is not received within the predetermined time, the RS returns to step 1215 to retransmit the scan notification message. The number of retransmissions of the scan notification message and the predetermined time may be set and changed by a system designer.

If the scan notification response message is received within the predetermined time, the RS performs a relay station operation other than transmitting / receiving traffic with the MSS in step 1219. If the MSS completes the scanning, the RS resumes communication with the MSS which has completed scanning in step 1221.

In step 1223, the RS checks whether a scan report (MOB_SCN-REP) message including a scan result is received from the MSS. If the scan report message is received, the RS proceeds to step 1225 to relay the scan report message received from the MSS to the base station. If the scan report message is not received within a predetermined time, the RS proceeds to step 1227 and transmits a scan end (MOB_SCN-FIN) message to the base station indicating the end of scanning.

Meanwhile, as a method of notifying the base station of the scan result of the MSS in step 1225 or notifying the end of the scan of the MSS to the base station in step 1227, the RS transmits a terminal scan result (SCAN-RESULT) message of the <Table 8>. May be transmitted to the base station. In addition, when the MSS scan report (MOB_SCN-REP) message is not received and any uplink data is received in step 1223, the RS does not need to transmit a control message indicating the end of the scan of the MSS. It can transmit to the base station.

13 is a flowchart illustrating an operation procedure of a base station in a broadband wireless communication system using a multi-hop relay scheme according to the third and fourth embodiments of the present invention.

Referring to FIG. 13, in step 1311, the base station receives a scan notification (MOB_SCN-INF) message notifying a scanning performance of at least one terminal from a relay station, and in step 1313, the base station receives a scan notification (MOB_SCN-INF) message for the scan notification (MOB_SCN-INF) message. As a response, a scan notification response (MOB_SCN-INFACK) message is transmitted to the relay station. In step 1315, the base station stops data transmission to the MSS that is performing scanning and buffers the data to the MSS.

During the buffering, the base station checks whether a scan report (MOB_SCN-REP) message including a scanning result is received from the relay station in step 1317. If the scan report (MOB_SCN-REP) message is received, the base station recognizes that the scanning operation of the MSS has been completed, and proceeds to step 1321 to transmit the buffered data to the MSS. Herein, in step 1317, the scan report (MOB_SCN-REP) message of the MSS received by the base station may be replaced by the terminal scan result (SCAN-RESULT) message of Table 8 including scan result information of the MSS. Of course.

If the scan report (MOB_SCN-REP) message is not received, the base station proceeds to step 1319 and checks whether a scan end (MOB_SCN-FIN) indicating the end of scanning is received. If the scan end message is not received, the base station returns to step 1317. If the scan end message is received, the base station proceeds to step 1321 and transmits the buffered data to the MSS. Here, the scan end (MOB_SCN-FIN) message may be replaced with the terminal scan result (SCAN-RESULT) message of the <Table 8> including the scan end information of the MSS. Alternatively, the base station may recognize the end of the scan of the MSS even when receiving any uplink data of the MSS without receiving a separate control message indicating the end of the scan of the MSS.

14 is a flowchart illustrating a scanning operation of a terminal MSS in a broadband wireless communication system using a multi-hop relay scheme according to an exemplary embodiment of the present invention.

Referring to FIG. 14, if it is determined that scanning is necessary, the MSS transmits a scan request (MOB_SCN-REQ) message to the serving relay station in step 1411. In step 1413, if a scan response (MOB_SCN-RSP) message having a non-zero scan interval is received from the relay station, the MSS proceeds to step 1415 and the MSS is included in the scan response (MOB_SCN-RSP) message received from the relay station. Scanning is performed for neighboring base stations including the serving base station and neighboring relay stations including the serving relay station according to the parameter.

In step 1417, the MSS checks whether the scanning operation is completed. When the scanning operation is completed, the MSS proceeds to step 1419 to resume communication with the serving relay station. Here, the MSS may transmit a scan report (MOB_SCN-REP) message including a scan result to the relay station or perform another communication procedure with the relay station without transmitting the scan report (MOB_SCN-REP) message.

Hereinafter, a block diagram of a terminal (MSS), a relay station (RS), and a base station (BS) according to the present invention will be described. Since the terminal MSS, the relay station RS, and the base station BS having the same interface module (communication module) have the same block configuration, the following description will describe operations of the terminal, relay station, and base station with one device. Shall be.

15 is a block diagram of a terminal (or relay station or base station) according to an embodiment of the present invention. The following description will focus on the control message processing.

First, referring to FIG. 15, a configuration of a terminal is as follows.

The interface module 1521 is a module for communicating with a relay station or a base station, and includes an RF processor and a baseband processor. The RF processor converts a signal received through an antenna into a baseband signal and provides the baseband signal to the baseband processor, and transmits a baseband signal from the baseband processor on an actual air. Transmit to and transmit through the antenna. For example, in the case of using a broadband wireless access method, the baseband processor transfers the signal from the RF processor and fast decodes the Fourier Transform (FFT) and transmits original information data to the controller 1519. Conversely, channel encoding and inverse fast fourier transform (IFFT) operations are performed on the data from the controller 1519 and provided to the RF processor.

The controller 1519 controls the overall operation of the terminal. For example, it performs processing and control for voice calls and data communication, and processes the scanning operation according to the present invention in addition to the usual functions. According to the present invention, the control unit 1519 provides a control message received from the relay station to the message processing unit 1511 and receives a message to be transmitted to the relay station from the message generating unit 1513 to the interface module 1521. do.

The storage unit 1517 stores a program for controlling the overall operation of the terminal and temporary data generated during program execution. That is, the storage unit 1517 may generally store data and control information to be transmitted to the relay station by the MSS.

The message processing unit 1511 decomposes the control message received from the relay station and notifies the control unit 1519 of the result. When the scan response (MOB_SCN-RSP) message shown in Table 5 is received according to the present invention, various control information included in the scan response message is extracted and provided to the controller 1519. Then, the controller 1519 controls the scanning processor 1515 according to the control information from the message processor 1511.

The scanning processor 1515 processes an operation for scanning neighboring base stations and neighboring relay stations according to the parameters set in the scan response message under the control of the controller 1519, collects the scanning result, and then controls the controller ( 1519). Then, the controller 1519 transmits the scanning result to the message generator 1513.

The message generator 1513 generates a scan request (MOB_SCN-REQ) message of Table 4 to be transmitted to the relay station under the control of the controller 1519, or includes the scan report of Table 6 including the scanning result ( A MOB_SCN-REP message is generated and delivered to the controller 1519. The message generated by the message generator 1513 is transferred to the interface module 1521 through the controller 1519.

In the configuration of the terminal described above, the controller 1519 controls the message processor 1511, the message generator 1513, and the scanning processor 1515. That is, the controller 1519 may perform the functions of the message processor 1511, the message generator 1513, and the scanning processor 1515. In the present invention, it is shown to configure them separately to explain each function separately. Therefore, in actual implementation, all of them may be configured to be processed by the controller 1519, and only some of them may be configured to be processed by the controller 1519.

Next, a configuration of the relay station will be described with reference to FIG. 15.

The interface module 1521 is a module for communicating with a terminal or a base station and includes an RF processor and a baseband processor. The RF processor converts a signal received through an antenna into a baseband signal and provides the baseband signal to the baseband processor, and transmits a baseband signal from the baseband processor on an actual air. Transmit to and transmit through the antenna. For example, when using a broadband wireless access method, the baseband processor controls the fast Fourier transform (FFT) and channel decodes a signal from the RF processor to control the original information data (traffic or control message). To pass). Conversely, channel data and IFFT (Inverse Fast Fourier Transform) calculation are performed on the information data from the controller 1519 and provided to the RF processor.

The controller 1519 controls the overall operation of the relay station. For example, it performs processing and control for voice call and data communication, and processes the scanning operation of the terminal according to the present invention in addition to the usual functions. According to the present invention, the control unit 1519 provides a control message received from the terminal or the base station to the message processing unit 1511 and receives a message to be transmitted to the terminal or the base station from the message generating unit 1513. 1521).

The storage unit 1517 stores a program for controlling the overall operation of the RS and a temporary data generated during the execution of the program. That is, the storage unit 1517 may store data and control information to be transmitted to the terminal or the base station.

The message processor 1511 decomposes the control message received from the terminal or the base station and notifies the controller 1519 of the result. According to the present invention, when the scan request (MOB_SCN-REQ) message of Table 4 and the scan report (MOB_SCN-REP) message of Table 6 are received from the terminal, or the scan response (MOB_SCN-RSP) message of Table 5 from the base station If the MOB_SCN-INFACK message in Table 10 and the SCAN-NOTIFY message in Table 7 and the SCAN-RESULT message in Table 8 are received, Various control information included therein is extracted and provided to the controller 1519. Then, the controller 1519 performs the processing according to the control information from the message processor 1511.

The scanning processor 1515 performs a function of managing terminals performing a scanning operation under the control of the controller 1519. According to the present invention, an operation of recognizing a terminal performing a scanning operation and an operation of stopping data transmission to the terminal are processed. In addition, the scanning processing unit 1515 processes an operation of recognizing the completion of scanning of the terminal, and resumes transmission of data buffered in the storage unit 1517 to the corresponding terminal.

The message generator 1513 generates a scan response (MOB_SCN-RSP) mesh of Table 5 to be transmitted to the terminal under the control of the controller 1519 and provides the message to the controller 1519. In addition, the message generator 1513 transmits the scan request (MOB_SCN-REQ) message of Table 4, the scan report (MOB_SCN-REP) message of Table 6, and the scan notification (MOB_SCN-INF) of Table 9 to be transmitted to the base station. ) Message, and the scan completion (MOB_SCN-FIN) message of Table 11 are generated and transmitted to the controller 1519. The message generated by the message generator 1513 is transferred to the interface module 1521 through the controller 1519.

In the above configuration of the relay station, the controller 1519 controls the message processor 1511, the message generator 1513, and the scanning processor 1515. That is, the controller 1519 may perform the functions of the message processor 1511, the message generator 1513, and the scanning processor 1515. In the present invention, it is shown to configure them separately to explain each function separately. Therefore, when the product is actually implemented, all of them may be configured to be processed by the controller 1519, and only some of them may be configured to be processed by the controller 1519.

Next, referring to FIG. 15, the configuration of the base station is as follows.

The interface module 1521 is a module for communicating with a terminal or a relay station and includes an RF processor and a baseband processor. The RF processor converts a signal received through an antenna into a baseband signal and provides the baseband signal to the baseband processor, and transmits a baseband signal from the baseband processor on an actual air. Transmit to and transmit through the antenna. For example, when using a broadband wireless access method, the baseband processor controls the fast Fourier transform (FFT) and channel decodes a signal from the RF processor to control the original information data (traffic or control message). To pass). Conversely, channel data and IFFT (Inverse Fast Fourier Transform) calculation are performed on the information data from the controller 1519 and provided to the RF processor.

The controller 1519 controls the overall operation of the base station. For example, it performs processing and control for voice call and data communication, and processes the scanning operation of the terminal according to the present invention in addition to the usual functions. According to the present invention, the control unit 1519 provides a control message received from a terminal or a relay station to the message processing unit 1511 and receives a message to be transmitted to the terminal or relay station from the message generating unit 1513. 1521).

The storage unit 1517 stores a program for controlling the overall operation of the base station and temporary data generated during program execution. That is, the storage unit 1517 may generally store data and control information to be transmitted to the terminal or the relay station.

The message processing unit 1511 decomposes the control message received from the terminal or the relay station and notifies the control unit 1519 of the result. According to the present invention, a scan request (MOB_SCN-REQ) message of Table 4, a scan report (MOB_SCN-REP) message of Table 6, a scan notification (MOB_SCN-INF) message of Table 9, and a scan of Table 11 from the relay station according to the present invention. When the end (MOB_SCN-FIN) message is received, various control information included in the received message is extracted and provided to the controller 1519. Then, the controller 1519 performs the processing according to the control information from the message processor 1511.

The scanning processor 1515 performs a function of managing terminals performing a scanning operation under the control of the controller 1519. According to the present invention, an operation of recognizing a terminal performing a scanning operation and an operation of stopping data transmission to the terminal are processed. In addition, the scanning processing unit 1515 processes an operation of recognizing the completion of scanning of the terminal, and resumes transmission of data buffered in the storage unit 1517 to the corresponding terminal.

The message generator 1513 generates a message to be transmitted to the terminal or the relay station under the control of the controller 1519 and provides the message to the controller 1519. According to the present invention, the scan response (MOB_SCN-RSP) message of Table 5 or the scan notification response (MOB_SCN-INFACK) message of Table 10 or the terminal scan notification (SCAN-NOTIFY) message of Table 7 or the A terminal scan result (SCAN-RESULT) message of Table 8 is generated and provided to the controller 1519. The message generated by the message generator 1513 is transferred to the interface module 1521 through the controller 1519.

In the configuration of the base station described above, the controller 1519 controls the message processor 1511, the message generator 1513, and the scanning processor 1515. That is, the controller 1519 may perform the functions of the message processor 1511, the message generator 1513, and the scanning processor 1515. In the present invention, it is shown to configure them separately to explain each function separately. Therefore, when the product is actually implemented, all of them may be configured to be processed by the controller 1519, and only some of them may be configured to be processed by the controller 1519.

Meanwhile, in the broadband wireless access communication system supporting the multi-hop relay method, the scanning operation is performed in addition to the scanning operation by the terminal request, which is started by the terminal transmitting a scan request (MOB_SCN-REQ) message as described above, and the scan request (MOB_SCN−). Scanning operation by the request of the relay station, which is initiated by the relay station transmitting the scan response (MOB_SCN-RSP) message to the terminal without receiving the REQ message from the terminal, and the base station transmitting the scan response (MOB_SCN-RSP) message to the terminal This may include a scanning operation by the request of the base station to start. In this case, the scanning operation according to the request of the relay station is a procedure in which the terminal transmits a scan request (MOB_SCN-REQ) message to the relay station during the scanning operation according to the terminal request, and the relay station transmits the scan request (MOB_SCN-REQ) to the base station. The same applies except for the procedure of relaying a message. In addition, the scanning operation by the request of the base station may be applied in the same manner except that the terminal transmits a scan request (MOB_SCN-REQ) message through the relay of the relay station during the scanning operation by the end of the month.

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. For example, the above-described message structures are just examples for better understanding of the present invention, and those skilled in the art can easily perform the modifications. 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.

As described above, the present invention uses a relay station capable of providing a multi-hop relay path between the MSS and the base station when the direct link channel situation between the base station and the MSS is poor in a broadband wireless access communication system using an OFDM / OFDMA scheme. As a result, the MSS may be provided with the same service and function as the case of performing communication using the direct link with the base station through the relay station. In addition, the present invention provides the same service and function between the MSS and the base station, it is possible for the relay station to select the signaling between the MSS and the base station to prevent radio link channel resource waste by relaying only necessary signaling without transmitting unnecessary signaling. . In addition, the present invention has the advantage of reducing the difference between the system that can occur due to the dual signaling between the relay station and the MSS and the relay station and the base station and to synchronize the system operation.

Claims (60)

In a communication method of a relay station in a cellular communication system using a multi-hop relay method, Transmitting a scan request message received from the terminal to the base station; And transmitting a scan response message including information necessary for scanning of the terminal received from the base station to the terminal. The method of claim 1, The scan request message includes information of neighboring base stations and neighboring relay stations desired to be scanned. The method of claim 1, The scan response message may include a scan section, a scan result report method, a scan report period, a type of information to be reported as a scan result, a scan start time, a scan repetition number, a time interval between scan operations, neighbor base stations and neighboring relay stations to be scanned. At least one of the information. The method of claim 1, And after receiving the scan request message, receiving a scan notification message indicating the scanning of the terminal from the base station. The method of claim 4, wherein The scan notification message may include at least one of a terminal identifier, a scan interval, a scan start time, a scan repeat count, and a time interval between scan operations. The method of claim 1, Receiving a scan report message including a scanning result from the terminal; Transmitting the scan report message to the base station. The method of claim 6, The scan report message may include at least one of a scan result report method, a type of information to be reported as a scan result, information of neighboring base stations and neighboring relay stations which have been scanned, and scanning result information. The method of claim 7, wherein The scan result information may be any one of a carrier to interference and noise ratio (CINR), a received signal strength indication (RSSI), and delay information. The method of claim 6, And after receiving the scan report message, receiving a scan result message indicating the scanning result of the terminal from the base station. The method of claim 9, The scan result message may include at least one of a terminal identifier, identifiers of nodes scanned by the terminal, and scanning result information. In a communication method of a relay station in a cellular communication system using a multi-hop relay method, Determining a scan schedule of the terminal by using information of the scan request message when receiving a scan request message from a terminal; And transmitting a scan response message including the determined scan schedule information to the terminal. The method of claim 11, The scan request message includes information of neighboring base stations and neighboring relay stations desired to be scanned. The method of claim 11, The scan response message may include a scan section, a scan result report method, a scan report period, a type of information to be reported as a scan result, a scan start time, a scan repetition count, a time interval between scan operations, neighbor base stations and neighbor relay stations to be scanned. At least one of the information. The method of claim 11, Transmitting the scan notification message to the base station after the scan response message is transmitted to the terminal, and notifying the terminal of the scanning performance; Receiving a response message to the scan notification message from the base station. The method of claim 14, The scan notification message, characterized in that it comprises at least one terminal information for performing the scanning. The method of claim 11, And buffering data to be transmitted to the terminal while the terminal performs the scanning. The method of claim 11, Receiving a scan report message including a scanning result from the terminal; And generating a message for reporting information of the scan report message and transmitting the message to the base station. The method of claim 17, The scan report message may include at least one of a scan result report method, a type of information to be reported as a scan result, information of neighboring base stations and neighboring relay stations which have been scanned, and scanning result information. The method of claim 11, Interrupting communication with the terminal while the terminal performs scanning; And when the communication with the terminal is resumed, transmitting a scan end message to the serving base station to notify the end of scanning of the terminal. The method of claim 19, The scan completion message, characterized in that it comprises at least one terminal information completed the scanning. In a communication method of a base station in a cellular communication system using a multi-hop relay method, Receiving a scan request message of the terminal from the relay station; Determining a scan schedule of the terminal by using the information of the scan request message; And transmitting a scan response message including the determined scan schedule information to the terminal through the relay station. The method of claim 21, And after transmitting the scan response message, transmitting a scan notification message for notifying the terminal to perform the scanning to the relay station. The method of claim 22, The scan notification message may include at least one of a terminal identifier, a scan interval, a scan start time, a scan repeat count, and a time interval between scan operations. The method of claim 21, And receiving a scan report message including a scanning result from the terminal. The method of claim 24, And when the scan report message is received, transmitting data buffered during the scanning of the terminal to the terminal through the relay station. The method of claim 24, And receiving a scan result message indicating the scanning result of the terminal to the relay station when the scan report message is received. The method of claim 26, The scan result message may include at least one of a terminal identifier, identifiers of nodes scanned by the terminal, and scanning result information. In a communication method of a base station in a cellular communication system using a multi-hop relay method, Receiving a scan notification message from the relay station to notify the terminal of scanning; Recognizing the scanning of the terminal by using the scan notification message; And transmitting a response message to the relay station in response to the scan notification message. The method of claim 28, Buffering data to be transmitted to the terminal while the terminal performs scanning; Transmitting the buffered data to the terminal through the relay station upon receiving a message reporting the scanning result of the terminal from the relay station or a scan termination message notifying the end of scanning of the terminal. . The method of claim 28, The scan notification message, characterized in that it comprises at least one terminal information for performing the scanning. A scanning method in a cellular communication system using a multi-hop relay method, Transmitting, by the terminal, a scan request message requesting scanning to the base station through the relay station; Transmitting, by the base station, a scan response message including information necessary for scanning of the terminal to the terminal through the relay station; And transmitting, by the base station, a scan notification message indicating the scanning of the terminal to the relay station. The method of claim 31, wherein The scan notification message may include at least one of a terminal identifier, a scan interval, a scan start time, a scan repeat count, and a time interval between scan operations. The method of claim 31, wherein Scanning, by the terminal, neighboring base stations and neighboring base stations using information of the scan response message; Transmitting, by the terminal, a scan report message including a scanning result to the base station through the relay station; And transmitting, by the base station, a scan result message indicating a scanning result of the terminal to the relay station. The method of claim 33, wherein And transmitting, by the base station, data buffered during the scanning of the terminal to the terminal through the relay station. The method of claim 33, wherein The scan result message may include at least one of a terminal identifier, identifiers of nodes scanned by the terminal, and scanning result information. A scanning method in a cellular communication system using a multi-hop relay method, Transmitting, by the terminal, a scan request message requesting scanning to the relay station; Transmitting, by the relay station, a scan response message including information necessary for scanning of the terminal to the terminal; And transmitting, by the relay station, a scan notification message to notify the base station that the terminal performs the scanning. The method of claim 36, The scan notification message, characterized in that it comprises at least one terminal information for performing the scanning. The method of claim 36, And transmitting, by the base station, a response message for the scan notification message to the relay station. The method of claim 36, Scanning, by the terminal, neighbor BSs and neighbor RSs using information of the scan response message; Transmitting, by the terminal, a scan report message including the scanning result to the relay station; And generating, by the relay station, a message for reporting the information of the scan report message and transmitting the message to the base station. The method of claim 39, And transmitting, by the relay station, data buffered during the scanning of the terminal to the terminal. The method of claim 39, And transmitting, by the base station, the buffered data to the relay station during scanning of the terminal. The method of claim 36, And transmitting, by the relay station, a scan end message for notifying the end of scanning of the terminal to the base station. The method of claim 42, wherein The scan completion message, characterized in that it comprises at least one terminal information completed the scanning. In a relay station device in a cellular communication system using a multi-hop relay method, A message processing unit for decomposing the scan notification message received from the base station; And a control unit for recognizing the scanning of the terminal by using the information of the scan notification message from the message processing unit. The method of claim 44, The scan notification message may include at least one of a terminal identifier, a scan interval, a scan start time, a scan repeat count, and a time interval between scan operations. The method of claim 44, The message processing unit decomposes a scan result message received from the base station, And the control unit recognizes the scanning result of the terminal by using the information of the scan result message from the message processing unit. 47. The method of claim 46 wherein The scan result message may include at least one of a terminal identifier, identifiers of nodes scanned by the terminal, and scanning results for the nodes. In a relay station device in a cellular communication system using a multi-hop relay method, A message processing unit for processing a scan request message received from the terminal; A message generator for generating a scan response message including information necessary for scanning of the terminal in response to the scan request message; And an interface module for transmitting a message from the message generator through an antenna. The method of claim 48, And the scan request message includes information of neighbor base stations and neighbor repeaters desired to be scanned. The method of claim 48, The scan response message may include a scan section, a scan result report method, a scan report period, a type of information to be reported as a scan result, a scan start time, a scan repetition count, a time interval between scan operations, neighbor base stations to be scanned, and a neighbor repeater. Device comprising at least one of the information. The method of claim 48, When receiving a scan report message including a scanning result from the terminal, the message generating unit, characterized in that for generating a message for reporting the information of the scan report message to the base station to provide to the interface module. The method of claim 51, The scan report message may include at least one of a scan result report method, a type of information to be reported as a scan result, information of neighboring base stations and neighboring relay stations which have been scanned, and scanning result information. The method of claim 48, And a storage unit for buffering data to be transmitted to the terminal during the scanning operation of the terminal. The method of claim 48, And transmitting the scan response message to the base station by generating a scan notification message for notifying the base station of a scanning operation of the terminal. The method of claim 54, The scan notification message, the device characterized in that it comprises at least one terminal information for performing the scanning. The method of claim 48, If communication is resumed after the scanning of the terminal is completed, the message generator, characterized in that to generate a scan end message for notifying the end of scanning of the terminal to the base station to provide to the interface module. The method of claim 56, wherein The scan end message, the device characterized in that it comprises at least one terminal information that completes scanning The method of claim 48, The interface module, characterized in that the module for orthogonal frequency division multiplexing (OFDM) communication. In a relay station device in a cellular communication system, A message processing unit for decomposing a scan notification message received from a first station; And a control unit for recognizing the scanning of the second station by using the information of the scan notification message from the message processing unit. In a relay station device in a cellular communication system, A message processing unit for processing a scan request message received from a first station; A message generator for generating a scan response message including information necessary for scanning of the first station in response to the scan request message; And an interface module for transmitting a message from the message generator through an antenna.

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