Patent Publication Number: US-2007097905-A1

Title: Method for transmitting and receiving data in a multi-hop wireless mobile communication system

Description:
PRIORITY  
      This application claims the benefit under 35 U.S.C. § 119(a) of an application filed in the Korean Intellectual Property Office on Oct. 28, 2005 and assigned Serial No. 2005-102361, the contents of which are incorporated herein by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates generally to a wireless mobile communication system, and in particular, to a method for transmitting and receiving data in a wireless mobile communication system using a multi-hop scheme.  
      2. Description of the Related Art  
      Presently, wireless mobile communication systems have developed from the 3 rd  Generation mobile communication system into the 4 th  Generation mobile communication system. Research on the 4 th  Generation mobile communication system is being conducted not only to provide a higher rate, but also to extend the wireless transmission range, i.e. the service area. A multi-hop scheme has been proposed for the extension of the service area. In the multi-hop scheme, a relay node designed at low cost for communication with the nodes located outside the cell coverage uses a method of relaying signals to the nodes located outside the cell coverage.  
      A Wideband Code Division Multiple Access (W-CDMA) system employs multi-hop technology in which a user node (UE) serves as a relay based on an Opportunity Driven Multiple Access/Time Division Duplexing (ODMA/TDD) scheme, thereby extending coverage of the cellular network. In ODMA/TDD system, when a UE located outside the cellular coverage desires to communicate with a Node B, a UE located in the intermediate route serves as a relay node.  
       FIG. 1  is a diagram illustrating a system configuration for performing multi-hop communication based on ODMA/TDD in the conventional W-CDMA communication system.  
      Referring to  FIG. 1 , a base station (or Node B)  100  can distinguish mobile stations (or UEs)  102  and  104  to which it can directly provide service, from mobile stations  106  to  112  located outside the cell coverage. Mobile stations  106  to  112  located outside the cell coverage communicate directly with the mobile station  102  or  104  located in the cell, or communicate with the base station  100  based on ODMA/TDD by a relay.  
       FIG. 2  is a diagram illustrating a frame structure used for multi-hop communication in the conventional W-CDMA communication system.  
      Referring to  FIG. 2 , a frame is composed of a plurality of slots, and among the slots, an ODMA Dedicated Channel (ODCH) and an ODMA Random Access Channel (ORACH) slots needed by a relay node to relay data are necessary. The ORACH, a contention-based channel, is used for transmitting a small amount of data, while the ODCH, a non-contention-based channel, is used for transmitting a large amount of data.  
      However, the ODCH and ORACH slots should occupy some of the general slots for relay in a fixed manner. This is because it is not possible to adaptively allocate the ODCH or the ORACH when the traffic load changes abruptly due to movement of a mobile station, or when the traffic change is considerable even in a short interval, like Internet service.  
      That is, when a more than required number of fixed ODCH and ORACH slots are allocated in the frame, resource waste occurs, and when a less than required number of the fixed ODCH and ORACH slots are allocated in the frame, time delay occurs during data transmission, making it impossible to satisfy Quality of Service (QoS) of the mobile station.  
     SUMMARY OF THE INVENTION  
      It is, therefore, an object of the present invention to provide a new frame structure in a multi-hop wireless mobile communication system.  
      It is another object of the present invention to provide a new operation scenario for transmitting and receiving data in a multi-hop wireless mobile communication system.  
      According to one aspect of the present invention, there is provided a method for transmitting and receiving data in a multi-hop wireless mobile communication system having a first mobile station (MS), a second MS, a base transceiver station (BTS), and a relay BTS. The method includes allowing the first MS to directly communicate with the BTS, and allowing the second MS to communicate with the BTS by relay of the relay BTS; performing communication between the BTS and the first MS and communication between the relay BTS and the second MS using a first frame; and performing communication between the BTS and the relay BTS using a second frame.  
      According to another aspect of the present invention, there is provided a method for exchanging data with a mobile station (MS) by a relay base transceiver station (BTS) in a multi-hop wireless mobile communication system having a BTS and the relay BTS, the relay BTS relaying an MS signal transmitted to the BTS. The method includes making access to the BTS using a first frame; receiving a resource allocated from the BTS after authentication thereof; if the MS attempts an access to the relay BTS, notifying the BTS of the attempt using a second frame; upon receipt of a notification indicating completed authentication on the MS from the BTS, notifying the MS of the completed authentication using the first frame; and allocating some or all of resources allocated from the BTS to the MS, and exchanging data with the MS using the allocated resource. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which:  
       FIG. 1  is a diagram illustrating a system configuration for performing multi-hop communication based on ODMA/TDD in the conventional W-CDMA communication system;  
       FIG. 2  is a diagram illustrating a frame structure used for multi-hop communication in the conventional W-CDMA communication system;  
       FIG. 3  is a diagram illustrating a configuration of a multi-hop wireless mobile communication system according to the present invention;  
       FIG. 4  is a diagram illustrating a multi-hop wireless mobile communication system using a Type-A frame according to the present invention;  
       FIG. 5  is a diagram illustrating a multi-hop wireless mobile communication system using a Type-B frame according to the present invention;  
       FIG. 6  is a diagram illustrating structures of a Type-A frame and a Type-B frame newly proposed in a multi-hop wireless mobile communication system according to the present invention;  
       FIG. 7  is a diagram illustrating a structure of data exchanged between a BTS and an MH-BTS in a multi-hop mobile communication system according to the present invention;  
       FIG. 8  is a diagram illustrating resource allocation information represented by MAP information in a multi-hop wireless mobile communication system according to the present invention;  
       FIGS. 9A and 9B  are diagrams illustrating exemplary periodic frame allocation methods in a multi-hop wireless mobile communication system according to the present invention;  
       FIG. 10  is a diagram illustrating an exemplary random frame allocation method in a multi-hop wireless mobile communication system according to the present invention;  
       FIG. 11  is a signaling diagram illustrating signals exchanged between an MS, a BTS, and an MH-BTS in a multi-hop wireless mobile communication system according to the present invention; and  
       FIG. 12  is a signaling diagram illustrating information inserted in each individual frame depending on signals exchanged between an MS, a BTS, and an MH-BTS in a multi-hop wireless mobile communication system according to the present invention. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
      Preferred embodiments of the present invention will now be described in detail with reference to the annexed drawings. In the following description, a detailed description of known functions and configurations incorporated herein has been omitted for clarity and conciseness.  
      The present invention provides a new frame structure for efficiently using a multi-hop scheme in a multi-hop wireless mobile communication system, and presents an operation scenario for exchanging data between a base transceiver station (BTS), a mobile station (MS), and a relay BTS, or multi-hop BTS (“MH-BTS”), according to the new frame structure.  
      The present invention is applicable to a wireless mobile communication system using a multi-hop scheme (“multi-hop wireless mobile communication system”), and is preferably applicable to a communication system using an Orthogonal Frequency Division Multiple Access (OFDMA) scheme.  
       FIG. 3  is a diagram illustrating a configuration of a multi-hop wireless mobile communication system according to the present invention.  
      Referring to  FIG. 3 , a BTS  300  communicates directly with an MS  340 , and an MH-BTS_A  320  communicates directly with an MS  360 . The MH-BTS 13 A  320  serves to relay the signals that the MS  360  transmits and receives to/from the BTS  300 . The MH-BTS_A  320  can either move or be fixed.  
      In the communication system where only the BTS and MS exist, when the MH-BTS is added, the system takes into consideration not only the resources for data exchange between the BTS and the MS, but also the resources for delay, i.e. wireless resources allocated for data exchange between the MH-BTS and the MS, and wireless resources allocated for data exchange between the MH-BTS and the BTS.  
      The present invention uses a Time Division Duplexing (TDD) technique that time-shares all wireless resources. Accordingly, the present invention newly proposes a Type-A frame for data exchange between the BTS/MH-BTS and the MS that communicates directly with the BTS/MH-BTS, and a Type-B frame for data exchange between the BTS and the MH-BTS. A detailed description of the Type-A and Type-B frame structures will be made with reference to  FIG. 6 .  
       FIG. 4  is a diagram illustrating a multi-hop wireless mobile communication system using a Type-A frame according to the present invention.  
      Referring to  FIG. 4 , while a BTS  400  provides a service to an MS 2   440  in its cell using a Type A-2 frame, an MH-BTS_A  420  also provides a service to an MS 1   460  in its cell using a Type A-1 frame. The Type A-1 and the Type A-2 are different names used for distinguishing channels, and both of them have the form of Type A.  
       FIG. 5  is a diagram illustrating a multi-hop wireless mobile communication system using a Type-B frame according to the present invention.  
      Referring to  FIG. 5 , the Type-B frame is used for data communication between a BTS  500  and an MH-BTS_A  520 . The BTS  500  and the MH-BTS_A  520  cannot provide a communication service to MSs  540  and  560  while communicating with each other using the Type-B frame.  
      Because the Type-A and Type-B frames are time-divided as described with reference to  FIGS. 4 and 5 , if the Type-A frame is used at a specified time, the Type-B frame cannot be used at the same time. On the contrary, if the Type-B frame is used at a specified time, the Type-A frame cannot be used at the same time. In addition, an entity allocating resources to an MH-BTS is a BTS, and the MH-BTS can send a resource allocation request to the BTS, reallocate resources to specific MSs using the resources allocated from the BTS, and relay signals using the reallocated resources.  
      The BTS selects one of the Type-A frame and the Type-B frame depending on traffic distribution. For example, if there is a large amount of data that the BTS exchanges with the MH-BTS, the BTS increases a frequency of use of the Type-B frame, and if there is a large amount of data that the BTS exchanges with an MS located in its own cell, the BTS increases a frequency of use of the Type-A frame.  
       FIG. 6  is a diagram illustrating structures of a Type-A frame and a Type-B frame newly proposed in a multi-hop wireless mobile communication system according to the present invention.  
      Referring to  FIG. 6 , a Type-A frame includes a preamble region  601 , a Frame Control Header (FCH) region  603 , a MAP region  605  including resource allocation information, a downlink (DL) region  607  where downlink data is allocated, an uplink (UL) region  609  where uplink data is allocated, and an access region  611 . Similarly to the Type-A frame, a Type-B frame also includes a preamble region  613 , an FCH region  615 , a MAP region  617 , a downlink region  619 , and an uplink region  621 . The only difference is that the Type-B frame includes a dedicated control channel region  623  instead of the access region  611  of the Type-A frame. A description will now be made of the scenarios where the Type-A frame and the Type-B frame are used.  
      First, it is assumed that a BTS communicates with an MS located in its own cell using the Type-A frame.  
      If the BTS maps its own BTS ID to the preamble region  601  and then transmits the signal to an MS, the MS can perform frame synchronization acquisition and channel estimation by receiving the preamble.  
      The FCH region  603  includes therein size information indicating a percentage of the MAP region  605  in the frame, Modulation and Coding Scheme (MCS) level information, an identifier for frame type identification, and information indicating the time the Type-A frame is to be used next. The information on the time the Type-A frame is to be used can include offset information corresponding to a difference between a frame index where the BTS currently uses the Type-A frame and a frame index where the BTS will next use the Type-A frame. If the current frame index is 3 and the offset value is 2, the BTS previously notifies the MS that it will use the Type-A frame in the next frame, i.e. a frame with frame index=5.  
      The MAP region  605  includes therein uplink/downlink resource allocation information, and the downlink region  607  and the uplink region  609  each include therein data and control information exchanged with the MS.  
      The access region  611  is used by an MS or an MH-BTS to randomly access the BTS.  
      Next, it is assumed that an MH-BTS communicates with an MS located in its own cell using the Type-A frame.  
      If the MH-BTS maps its own MH-BTS ID to the preamble region  601  and then transmits the signal to an MS, the MS can perform frame synchronization acquisition and channel estimation by receiving the preamble.  
      The FCH region  603  includes therein size information indicating a percentage of the MAP region  605  in the frame, MCS level information, an identifier for frame type identification, and information indicating the time the Type-A frame is to be used next, i.e. an offset value.  
      The MAP region  605  includes therein uplink/downlink resource allocation information, and the downlink region  607  and the uplink region  609  each include therein data and control information exchanged with the MS.  
      The access region  611  is used by an MS to randomly access the MH-BTS.  
      A description will now be made of a scenario where the BTS and the MH-BTS use the Type-B frame.  
      When the BTS and the MH-BTS use the Type-B frame, an ID of the BTS is mapped to the preamble region  613 , and the MS can acquire synchronization with a tracking mode or an initial mode and perform channel estimation using the preamble.  
      The FCH region  615  includes therein size information indicating a percentage of the MAP region  617  in the frame, MCS level information, an identifier for frame type identification, and information indicating the time the Type-B frame is to be used next, i.e. an offset value.  
      The MAP region  617  includes therein uplink/downlink resource allocation information, and the downlink region  619  and the uplink region  621  each include therein data and control information exchanged between the BTS and the MH-BTS.  
      The dedicated control channel region  623  is used by the MH-BTS to request resource allocation. The dedicated control channel region  623  includes Acknowledge (ACK)/Negative-Acknowledge (NACK) information, and is used by the MH-BTS to transmit fast feedback-required control information to the BTS.  
      Because the signals exchanged between the BTS and the MH-BTS include data for a plurality of MSs, the BTS and the MH-BTS can perform efficient data exchange by aggregating data of the same type and distinguishing the data with a relay header.  
       FIG. 7  is a diagram illustrating a structure of data exchanged between a BTS and an MH-BTS in a multi-hop mobile communication system according to the present invention.  
      Referring to  FIG. 7 , the data exchanged between the BTS and the MH-BTS includes a relay header region  701 , a payload region  705 , and a Medium Access Control (MAC) header region 703 for distinguishing each payload.  
      The relay header region  701  includes message type information, MH-BTS ID information, and total message length information. The MH-BTS ID information is used by the BTS to determine with which MH-BTS the corresponding data is associated. The message type information is used to determine to which message (for example, access, authentication, etc.) the transmission/reception information corresponds. The total length information is used to indicate an end of the message.  
      The MAC header region  703  includes destination information and length information of a payload, and allows the BTS and the MH-BTS to decode the MAC header and determine with which MS the corresponding payload is associated.  
      The resource allocation information included in the MAC region  605  or  617  shown in  FIG. 6  represents resource allocation information corresponding to the next symbol time frame. A description thereof will be made with reference to the diagram of  FIG. 8 , which illustrates resource allocation information represented by MAP information in a multi-hop wireless mobile communication system according to an embodiment of the present invention.  
      Referring to  FIG. 8 , in a time interval ‘t’, a MAP region  800  of a Type-A frame includes resource allocation information for a downlink  810  and an uplink  820  of the Type-A frame in a time interval ‘t+2’ where the next Type-A frame is used. In addition, in a time interval ‘t+1’, a MAP region  850  of a Type-B frame includes resource allocation information for a downlink  860  and an uplink  870  of the Type-B frame in a time interval ‘t+3’ where the next Type-B frame is used.  
      A description will now be made of a method in which the BTS allocates the Type-A frame and the Type-B frame.  
      The frame allocation method is provided on the assumption that when the BTS and the MH-BTS perform communication using the Type-B frame, they do not use the Type-A frame for communication with the MS, and when the BTS or the MH-BTS communicates with the MS using the Type-A frame, it does not use the Type-B frame.  
       FIGS. 9A and 9B  are diagrams illustrating exemplary periodic frame allocation methods in a multi-hop wireless mobile communication system according to the present invention.  
      Referring to  FIGS. 9A and 9B , a BTS inserts Type-B frame use period information in an FCH in the form of an offset.  FIG. 9A  illustrates an exemplary frame allocation method where the Type-A frame and the Type-B frame are alternately used one by one, and  FIG. 9B  illustrates an exemplary frame allocation method where the Type-B frame is used at periods of 3 frames. In the case of  FIG. 9A , an offset value is set to ‘2’ in the FCH of the Type-B frame, and in the case of  FIG. 9B , an offset value is set to ‘3’ in the FCH of the Type-B frame. If it is provided that the system uses a frame having a specific type at a specific period, the offset value is specified in an FCH of an initial specific-type frame only once, and may not be specified in an FCH of the next frame. That is, the offset value is set to ‘1’ only in the FCHs of a Type-A frame  901  and a Type-B frame  903  of  FIG. 9A , and no separate offset value can be specified in FCHs of the next frames  905  to  915 . However, if there is a situation where the offset value in the frames should change, the offset value can be re-specified together with an indicator indicating the offset change.  
      Table 1 below shows exemplary information inserted in an FCH in each of the frames of  FIGS. 9A and 9B .  
                       TABLE 1                          For frames of  FIG. 9A         For frames of  FIG. 9B                                   Information       Information       Frame #   inserted in FCH   Frame #   inserted in FCH               901   F_type: A   917   F_type: B           Offset: 2       Offset: 3       903   F_type: B   919   F_type: A           Offset: 2       Offset: 1       905   F_type: A   921   F_type: A           Offset: 2 (option)       Offset: 2       907   F_type: B   923   F_type: B           Offset: 2 (option)       Offset: 3       909   F_type: A   925   F_type: A           Offset: 2 (option)       Offset: 1       911   F_type: B   927   F_type: A           Offset: 2 (option)       Offset: 2       913   F_type: A   929   F_type: B           Offset: 2 (option)       Offset: 3       915   F_type: B   931   F_type: A           Offset: 2 (option)       Offset: 1                  
 
      In Table 1, F_type is used for distinguishing between a Type-A frame and a Type-B frame, and an Offset value includes the information indicating in which frame following the current frame a frame of the same type is to be used. For example, information inserted in an FCH of the frame  901  indicates that the current frame is a Type-A frame, and the Type-A frame will be used again in the second frame.  
       FIG. 10  is a diagram illustrating an exemplary random frame allocation method in a multi-hop wireless moble communication system according to the present invention.  
      Referring to  FIG. 10 , compared with the periodic frame allocation method,a random frame allocation method is advantageous in terms of resource allocation efficiency, as it can dynamically consider resource allocation. A BTS, when it randomly allocates frames, inserts an offset value in an FCH of every frame to inform the MH-BTS when the same frame will be used again.  
      Table 2 below shows exemplary information inserted in an FCH of the frame of  FIG. 10 .  
                   TABLE2                       Frame #   Information inserted in FCH                  1001   F_type: A           Offset: 3       1003   F_type: B           Offset: 1       1005   F_type: B           Offset: 2       1007   F_type: A           Offset: 2       1009   F_type: B           Offset: 3       1011   F_type: A           Offset: 1       1013   F_type: A           Offset: 2       1015   F_type: B           Offset: 4                  
 
      When there is relay traffic, i.e. when there is data that the BTS will transmit to the MH-BTS, or when the MH-BTS sends a request for uplink resource allocation to the BTS, the BTS appropriately determines an offset value such that it can rapidly use the Type-B frame. However, if there is no relay traffic, the BTS decreases a frequency of use of the Type-B frame by multiplying an offset value inserted in an FCH of the Type-B frame by a predetermined integer.  
       FIG. 11  is a signaling diagram illustrating signals exchanged between an MS, a BTS, and an MH-BTS in a multi-hop wireless mobile communication system according to the present invention.  
      Referring to  FIG. 11 , an MS 2   1100  and an MH-BTS  1150  perform random access to a BTS  1130  through an access channel of a Type-A frame (Steps  1101  and  1117 ). Thereafter, the BTS  1130  performs authentication on the MS 2   1100  and the MH-BTS  1150  in the Type-A frame (Steps  1103  and  1119 ), and allocates basic resources to the authenticated MS 2   1100  and MH-BTS  1150  (Steps  1105  and  1121 ). If even the MH-BTS  1150  performs initial network entry to the BTS  1130 , it uses the Type-A frame, and after completion of the initial network entry, performs communication with the BTS  1130  using only the Type-B frame.  
      The MS 2   1100  requests the resources necessary for data exchange using the basic resources allocated from the BTS  1130  (Step  1107 ). The MH-BTS  1150  recognizes access attempt from an MS 1   1170  connected thereto in one hop (Step  1123 ). Upon recognizing the access attempt of the MS 1   1170 , the MH-BTS  1150  relays access information of the MS 1   1170  at the time the BTS  1130  uses the Type-B frame (Step  1125 ). In the next Type-B frame, the BTS  1130  completes authentication on the MS 1   1170  to the MH-BTS  1150  (Step  1127 ). The MH-BTS  1150  provides authentication-completed information to the MS 1   1170  (Step  1131 ), allocates basic resources to the MS 1   1170  (Step  1133 ), and receives a required-resource allocation request from the MS 1   1170  (Step  1135 ).  
      Upon receipt of the required-resource allocation request from the MS 1   1170 , the MH-BTS  1150  sends a required-resource allocation request to the BTS  1130  using the Type-B frame (Step  1137 ), and is allocated uplink resources from the BTS  1130  (Step  1139 ). The MH-BTS  1150  allocates some or all of its allocated uplink resources to the MS 1   1170  (Step  1141 ), and receives data from the MS 1   1170  (Step  1143 ). The non-described steps include steps in which the BTS  1130  or the MH-BTS  1150  allocates wireless resources to the MSs  1100  and  1170  and receives data therefrom, and steps in which resource allocation request, resource allocation, and data exchange are performed between the BTS  1130  and the MH-BTS  1150 . These steps are similar to the steps described above, so a description thereof will be omitted.  
      As described above, signal exchange between the BTS  1130  and the MS 2   1100  and signal exchange between the MH-BTS  1150  and the MS 1   1170  are performed using the Type-A frame, and signal exchange between the BTS  1130  and the MH-BTS  1150  is performed using the Type-B frame. Exchange of control information and data between the BTS  1130  and the MH-BTS  1150  is achieved based on a message in the Type-B frame. Therefore, the BTS  1130  and the MH-BTS  1150  can distinguish between a source MS and a target MS according to MAC header information of received data. For example, in step  1125  of  FIG. 11 , the BTS  1130  can recognize that the corresponding access is an access from the MS 1   1170 , based on the MAC header information of a relay access message received from the MH-BTS  1150 .  
       FIG. 12  is a signaling diagram illustrating information inserted in each individual frame depending on signals exchanged between an MS, a BTS, and an MH-BTS in a multi-hop wireless mobile communication system according to the present invention.  
      Referring to  FIG. 12 , an MS 2   1200  and an MH-BTS  1240  are connected to a BTS  1220  in one hop, and an MS 1   1260  and an MS 3   1280  are connected to the BTS  1220  in two hops via the MH-BTS  1240 . Signal exchange between the MSs  1200 ,  1260  and  1280 , and the BTS  1220  or the MH-BTS  1240  is the same as that described in  FIG. 11 , so a detailed description thereof will be omitted herein. The information included in each individual frame is shown in Table 3 below.  
                                       TABLE 3                       Frame                               #   Preamble   FCH   MAP   DL   UL   Access                  1201   BTS_ID:   F_type:   —   —   —   Access           B1   A               information               Offset: 1               of MS2 and                               access                               information                               of MH-BTS       1203   BTS_ID:   F_type:   —   Authentication   —   —           B1   A       information               Offset: 1       for MS2 and                       authentication                       information                       for MH-BTS       1205   BTS_ID:   F_type:   Location   —   —   —           B1   A   information               Offset: 1   of UL                   resource                   allocated to                   MS2 and                   Location                   information                   of UL                   resource                   allocated to                   MH-BTS       1207   BTS_ID:   F_type:   —   —   Resource   —           B1   A           request               Offset: 3           information                           of MS2       1209   BTS_ID:   F_type:   —   —   Access           B1   B           information               Offset: 1           of MS1 and                           MS3       1211   BTS_ID:   F_type:   —   Authentication   —           B1   B       information               Offset: 4       for MS1 and                       MS3       1215   BTS_ID:   F_type:   Location   —   —   —           B1   A   information               Offset: 1   of UL                   resource                   allocated to                   MS2       1217   BTS_ID:   F_type:   —   —   UL data of   —           B1   A           MS2               Offset: 1       1221   BTS_ID:   F_type:   —   —   Resource           B1   B           request               Offset: 1           information                           of MS1 and                           MS3       1223   BTS_ID:   F_type:   Location   —   —           B1   B   information               Offset: 3   of UL                   resource                   allocated to                   MS1 and                   MS3       1225   BTS_ID:   F_type:   Location   —   —   —           B1   A   information               Offset: 1   of DL                   resource                   allocated to                   MS2       1227   BTS_ID:   F_type:   —   DL data to   —   —           B1   A       MS2               Offset: 3       1229   BTS_ID:   F_type:   Location   —   UL data of           B1   B   information       MS1 and               Offset: 1   of UL       MS3                   resource                   allocated to                   MS1 and                   MS3       1231   BTS_ID:   F_type:   —   UL data to   —           B1   B       MS1 andMS3               Offset: 4       1237   MH-   F_type:   —   —   —   Access           BTS_ID:   A               information           M1   Offset: 3               of MS1 and                               access                               information                               ofMH-BTS       1239   MH-   F_type:   —   Authentication   —   —           BTS_ID:   A       information           M1   Offset: 1       for MS1 and                       authentication                       information                       for MS3       1241   MH-   F_type:   Location   —   —   —           BTS_ID:   A   information           M1   Offset: 1   of resource                   allocated to                   MS1 and                   location                   information                   of resource                   allocated to                   MS3       1243   MH-   F_type:   —   —   Resource   —           BTS_ID:   A           request           M1   Offset: 3           information                           of MS1 and                           resource                           request                           information                           ofMS3       1245   MH-   F_type:   Location   —   —   —           BTS_ID:   A   information           M1   Offset: 1   of UL                   resource                   allocated to                   MS1 and                   location                   information                   of UL                   resource                   allocated to                   MS3       1247   MH-   F_type:   —   —   UL data of   —           BTS_ID:   A           MS1 and           M1   Offset: 3           UL data of                           MS3       1249   MH-   F_type:   Location   —   —   —           BTS_ID:   A   information           M1   Offset: 1   of DL                   resource                   allocated to                   MS1 and                   location                   information                   of DL                   resource                   allocated to                   MS3       1251   MH-   F_type:   —   DL data to   —   —           BTS_ID:   A       MS1 and DL           M1   Offset: 1       data to MS3                  
 
      Table 3 shows information and data included in each region of the frame structure of  FIG. 6 . Herein, an ID of a BTS is denoted by B 1 , and an ID of an MH-BTS is denoted by M 1 .  
      As can be understood from the foregoing description, the present invention provides new frames and an operation method thereof so as to allow a BTS and a relay BTS (MH-BTS) serving as a relay to simultaneously operate in a multi-hop wireless mobile communication system, thereby contributing to improvement in wireless resource efficiency. In addition, because a data exchange method between the BTS and the MS is equal to a data exchange method between the BTS and the relay BTS, the new system can reduce its system complexity compared with other systems having a relay function.  
      While the invention has been shown and described with reference to a certain preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.