Abstract:
Provided is a network re-entry method and apparatus in a mobile communication system. The network re-entry method includes sending, by a group delegate Mobile Station (MS) among MSs of a group, a ranging code based on a group Identifier (ID) to a Base Station (BS) and receiving, by the MSs, a Ranging-Response (RNG-RSP) message comprising a ranging status for the group from the BS.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) AND CLAIM OF PRIORITY 
       [0001]    The present application is related to and claims the benefit under 35 U.S.C. §119(a) of a Chinese Patent Application filed in the China Patent Trademark Office on Jan. 31, 2011 and assigned Serial No. 201110036008.X, the entire disclosure of which is hereby incorporated by reference. 
       TECHNICAL FIELD OF THE INVENTION 
       [0002]    The present invention relates to mobile communication systems, and more particularly, to a network reentry method and apparatus in a mobile communication system. 
       BACKGROUND OF THE INVENTION 
       [0003]    A Mobile Station (MS) usually operates according to a method shown in  FIG. 1  to access a network. Herein, the access to the network may include reentry to the network. 
         [0004]      FIG. 1  is a diagram illustrating an operation between an MS and a Base Station (BS) in order for the MS to access the network in a conventional mobile communication system. 
         [0005]    Referring to  FIG. 1 , in step  101 , the MS performs downlink synchronization. In step  102 , the MS obtains system information from the BS. The system information generally includes access codes and access opportunity information. 
         [0006]    In step  103 , the MS accesses the network after performing backoff processing. 
         [0007]    In step  104 , the MS sends an Initial Reference Code (IRC) to a Base Station (BS) included in a ranging opportunity. In this step, when the MS has no available ranging opportunity, e.g., when the access operation has expired or the number of access operations exceeds a threshold, step  104  is continued or the access operation is terminated, the factors of which may be determined according to practical applications. 
         [0008]    In step  105 , the MS receives a Ranging-Acknowledgement (RNG-ACK) message or an Advanced Air Interface_Ranging-Acknowledgement (AAI_RNG-ACK) message from the BS, where the RNG-ACK message includes a response of the BS to the detected IRC. 
         [0009]    In step  106 , the BS sends a Code Division Multiple Access (CDMA) Allocation A-MAP Information Element (IE) message to the MS to allocate Ranging-Request (RNG-REQ) resources to the MS. 
         [0010]    In step  107 , the MS sends a RNG-REQ message to the BS after receiving the CDMA Allocation A-MAP IE message to inform the BS of information containing an Identifier (ID) of the MS, and then continues accessing the network. 
         [0011]    In step  108 , the BS sends a Ranging-Response (RNG-RSP) message to the MS and allocates a temporary Station Identifier (STID) to the MS. 
         [0012]    In step  109 , after the MS receives the RNG-RSP message, the BS and the MS perform capability negotiation, the MS sends a Registration-Request (REG-REQ) message to the BS, and then the BS sends a Registration-Response (REG-RSP) message that includes the STID to the MS. 
         [0013]    Thus, through steps  101  through  109 , the operation in which the MS accesses the network is completed. 
         [0014]    Further, the MS may operate in the following order to access the network. 
         [0015]    First, the MS obtains system information. Second, the MS sends an IRC to the BS in a ranging opportunity. 
         [0016]    Again, the MS listens to and receives a RNG-ACK message or a CDMA Allocation A-MAP IE message from the BS, where the RNG-ACK message or the CDMA Allocation A-MAP IE message includes a response of the BS to the detected IRC. In this step, according to receiving instances, the MS may obtain the system information or terminate the access operation because of various factors, which may be determined according to practical applications. For example, the access operation may be terminated when the MS does not receive the response to the IRC sent by the MS and does not have an available ranging opportunity, e.g., when the access operation has expired, the number of access operations exceeds a threshold or, when the response received by the MS indicates “abort”. According to receiving instances, the MS may send the IRC to the BS, for example, when the MS does not receive the response to the IRC sent by the MS and has an available ranging opportunity, or when the response received by the MS indicates “continue”. When the response indicates “abort”, the BS may configure a timer for the MS, and when the timer has timed out, the MS may access the network again. 
         [0017]    When sending the IRC to the BS, the MS randomly selects the ranging opportunity and the IRC according to a backoff window. 
         [0018]    Finally, the MS continues accessing the network after the MS receives the RNG-ACK message indicating “success” and/or the CDMA Allocation A-MAP IE message, and sends a RNG-REQ message to the BS to inform the BS of information containing an ID of the MS. 
         [0019]    As can be seen from the above description, the conventional procedure that the MS accesses the network may be applicable to a single MS. In addition, the conventional MS obtains the IRC first when accessing the network, the IRC is selected randomly when the MS accesses the network, and the number of available IRCs is finite. Therefore, the conventional network access method for the MS may result in a conflict, such as when two or more MSs inadvertently select the same IRC, the MSs sending the same IRC may not all access the network successfully or all the MSs sending the same IRC may not access the network successfully. Especially, with the development of Machine to Machine (M2M) technology, more MSs may access the network at the same time, which increases the possibility of conflict, and thus result in that some MSs cannot access the network successfully. 
       SUMMARY OF THE INVENTION 
       [0020]    To address the above-discussed deficiencies of the prior art, it is a primary object to provide a network access method and apparatus which allows a plurality of MSs to access a network in a mobile communication system. 
         [0021]    According to an aspect of the present invention, there is provided a network reentry method in a mobile communication system, the method including sending, by a group delegate Mobile Station (MS) among MSs of a group, a ranging code based on a group Identifier (ID) to a Base Station (BS) and receiving, by the MSs, a Ranging-Response (RNG-RSP) message comprising a ranging status for the group from the BS. 
         [0022]    According to another aspect of the present invention, there is provided a network reentry method at a Base Station (BS) in a mobile communication system, the method including allocating a dedicated ranging code to a group delegate Mobile Station (MS) among MSs of a group, receiving a ranging code based on a group Identifier (ID) generated according to the dedicated ranging code from the group delegate MS, and sending a Ranging-Response (RNG-RSP) message comprising a ranging status for the group to the MSs. 
         [0023]    According to another aspect of the present invention, there is provided a network reentry apparatus in a mobile communication system, the apparatus including a controller by which a group delegate Mobile Station (MS) among MSs of a group determines a ranging code based on a group Identifier (ID), a sender by which the group delegate MS sends the ranging code based on the group ID to a Base Station (BS), and a receiver by which the MSs receive a Ranging-Response (RNG-RSP) message comprising a ranging status for the group from the BS. 
         [0024]    According to another aspect of the present invention, there is provided a network reentry apparatus at a Base Station (BS) in a mobile communication system, the apparatus including a controller for allocating a dedicated ranging code to a group delegate Mobile Station (MS) among MSs of a group, a receiver for receiving a ranging code based on a group Identifier (ID) generated according to the dedicated ranging code from the group delegate MS, and a sender for sending a Ranging-Response (RNG-RSP) message comprising a ranging status for the group to the MSs. 
         [0025]    Before undertaking the DETAILED DESCRIPTION OF THE INVENTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or,” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like; and the term “controller” means any device, system or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware or software, or some combination of at least two of the same. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]    For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts: 
           [0027]      FIG. 1  illustrates an example operation between an MS and a BS in order for the MS to access the network in a conventional mobile communication system; 
           [0028]      FIG. 2  illustrates an example operation between an MS and a BS in order for the MS to access the network in a mobile communication system according to a first embodiment of the present invention; 
           [0029]      FIG. 3  illustrates an example operation between an MS and a BS in order for the MS to access the network in a mobile communication system according to a second embodiment of the present invention; and 
           [0030]      FIG. 4  illustrates an example method for selecting a group delegate through communication between an MS and a BS according to one or more embodiments of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0031]      FIGS. 2 through 4 , discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged communication networks. Hereinafter, exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings. Herein, only necessary parts for understanding of operations according to the present invention will be described, and other parts will not be described not to obscure the subject matter of the present invention. 
         [0032]    Before describing specific embodiments, concepts of group, group delegate and group member will be described. 
         [0033]    The group includes an entity composed of MSs that have one or more common attributes, where the one or more common attributes may be the same or similar service, the same or similar reporting period, belonging to the same subscriber, adjacent geography location, and so on. 
         [0034]    The group delegate is a certain MS which can represent all or particular part of MSs in the group to execute a specific function. There may alternatively be one or more group delegates in one group, and the group delegate may be any one MS in the group. 
         [0035]    The group members are the MSs other than the group delegate in the group. 
         [0036]    It should be described that, when the embodiments of the present invention are to be implemented, the MSs may be delegated into groups in advance according to one or more common attributes, which can be performed according to a conventional mode. 
         [0037]    It should also be noted that, in order to decrease the number of MSs accessing the network over a period of time, the period of time in which the MSs access the network may be delineated into time segments, so that a finite number of MSs may access the network in a certain time segment, for decreasing potential conflict. 
         [0038]    In order for the MS to access the network in a mobile communication system, the following operations are performed between the MS and the BS according to certain embodiments of the present invention. Herein, operations will be described in which the MSs are initially delegated in groups and a group delegate for each group is selected. A method for selecting the group delegate will be described in detail for each embodiment. 
         [0039]    In a first embodiment of the present invention, a MS first learns of its own group according to a message sent by the BS or according to a preconfiguration mode. The MSs in each group determine a GDC of the group according to the message sent by the BS. The group delegate sends the Group Delegate Code (GDC) allocated to the group to the BS in a ranging opportunity. Each MS in the group receives a RNG-ACK message and/or a group access resource allocation message from the BS. After receiving backoff information broadcasted by the BS and performing backoff processing, a MS receiving a message of allowing accessing the network in the group sends a randomly selected IRC to the BS on the ranging opportunity. 
         [0040]    The MS sending the IRC receives the RNG-ACK message and/or a CDMA Allocation A-MAP IE message from the BS, where the RNG-ACK message and/or the CDMA Allocation A-MAP IE message includes a response to the MS sending the IRC. After receiving the RNG-ACK message and/or the CDMA Allocation A-MAP IE message, the MS sends a RNG-REQ message to the BS and thereafter accesses the network. 
         [0041]    In a second embodiment, a MS learns its own group according to a message sent by the BS or according to a preconfiguration mode. The MSs in each group determine a GDC of the group according to the message sent by the BS. The group delegate sends the GDC to the BS in a ranging opportunity. Each MS in the group receives a RNG-ACK message from the BS. An MS receiving a message of allowing access to the network in the group sends a pre-allocated IRC to the BS on the ranging opportunity. 
         [0042]    The MS sending the IRC receives the RNG-ACK message and/or a CDMA Allocation A-MAP IE message from the BS, where the RNG-ACK message and/or the CDMA Allocation A-MAP IE message includes a response to the MS sending the IRC. After receiving the RNG-ACK message and/or the CDMA Allocation A-MAP IE message, the MS sends a RNG-REQ message to the BS and thereafter accesses the network. 
         [0043]    In order to make the object(s), technical solution(s) and merits of the present invention clearer, the first and second embodiments of the present invention will be described in detail hereinafter with reference to  FIGS. 2 and 3 . 
         [0044]      FIG. 2  illustrates an example operation between an MS and a BS for the MS to access the network in a mobile communication system. Although not shown in the drawings, each of the MS and the BS includes at least a sender, a receiver, and a controller, and the sender and the receiver transmit and receive messages, and the controller of the MS and the BS controls the operations according to the first embodiment of the present invention. 
         [0045]    Referring to step  201 , MSs in a group determine a GDC of the group and corresponding resources according to a message sent by a BS. It should be described that the GDC may also be called as a Group Access Code, or a Group Initial Reference Code (GIRC) or a ranging code. The GDC may include one or more codes. The GDC may be a code in a conventional IRC, or a code reallocated to the MSs by the system. 
         [0046]    Each group may correspond to an initial GDC, and the initial GDC based on the group ID can be obtained according to a following formula: 
         [0000]        C   M2M group RP =mod( ID   M2M Group   ,N   M2M group )  (1),
 
         [0047]    wherein ID M2M Group  is a group ID, N M2M group  is the number of GDCs, and mod( ) represents obtaining modulus. 
         [0048]    If one frame includes multiple random access opportunities, each group selects a random access opportunity according to a following formula: 
         [0000]        IdX   Ranging Opp =mod(floor( ID   M2M Group   ,N   M2M group ), N   Opp )  (2),
 
         [0049]    wherein N Opp  is the number of random access opportunities, and floor( ) represents taking an integer not larger than the number of random access opportunities. 
         [0050]    The GDCs of group and M2M additional initial ranging codes should be orthogonal with GDCs because these ranging codes are transmitted on a random access opportunity and need to be fully utilized. To this end, a code dynamic partitioning method may be adopted. By the code dynamic partitioning method, the orthogonal intersection between two kinds of codes may be guaranteed, code resources can be fully utilized, and the BS may identify access motives of different MSs according to different kinds of codes. Specifically, there are two code dynamic partitioning methods: 
         [0051]    1. If a Zadoff-Chu sequence with a cyclic shift function is used for generating the GDC, the Zadoff-Chu sequence may be defined as: 
         [0000]        X   p ( k )=exp(− j ·π·( r   p   ·k ( k+ 1)+2 ·k·s   p   ·N   CS )/ N   RP )  (3),
 
         [0052]    where k=0, 1, . . . , NRP−1, where p is a sequence number of the GDC. r p  may be defined as: 
         [0000]    
       
         
           
             
               
                 
                   
                     
                       r 
                       p 
                     
                     = 
                     
                       mod 
                       ( 
                       
                         
                           
                             
                               ( 
                               
                                 1 
                                 - 
                                 
                                   2 
                                   · 
                                   
                                     mod 
                                      
                                     
                                       ( 
                                       
                                         
                                           ⌊ 
                                           
                                             p 
                                             
                                               M 
                                               
                                                 n 
                                                  
                                                 
                                                     
                                                 
                                                  
                                                 s 
                                               
                                             
                                           
                                           ⌋ 
                                         
                                         , 
                                         2 
                                       
                                       ) 
                                     
                                   
                                 
                               
                               ) 
                             
                             · 
                             
                               ( 
                               
                                 
                                   ⌊ 
                                   
                                     
                                       p 
                                       
                                         M 
                                         
                                           n 
                                            
                                           
                                               
                                           
                                            
                                           s 
                                         
                                       
                                     
                                     2 
                                   
                                   ⌋ 
                                 
                                 + 
                                 
                                   r 
                                   
                                     n 
                                      
                                     
                                         
                                     
                                      
                                     s 
                                      
                                     
                                         
                                     
                                      
                                     0 
                                   
                                 
                               
                               ) 
                             
                           
                           + 
                           
                             N 
                             RP 
                           
                         
                         , 
                         
                           N 
                           RP 
                         
                       
                       ) 
                     
                   
                   , 
                 
               
               
                 
                   ( 
                   4 
                   ) 
                 
               
             
           
         
       
     
         [0053]    wherein p=0, 1, 2 . . . N cont−1 , N cont +N dedi , . . . , N cont +N dedi +N M2M group +N M2M Add −1, s p =mod(p,M ns ). r ns0  is broadcasted in a Secondary-Super Frame Header (S-SFH), M ns  is the times of cyclic shift of the Zadoff-Chu sequence&#39;s root, N cont  is a sum of initial ranging codes N IN  for general random access and handover ranging codes N HO , N dedi  is dedicated ranging codes, N M2M group  is GDCs, N M2M Add  is newly-added initial ranging codes for an M2M application. There is no intersection between two kinds of codes. Specifically, N cont  is a sum of the number (0˜N IN −1) of initial ranging codes N IN  for general random access in each sector and the number (N IN ˜N IN +N HO −1) of handover ranging codes, N dedi  is dedicated Ranging codes, which is represented with (N cont ˜N cont +N dedi −1) and includes 32 dedicated ranging codes at most, N M2M group  is GDCs allocated to the M2M group by each sector, which is represented with (N cont +N dedi ˜N cont +N dedi +N M2M group −1) and includes a maximum of 32 GDCs, and N M2M add  is newly-added initial ranging codes for an M2M application, which is represented with (N cont +N dedi +N M2M group ˜N cont +N dedi +N M2M group +N M2M add −1) and includes a maximum of 32 additional ranging codes. The M2M MS may randomly select ranging codes from the initial ranging codes N IN  for general random access and N M2M add  to perform initial access. N CS  is a unit of cyclic shift, and N RP  is the length of ranging codes. 
         [0054]    The foregoing is only an example, the allocation of ranging codes may be performed in a sequence, but the sequence of allocating the GDCs of the M2M group and allocating the M2M additional codes may be unimportant, the M2M additional codes may be allocated initially, and then the GDCs of the M2M group may be allocated. Table 1 shows how GDCs are allocated of the M2M group and the M2M additional codes, and how a subset or deduction of this table may be used in practical applications. 
         [0000]    
       
         
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
             
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
             
               
               
             
               
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
             
             
               
                   
                 Partition Index 
               
             
          
           
               
                   
                 0 
                 1 
                 2 
                 3 
                 4 
                 5 
                 6 
                 7 
                 8 
                 9 
                 10 
                 11 
                 12 
                 13 
                 14 
                 15 
                 16 
                 17 
                 18 
                 19 
                 20 
                 21 
               
               
                   
               
               
                 Number of 
                 0 
                 0 
                 0 
                 0 
                 0 
                 0 
                 0 
                 8 
                 8 
                 8 
                 8 
                 8 
                 8 
                 8 
                 8 
                 8 
                 16 
                 16 
                 16 
                 16 
                 16 
                 16 
               
               
                 the M2M 
               
               
                 Group 
               
               
                 codes, 
               
               
                 N M2M Group   
               
               
                 Number of 
                 8 
                 16 
                 32 
                 40 
                 48 
                 56 
                 64 
                 0 
                 8 
                 16 
                 24 
                 32 
                 40 
                 48 
                 56 
                 64 
                 0 
                 8 
                 16 
                 24 
                 32 
                 40 
               
               
                 the M2M 
               
               
                 additional 
               
               
                 code 
               
               
                 N M2M Add   
               
               
                   
               
             
          
           
               
                   
                 Partition Index 
               
             
          
           
               
                   
                 22 
                 23 
                 24 
                 25 
                 26 
                 27 
                 28 
                 29 
                 30 
                 31 
                 32 
                 33 
                 34 
                 35 
                 36 
                 37 
                 38 
                 39 
                 40 
               
               
                   
               
               
                 Number of 
                 16 
                 24 
                 24 
                 24 
                 24 
                 24 
                 24 
                 32 
                 32 
                 32 
                 32 
                 32 
                 40 
                 40 
                 40 
                 40 
                 48 
                 48 
                 48 
               
               
                 the M2M 
               
               
                 Group 
               
               
                 codes, 
               
               
                 N M2M Group   
               
               
                 Number of 
                 48 
                 0 
                 8 
                 16 
                 24 
                 32 
                 40 
                 0 
                 8 
                 16 
                 24 
                 32 
                 0 
                 8 
                 16 
                 24 
                 0 
                 8 
                 16 
               
               
                 the M2M 
               
               
                 additional 
               
               
                 code 
               
               
                 N M2M Add   
               
               
                   
               
             
          
           
               
                   
                 Partition Index 
               
             
          
           
               
                   
                   
                 22 
                 23 
                 24 
               
               
                   
                   
               
               
                   
                 Number of the M2M 
                 56 
                 56 
                 64 
               
               
                   
                 Group codes, 
               
               
                   
                 N M2M Group   
               
               
                   
                 Number of the M2M 
                 0 
                 8 
                 0 
               
               
                   
                 additional code 
               
               
                   
                 N M2M Add   
               
               
                   
                   
               
             
          
         
       
     
         [0055]    Since the dedicated ranging codes and the regular codes are transmitted on different ranging resources, the allocation of the dedicated ranging codes may not be considered, but only the initial ranging codes N IN  for general random access and the handover ranging codes N HO  are considered. N M2M group  is GDCs allocated to the M2M group by each sector, which is represented with (N cont ·N cont +N M2M group −1), and N M2M add  is newly-added ranging codes for an M2M application, which is represented with (N cont +N M2M group ˜N cont +N M2M group +N M2M add −1). If the handover ranging codes are not considered, other codes except regular initial access ranging codes are all allocated to M2M group GDCs and M2M additional codes. N M2M group  may be represented with (N IN ˜N IN +N M2M group −1), and N M2M add  may be represented with (N IN +N M2M group ˜N IN +N M2M group +N M2M add −1). 
         [0056]    Table 2 shows a schematic code allocation table. The number of initial ranging codes N IN  for general random access is represented with (0˜N IN −1), and the number of handover ranging codes is represented with (N IN ˜N IN +N HO −1). N M2M add  is newly-added initial codes for an M2M application, which is represented with (N IN +N HO ˜N IN +N HO +N M2M add −1) and includes a maximum of 32 additional ranging codes, N M2M group  is GDCs allocated to the M2M group by each sector, which is represented with (N IN +N HO +N M2M add ˜N IN +N HO +N M2M add +N M2M group −1) and includes a maximum of 32 GDCs. 16 types of configuration may be represented with 4 bits of information, and thus, the allocation of different kinds of codes shown in Table 2 may be obtained using 4 bits of a superframe header. If the number of redundant codes is finite, such as 32 codes, the GDCs and the newly-added initial ranging codes for an M2M application may share the codes. The specific allocation refers to a code allocation table shown in Table 3. For a case that the number of codes is finite, the GDCs and the newly-added initial ranging codes for an M2M application may share the codes, but the sharing proportion is not limited to Table 3. 
         [0000]    
       
         
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE 2 
               
             
             
               
                   
                   
               
               
                   
                 Partition Index 
               
             
          
           
               
                   
                 0 
                 1 
                 2 
                 3 
                 4 
                 5 
                 6 
                 7 
                 8 
                 9 
                 10 
                 11 
                 12 
                 13 
                 14 
                 15 
               
               
                   
                   
               
             
          
           
               
                 Number of the 
                 8 
                 8 
                 8 
                 8 
                 16 
                 16 
                 16 
                 16 
                 24 
                 24 
                 24 
                 24 
                 32 
                 32 
                 32 
                 32 
               
               
                 initial RP codes, 
               
               
                 N IN   
               
               
                 Number of the 
                 8 
                 16 
                 24 
                 32 
                 8 
                 16 
                 24 
                 32 
                 8 
                 16 
                 24 
                 32 
                 8 
                 16 
                 24 
                 32 
               
               
                 handover RP 
               
               
                 codes, N HO   
               
               
                 Number of the M2M 
                 8 
                 16 
                 24 
                 32 
                 8 
                 16 
                 24 
                 32 
                 8 
                 16 
                 24 
                 32 
                 8 
                 16 
                 24 
                 32 
               
               
                 additional codes 
               
               
                 N M2M Add   
               
               
                 Number of the M2M 
                 8 
                 8 
                 8 
                 8 
                 16 
                 16 
                 16 
                 16 
                 24 
                 24 
                 24 
                 24 
                 32 
                 32 
                 32 
                 32 
               
               
                 Group codes, 
               
               
                 N M2M Group   
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE 3 
               
             
             
               
                   
                   
               
               
                   
                 Partition Index 
               
             
          
           
               
                   
                 0 
                 1 
                 2 
                 3 
                 4 
                 5 
                 6 
                 7 
                 8 
                 9 
                 10 
                 11 
                 12 
                 13 
                 14 
                 15 
               
               
                   
                   
               
             
          
           
               
                 Number of the 
                 8 
                 8 
                 8 
                 8 
                 16 
                 16 
                 16 
                 16 
                 24 
                 24 
                 24 
                 24 
                 32 
                 32 
                 32 
                 32 
               
               
                 initial RP codes, 
               
               
                 N IN   
               
               
                 Number of the 
                 8 
                 16 
                 24 
                 32 
                 8 
                 16 
                 24 
                 32 
                 8 
                 16 
                 24 
                 32 
                 8 
                 16 
                 24 
                 32 
               
               
                 handover RP 
               
               
                 codes, N HO   
               
               
                 Number of the M2M 
                 8 
                 16 
                 24 
                 32 
                 8 
                 16 
                 24 
                 32 
                 8 
                 16 
                 24 
                 32 
                 8 
                 16 
                 24 
                 32 
               
               
                 additional code 
               
               
                 N M2M Add   
               
               
                 Number of the M2M 
                 24 
                 16 
                 8 
                 0 
                 24 
                 16 
                 8 
                 0 
                 24 
                 16 
                 8 
                 0 
                 24 
                 16 
                 8 
                 0 
               
               
                 Group codes, 
               
               
                 N M2M Group   
               
               
                   
               
             
          
         
       
     
         [0057]    2. If a ranging opportunity is allocated to a synchronized AMS, the initial ranging codes may be extended, and Zadoff-Chu sequences with filling and cyclic shift functions may be taken as the ranging codes, which are represented by: 
         [0000]        X   p ( n,k )−exp((− j ·π( r   p ·( n· 71 +k )·( n· 71 +k+ 1))/211+2· k·s   p   ·N   rcs   /N   FFT )),  (5),
 
         [0058]    wherein K=0, 1, . . . , N RP −1; n=0, 1, 2, where p is a sequence number of the ranging code. r p  may be defined as: 
         [0000]    
       
         
           
             
               
                 
                   
                     
                       r 
                       p 
                     
                     = 
                     
                       mod 
                       ( 
                       
                         
                           
                             
                               ( 
                               
                                 1 
                                 - 
                                 
                                   2 
                                   · 
                                   
                                     mod 
                                      
                                     
                                       ( 
                                       
                                         
                                           ⌊ 
                                           
                                             p 
                                             
                                               M 
                                               s 
                                             
                                           
                                           ⌋ 
                                         
                                         , 
                                         2 
                                       
                                       ) 
                                     
                                   
                                 
                               
                               ) 
                             
                             · 
                             
                               ( 
                               
                                 
                                   ⌊ 
                                   
                                     
                                       p 
                                       
                                         M 
                                         
                                           n 
                                            
                                           
                                               
                                           
                                            
                                           s 
                                         
                                       
                                     
                                     2 
                                   
                                   ⌋ 
                                 
                                 + 
                                 
                                   r 
                                   
                                     n 
                                      
                                     
                                         
                                     
                                      
                                     s 
                                      
                                     
                                         
                                     
                                      
                                     0 
                                   
                                 
                               
                               ) 
                             
                           
                           + 
                           211 
                         
                         , 
                         211 
                       
                       ) 
                     
                   
                   , 
                 
               
               
                 
                   ( 
                   6 
                   ) 
                 
               
             
           
         
       
     
         [0059]    wherein p=0, 1, 2 . . . N cont −1, N cont +N dedi , . . . , N cont +N dedi +N M2M group +N M2M Add −1, and s p =mod(p,M s ). 
         [0060]    For a home BS, N cont  represents ranging codes for general initial access, the sum N dedi  of the handover codes and periodic ranging codes are dedicated ranging codes, N M2M group  is GDCs allocated to the M2M group, and N M2M Add  is additional codes for an M2M application. There is no intersection between two kinds of codes. N cont  is a sum of the number (0˜N IN −1) of ranging codes for general initial access in each sector, the number (N IN ˜N IN +N HO −1) of handover ranging codes and the number (N IN +N HO ˜N IN +N HO +N PE −1) of periodic ranging codes. N dedi  is dedicated ranging codes, which is represented with (N cont ˜N cont +N dedi −1) and includes a maximum of 32 ranging codes, N M2M add  is newly-added codes for an M2M application, which is represented with N cont +N dedi ˜N cont +N dedi +N M2M add −1) and includes a maximum of 32 ranging codes. N M2M group  is codes allocated to the M2M group by each sector, which is represented with (N cont +N dedi +N M2M add ˜N cont +N dedi ++N M2M add +N M2M group −1) and includes a maximum of 32 ranging codes. The M2M MS may randomly select GDC ranging codes from N IN  and N M2M add  to perform initial access. Since the dedicated ranging codes and the regular codes are transmitted on different ranging resources, the allocation of the dedicated ranging codes may not be considered, while only the initial ranging codes N IN  for general random access, the handover ranging codes N HO  and the periodic ranging codes are considered. N M2M add  is newly-added codes for an M2M application, which is represented with (N cont ˜N cont +N M2M add −1) and includes a maximum of 32 ranging codes. N M2M group  is codes allocated to the M2M group by each sector, which is represented with (N cont +N M2M add ˜N cont +N M2M add +N M2M group −1) and includes a maximum of 32 ranging codes. Table 4 shows an example code allocation table, which is a subset or deduction of this table may be used in practical applications. The foregoing is only an example, the allocation of ranging codes may be performed in a sequence, but the sequence of allocating the GDCs of the M2M group and allocating the M2M addition codes is unimportant, the M2M addition codes may be allocated initially, and then the GDCs of the M2M group may be allocated. 
         [0000]    
       
         
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 4 
               
               
                   
               
               
                   
                 Number of 
                 Number of 
                 Number of 
                   
                   
               
               
                 Parti- 
                 the initial 
                 the handover 
                 the periodic 
                 Number of 
                 Number of 
               
               
                 tion 
                 RP codes, 
                 RP codes, 
                 RP codes, 
                 M2M Add 
                 M2M Group 
               
               
                 Index 
                 NIN 
                 NHO 
                 NPE 
                 N M2M Add   
                 N M2M group   
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 0 
                 4 
                 4 
                 4 
                 4 
                 4 
               
               
                 1 
                 4 
                 8 
                 4 
                 8 
                 4 
               
               
                 2 
                 4 
                 16 
                 4 
                 16 
                 4 
               
               
                 3 
                 4 
                 24 
                 4 
                 24 
                 4 
               
               
                 4 
                 8 
                 4 
                 8 
                 4 
                 8 
               
               
                 5 
                 8 
                 8 
                 8 
                 8 
                 8 
               
               
                 6 
                 8 
                 16 
                 8 
                 16 
                 8 
               
               
                 7 
                 8 
                 24 
                 8 
                 24 
                 8 
               
               
                 8 
                 16 
                 4 
                 16 
                 4 
                 16 
               
               
                 9 
                 16 
                 8 
                 16 
                 8 
                 16 
               
               
                 10 
                 16 
                 16 
                 16 
                 16 
                 16 
               
               
                 11 
                 16 
                 24 
                 16 
                 24 
                 16 
               
               
                 12 
                 24 
                 4 
                 24 
                 4 
                 24 
               
               
                 13 
                 24 
                 8 
                 24 
                 8 
                 24 
               
               
                 14 
                 24 
                 16 
                 24 
                 16 
                 24 
               
               
                 15 
                 24 
                 24 
                 16 
                 24 
                 24 
               
               
                   
               
             
          
         
       
     
         [0061]    For a case that a ranging GDC opportunity multiplexes Frequency Division Multiplex (FDM) resources in a wireless Metropolitan Area Network-Orthogonal Frequency Division Multiple Access (MAN-OFDMA) system and an advanced wireless MAN-OFDMA system, the number of ranging GDCs may be 256, each BS uses one group of ranging GDCs, and the initial number of the ranging GDCs in this group is rns0, a sequence which can be used by the BS is between rns0 and ((N IN +N HO +N PE +N dedi +N M2M group +N M2M add ) mod 256). N IN  is initial ranging GDCs, N HO  is initial handover ranging GDCs, N PE  is periodic ranging GDCs, N dedi  is dedicated ranging GDCs, N M2M group  is group ranging GDCs, and N M2M add  is M2M additional ranging GDCs. 
         [0062]    The number of codes contained in the N M2M add  is a maximum of 32, and the N M2M add  is obtained through shifting from 144×((rns0+N IN +N HO +N PE +N dedi ) mod 256) to 144×((rns0+N IN +N HO +N PE +N dedi +N M2M add ) mod 256)−1 by a Pseudo Random Binary Sequence (PRBS) generator. 
         [0063]    The number of codes included in the N M2M group  is a maximum of 32, and the N M2M group  is obtained through shifting from 144×((rns0+N IN +N HO +N PE +N dedi +N M2M add ) mod 256) to 144×((rns0+N IN  N HO +N PE +N dedi +N M2M add +N M2M group ) mod 256)-1 by the PRBS generator. 
         [0064]    Since the dedicated ranging codes and the regular codes occupy different resources, the allocation of the dedicated ranging codes may not be considered, but only the initial ranging codes, the handover ranging codes and periodic ranging codes are considered. The number of codes contained in the N M2M add  is a maximum of 32, and is obtained through shifting from 144×((rns0+N IN +N dedi ) mod 256) to 144×((rns0+N IN +N dedi +N M2M add ) mod 256)−1 by the PRBS generator. The number of codes contained in the N M2M group  is a maximum of 32 codes, and is obtained through shifting from 144×((rns0+N IN +N dedi +N M2M add ) mod 256) to 144×((rns0+N IN +N dedi +N M2M add +N M2M group ) mod 256)−1 by the PRBS generator. The N M2M group  is codes allocated to the M2M group by each sector, which can be obtained through shifting from 144×((rns0+N IN +N HO +N PE ) mod 256) to 144×((rns0+N IN +N HO +N PE +N M2M group ) mod 256)−1 by the PRBS generator. 
         [0065]    If the handover codes and periodic codes are not considered, other codes except regular initial ranging codes are all allocated to the M2M group and the additional codes, the N M2M  add may be obtained through shifting from 144×((rns0+N IN ) mod 256) to 144×((rns0+N IN +N M2M add ) mod 256)−1 by the PRBS generator, and the N M2M group  may be obtained through shifting from 144×((rns0+N IN +N M2M add ) mod 256) to 144×((rns0+N IN +N M2M group +N M2M add ) mod 256)-1 by the PRBS generator. Table 5 shows the allocation of the N M2M group  and the N M2M Add . 
         [0000]    
       
         
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE 5 
               
             
             
               
                   
                   
               
               
                   
                 Partition Index 
               
             
          
           
               
                   
                 0 
                 1 
                 2 
                 3 
                 4 
                 5 
                 6 
                 7 
                 8 
                 9 
                 10 
                 11 
                 12 
                 13 
                 14 
                 15 
               
               
                   
                   
               
             
          
           
               
                 Number of 
                 8 
                 8 
                 8 
                 8 
                 16 
                 16 
                 16 
                 16 
                 24 
                 24 
                 24 
                 24 
                 32 
                 32 
                 32 
                 32 
               
               
                 the M2M 
               
               
                 Group 
               
               
                 codes, 
               
               
                 NM2M Group 
               
               
                 Number of 
                 8 
                 16 
                 24 
                 32 
                 8 
                 16 
                 24 
                 32 
                 8 
                 16 
                 24 
                 32 
                 8 
                 16 
                 24 
                 32 
               
               
                 the M2M 
               
               
                 additional 
               
               
                 code 
               
               
                 NM2M Add 
               
               
                   
               
             
          
         
       
     
         [0066]    Though codes for an M2M application are added, more ranging opportunities are used to increase access resources, so that more M2M MSs can access the network. Therefore, new random access opportunities are defined in the present invention. Since each superframe includes 4 frames and the first and second frames are respectively allocated to the regular initial access opportunity and a synchronized access opportunity, the ranging resources of the third and fourth frames are taken as the M2M additional initial access opportunity in the present invention. The specific access opportunity allocation is shown in Table 6. 
         [0067]    Table 6 shows four allocation cases: 
         [0068]    Case1: Dedicated ranging channel for M2M is allocated/configured in every frame of one superframe. 
         [0069]    Case2: Dedicated ranging channel for M2M is allocated/configured in third frame of one superframe and does not conflict with normal/regular ranging opportunities. 
         [0070]    Case3: Dedicated ranging channel for M2M is allocated/configured in fourth frame of one superframe and does not conflict with normal/regular ranging opportunities. 
         [0071]    Case4. Dedicated ranging channel for M2M is allocated/configured in third and fourth frame of one superframe and does not conflict with normal/regular ranging opportunities. The M2M group GDCs and M2M additional codes may be transmitted in an original regular initial access opportunity, an additional initial access opportunity and a dynamic initial access opportunity. 
         [0000]    
       
         
               
               
             
           
               
                 TABLE 6 
               
               
                   
               
               
                 Configurations 
                 The AAI subframe allocating the NS-RCH 
               
               
                   
               
             
             
               
                 0 
                 (OSF + 2) th  UL AAI subframe in every frame 
               
               
                   
                 except the AAI subframe that has already been 
               
               
                   
                 used for a regular allocation. 
               
               
                 1 
                 OSF th  UL AAI subframes in the third frame in 
               
               
                   
                 every superframe except the AAI subframe that 
               
               
                   
                 has already been used for a regular allocation. 
               
               
                 2 
                 OSF th  UL AAI subframe in the third frame in 
               
               
                   
                 every even numbered superframe, i.e., 
               
               
                   
                 mod(superframe number, 2) = 0 except the AAI 
               
               
                   
                 subframe that has already been used for a 
               
               
                   
                 regular allocation. 
               
               
                 3 
                 OSF th  UL AAI subframe of the third frame in 
               
               
                   
                 every 4 th  superframe, i.e. mod(superframe 
               
               
                   
                 number, 4) = 0 except the AAI subframe that 
               
               
                   
                 has already been used for a regular allocation. 
               
               
                 4 
                 OSF th  UL AAI subframes in the last frame in 
               
               
                   
                 every superframe except the AAI subframe that 
               
               
                   
                 has already been used for a regular allocation. 
               
               
                 5 
                 OSF th  UL AAI subframe in the last frame in 
               
               
                   
                 every even numbered superframe, i.e., 
               
               
                   
                 mod(superframe number, 2) = 0 except the AAI 
               
               
                   
                 subframe that has already been used for a 
               
               
                   
                 regular allocation. 
               
               
                 6 
                 OSF th  UL AAI subframe of the last frame in 
               
               
                   
                 every 4 th  superframe, i.e. mod(superframe 
               
               
                   
                 number, 4) = 0 except the AAI subframe that 
               
               
                   
                 has already been used for a regular allocation. 
               
               
                 7 
                 OSF th  UL AAI subframes in the third and last 
               
               
                   
                 frame in every superframe except the AAI 
               
               
                   
                 subframe that has already been used for a 
               
               
                   
                 regular allocation. 
               
               
                 8 
                 OSF th  UL AAI subframe in the third and last 
               
               
                   
                 frame in every even numbered superframe, i.e., 
               
               
                   
                 mod(superframe number, 2) = 0 except the AAI 
               
               
                   
                 subframe that has already been used for a 
               
               
                   
                 regular allocation. 
               
               
                 9 
                 OSF th  UL AAI subframe of the third and last 
               
               
                   
                 frame in every 4 th  superframe, i.e. 
               
               
                   
                 mod(superframe number, 4) = 0 except the AAI 
               
               
                   
                 subframe that has already been used for a 
               
               
                   
                 regular allocation. 
               
               
                   
               
             
          
         
       
     
         [0072]    Table 7 shows the M2M group GDCs and the M2M additional ranging codes broadcasted in S-SFH SP1, while Table 8 shows the support that the BS responds to the received initial ranging codes including regular initial ranging codes and additional ranging codes sent by M2M with an ACK message in an AAI-RNG-ACK message. Table 9 shows the support that the BS responds to the M2M group GDCs with an ACK message in an AAI-RNG-ACK message. 
         [0000]    
       
         
               
               
               
             
           
               
                 TABLE 7 
               
               
                   
               
               
                   
                 Size 
                   
               
               
                 Syntax 
                 (bit) 
                 Description 
               
               
                   
               
             
             
               
                 . . . 
                 . . . 
                 . . . 
               
               
                 Reserved 
               
               
                 Support of M2M devices 
                 1 
                 Indicates whether system 
               
               
                   
                   
                 supports M2M devices or not 
               
               
                   
                   
                 0b0: No support 
               
               
                   
                   
                 0b1: Support 
               
               
                 If (Support of M2M 
                   
                 Indicates support of the M2M 
               
               
                 devices) 
                   
                 devices, when Support of M2M 
               
               
                   
                   
                 devices is 0b1 
               
               
                 The M2M Group and 
                 4 
                 Indicates the number of M2M 
               
               
                 individual additional RP 
                   
                 Group and individual 
               
               
                 code partition information 
                   
                 additional initial RP codes 
               
               
                 for the NS-RCH 
                   
                 (NM2M group and NM2M add) 
               
               
                   
                   
                 according to the Table 1 or 2. 
               
               
                 Allocation periodicity of 
                 4 
                 Indicates the periodicity of 
               
               
                 the additional NS-RCH for 
                   
                 the additional NS-RCH 
               
               
                 M2M devices 
                   
                 allocation for M2M devices 
               
               
                   
                   
                 according to the Table 5. 
               
               
                 Start RP code information 
                 4 
                 Indicates the kns which is the 
               
               
                 of the 
                   
                 parameter controlling the 
               
               
                 NS-RCH 
                   
                 start root index of the RP 
               
               
                   
                   
                 codes (rns0). 
               
               
                   
                   
                 rns0 (kns) = 4xkns + 1 for 
               
               
                   
                   
                 NS-RCH format 0. 
               
               
                   
                   
                 rns0 (kns) = 16xkns + 1 for 
               
               
                   
                   
                 NS-RCH format 1. 
               
               
                   
                   
                 The range of values is 
               
               
                   
                   
                 0 ≦ kns ≦ 15 
               
               
                 Number of the cyclic 
                 2 
                 Indicates the number of cyclic 
               
               
                 shifted RP codes per root 
                   
                 shifted codes per root index 
               
               
                 index for the NSRCH 
                   
                 (Mns) for RP codes 
               
               
                 Subframe offset of the 
                 2 
                 Indicates the subframe offset 
               
               
                 additional NS-RCH for M2M 
                   
                 (OSF) of the NS-RCH allocation 
               
               
                 devices 
                   
                 related to the Table 5 except 
               
               
                   
                   
                 the AAI subframe that has 
               
               
                   
                   
                 already been used for a 
               
               
                   
                   
                 regular allocation. 
               
               
                 NS-RCH formats 
                 1 
                 Indicates the NS-RCH formats 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
               
               
               
             
           
               
                 TABLE 8 
               
               
                   
               
               
                 Field 
                 Size 
                 (bits) 
                 Description 
               
               
                   
               
             
             
               
                 . . . 
                 . . . 
                 . . . 
                 . . . 
               
               
                 For (j = 0; 
                   
                 The number of ranging 
                 N_Received_Codes 
               
               
                 j&lt;N_Received_Co 
                   
                 preamble code 
                 should include 
               
               
                 des; j++) { 
                   
                 indices (i.e. 
                 additional M2M 
               
               
                   
                   
                 N_Received_Codes)[1 . . . 
                 initial ranging 
               
               
                   
                   
                 64] detected in this 
                 codes if M2M 
               
               
                   
                   
                 corresponding ranging 
                 additional initial 
               
               
                   
                   
                 opportunity. 
                 ranging code is 
               
               
                   
                   
                   
                 supported 
               
               
                 Index Ranging 
                 6 
                 Index received in 
                 Index should 
               
               
                 preamble code 
                   
                 this ranging 
                 indicate 
               
               
                   
                   
                 opportunity. 
                 additional M2M 
               
               
                   
                   
                   
                 initial ranging 
               
               
                   
                   
                   
                 codes if M2M 
               
               
                   
                   
                   
                 additional initial 
               
               
                   
                   
                   
                 ranging code is 
               
               
                   
                   
                   
                 supported 
               
               
                 Ranging Status 
                 2 
                 Indicate whether 
               
               
                   
                   
                 ranging preamble 
               
               
                   
                   
                 code or UL burst is 
               
               
                   
                   
                 received within 
               
               
                   
                   
                 acceptable limits 
               
               
                   
                   
                 by ABS. 
               
               
                   
                   
                 0b00 = success 
               
               
                   
                   
                 0b01 = abort 
               
               
                   
                   
                 0b10 = continue 
               
               
                 If (Ranging 
               
               
                 Status == 0b01) 
               
               
                 { 
               
               
                 Ranging Abort 
                 16 
                 Timer defined by an 
               
               
                 Timer 
                   
                 ABS to prohibit the 
               
               
                   
                   
                 AMS from attempting 
               
               
                   
                   
                 network entry at this 
               
               
                   
                   
                 ABS, for a specific 
               
               
                   
                   
                 time duration. 
               
               
                   
                   
                 Value: 0 (Do not 
               
               
                   
                   
                 try ranging again 
               
               
                   
                   
                 at the ABS.) 
               
               
                   
                   
                 Value: 1-65535, In 
               
               
                   
                   
                 units of seconds 
               
               
                 }else if 
               
               
                 (Ranging Status 
               
               
                 ==0b10) { 
               
               
                 Adjustment 
                 3 
                 Bit#0: Time offset 
               
               
                 parameters 
                   
                 adjustment indication. 
               
               
                 indication 
                   
                 Bit#1: Power level 
               
               
                 (API) 
                   
                 adjustment indication 
               
               
                   
                   
                 Bit#2: Frequency 
               
               
                   
                   
                 offset adjustment 
               
               
                   
                   
                 Indication 
               
               
                 If( API 
               
               
                 Bit#0==0b1 ) { 
               
               
                 Timing offset 
                 15 
               
               
                 adjustment 
               
               
                 } 
               
               
                 If( API 
               
               
                 Bit#1==0b1 ) { 
               
               
                 Power level 
                 4 
               
               
                 adjustment 
               
               
                 } 
               
               
                 If (API 
               
               
                 Bit#2==0b1) { 
               
               
                 Frequency 
                 9 
               
               
                 offset 
               
               
                 adjustment 
               
               
                 } 
               
               
                 } 
               
               
                 } 
               
               
                 . . . 
                 . . . 
                 . . . 
                 . . . 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
               
               
               
             
               
               
               
             
           
               
                 TABLE 9 
               
               
                   
               
               
                   
                 Size 
                   
                   
               
               
                 Field 
                 (bits) 
                 Value/Description 
                 Condition 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 For (j=0; 
                   
                 The number of ranging 
               
               
                 j&lt;N_Received_Codes 
                   
                 preamble code 
               
               
                 for M2M group; 
                   
                 indices(i.e. 
               
               
                 j++) { 
                   
                 N_Received_Codes)[1 . . . 
               
               
                   
                   
                 64] detected in this 
               
               
                   
                   
                 corresponding ranging 
               
               
                   
                   
                 opportunity. 
               
               
                 Ranging Status 
                 2 
                 Indicate whether ranging 
               
               
                   
                   
                 preamble code or UL burst 
               
               
                   
                   
                 is received within 
               
               
                   
                   
                 acceptable limits by ABS. 
               
               
                   
                   
                 0b00 = success for M2M 
               
               
                   
                   
                 Group 
               
               
                   
                   
                 0b01 = abort for M2M 
               
               
                   
                   
                 Group 
               
               
                   
                   
                 0b10 = continue 
               
               
                 If (Ranging Status 
               
               
                 == 0b01) { 
               
               
                 Ranging Abort 
                 16 
                 Timer defined by an ABS 
               
               
                 Timer 
                   
                 to prohibit the AMS from 
               
               
                   
                   
                 attempting network entry 
               
               
                   
                   
                 at this ABS, for a 
               
               
                   
                   
                 specific time duration. 
               
               
                   
                   
                 Value: 0 (Do not try 
               
               
                   
                   
                 ranging again at the 
               
               
                   
                   
                 ABS.) 
               
               
                   
                   
                 Value: 1-65535, In units 
               
               
                   
                   
                 of seconds 
               
               
                 }else if (Ranging 
               
               
                 Status ==0b10) { 
               
               
                 Adjustment 
                 3 
                 Bit#0: Time offset 
               
               
                 parameters 
                   
                 adjustment indication. 
               
               
                 indication 
                   
                 Bit#1: Power level 
               
               
                 (API) 
                   
                 adjustment indication 
               
               
                   
                   
                 Bit#2: Frequency offset 
               
               
                   
                   
                 adjustment Indication 
               
               
                 If( API Bit#0==0b1 
               
               
                 ) { 
               
               
                 Timing offset 
                 15 
               
               
                 adjustment 
               
               
                 } 
               
               
                 If( API Bit#1==0b1 
               
               
                 ) { 
               
               
                 Power level 
                 4 
               
               
                 adjustment 
               
               
                 } 
               
               
                 If (API 
               
               
                 Bit#2==0b1) { 
               
               
                 Frequency offset 
                 9 
               
               
                 adjustment 
               
               
                 } 
               
               
                 } 
               
               
                 } 
               
               
                   
               
             
          
         
       
     
         [0073]    Referring back to  FIG. 2 , in step  202 , the MSs in the group selects a group delegate of the group according to the message sent by the BS. 
         [0074]    It should be described that, the group delegate may be selected, but is not limited to, by calculating a formula (mod (group member ID, k) or (mod (group member ID, f(k, frame number)), where k is a positive integer and may be determined by the BS, and f(k, frame number) is a function related to k and the frame number, i.e., the value of f(k, frame number) is related to both k and time. The group delegate may be pre-selected. 
         [0075]    It should be also noted that, the group delegate may be selected before step  201 , and may be selected by the MS and the BS together as shown in  FIG. 4 . Thus, there is signaling interaction between the BS and the MS when the group delegate is selected. There are three modes for selecting the group delegate, such as a preconfiguration mode, a random selection mode of the MS, and a cooperation method of the BS (selected by the network) and the MS. 
         [0076]    In step  203 , the group delegate sends the GDC based on the group ID to the BS in a ranging opportunity. 
         [0077]    In step  203 , the selection of the ranging opportunity in an example is implemented as follows: if a data frame only includes one ranging opportunity, the GDC is sent in the ranging opportunity; if the data frame includes multiple ranging opportunities, one ranging opportunity is selected from the multiple ranging opportunities according to a formula mod (floor (ID M2M Group, NM2M group), NOpp). 
         [0078]    In step  204 , each MS in the group receives a RNG-ACK message and/or a group access resource allocation message from the BS. 
         [0079]    It should be noted that, after receiving the GDC, the BS sends the RNG-ACK message and/or the group access resource allocation message to the MS, and the message includes three types of information. The first type of information indicates identification and success, such as all or part of MSs in the group are allowed to access the network. The second type of information indicates that the GDC continues to be sent to correct timing, frequency offset and power adjustment, and if receiving this information, the group delegate should perform adjustment according to the information, and then performs step  203 . The third type of information indicates abort or prohibiting sending, such as rejecting the group to access the network, at the same time, a timer may be configured for the MSs in the group, and the MSs in the group can access the network again when the timer expires. The time duration of the timer may be configured with a new value, and may be referred to as a group timer. The value may be configured according to practical requirements, and may be different from the time duration of a conventional timer for abort in the network. The above three types of information may be used individually or in combination. For example, the first type of information may be given to one part of group members in the group, and the third type of information may be given to the other one part of group members in the group. 
         [0080]    It should also be noted that, if the GDC obtained by the BS does not meet the requirements of the BS, the BS includes a continue instruction in the message sent by the BS to make the group continue in sending the GDC, generally make the group delegate sending the GDC last time continue in sending the GDC, and further guarantee that the BS can correctly receive the GDC. Table 9 shows ACK information of group ranging codes which is added in a ranging ACK signaling sent to the MSs in the group by the BS. 
         [0081]    As mentioned previously, if the MSs receive continue or abort information from the BS, the selected group delegate is not changed; however, if the MSs receive success information, the selected group delegate changes back into a group member. 
         [0082]    It should also be noted that, if there is a time difference between the MSs, in order to prevent losing the information sent by the BS, the group members and/or the group delegate may need to receive the information from the BS in advance. 
         [0083]    The MSs in the group will respond to different ACK information with different responses. For example, if success information is received as shown in  FIG. 2 , the MSs will obtain an initial value and end value of a backoff window, and access the network after performing backoff processing. It should be noted that, when the initial value and end value of the backoff window are defined, a window space larger than that of a general subscriber is considered to decrease conflict and access delay caused when a large number of M2M access the network. Abort information indicates that all or a particular part of MSs in the group will access the network after a delay time (according to an abort timer). Continue information indicates that the group delegate in the M2M group will adjust its own timing or power parameters to continue sending the GDC of the group. 
         [0000]    
       
         
               
               
               
             
           
               
                 TABLE 10 
               
               
                   
               
               
                   
                 Size 
                   
               
               
                 Syntax 
                 (bit) 
                 Description 
               
               
                   
               
             
             
               
                 Initial ranging 
                 4 
                 Initial backoff window size for initial 
               
               
                 backoff start for 
                   
                 ranging contention, expressed as a power of 
               
               
                 M2M Group 
                   
                 2. Values of n range 0-15 
               
               
                 Initial ranging 
                 4 
                 Final backoff window size for initial 
               
               
                 backoff end for 
                   
                 ranging contention, expressed as a power of 
               
               
                 M2M Group 
                   
                 2. Valuesof n range 0-15 
               
               
                   
               
             
          
         
       
     
         [0084]    In step  205 , the MSs allowed accessing the network in the group receive backoff information which is sent by the BS and is contained in a superframe header for the group, individual or the prior art, perform backoff processing, select a ranging opportunity after the backoff processing, randomly select an IRC, and send the IRC to the BS. 
         [0085]    In step  206 , the MSs sending the IRC receive a RNG-ACK message and/or a CDMA Allocation A-MAP IE message from the BS, where the RNG-ACK message and/or the CDMA Allocation A-MAP IE message includes a response of the BS to the detected IRC. 
         [0086]    In step  207 , the MSs send a RNG-REQ message to the BS after receiving the RNG-ACK message containing success ACK information of the ranging signal, and/or receiving a corresponding CDMA Allocation A-MAP IE message, and/or receiving a corresponding group access resource allocation message, to inform the BS of information containing the MSs&#39; IDs, and continue in accessing the network. 
         [0087]      FIG. 3  illustrates an example operation between an MS and a BS for the MS to access the network in a mobile communication system according to a second embodiment of the present invention. Although not shown in the drawings, each of the MS and the BS includes at least a sender, a receiver, and a controller, and the sender and the receiver transmit and receive messages, and the controller of the MS and BS controls the operations according to the second embodiment of the present invention. 
         [0088]    Referring to  FIG. 3 , in step  301 , MSs in a group determine a GDC of the group and corresponding resources according to a message sent by a BS. 
         [0089]    In step  302 , the MSs in the group determine a group delegate of the group according to the message sent by the BS. It should be note that, step  302  may be performed before step  301 , and the determining of the group delegate is the same as step  201  of  FIG. 2 , and will not be described in detail. 
         [0090]    In step  303 , the group delegate sends the GDC of the group to the BS in a ranging opportunity. 
         [0091]    In step  304 , each MS in the group receives a RNG-ACK message and/or a group access resource allocation message from the BS. 
         [0092]    In step  305 , the MSs allowed to access the network in the group send an IRC pre-allocated to the MS to the BS in the ranging opportunity. The ranging opportunity may be pre-allocated to the MS. 
         [0093]    It should be noted that, in step  305 , each MS allowed to access the network in the group may be preconfigured with the ranging opportunity and IRC to reduce or eliminate any conflicts from occurring when the MSs are allowed to access the network in the group access the network, and further allow the MSs to successfully access the network. 
         [0094]    In step  306 , the MSs sending the IRC listen to and receive a RNG-ACK message and/or a CDMA Allocation A-MAP IE message from the BS, where the RNG-ACK message and/or the CDMA Allocation A-MAP IE message includes a response of the BS to the detected IRC. 
         [0095]    In step  307 , the MSs send a RNG-REQ message to the BS after receiving the RNG-ACK message including success ACK information of the ranging signal, and/or receiving a corresponding CDMA Allocation A-MAP IE message, and/or receiving a group access resource allocation message, to inform the BS of information containing the MSs&#39; IDs, and continue in accessing the network. 
         [0096]    The difference between the first embodiment and the second embodiment lies in the difference between step  205  and step  305 . 
         [0097]    The sequence of step  201  and step  202  may be changed as long as the two steps are performed before step  203 . In some cases, the time of performing the two steps in advance is not limited. Similarly, steps  301  and  302  are similar with steps  201  and  202 . 
         [0098]    It should be noted that, steps  205  through  206  and steps  305  through  306  may be omitted in some cases. Steps  201  and/or  202  and steps  301  and/or  302  may be implemented according to a third embodiment. 
         [0099]      FIG. 4  illustrates an example method for selecting a group delegate through communication between an MS and a BS according to certain embodiments of the present invention. 
         [0100]    In step  401 , a MS in the group receives a message sent by the BS, determines information of the group to which the MS belongs and the configuration of the group, which include at least one of: a group ID, a GDC and corresponding resources, such as a corresponding ranging opportunity, a frame number, a Group ID, a paging group ID, and so on. 
         [0101]    In step  402 , the MSs in the group determine the group delegate of the group according to the message sent by the BS. The message sent by the BS includes at least one of: the value k (referring to step  202 ), a time parameter for selecting the group delegate, such as a frame number or a superframe number (referring to “(mod (group member ID, f(k, frame number)”) in step  202 ), and the number of MSs in the group. 
         [0102]    In step  403 , the MS that will become the group delegate sends a message to the BS, to inform the BS that the MS will become the group delegate. 
         [0103]    In step  404 , the BS sends a message to the MSs in the group, and responds to the MS which will become the group delegate. The response may be sent to the group delegate or to the group. 
         [0104]    The IRC in the above embodiments may be an IRC in the conventional system, and may also be an IRC specially allocated to the MSs in the group. The IRC in the above embodiments may be sent in a ranging opportunity in the conventional system, and may also be sent in a ranging opportunity specially allocated to the MSs in the group. In additional, as in the ranging opportunity in the conventional system, both the IRC in the conventional system and the IRC specially allocated to the MSs in the group may be sent. 
         [0105]    In the above embodiments, the M2M group and the ranging opportunity are only examples, and the method may be applied to other groups and opportunities in practical applications. 
         [0106]    In summary, in the network access method of the MS provided by the embodiments of the present invention, a large number of MSs are delegated in groups, the group delegate in each group may request the BS through one or more GDCs to access the network, after receiving the message of allowing accessing the network, the MSs in this group send the IRC request or directly sends the RNG-REQ message to the BS to access the network. Since the MSs are delegated in groups in the various embodiments of the present invention, the number of MSs sending the access codes is decreased relatively, and thus the conflict occurred when the MSs access the network can be decreased. 
         [0107]    Further, in the embodiments of the present invention, the MSs allowed to access the network in the group may be configured with different IRCs, so that the MSs request to access the network with different IRCs to reduce or eliminate any conflicts when the MSs access the network. 
         [0108]    As can be seen, since the MSs are delegated in groups, that is, the number of MSs sending the IRC in a period of time is decreased, potential conflicts when the MSs access the network can be decreased. 
         [0109]    Further, in the present invention, the MSs in the group which are allowed to access the network may be allocated with different IRCs, so that each MS may request to access the network using different IRCs, to avoid any conflicts when the MSs access the network. 
         [0110]    Other various effects may have been directly or implicitly disclosed in the detailed description according to the embodiments of the present invention. 
         [0111]    The foregoing is only the preferred examples of the present invention and is not used to limit the protection scope of the present invention. Any modification, equivalent substitution and improvement without departing from the principle of the present invention are within the protection scope of the present invention. 
         [0112]    Although the present disclosure has been described with an exemplary embodiment, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims.