Patent Publication Number: US-2009232060-A1

Title: Method, wireless communication system, communication apparatus, and tangible machine-readable medium for establishing a routing path during a network entry process of a subscriber station based on a multi-hop relay standard

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a method, a wireless communication system, a communication apparatus, and a tangible machine-readable medium for establishing a routing path. More specifically, the present invention relates to a method, a wireless communication system, a communication apparatus, and a tangible machine-readable medium for establishing a routing path during a network entry process of a subscriber station (SS) based on a multi-hop relay standard. 
     2. Descriptions of the Related Art 
     Although the IEEE 802.16 standard already provides greater bandwidths, lower building cost, better service quality and expansibility, there still exist some defects of coverage and signal quality of the IEEE 802.16 standard. Therefore, the IEEE 802.16j standard working group established a multi-hop relay study group in July, 2005 for building a multi-hop relay standard. 
     In conventional IEEE 802.16 standard, network entry process is easily to execute because a base station (BS) and a plurality of subscriber stations (SSs) transmit data to each other directly. But in the multi-hop relay standard, such as the IEEE 802.16j standard or the IEEE 802.16m standard, there are relay stations (RSs) to relay data between the BS and the SSs. Accordingly, the routing paths between the BS and the SSs are more complicated because of data&#39;s relay, so that the network entry process will be more difficult between the BS and the SSs. 
     When an SS, such as a mobile station (MS), enters into a multi-hop relay stations (MR-RSs) network under the IEEE 802.16j during a network entry process, a solution to choosing and/or managing routing paths of the MR-RSs network under the IEEE 802.16j standard which transmit data from a BS to the SS is desired. 
     SUMMARY OF THE INVENTION 
     One objective of this invention is to provide a method for establishing a routing path during a network entry process of an SS based on a multi-hop relay standard. The method comprises the following steps: transmitting a ranging request (RNG-REQ) of the SS with a ranging connection identification (CID) from the SS to an RS; allocating an SS CID for the SS; transmitting a ranging response (RNG-RSP) having the SS CID with the ranging CID from the RS to the SS; transmitting a request message with the SS CID from the SS to a BS through the RS; and transmitting a response message from the BS to the SS through the RS after receiving the request message. The routing path of the SS is updated into a routing table of the RS according to one of the request message and the response message. 
     Another objective of this invention is to provide a wireless communication system for establishing a routing path during a network entry process of an SS based on a multi-hop relay standard. The wireless communication system comprises a BS, an SS, and an RS. The SS transmits an RNG-REQ of the SS to the RS with a ranging CID. The RS allocates an SS CID for the SS, and transmits an RNG-RSP having the SS CID to the SS with the ranging CID. Then the SS transmits a request message with the SS CID to the BS through the RS. Finally, the BS transmits a response message to the SS through the RS after receiving the request message. The routing path of the SS is updated into a routing table of the RS according to one of the request message and the response message. 
     Another objective of this invention is to provide a communication apparatus for establishing a routing path during a network entry process of an SS based on a multi-hop relay standard. The communication apparatus comprises a receiving module, a memory, a processor, and a transmitting module. The receiving module receives a request message or a response message. The memory stores a routing table. 
     In one way, when the receiving module receives the request message, such as an SS basic capability request (SBC-REQ), the processor processes the request message to retrieval SS information having an SS CID and the routing path of the SS, and to update the SS CID and the routing path of the SS into the routing table. The transmitting module transmits the request message with the SS CID to the BS. 
     In the other way, when the receiving module receives the response message, such as an SS basic capability response (SBC-RSP), which has an SS CID and the routing path of the SS, the processor updates the SS CID and the routing path of the SS into the routing table after receiving the response message. Finally, the transmitting module transmits the response message with an RS CID to the SS. 
     Another objective of this invention is to provide a tangible machine-readable medium having executable code to cause a machine to perform a method for establishing a routing path during a network entry process of an SS based on a multi-hop relay standard. The method comprises the following steps: transmitting an RNG-REQ of the SS with a ranging CID from the SS to an RS; allocating an SS CID for the SS; transmitting an RNG-RSP having the SS CID with the ranging CID from the RS to the SS; transmitting a request message with the SS CID from the SS to a BS through the RS; and transmitting a response message from the BS to the SS through the RS after receiving the request message. The routing path of the SS is updated into a routing table of the RS according to one of the request message and the response message. 
     The aforesaid method can be executed by wireless communication apparatus, such as a BS or an RS in the wireless communication system. By receiving a request message (i.e. SBC-REQ) or a response message (i.e. SBC-RSP) and updating the SS CID and the routing path of the SS into a routing table which is stored in the RS, this invention can choose and/or manage routing paths of the RS of the wireless communication system. Thus, data of the wireless communication system based on a multi-hop relay standard can be transmitted successfully among the BS, RSs, and SSs. 
     The detailed technology and preferred embodiments implemented for the subject invention are described in the following paragraphs accompanying the appended drawings for people skilled in this field to well appreciate the features of the claimed invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a multi-hop relay wireless communication system of a first embodiment of the present invention; 
         FIG. 2  illustrates a block diagram of an RS of the first embodiment; 
         FIG. 3  illustrates diagrams of data transmission of network entry process of an SS of the first embodiment; 
         FIG. 4  is a flow chart illustrating a second embodiment of the present invention; 
         FIG. 5  is a flow chart illustrating request message processing of the second embodiment; and 
         FIG. 6  is a flow chart illustrating response message processing of the second embodiment. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As illustrated in  FIG. 1 , a first embodiment of the present invention is a multi-hop relay wireless communication system  1  based on a multi-hop relay standard, such as IEEE 802.16j standard. The multi-hop relay wireless communication system  1  comprises a BS  101 , a plurality of RSs  103 ,  105 , and an SS  107 . For the sake of simplification, two RSs (RS 1    103 , and RS 2    105 ) are illustrated. The SS  107  can be an MS or another RS which can provide functions based on the multi-hop relay standard. The RSs  103 ,  105  of the multi-hop relay wireless communication system  1  is illustrated in  FIG. 2 , which comprises a receiving module  201 , a processor  203 , a transmitting module  205 , a memory  207 , and a timer  209 . Data transmission of network entry process of the SS  107  based on the multi-hop relay wireless communication system  1  is illustrated in  FIG. 3 . 
     In  FIG. 3 , because the RS 1    103  and the RS 2    105  have entered into the multi-hop relay stations system  1 , the SS  107  can execute the network entry process to enter into the multi-hop relay stations system  1  via the RS 1    103  and the RS 2    105 . The SS  107  will select the nearest RS to connect so that the network entry process of the SS  107  will be executed in the shortest time period. In this embodiment, the nearest RS is the RS 2    105 . When starting the network entry process, the SS  107  transmits an RNG-REQ RNG M-r2  which comprises an SS MAC address of the SS  107  with a ranging CID to the RS 2 . The ranging CID is used in the network entry process. After the receiving module  201  of the RS 2    105  receives the RNG-REQ RNG M-r2  and the processor  203  of the RS 2    105  processes the RNG-REQ RNG M-r2 , the RS 2    105  will allocate an SS basic CID and an SS primary CID for the SS  107 . Then the RS 2    105  transmits an RNG-RSP RNG r2-M  which comprises the SS basic CID and the SS primary CID of the SS  107  with HMAC/CMAC with the ranging CID to the SS  107 , so that the SS  107  will be assigned the SS basic CID and the SS primary CID. 
     Then, the SS  107  transmits one request message, such as an SBC-REQ SBC M-r2  with the SS basic CID to the RS 2    105 , the RS 2    105  transmits another request message, such as an SBC-REQ SBC r2-r1  which comprises the SS information (i.e. SS MAC address) with the SS basic CID to the RS 1    103 , and the RS 1    103  transmits the other request message, such as an SBC-REQ SBC r1-B  which comprises the SS information with the SS basic CID to the BS  101 . 
     After processing the SBC-REQ SBC r1-B , the BS  101  transmits one response message, such as an SBC-RSP SBC B-r1  which comprises the SS basic CID, the SS primary CID, and a routing path of the SS  107  with HMAC/CMAC with an RS 1  CID to the RS 1    103 . After that, the RS 1    103  transmits another response message, such as an SBC-RSP SBC r1-r2  which comprises the SS basic CID and the SS primary CID with HMAC/CMAC with an RS 2  CID to the RS 2    105 . Finally, the RS 2    105  transmits the other response message, such as an SBC-RSP SBC r2-M  to the SS  107  with the SS basic CID. 
     There are two ways to update the SS basic CID, the SS primary CID, and the routing path of the SS  107  into a routing table which is stored in the memory  207  of the RS 1    103 . One way is that the processor  203  of the RS 1    103  processes the SBC-REQ SBC r2-r1  to retrieval the SS information. Then the RS 1    103  updates the SS basic CID, the SS primary CID, and the routing path of the SS  107  into the routing table according to the SBC-REQ SBC r2-r1  and the SS information. 
     Another way is that the RS 1    103  updates the SS basic CID, the SS primary CID, and the routing path of the SS  107  into the routing table according to the SBC-RSP SBC B-r1  and the SS information after the receiving module  201  of the RS 1    103  receives the SBC-RSP SBC B-r1 . 
     After the routing table of the RS 1    103  is updated, a timer  209  of the RS 1    103  starts a timeout period to wait the BS  101  to transmit a dynamic service addition request (DSA-REQ). Similarly, a timer  209  of the RS 2    105  starts another timeout period to wait the BS  101  to transmit a DSA-REQ through the RS 1    103 . 
     This invention is not limited that only the routing table the RS 1    103  is updated, any other RSs (i.e. RS 2    105 ) in the multi-hop relay wireless communication system  1  also can update the routing table thereof as the operations described in the above description. Those skilled in the art can understand the corresponding operations of the update of the routing table by the explanation of the first embodiment. 
     Second, the SS  107  transmits a PKM-REQ PKM M-r2  with the SS primary CID to the RS 2    105 , the RS 2    105  transmits a PKM-REQ PKM r2-r1  with the SS primary CID to the RS 1    103 , and the RS 1    103  transmits a PKM-REQ PKM r1-B  with the SS primary CID to the BS  101 . After processing the PKM-REQ PKM r1-B , the BS  101  transmits a PKM-RSP PKM B-r1  with the SS primary CID to the RS 1    103 , the RS 1    103  transmits a PKM-RSP PKM r1-r2  with the SS primary CID to the RS 2    105 , and the RS 2    105  transmits a PKM-RSP PKM r2-M  with the SS primary CID to the SS  107 . 
     Third, the SS  107  transmits an REG-REQ REG M-r2  with HMAC/CMAC with the SS primary CID to the RS 2    105 , the RS 2    105  transmits an REG-REQ REG r2-r1  with HMAC/CMAC with the SS primary CID to the RS 1    103 , and the RS 1    103  transmits an REG-REQ REG r1-B  with HMAC/CMAC with the SS primary CID to the BS  101 . After processing the REG-REQ REG r1-B , the BS  101  transmits an REG-RSP REG B-r1  with HMAC/CMAC with the SS primary CID to the RS 1    103 , the RS 1    103  transmits an REG-RSP REG r1-r2  with HMAC/CMAC with the SS primary CID to the RS 2    105 , and the RS 2    105  transmits an REG-RSP REG r2-M  with HMAC/CMAC with the SS primary CID to the SS  107 . 
     Finally, the BS  101  transmits a DSA-REQ DSA B-r1  which comprises the SS basic CID with HMAC/CMAC with the RS 2  primary CID to the RS 1    103  and the RS 1    103  transmits a DSA-REQ DSA r1-r2  which comprises the SS basic CID with HMAC/CMAC with the RS 2  primary CID to the RS 2    105 . If the RS 1    103  receives the DSA-REQ DSA B-r1  in the timeout period which is started by the timer  209  of the RS 1    103 , the SS basic CID, the SS primary CID, and the routing path of the SS  107  stored in the routing table of the RS 1    103  will be kept. Otherwise, if the RS 1    103  receives the DSA-REQ DSA B-r1  out of the timeout period which is started by the timer  209  of the RS 1    103 , the SS basic CID, the SS primary CID, and the routing path of the SS  107  stored in the routing table of the RS 1    103  will be removed. 
     A second embodiment of this invention is a method for establishing a routing path during a network entry process of an SS based on a multi-hop relay standard, which is a method applied to the multi-hop relay wireless communication system  1  described in the first embodiment. More specifically, the method of the second embodiment which is illustrated in  FIG. 4 ,  FIG. 5 , and  FIG. 6  can be implemented by an application program controlling various modules of a wireless communication apparatus in the multi-hop relay wireless communication system  1 . This application program may be stored in a tangible machine-readable medium, such as a read only memory (ROM), a flash memory, a floppy disk, a hard disk, a compact disk, a mobile disk, a magnetic tape, a database accessible to networks, or any other storage media with the same function and well known to those skilled in the art. 
     In step  401 , an RNG-REQ of the SS, such as the SS  107 , is transmitted with a ranging CID from the SS to an RS, Next in step  403 , an SS CID for the SS is allocated by the RS. In step  405 , an RNG-RSP having the SS CID is transmitted with the ranging CID from the RS to the SS. Then, in step  407 , a request message (i.e. SBC-REQ) is transmitted with the SS CID from the SS to a BS, such as the BS  101 , through the RS. Finally, in step  409 , a response message (i.e. SBC-RSP) is transmitted from the BS to the SS through the RS after the request message is received. 
     One way to update the SS basic CID, the SS primary CID, and the routing path of the SS, step  407  further comprises some steps illustrated in  FIG. 5 . In step  501 , another request message is transmitted with the SS CID from the SS to the RS. In step  503 , the request message transmitted from the SS to the RS is processed to retrieval SS information. Finally, in step  505 , the SS basic CID, the SS primary CID, and the routing path of the SS are updated into a routing table of the RS according to the request message and the SS information. 
     Another way to update the SS basic CID, the SS primary CID, and the routing path of the SS, step  409  further comprises some steps illustrated in  FIG. 6 . In step  601 , another response message having the SS CID and the routing path of the SS is transmitted with an RS CID from the BS to the RS. In step  603 , the SS basic CID, the SS primary CID, and the routing path of the SS are updated into a routing table of the RS after the RS receives the response message. 
     In addition to the steps revealed in  FIG. 4 ,  FIG. 5 , and  FIG. 6 , the second embodiment can also execute all the operations of the first embodiment, in which those skilled in the art can understand the corresponding steps and operations of the second embodiment by the explanation of the first embodiment, and thus no necessary detail is given. 
     Accordingly, by receiving an SBC-REQ or an SBC-RSP, and updating the SS CID and the routing path of the SS into a routing table which is stored in the RS, this invention can choose and/or manage relay paths of the RS of the wireless communication system. Thus, data of the wireless communication system based on a multi-hop relay standard can be transmitted successfully among the BS, RSs, and SSs. 
     The above disclosure is related to the detailed technical contents and inventive features thereof. People skilled in this field may proceed with a variety of modifications and replacements based on the disclosures and suggestions of the invention as described without departing from the characteristics thereof. Nevertheless, although such modifications and replacements are not fully disclosed in the above descriptions, they have substantially been covered in the following claims as appended.