Abstract:
A connection node, a method, a computer program, and a computer readable medium thereof for recalculating a transmission opportunity when an apparatus requests to enter a wireless network are provided. A receiving module receives a mesh network entry message transmitted from the apparatus. A memory stores an identification of a sponsor node. A processing module determines whether an original neighboring node list comprises the identification. If no, the processing module updates the original neighboring node list according to the identification, and recalculates a transmission opportunity of a mesh network configuration message of the connection node. Finally, a transmission module transmits the mesh network configuration message according to the transmission opportunity in order to solve the problem that mesh network configuration messages of nodes collide with each other of the prior art.

Description:
[0001]    This application claims the benefit of priority based on Taiwan Patent Application No. 095144831 filed on Dec. 1, 2006 of which the contents are incorporated herein by reference in its entirety. 
       CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0002]    Not applicable. 
       BACKGROUND OF THE INVENTION 
       [0003]    1. Field of the Invention 
         [0004]    The present invention relates to a connection node, a method, and a computer readable medium thereof for recalculating a transmission opportunity when an apparatus enters a wireless network. 
         [0005]    2. Descriptions of the Related Art 
         [0006]    With the rapid development of the computer network, various broadband services are now essential to the information industry. However, only part of computer users in the whole world can use high speed wired broadband services, such as the digital subscribe line (DSL) and the cable broadband access. From network telecommunication service providers point of view, they desire to expand the coverage range of the broadband network. However, the related infrastructure costs for building the wired network make the providers move back. Broadband wireless techniques, hence, become an important solution. In light of communication distance, the current techniques of the wireless network can be classified into the wide area network (WAN), the metropolitan area network (MAN), the local area network (LAN), and the personal area network (PAN). 
         [0007]    IEEE 802.16, worldwide interoperability for microwave access (WiMax), is a newly developing wireless transmission standard. The original establishing objective is to set up a radio standard of the metropolitan network to provide a wireless broadband connection technique of “the last mile” for the telecommunication industry. After continuously improved by the researchers of IEEE 802.16, more market requests can be supported now, such as various mobile and high speed broadband applications. Furthermore, comparing with IEEE 802.11, i.e., Wi-Fi and the third generation mobile communication (3G) technique, IEEE 802.16 has the advantages of larger network bandwidth, lower construction cost, better service quality, better expansibility, and extending the usage mode of a Wi-Fi hot spot. 
         [0008]    IEEE 802.16 defines two operation modes. One is the point to multipoint (PMP) mode which is used in the aforementioned wireless broadband connection technique of “the last mile” to replace the conventional fixed network, such as the asymmetric digital subscriber line (ADSL) or the T1 subscriber line. The other operation mode is the mesh mode which provides a high speed and reliable backbone network. After several years&#39; research for the PMP mode, the current techniques are very mature and already applied widely. Although the mesh mode has many advantages, it involves a more complicated technique and does not mature yet. Hence, the mesh mode still requires a lot of development. 
         [0009]      FIG. 1  depicts a common wireless network  1  which uses the mesh operation mode of the IEEE 802.16. The wireless network  1  comprises a base station  101 , a plurality of connection nodes  103 ,  105 , . . . ,  111  and an apparatus  113  which is about to enter the wireless network  1 . The apparatus  113  has an effective connection range  100 . The connection node  107  has an effective connection range  102 . The connection node  111  has an effective connection range  104 . When the apparatus  113  intends to enter the wireless network  1 , a network entry process is required to be executed so that the entering may be finished smoothly. The connection nodes  103 ,  105 , . . . ,  111  and the apparatus  113  can be anyone of a gateway, a router, and a terminal apparatus that transmits data under the mesh operation mode of the IEEE 802.16. 
         [0010]    While the network entry process is executed, the apparatus  113  needs to search for a connection node as its sponsor node within the effective connection range  100  to assist the apparatus  113  and the base station  101  in performing the required process for data transmissions, such as authorization and registration. Assuming that the apparatus  113  selects the connection node  107  as its sponsor node, a mesh network entry message (MSH-NENT)  106  will be transmitted to the connection node  107 . The connection node  107  will respond a mesh network configuration message (MSH-NCFG)  108  to the apparatus  113  for the following data transmission process. 
         [0011]    Since the effective connection range  100  of the apparatus  113  covers the connection nodes  107  and  111 , the apparatus  113  not only receives the mesh network configuration message  108  from the connection node  107 , but also receives a mesh network configuration message  110  from the connection node  111 . Although the effective connection range  102  and the effective connection range  104  both cover the apparatus  113 , the effective connection range  104  does not cover the connection node  107 . 
         [0012]    When the connection node  111  intends to transmit the mesh network configuration message  110 , a transmission opportunity for the mesh network configuration message  110  is calculated first according to the current specification of the IEEE 802.16 standard, wherein the transmission opportunity is used for the connection node  111  to control the timing for transmitting the mesh network configuration message  110 . The transmission opportunity is calculated according to a neighboring node list stored in the connection node  111 . More particularly, the calculation of the transmission opportunity takes the connection nodes  103  and  109  covered by the effective connection range  104  into account to avoid a collision between the mesh network configuration message  110  and a mesh network configuration message transmitted from the connection nodes  103  or  109 . It is noted that although the apparatus  113  is within the effective connection range  104 , it does not join the wireless network  1  yet. Thus, it is not considered when the transmission opportunity of the mesh network configuration message  110  is calculated. Since the effective connection range  104  does not cover the connection node  107 , the neighboring node list of the connection node  111  does not record any data about the connection node  107 . Therefore, when the connection node  111  calculates the transmission opportunity of the mesh network configuration message  110 , the influence from the connection node  107 , the sponsor node of the apparatus  113 , is not considered. Therefore, when the connection node  107  responds the mesh network configuration message  108  to the apparatus  113 , it is highly possible to collide with the mesh network configuration message  110 . Under the circumstance, the apparatus  113  cannot read the mesh network configuration message  108  correctly so that the apparatus  113  fails to continue the following data transmission process for entering the wireless network  1 . 
         [0013]    According to the aforementioned descriptions, due to the collision between the mesh network configuration message  108  and the mesh network configuration message  110 , the success ratio for the apparatus  113  to join the wireless network  1  is reduced significantly. Therefore, how to make the node  111  consider the influence of the sponsor node of the apparatus  113  when the node  111  calculates its own transmission opportunity without changing the IEEE 802.16 specification is still an urgent topic for the industry to endeavor. 
       SUMMARY OF THE INVENTION 
       [0014]    One objective of this invention is to provide a method for a connection node to re-calculate a transmission opportunity when an apparatus requests to join a wireless network. The method comprises the following steps of: receiving a mesh network entry message transmitted from the apparatus; storing an identification of a sponsor node of the wireless network according to the mesh network entry message; determining whether an original neighboring node list comprises the identification; if not, adding the identification into the original neighboring node list to update the original neighboring node list; if the original neighboring node list does not comprises the identification, calculating a first transmission opportunity of a mesh network configuration message of the connection node according to the updated neighboring node list; and transmitting the mesh network configuration message of the connection node according to the first transmission opportunity. 
         [0015]    A further objective of this invention is to provide a computer readable medium for storing a computer program. The computer program makes a connection node execute a method of re-calculating a transmission opportunity when an apparatus requests to join a wireless network. The method comprises the following steps of: making a receiving module receive a mesh network entry message from the apparatus; making a memory store an identification of a sponsor node of the wireless network according to the mesh network entry message; making a process module determine whether an original neighboring node list comprises the identification; if no, making the process module add the identification into the original neighboring node list to update the original neighboring node list; making the process module calculate a first transmission opportunity of a mesh network configuration message of the connection node according to the updated neighboring node list; and making a transmission module transmit the mesh network configuration message of the connection node according to the first transmission opportunity. 
         [0016]    Yet a further objective of this invention is to provide a connection node capable of re-calculating a transmission opportunity when an apparatus requests to join a wireless network. The connection node comprises a receiving module, a memory, a processing module, and a transmission module. The receiving module is used for receiving a mesh network entry message from the apparatus. The memory is used for storing an identification of a sponsor node of the wireless network according to the mesh network entry message. The processing module is used for determining whether an original neighboring node list comprises the identification. If the original neighboring node list does not comprise the identification, the processing module adds the identification into the original neighboring node list to update the original neighboring node list, and calculates a first transmission opportunity of a mesh network configuration message of the connection node according to the updated neighboring node list. The transmission module transmits the mesh network configuration message of the connection node according to the first transmission opportunity. 
         [0017]    This invention is capable of adjusting the neighboring node list of a connection node according to the identification of the sponsor node so that the calculation of the transmission opportunity of the connection node may consider the influence of the sponsor node with reference to the neighboring node list. Without changing the IEEE 802.16 specification, the invention solves the problem that, when an apparatus is about to join a wireless network, a collision will occurs if other connection nodes simply calculates the transmission opportunity based on the neighboring node list without comprising the identification of the sponsor node. This invention increases the whole efficiency and usability of the IEEE 802.16 mesh network with high density distribution of nodes. When the nodes of the IEEE 802.16 mesh network are deployed in a large number in the future, a new node can enter the mesh network quickly 
         [0018]    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 the art to well appreciate the features of the claimed invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is a schematic diagram of a conventional wireless network under an IEEE 802.16 mesh operation mode; 
           [0020]      FIG. 2  is a schematic diagram of a wireless network of a first embodiment of this invention; 
           [0021]      FIG. 3  is a schematic diagram of a connection node of the first embodiment; and 
           [0022]      FIG. 4  is a flow chart of a second embodiment and a third embodiment of this invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0023]    A first embodiment of this invention is shown in  FIG. 2  which is a wireless network  2  under IEEE 802.16 mesh mode operation. The wireless network  2  comprises a base station  201 , a plurality of nodes  203 ,  205 ,  207 ,  209 ,  211  and an apparatus  213  which is about to join the wireless network  2 , wherein the node  211  is a connection node located within an effective connection range  200  of the apparatus  213  in this embodiment. In response to the joining of the apparatus  213 , the connection node  211  has to re-calculate its own transmission opportunity. The connection node  211 , as shown in  FIG. 3 , comprises a receiving module  2111 , a memory  2113 , a processing module  2115 , and a transmission module  2117 . The nodes  203 ,  205 ,  207 ,  209 , the connection node  211 , and the apparatus  213  can be anyone of a gateway, a router, and a terminal apparatus operate under the IEEE 802.16 mesh mode. 
         [0024]    The apparatus  213  has an effective connection range  200 . The node  207  has an effective connection range  202 . The connection node  211  has an effective connection range  204 . When the apparatus  213  intends to join the wireless network  2 , it must search for a connection node as its sponsor node which is covered by the effective connection range  200 . In this embodiment, assume that the node  207  is the sponsor node of the apparatus  213 . After the apparatus  213  assigns the sponsor node  207 , a mesh network entry message  206  is transmitted to the sponsor node  207 . Then the apparatus  213  waits for a mesh network configuration message  208  from the sponsor node  207  to perform the following data transmission process. When the apparatus  213  transmits the mesh network entry message  206 , the receiving module  2111  of the connection node  211  also receives the mesh network entry message  206  since the connection node  211  is also within the effective connection range  200 . The processing module  2115  stores an identification of the sponsor node  207  carried by the mesh network entry message  206  into the memory  2113 . After that, the processing module  2115  determines whether an original neighboring node list stored in the memory  2113  comprises the identification of the sponsor node  207 . If no, the processing module  2115  adds the identification of the sponsor node  207  into the original neighboring node list to update the original neighboring node list and calculates the transmission opportunity of the mesh network configuration message  210  according to the updated neighboring node list. That is, the nodes  203 ,  209 , and the sponsor node  207  are considered while calculating a suitable timing for transmitting the mesh network configuration message  210 . Finally, the transmission module  2117  transmits the mesh network configuration message  210  according to the updated transmission opportunity. 
         [0025]    Under another condition, if the effective connection range  204  covers the sponsor node  207 , the processing module  2115  will determine that the original neighboring node list already comprises the identification of the sponsor node  207 . Therefore, while the transmission opportunity of the mesh network configuration message  210  is calculated, the influence of the sponsor node  207  has been considered. The processing module  2115  calculates the transmission opportunity directly according to the original neighboring node list, and the transmission module  2117  transmits the mesh network configuration message  210  according to the transmission opportunity. 
         [0026]    According to the aforementioned descriptions, even if the effective connection range  204  does not cover the sponsor node  207 , the processing module  2115  can still obtain the identification of the sponsor node  207  from the mesh network entry message  206  to update the original neighboring node list of the connection node  211 . Therefore, the influence of the sponsor node  207  can be considered while calculating the transmission opportunity of the mesh network configuration message  210 . The possibility of collision between the transmissions of the mesh network configuration message  208  and the mesh network configuration message  210  is avoided. In other words, a success ratio for the apparatus  213  joining the wireless network  2  is improved. 
         [0027]    The invention does not limit how the connection node  211  obtains the identification of the sponsor node  207 . The first embodiment of this invention adopts the network entry message  206  to obtain the identification of the sponsor node  207 . However, this is only an example. Furthermore, when the apparatus  213  is about to join the wireless network  2 , the connection node  211  can obtain the identification of the sponsor node  207  indirectly from the base station  201 . Those skilled in the art can easily realize other ways to obtain the identification of the sponsor node  207 . 
         [0028]    A second embodiment of this invention is to provide a method for re-calculating a transmission opportunity when an apparatus is about to join a wireless network, the method is applied to the connection node  211  as described in the first embodiment. More practically, the method of the second embodiment is applied by a computer program to control each module of the connection node  211 . The corresponding flow chart is shown in  FIG. 4 . 
         [0029]    At first, step  401  is executed for making the apparatus choose a sponsor node. That is, the apparatus  213  chooses a sponsor node first. Next, step  403  is executed that the computer program makes the receiving module  2111  receive a mesh network entry message from the apparatus. Then step  405  is executed that the computer program makes the memory  2113  store an identification of the sponsor node according to the mesh network entry message by a processing module  2115 . Step  407  is executed that the computer program makes the processing module  2115  determine whether an original neighboring node list stored in the memory  2113  comprises the identification. If no, step  409  is executed that the computer program makes the processing module  2115  add the identification into the original neighboring node list to update the original neighboring node list. Next, step  411  is executed that the computer program makes the processing module  2115  calculate a transmission opportunity according to the updated neighboring node list. Final, step  413  is executed that the computer program makes the transmission module  2117  transmit the mesh network configuration message according to the transmission opportunity. 
         [0030]    In step  407 , if the original neighboring node list comprises the identification, step  415  is executed that the computer program makes the processing module  2115  calculate a transmission opportunity according to the original neighboring node list. Refer back to step  413 , it is executed that the computer program makes the transmission module  2117  transmit the mesh network configuration message according to the transmission opportunity. 
         [0031]    Except the steps revealed in  FIG. 4 , the second embodiment can also execute all the operations of the first embodiment, 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 unnecessary detail is given. 
         [0032]    A third embodiment of this invention is to provide another method for a connection node to re-calculate a transmission opportunity when an apparatus is about to join a wireless network. A flow chart of this method is shown in  FIG. 4 . 
         [0033]    At first, step  401  is executed for choosing a sponsor node. Step  403  is executed for receiving a mesh network entry message from the apparatus. Step  405  is executed for storing an identification of the sponsor node according to the mesh network entry message. Step  407  is executed for determining whether an original neighboring node list comprises the identification. If no, step  409  is executed for making the identification be added into the original neighboring node list to update the original neighboring node list. Next, step  411  is executed for calculating a transmission opportunity of a mesh network configuration message according to the updated neighboring node list. Finally, step  413  is executed for transmitting the mesh network configuration message according to the transmission opportunity. 
         [0034]    In step  407 , if the original neighboring node list comprises the identification, step  415  is executed for calculating the transmission opportunity of the mesh network configuration message according to the original neighboring node list. Refer back to step  413 , it is executed for transmitting the mesh network configuration message according to the transmission opportunity 
         [0035]    Except the steps revealed in  FIG. 4 , the third embodiment can also execute all the operations of the first embodiment, those skilled in the art can understand the corresponding steps or operations of the third embodiment by the explanation of the first embodiment, and thus no unnecessary detail is given. 
         [0036]    According to the aforementioned descriptions, this invention updates the neighboring node list of the connection nodes which comprises the identification of the sponsor node according to the mesh network entry message, and recalculates the transmission opportunity of the mesh network configuration message transmitted by the connection nodes. Under the premise of not changing the IEEE 802.16 specification, a collision condition among the mesh network configuration messages is successfully avoided. 
         [0037]    The above disclosure is related to the detailed technical contents and inventive features thereof. People skilled in the art 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.