Abstract:
A method for discovering a network service provider, a network side transmitting apparatus and a network discovering apparatus for a user side device are disclosed. The method is used in a wireless communication network which includes a network access provider, a user side device and a network service provider. The method includes: issuing, by a network side, information that identifies a network access provider sharing mode; discovering the network service provider by the user side device in a manner corresponding to the information that identifies the network access provider sharing mode, when the user side device accesses the network. The present invention discovers a network service provider by incorporating different network access provider sharing modes into the existing wireless communication networks, and thus can utilize network resources effectively.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS  
       [0001]     The present application is a continuation of PCT Application No. PCT/CN2006/001625, filed on Jul. 10, 2006, which claims a priority to Chinese Patent Application No. 200510035719.X, filed on Jul. 8, 2005. All of these applications are incorporated herein by reference for all purposes. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to access technology in a wireless communication network, and more specifically, the present invention relates to a method and apparatus for discovering a network service provider when a user side device accesses a wireless communication network.  
       BACKGROUND OF THE INVENTION  
       [0003]     As the development of wireless communication technology, new forms of wireless communication networks are continuously emerging, for example, currently fast-developed Worldwide Interoperability for Microwave Access Forum (WiMax) network, Wireless Local Area Network (WLAN) and so on. Generally, the wireless communication networks include user side devices, Network Access Providers (NAPs) operated by different operators, and Network Service Providers (NSPs). The WiMax network based on the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard, which can provide higher accessing rate, is used hereinafter as an example for illustration.  
         [0004]     Referring to  FIG. 1 , it is a schematic diagram of the WiMax network reference model in non-roaming situation. In non-roaming situation, an Access Service Network (ASN)  110  is connected to a Connection Service Network (CSN)  120 , and a Subscriber Station/Mobile Subscriber Station (SS/MSS)  130  accesses the CSN  120  via the ASN  110 .  
         [0005]     Referring to  FIG. 2 , it is a schematic diagram of the WiMax network reference model in roaming situation. In roaming situation, the ASN  110  is connected to a Visited CSN  121 , and the Visited CSN  121  is connected to a Home CSN  122 . The SS/MSS  130  is authenticated on the Home CSN  122  via the ASN  110  and the Visited CSN  121 , and enjoys services provided by the Visited CSN  121  and the Home CSN  122 .  
         [0006]     Generally, the ASN is operated by the NAP and the CSN is operated by the NSP. In practical deployment, the NAP, a Visited NSP and a Home NSP may be operated by different operators, and the same area may be covered by several ASNs and each ASN may be connected with several NSPs. Currently, in the WiMax network, there are two different deployment modes: one is “NAP+NSP” mode, that is, there is an one-to-one correspondence between the NAPs and the NSPs; and another is “NAP+Sharing” mode, that is, one NAP has a roaming agreement with a plurality of NSPs and shared by the plurality of NSPs.  
         [0007]      FIG. 3  shows a possible deployment mode in a WiMax network.  
         [0008]     An ASN  111  of a NAP_ 4  and an ASN  112  of a NAP_ 6  both have coverage in the same area. A CSN  1201  of a NSP_ 1 , a CSN  1202  of a NSP_ 2  and a CSN  1203  of a NSP_ 3  share the ASN  111  of the NAP_ 4 . The ASN  112  of the NAP_ 6  is bound with a CSN  1204  of a NSP_ 6 . An SS/MSS  131  and an SS/MSS  132  visit the network via the ASNs  111  and  112  respectively.  
         [0009]     As for the mode in which the ASN is shared, a user side device may encounter an issue of how to know by which NSPs the current ASN is shared, that is, how to know which NSPs can be used through the current ASN. This is the NSP selection issue in a wireless communication network, that is, how does the network side provide currently available network information for the user side device, so that the user side device can select one NSP from the information of all accessible NSPs at the current position to access the network.  
         [0010]     Currently, there are two mechanisms to discovering a NSP in a wireless communication network.  
         [0011]     One mechanism is to derive information of an available NSP list mainly by using the “Operator ID” in a DL_MAP message. This mechanism is suitable for not only the “NAP+NSP” mode, but also the “NAP+Sharing” mode. For the “NAP+NSP” mode, it is convenient for the user side device to obtain information of the NSPs supported by the NAP according to the correspondence between the NAPs and NSPs. For the “NAP+Sharing” mode, however, the correspondence between the NAPs and NSPs is more complicated, and it is more difficult to be reflected in time in the user side device after being updated.  
         [0012]     Another mechanism is the so-called dynamic NSP discovering mechanism. A Base Station (BS) broadcasts information of the NSPs supported by the current NAP, and the user side device receives relevant broadcasting messages to obtain information of the NSPs during initial scanning. Such a mechanism is more suitable for the “NAP+Sharing” mode, but for the “NAP+NSP” mode, it may cause waste of resources and time.  
         [0013]     Moreover, since the broadcasting cycle of the relevant NSP information is long, it takes long time to wait in the NSP discovering. In addition, the relevant messages need to be broadcasted, and sometimes user side devices need to initiatively request for broadcasting messages, which will occupy uplink and downlink air interface resources.  
         [0014]     Therefore, how to combine the above two mechanisms in existing wireless communication networks to utilize the network resources effectively is an issue in the art currently.  
       SUMMARY OF THE INVENTION  
       [0015]     The present invention provides a method and apparatus for discovering a network service provider, which may improve the utilization ratio of network resources and efficiency of NSP discovering in conjunction with the currently available different NSP sharing modes.  
         [0016]     The method for discovering a network service provider of the present invention is used to be utilized in a wireless communication network which includes a network access provider, a user side device and a network service provider. The method includes:  
         [0017]     issuing, by a network side, information that identifies a network access provider sharing mode;  
         [0018]     discovering the network service provider by the user side device in a manner corresponding to the information that identifies a network access provider sharing mode, when the user side device accesses the network.  
         [0019]     The issuing by the network side information that identifies the network access provider sharing mode includes: carrying the information via a downlink message issued by the network side.  
         [0020]     Optionally, before the discovering the network service provider by the user side device, the method includes:  
         [0021]     receiving, by the user side device, the downlink message issued by the network side;  
         [0022]     obtaining a logic field of a network access provider identifier NAP_ID in the downlink message;  
         [0023]     determining the network access provider sharing mode utilized by the network access provider according to the logic field of the network access provider identifier NAP_ID.  
         [0024]     Optionally, before the discovering the network service provider by the user side device, the method includes:  
         [0025]     receiving, by the user side device, the downlink message issued by the network side;  
         [0026]     obtaining a message element that identifies the network access provider sharing mode in the downlink message;  
         [0027]     determining the network access provider sharing mode utilized by the network access provider according to the message element that identifies the network access provider sharing mode.  
         [0028]     The downlink message may be a downlink mapping message DL_MAP.  
         [0029]     The network access provider sharing mode may include a “NAP+NSP” mode and a “NAP+Sharing” mode.  
         [0030]     The discovering the network service provider corresponding to the “NAP+NSP” mode includes:  
         [0031]     obtaining information of the network service provider supported by the network access provider according to a correspondence between the network access provider and the network service provider;  
         [0032]     adding the obtained network service provider information into information of available network service providers.  
         [0033]     The discovering the network service provider corresponding to the “NAP+Sharing” includes: 
        actively requesting or passively receiving information of the network service provider corresponding to the network access provider, wherein the information is issued by the network side;        
 
         [0035]     adding the obtained information of the network service provider into the information of available network service providers.  
         [0036]     The discovering the network service provider corresponding to the “NAP+Sharing” mode includes:  
         [0037]     determining, by the user side device, whether there has been stored information of the network service provider corresponding to the current network access provider; if yes, obtaining the information of the network service provider corresponding to the network access provider stored by the user side device; otherwise, actively requesting or passively receiving the information of the network service provider corresponding to the network access provider issued by the network side.  
         [0038]     The network side transmitting apparatus of the present invention includes:  
         [0039]     an information transmitting apparatus, used to transmit, on the network side, information that identifies a network access provider sharing mode.  
         [0040]     The information transmitting apparatus may include:  
         [0041]     a message encapsulating apparatus, used to encapsulate the information that identifies the network access provider sharing mode into a downlink message to be issued by the network side.  
         [0042]     Accordingly, the network discovering apparatus for a user side device of the present invention is used to be utilized in a wireless communication network which includes a network access provider, a user side device and a network service provider. The apparatus includes:  
         [0043]     a receiving means, used to receive information issued by a network side that identifies a network access provider sharing mode, when the user side device accesses the network; 
        a discovering means, used to discover a network service provider in a manner corresponding to the information issued by the network side that identifies a network access provider sharing mode.        
 
         [0045]     The receiving means includes:  
         [0046]     a first message receiving unit, used to receive a downlink message issued by the network side;  
         [0047]     a first obtaining unit, used to obtain a logic field of a network access provider identifier NAP_ID in the downlink message;  
         [0048]     and the discovering means includes:  
         [0049]     a first determining unit, used to determine the network access provider sharing mode utilized by the network access provider according to the logic field of the network access provider identifier NAP_ID;  
         [0050]     a first discovering unit, used to discover the corresponding network service provider according to the determined network access provider sharing mode.  
         [0051]     The first discovering unit includes:  
         [0052]     a “NAP+NSP” mode discovering unit, used to obtain information of the network service provider supported by the network access provider according to a correspondence between the network access provider and network service provider, and add the obtained information of the network service provider into information of available network service providers;  
         [0053]     a “NAP+Sharing” mode discovering unit, used to actively request or passively receive information of the network service provider corresponding to the network access provider issued by the network side, and add the obtained information of the network service provider into the information of available network service providers.  
         [0054]     The receiving means includes:  
         [0055]     a second message receiving unit, used to receive a downlink message issued by the network side for the user side device;  
         [0056]     a second obtaining unit, used to obtain a message element in the downlink message that identifies the network access provider sharing mode;  
         [0057]     and the discovering apparatus includes:  
         [0058]     a second determining unit, used to determine the network access provider sharing mode utilized by the network access provider according to the message element that identifies the network access provider sharing mode;  
         [0059]     a second discovering unit, used to discover the corresponding network service provider according to the determined network access provider sharing mode.  
         [0060]     The second discovering unit includes:  
         [0061]     a “NAP+NSP” mode discovering unit, used to obtain information of the network service provider supported by the network access provider according to a correspondence between the network access provider and network service provider, and add the obtained network service provider information into information of available network service providers; and  
         [0062]     a “NAP+Sharing” mode discovering unit, used to actively request or passively receive information of the network service provider corresponding to the network access provider issued by the network side, and add the obtained information of the network service provider information into the information of available network service providers.  
         [0063]     Compared with the prior art, the present invention has the following advantages:  
         [0064]     in the present invention, NSP discovering is performed in a manner corresponding to the information of the NAP sharing mode issued by the network side when the user side device accesses the network. Thus the user side device can perform NSP discovering according to different NAP sharing modes. For example, in the case that “NAP+NSP” mode can be utilized, the discovering is performed according to the correspondence. On one hand, it is possible to avoid message communication between the user side device and the network side to a great extent during the NSP discovering, so as to avoid extra consumption of air interface resources. On the other hand, in a normal situation, it can effectively reduce time consumption in the network discovering and selecting. Thus, it may greatly improve the utilization of network resources and the efficiency of NSP discovering. 
     
    
     DESCRIPTION OF THE DRAWINGS  
       [0065]      FIG. 1  is a schematic diagram of a WiMax network reference model in non-roaming situation in the prior art.  
         [0066]      FIG. 2  is a schematic diagram of a WiMax network reference model in roaming situation in the prior art.  
         [0067]      FIG. 3  is a schematic diagram of a WiMax network deployment mode in the prior art.  
         [0068]      FIG. 4  is a flow chart for discovering a NSP according to the present invention.  
         [0069]      FIG. 5  is a flow chart of a first embodiment of the present invention.  
         [0070]      FIG. 6  is a flow chart of a second embodiment of the present invention.  
         [0071]      FIG. 7  is a flow chart of a third embodiment of the present invention.  
         [0072]      FIG. 8  is a flow chart of a fourth embodiment of the present invention.  
         [0073]      FIG. 9  is a schematic construction diagram of an embodiment of the network side transmitting apparatus of the present invention.  
         [0074]      FIG. 10  is a schematic construction diagram of an embodiment of the user side network discovering of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0075]     The user side device referred to in the present invention is generally a mobile subscriber station (MSS) or a subscriber station (SS).  
         [0076]     Generally, for a user side device to select a suitable network access, it needs to go through four stages as follows.  
         [0077]     In a stage of discovering a NAP: the SS/MSS discovers all NAP networks accessible from its current position (the coverage areas of the NAP networks include the current position of the SS/MSS).  
         [0078]     In a stage of discovering a NSP list for the current NAP: for each accessible NAP network, the NSPs which can be accessed through the NAP network are discovered.  
         [0079]     In a stage of obtaining and selecting all currently available NSPs: all the NSPs that can be accessed by the SS/MSS from the current position are enumerated to form a list, and a suitable NSP is selected from the list according to a certain rule.  
         [0080]     In a stage of accessing the network according to the selected NSP: a suitable NAP is selected (if a NSP may be accessed through two or more NAPs) according to the selected NSP and an initial accessing is performed.  
         [0081]     The improvement of the present invention mainly relates to the above mentioned stage of discovering a NAP and the stage of discovering a NSP list for the current NAP.  
         [0082]     Referring to  FIG. 4 , it is a flow chart of a method for discovering a NSP according to the present invention. The method mainly includes the steps as follows.  
         [0083]     In Step  11 , the network side issues information that identifies the network access provider sharing mode. According to a specific network situation, the information that identifies the network access provider sharing mode can be carried by a corresponding downlink message, such as a downlink mapping message DL_MAP issued by the network side, or other messages that can carry corresponding information, which will not be described here.  
         [0084]     In Step  12 , when the user side device accesses the network, the network service provider is discovered in a manner corresponding to the information of the network access provider sharing mode issued by the network side.  
         [0085]     Now specific embodiments will be described for illustration.  
         [0086]     Referring to  FIG. 5 , it is a flow chart of a first embodiment of the present invention.  
         [0087]     In this embodiment, different values of a logic field of the network access provider identifier NAP_ID in the downlink mapping message DL_MAP are utilized to identify the network access provider sharing modes, that is, description on the structure of the logic field of the NAP_ID is introduced, so that the NAP_ID can reflect whether the NAP corresponding to the NAP_ID is using the “NAP+NSP” mode or the “NAP Sharing” mode. For example, when the first bit of the NAP_ID has a value of 0, it means that the “NAP+NSP” mode is used, and when the first bit of the NAP_ID has a value of 1, it means that the “NAP Sharing” mode is used.  
         [0088]     When the SS/MSS performs a network discovering, it judges the relevant information in the NAP_ID. The specific process is as follows.  
         [0089]     In Step  101 , downlink synchronization is established.  
         [0090]     In Step  102 , a DL_MAP message is received, and information of the NAP_ID is obtained from “Operator ID”.  
         [0091]     In Step  103 , it is determined according to the NAP_ID whether the current NAP uses the “NAP+NSP” mode or the “NAP Sharing” mode; if the “NAP Sharing” mode is used, the process proceeds to Step  104 ; otherwise, the process proceeds to Step  105 .  
         [0092]     In Step  104 , information of NSPs corresponding to the NAP is obtained from a BS by actively requesting or passively receiving, and the process proceeds to Step  106 .  
         [0093]     In Step  105 , the information of a NSP supported by the NAP is obtained according to the correspondence between the NAP and the NSP.  
         [0094]     In Step  106 , the NSP(s) corresponding to the current NAP is/are stored to an available NSP list (temporary), and the network discovering process for the BS terminates.  
         [0095]     Referring to  FIG. 6 , it is a flow chart of a second embodiment of the present invention.  
         [0096]     In this embodiment, the message element which identifies the network access provider sharing mode is carried in the downlink mapping message DL_MAP, that is, a message element is added in the DL_MAP message. The message element can reflect whether the corresponding NAP uses “NAP+NSP” mode or “NAP Sharing” mode. For example, when a certain message element (TLV) is included in the DL_MAP message, it means that the “NAP sharing” mode is used, and when the corresponding message element is not included in the DL_MAP message, it means that the “NAP+NSP” mode is used.  
         [0097]     When the SS/MSS performs network discovering, it judges relevant information in a DL_MAP message, and detailed process is as follows.  
         [0098]     In Step  201 , downlink synchronization is established.  
         [0099]     In Step  202 , the “Operator ID” in the DL_MAP message is parsed and the NAP_ID is obtained; a sharing identifier of the NAP to which a current BS pertains is obtained from a relevant TLV.  
         [0100]     In Step  203 , it is determined according to the NAP sharing identifier whether the current NAP uses the “NAP+NSP” mode or the “NAP Sharing” mode; if the “NAP Sharing” mode is used, the process proceeds to Step  204 ; otherwise, the process proceeds to Step  205 .  
         [0101]     In Step  204 , information of NSPs corresponding to the NAP is obtained from the BS by actively requesting or passively receiving.  
         [0102]     Step  205 , information of a NSP supported by the NAP is obtained according to the correspondence between the NAP and the NSP.  
         [0103]     Step  206 , the NSP(s) corresponding to the current NAP is/are stored to an available NSP list (temporary), and the network discovering process for the BS terminates.  
         [0104]     Referring to  FIG. 7 , it is a flow chart of a third embodiment of the present invention.  
         [0105]     Based on the first embodiment, it is further determined for the “NAP Sharing” mode whether there is information of the NSP list supported by the current NAP stored in the SS/MSS; if yes, use the stored list information; otherwise, receive relevant information from the network side.  
         [0106]     When the SS/MSS performs network discovering, it judges the relevant information in the NAP_ID; in the “NAP Sharing” mode, it is determined whether the SS/MSS has stored the information of the NSP list supported by the current NAP. The detailed process is as follows.  
         [0107]     In Step  301 , downlink synchronization is established.  
         [0108]     In Step  302 , a DL_MAP message is received, and information of the NAP_ID is obtained from “Operator ID”.  
         [0109]     In Step  303 , it is determined according to the NAP_ID whether the current NAP uses the “NAP+NSP” mode or “NAP Sharing” mode; if the “NAP Sharing” mode is used, the process proceeds to Step  304 ; otherwise, the process proceeds to Step  308 .  
         [0110]     In Step  304 , it is determined whether the NAP_ID is stored in NAP/NSP configuration information; if not, the process proceeds to Step  305 ; otherwise, the process proceeds to Step  307 .  
         [0111]     In Step  305 , information of NSPs corresponding to the NAP is obtained from the BS by actively requesting or passively receiving.  
         [0112]     In Step  306 , the obtained NSP/NAP correspondence is stored, and the process proceeds to Step  309 .  
         [0113]     In Step  307 , information of NSPs corresponding to the ASN is obtained from the stored information in the SS/MSS, and the process proceeds to Step  309 .  
         [0114]     In Step  308 , the information of a NSP supported by the NAP is obtained according to the correspondence between the NAP and the NSP, and the process proceeds to Step  309 .  
         [0115]     In Step  309 , the NSP(s) corresponding to the current NAP is/are stored to an available NSP list (temporary), and the network discovering process for the BS terminates.  
         [0116]     Referring to  FIG. 8 , it is a flow chart of a fourth embodiment of the present invention.  
         [0117]     Based on the second embodiment, it is further determined for the “NAP Sharing” mode whether there is information of the NSP list supported by the current NAP stored in the SS/MSS; if yes, use the stored list information directly; otherwise, receive relevant information from the network side.  
         [0118]     When the SS/MSS performs network discovering, it judges the relevant information in an DL_MAP message; in the “NAP Sharing” mode, it is determined whether the SS/MSS has stored the information of the NSP list supported by the current NAP. The detailed process is as follows.  
         [0119]     In Step  401 , downlink synchronization is established.  
         [0120]     In Step  402 , the “Operator ID” in the DL_MAP message is parsed and the NAP_ID is obtained; the sharing identifier of the NAP to which the current BS pertains is obtained from a relevant TLV.  
         [0121]     In Step  403 , it is determined whether the current NAP is using the “NAP+NSP” mode or the “NAP Sharing” mode according to the sharing identifier of the NAP; if the “NAP Sharing” mode is used, the process proceeds to Step  404 ; otherwise, the process proceeds to Step  408 .  
         [0122]     In Step  404 , it is determined whether the NAP_ID is stored in NAP/NSP configuration information; if not, the process proceeds to Step  405 ; otherwise, the process proceeds to Step  407 .  
         [0123]     In Step  405 , information of NSPs corresponding to the NAP is obtained from the BS by actively requesting or passively receiving.  
         [0124]     In Step  406 , the obtained NSP/NAP correspondence is stored, and the process proceeds to Step  409 .  
         [0125]     In Step  407 , information of NSPs corresponding to the ASN is obtained from the stored information in the SS/MSS, and the process proceeds to Step  409 .  
         [0126]     In Step  408 , information of a NSP supported by the NAP is obtained according to the correspondence between the NAP and the NSP.  
         [0127]     In Step  409 , the NSP(s) corresponding to the current NAP is/are to the available NSP list (temporary), and the network discovering process for the BS terminates.  
         [0128]     Referring to  FIG. 9 , it is a schematic construction diagram of an embodiment of the network side transmitting apparatus of the present invention.  
         [0129]     The network side transmitting apparatus in the embodiment of the present invention includes:  
         [0130]     an information transmitting apparatus  21 , used to issue, on the network side, information that identifies a network access provider sharing mode.  
         [0131]     In a specific implementation, the information that identifies a network access provider sharing mode can be packaged into a message, for example, can be carried by a DL_MAP message. The information transmitting apparatus  21  in the present invention may include:  
         [0132]     a message encapsulating apparatus, used to encapsulate the information that identifies a network access provider sharing mode into a downlink message (for example, the DL_MAP message) to be issued by the network side.  
         [0133]     The network discovering apparatus for a user side device in the present invention will be illustrated below. Referring to  FIG. 10 , the network discovering apparatus for a user side device in the present invention mainly includes:  
         [0134]     a receiving means  22 , used to receive information issued by a network side that identifies a network access provider sharing mode, when the user side device accesses the network;  
         [0135]     a discovering means  23 , used to discover a network service provider in a manner corresponding to the information issued by the network side that identifies a network access provider sharing mode.  
         [0136]     In a specific implementation, the receiving means  22  in an embodiment of the present invention may include:  
         [0137]     a message receiving unit, used to receive a downlink message issued by the network side, wherein referring to the previous description, the downlink message in the present invention may be a downlink mapping message DL_MAP;  
         [0138]     an obtaining unit, used to obtain a logic field of a network access provider identifier NAP_ID in the downlink message.  
         [0139]     In addition, the discovering means  23  in the present invention may include:  
         [0140]     a determining unit, used to determine a network access provider sharing mode utilized by the network access provider according to the logic field of the network access provider identifier NAP_ID;  
         [0141]     a discovering unit, used to discover a corresponding network service provider according to the determined network access provider sharing mode.  
         [0142]     In addition, in another embodiment of the present invention, the receiving means may include:  
         [0143]     a second message receiving unit, used, for the user side device, to receive a downlink message issued by the network side;  
         [0144]     a second obtaining unit, used to obtain a message element in the downlink message that identifies a network access provider sharing mode;  
         [0145]     the discovering means includes:  
         [0146]     a second determining unit, used to determine a network access provider sharing mode utilized by the network access provider according to the message element that identifies a network access provider sharing mode;  
         [0147]     a second discovering unit, used to discover a corresponding network service provider according to the determined network access provider sharing mode.  
         [0148]     In addition, for different network access provider sharing modes, the discovering unit of the present invention may include:  
         [0149]     a “NAP+NSP” mode discovering unit, used to obtain information of a network service provider supported by the network access provider according to a correspondence between the network access provider and network service provider, and add the obtained network service provider information into information of available network service providers; and  
         [0150]     a “NAP+Sharing” mode discovering unit, used to actively request or passively receive information of network service providers corresponding to the network access provider, which information is issued by the network side, and add the obtained network service provider information into the information of available network service providers.  
         [0151]     Above description is only preferred embodiments of the present invention, and they are not meant to limit the protect scope of the present invention. Any modifications, alternatives and improvements within the spirit and scope of the present invention should be included in the scope of the claims of the present invention.