Abstract:
A routing strategy provision unit sends routing strategies of local IP access to radio side network elements; the radio side network elements receive the routing strategies of local IP access. The radio side network elements are able to acquire the routing strategies of local IP access at the network element level or the user level, so that the radio side network elements transmit data according to the routing strategies, and the radio side network elements can effectively offload the data with the acquired routing strategies. Besides, the routing strategies might be for users, that is, different routing strategies might be made for different users, thereby improving the user experience and promoting generalization and popularization of services.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a 371 U.S. National Stage of International Application No. PCT/CN2010/076004, filed Aug. 13, 2010, and claims priority to Chinese patent application No. 200910091983.3, filed Sep. 3, 2009, the disclosures of which are herein incorporated by reference in their entirety. 
     TECHNICAL FIELD 
     The present invention relates to mobile communication technologies, and more particularly, to a method and a system for acquiring a routing strategy. 
     BACKGROUND OF THE RELATED ART 
     In order to maintain the competitiveness of the third generation mobile communication system in the field of communication, to provide mobile communication services with faster speed, lower delay and more personalization for users, and meanwhile to reduce the operator&#39;s operating costs, the third Generation Partnership Project (3GPP) standard working group is committing to the research of the Evolved Packet System (EPS).  FIG. 1  is a schematic diagram of structure of the EPS, and as shown in  FIG. 1 , the whole EPS is divided into two parts: the radio access network and the core network. The core network comprises Home Subscriber Server (HSS)  101 , Mobility Management Entity (MME)  102 , Serving General Packet Radio Service (GPRS) Support Node (SGSN)  103 , Policy and Charging Rule Function (PCRF)  104 , Serving Gateway (S-GW)  105 , PDN Gateway (P-GW)  106  and Packet Data Network (PDN)  107 . The functions of each part are as follows. 
     The HSS  101  is the permanent storage site of user subscription data and is located in the user subscribed home network. 
     The MME  102  is the storage site of the user subscription data in the current located network and is responsible for the non-access stratum signaling management from the user equipment to the network, the security verification function of the user equipment, the mobility management of the user equipment, tracking and paging management function in the idle mode of the user equipment as well as bearer management. 
     The SGSN  103  is the serving support node for the user equipment accessing the core network in the GSM EDGE Radio Access Network (GERAN) and the Universal Terrestrial Radio Access Network (UTRAN), and its function is similar to the MME  102  and is responsible for functions of location update, paging management, and bearer management etc. of the user equipment. 
     The S-GW  105  is the gateway from the core network to the ratio access network and is responsible for functions of the user plane bearer from the user equipment to the core network, data cache in the idle mode of the user equipment, the network side initiating a service request, and functions of legal interception, packet data routing and forwarding; and it is responsible for performing statistic of the situation of the user equipment using the radio access network, generating the bill of the user equipment using the radio access network, and transmitting the bill to the charging gateway. 
     The P-GW  106  is the gateway for the EPS interacting with the external PDN  107  of the EPS, it is respectively connected to the Internet and the PDN  107 , and is responsible for functions of the user equipment&#39;s Internet Protocol (IP) address allocation, charging function, packet filtering, and strategy control, and so on. 
     The PDN  107  is the operator&#39;s IP service network, and it provides IP service to the user equipments via the operator&#39;s core network. 
     The PCRF  104  is the server responsible for providing rules of charging control, online credit control, threshold control, and quality of service (QoS) strategies and so on in the EPS. 
     The radio access network is composed of the E-UTRAN NodeB (eNB)  111  and the third-generation (3G) Radio Network Controller (RNC)  112 , and it is mainly responsible for sending and receiving radio signals, interacting with the user equipment via the air interface, managing the radio resource, resource scheduling and access control of the air interface and so on. 
     The above SGSN  103  is an upgraded SGSN, and it can support the S4 interface with the S-GW  105  and interconnects with MME  102  using the GPRS Tunneling Protocol (GTP) v2. However, for the SGSN  103  supporting the 3G core network, the PS domain network architecture is different from that in  FIG. 1 , and at this point, the SGSN  103  and the MME  102  connect via the Gn interface and interconnect using the GTPv1; the SGSN  103  cannot connect with the S-GW  105  and directly accesses the PDN  107  by connecting the Gateway GPRS Support Node (GGSN) via the Gn interface. 
     The Home NodeB (HNB) or the Home eNodeB (HeNB) is a class of miniature and low-power NodeBs, acts as the dedicated resources of certain users, is deployed in private places such as homes, groups, companies or schools for use, and is mainly for providing higher service speed for users and reducing the cost needed in using the high-speed services and meanwhile making up the lack of the coverage of the existing distributed cellular radio communication systems. The HNB has the advantages of affordable, convenient, low-power output, plug and play, broadband access, and using single-mode terminals, and so on. 
     The Home NodeB can be applied in the 3G or Long Term Evolution (LTE) mobile communication network. In order to facilitate the management of the home NodeB, a new network element, namely the HNB gateway, is introduced into the mobile communication network. The main functions performed by the HNB gateway are: verifying the security of the Home NodeB, maintaining and managing the operation of the HNB, configuring and controlling the HNB according to the operator&#39;s requirements, and exchanging data information between the core network and the HNB. 
       FIG. 2  is a schematic diagram of the network architecture of the 3G HNB, as shown in  FIG. 2 , the 3G home NodeB (HNB)  201  connects to the HNB gateway (HNB GW)  202  via the newly defined luh interface, and the HNB GW  202  provides the luPS interface to the packet domain and the luCS interface to the circuit domain in the core network. For the 3G mobile communication network, the HNB GW  202  is a required deployment to shield the effects to the user equipment and network side after introducing the HNB  201 . 
     For the LTE mobile communication network, the HeNB GW is an optional deployment, and therefore, there are two methods for connecting the LTE HeNB and the core network; one is that the HeNB  301  directly connects with network elements in the core network, as shown in  FIG. 3 ; the other is that the HeNB  401  connects with network elements in the core network via the HeNB GW  402 , as shown in  FIG. 4A . For the scenario of introducing the HNB gateway as shown in  FIG. 4A , the HeNB gateway might not integrate the user plane functions, and the user plane is established directly between the HeNB gateway and the user plane gateway of the core network, which enable to flatten the user plane and decrease the data transmission delay, and its structure is shown as  FIG. 4B . 
     Besides supporting to access the core network, the HNB might also support the local IP access (LIPA) function, under the condition that the HNB has the local IP access capability and the user subscription allows the local IP access, the local access of the user to other IP devices in the home network or the Internet can be implemented, and the other IP devices are devices except the user equipment in the home network. With the local IP access function, the Internet data service offload can be implemented, so as to reduce the load of the core network, and the access to the devices in the home network can be forwarded without passing the core network, and the data transmission is convenient and efficient. 
     The local IP access function might also be applied in the macro cell or the HNB GW, its main purpose is similar to the HNB, and it is applied more in such a scenario that the local IP accesses Internet, so as to reduce the load of the core network. 
       FIG. 5  is a schematic diagram of a method for implementing the local IP access function, as shown in  FIG. 5 , the data sent by the user equipment  501  to the home network  502 , the Internet  503  and the core network  504  can share the same PDN connection, the data offload function unit in the radio side network elements  505  can fulfill the selection of the data packet routing, the Network Address Translation (NAT) function unit  506  translates the user internal address to the outside. The data offload function unit and the NAT function unit  506  might be deployed with the NodeB (such as HNB, and macro NodeB) together or the HNB gateway, or might be deployed separately. 
     Currently, there is no definite solution of the method for acquiring the routing strategies applied by the data offload function unit in the radio side network elements. 
     SUMMARY 
     In view of this, the main object of the present document is to provide a method and a system for acquiring a routing strategy so that radio side network elements can acquire routing strategies of the local IP access. 
     To achieve the above object, the technical scheme of the present document is implemented as follows. 
     A method for acquiring a routing strategy comprises: 
     a routing strategy provision unit sending a routing strategy of local IP access to a radio side network element; and 
     the radio side network element receiving the routing strategy of the local IP access. 
     The routing strategy is a routing strategy for the network element, and the routing strategy provision unit is a radio side network element management system, 
     the routing strategy provision unit sends the routing strategy of the local IP access to a radio side network element comprises: when the radio side network element powers on or the routing strategy changes, the radio side network element management system sending the routing strategy of the local IP access to the radio side network elements. 
     The routing strategy provision unit is a mobility management element, 
     the routing strategy is a routing strategy for a network element, the process of the routing strategy provision unit sending the routing strategy of the local IP access to the radio side network elements comprises: the mobility management element locally configuring a general routing strategy of the local IP access to send to the radio side network element; 
     the routing strategy is a routing strategy for a user, and before the routing strategy provision unit sending the routing strategies of the local IP access to the radio side network elements, the method further comprises: when a user equipment registers to the network or a location of the user equipment changes, or the routing strategy changes, a Home Subscriber Server (HSS) sending the routing strategy of the local IP access to the mobility management element. 
     The routing strategy provision unit is a mobility management element, 
     the routing strategy provision unit sending the routing strategy to the radio side network element comprises: a new mobility management element sending the routing strategy of the local IP access from an original mobile management element to the radio side network element. 
     The routing strategy provision unit is any other radio side network elements except said radio side network element, 
     the routing strategy provision unit sending the routing strategy to the radio side network element comprises: a source radio side network element sending the routing strategy of the local access to the radio side network element. 
     The routing strategy is: a routing strategy for a network element, or a routing strategy for a user. 
     A system for acquiring a routing strategy comprises: 
     a routing strategy provision unit, which is used to send a routing strategy of local IP access to a radio side network element; and 
     the radio side network element, which is used to receive the routing strategy of the local IP access. 
     The routing strategy provision unit is: a radio side network element management system, or a mobility management element, or another radio side network element; and/or, 
     the radio side network element is: a home NodeB, or a macro NodeB, or a HNB gateway or a data offload function unit; and/or, 
     the routing strategy is: a routing strategy for a radio side network element, or a routing strategy for a user. 
     The mobility management element is: a Serving General Packet Radio Service Support Node (SGSN), or a mobility management entity (MME). 
     The routing strategy provision unit is a mobility management element, the routing strategy is the routing strategy for a user, and the system further comprises a HSS which is used to provide the routing strategy of the local IP access for the mobility management element. 
     The data offload function unit might be deployed with the HNB, the macro NodeB, or the HNB gateway, or might be deployed separately. 
     A range of the local IP access is: the local access of the user to all IP devices except a user equipment in the home network or the Internet. 
     The present document provides a solution for radio side network elements acquiring routing strategies. With the solution of the present document, the radio side network elements might acquire the routing strategies of the local IP access of the network element level or the user level, thus the network element at the radio side is enabled to transmit the data according to the routing strategies, so that the radio side network elements can effectively offload the data based on the acquired routing strategies. 
     In addition, in the solution of the present document, the routing strategies might be for the users, that is, different routing strategies might be made for different users, which will certainly improve the user experience and can contribute to the generalization and popularization of services. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic diagram of the structure of the EPS; 
         FIG. 2  is a schematic diagram of the network architecture of a 3G HNB; 
         FIG. 3  is the schematic diagram  1  of the network architecture of a LTE HNB; 
         FIG. 4A  is the schematic diagram  2  of the network architecture of a LTE HNB; 
         FIG. 4B  is the schematic diagram  3  of the network architecture of a LTE HNB; 
         FIG. 5  is the schematic diagram of a method for implementing the local IP access function; 
         FIG. 6  is a structural diagram of a system for implementing to acquire routing strategies according to the present document; 
         FIG. 7  is a flow chart of the radio side network element management system configuring routing strategies according to the present document; 
         FIG. 8  is the schematic diagram  1  of a procedure of acquiring routing strategies when a user initiates an attachment process according to the present document; 
         FIG. 9  is the schematic diagram  2  of a procedure of acquiring routing strategies when a user initiates an attachment process according to the present document; 
         FIG. 10  is the schematic diagram  1  of a procedure of acquiring routing strategies when a user initiates a service request process according to the present document; 
         FIG. 11  is the schematic diagram  2  of a procedure of acquiring routing strategies when a user initiates a service request process according to the present document; 
         FIG. 12  is a schematic diagram of a procedure of acquiring routing strategies when a user initiates a context activation process according to the present document; 
         FIG. 13  is a schematic diagram of a procedure of acquiring routing strategies when a user initiates a routing area update process according to the present document; 
         FIG. 14  is a schematic diagram of a procedure of acquiring routing strategies when a user initiates a tracking area update process according to the present document; 
         FIG. 15  is the schematic diagram  1  of a procedure of the destination radio side network element acquiring routing strategies in a handover process according to the present document; 
         FIG. 16  is the schematic diagram  2  of a procedure of the destination radio side network element acquiring routing strategies in a handover process according to the present document; 
         FIG. 17  is the schematic diagram  1  of a procedure of acquiring the routing strategies when updating the routing strategies according to the present document; 
         FIG. 18  is the schematic diagram  2  of a procedure of acquiring the routing strategies when updating the routing strategies according to the present document. 
     
    
    
     DETAILED DESCRIPTION 
     In the present document, the routing strategy provision unit sends routing strategies of the local IP access to the radio side network elements; the radio side network elements receive the routing strategies of the local IP access. The radio side network element might be a home NodeB, a macro NodeB, a HNB gateway, or a data offload function unit. The data offload function unit might be deployed with the home NodeB, the macro NodeB, or the HNB gateway, or might be deployed separately. The routing strategy provision unit might be a radio side network element management system, a mobility management element, or other radio side network elements; wherein the mobility management element might be the SGSN or the MME. The routing strategies comprise but are not limited to the corresponding relationship between the routing options and the destination address to which the data is transmitted; the routing strategies might be routing strategies of the network element level, that is, routing strategies for the radio side network elements, or might be routing strategies of the user level, namely the routing strategies for the users. The routing strategy provision unit might send the routing strategies to the radio side network elements when the radio side network elements execute a process related to the local IP access function; or might send the corresponding routing strategies to the radio side network elements when the radio side network elements power on or the routing strategies are updated. 
     The routing strategies for the radio side network elements might be configured by the radio side network element management system, and the radio side network element management system can send the routing strategies to the radio side network elements when the radio side network elements power on; when the routing strategies change, the radio side network element management system sends the updated routing strategies to the radio side network elements. The routing strategies for the radio side network elements might also be configured by the core network, when the user&#39;s local IP access function is enabled, the mobility management element in the core network sends the routing strategies to the radio side network elements; accordingly, when the routing strategies change, the mobility management unit sends the updated routing strategies to the radio side network elements. 
     The routing strategies for the users might be stored in the HSS in the form of subscription data. When a user registers to the network or initiates a location update, and so on, the HSS might send the routing strategies to the mobility management element for storing; when the user&#39;s local IP access function is enabled, the mobility management element further sends the routing strategies to the radio side network elements. When the routing strategies for the users change, the HSS sends the updated routing strategies to the mobility management element, if the user equipment is in idle state, the mobility management element stores the received routing strategies, and if the user equipment is in the connection state and there is the radio bearer, the mobility management element sends the routing strategies to the radio side network elements via the S1 or lu interface message. 
     In addition, when the handover of the user equipment occurs, the source radio side network element or the original mobility management element might be used to send the routing strategies to the destination radio side network element. 
     Based on the above solution, the system for implementing to acquire the routing strategies provided in the present document comprises: the radio side network elements  601  and the routing strategy provision unit  602 , as shown in  FIG. 6 , where the routing strategy provision unit  602  is used to send the routing strategies of the local IP access to the radio side network elements  601 ; the radio side network elements  601  are used to receive the routing strategies of the local IP access. The implementation of the relevant parts is identical with the above description, and is not repeated here. The routing strategy provision unit  602  is a mobility management element, the routing strategies are routing strategies for the users, and the system might further comprise the HSS  603  for providing the routing strategies of the local IP access for the mobility management element. 
     In the following, a plurality of specific embodiments is used to describe the specific implementation of the present document in more detail. The routing strategies in each of the following specific embodiments all refer to the routing strategies of the local IP access. 
       FIG. 7  is a schematic diagram of the procedure of the radio side network element management system configuring the routing strategies according to the present document, and as shown in  FIG. 7 , the procedure specifically comprises the following steps. 
     Step  701 : the radio side network element  11 , such as the home NodeB, macro NodeB, HNB gateway or data offload function unit powers on, and then establishes a secure IP layer security protocol (IPSec) tunnel with the security gateway  12 . The data offload function unit might be deployed with the HNB, the macro NodeB, or the HNB gateway, or might be deployed separately. 
     Step  702 : The radio side network element  11  queries to get the address of the radio side network element management system  13  via the domain name server (DNS), and establishes a TR-069 customer premise equipment (CPE) Wide Area Network Management Protocol (TR-069 CWMP) session with the radio side network element management system  13  based on this address. 
     Step  703 : the radio side network element  11  uses the TR-069 notification request message to report the location parameter and the radio side network element identifier to the radio side network element management system  13  after completing to establish the session. 
     Step  704 : the radio side network element management system  13  receives the TR-069 notification request message, and then returns a TR-069 notification response message to the radio side network element  11  to notify the radio side network element  11  to accept the information of the radio side network element  11 . 
     Step  705 : the radio side network element management system  13  uses the TR-069 parameter setting request message to send the radio side network element parameter information including the radio configuration parameter, the S-GW address, and the routing strategies, and so on to the radio side network element  11 , and the radio side network element parameter information; wherein the routing strategies are for the radio side network elements and might be the corresponding relationship between the packet destination address and the two routing options of the local IP access or the core network access; also might be a relationship between the local IP access type and the routing options, wherein the Local IP access type is the local IP access to Internet, or the local IP access to home network, and so on. 
     The routing strategies for the radio side network elements might be set by the administrator and stored in the radio side network element management system  13 , and also might be set by the radio side network element management system  13  according to the setting rules. 
     Step  706 : the radio side network element  11  receives the TR-069 parameter value setting request message, and then updates the parameter configuration, and then returns the TR-069 parameter value setting response message to the radio side network element management system  13 . 
     Step  707 : the radio side network element  11  initiates to terminate the TR-069 CWMP session with the radio side network element management system  13 , and releases the corresponding session connection. 
     When the routing strategies for the radio side network elements change, the updated routing strategies can be sent to the radio side network element  11  by the radio side network element management system  13  directly by step  705 , so that the radio side network element  11  can update the routing strategies. 
       FIG. 8  is the schematic diagram  1  of the procedure of acquiring the routing strategies when a user initiates an attachment process according to the present document, and as shown in  FIG. 8 , the procedure specifically comprises the following steps. 
     Step  801 : when powering on, the user equipment  21  initiates an attachment process to register to the core network, and the user equipment  21  sends an attach request message to the SGSN  23 . 
     Step  802 : the SGSN  23  receives the attach request message, and then authenticates the user, and after the user passes the authentication, step  803  is performed; if the user does not pass the authentication, the SGSN  23  rejects the attach request message from the user equipment  21 . 
     Step  803 : the SGSN  23  determines that the SGSN  23  itself does not store the user subscription data and sends an update location request message including the information of SGSN identifier, the user identifier, and the update type and so on to the HSS  24 . 
     After the HSS  24  receives the update location request message, if the SGSN  23  is a SGSN supporting the Gn/Gp interface, then step  804   a  is performed; if the SGSN  23  is a SGSN supporting the S4 interface, then step  804   b  is performed. 
     Step  804   a : the HSS  24  and the SGSN  23  supporting the Gn/Gp interface use the mobile application part (MAP) protocol to interact, the HSS  24  uses the insert subscriber data process to send the user subscription data and the routing strategies to the SGSN  23 , and the SGSN  23  stores the received user subscription data and the routing strategies. The SGSN  23  returns an insert subscriber data acknowledgement message to the HSS  24 . 
     The routing strategies are for the users and might be the corresponding relationship between the packet destination address and either of the two routing options of the local IP access and the core network access; it might also be the relationship between the local IP access type and the routing option, and the local IP access type might be the local IP access to Internet, or the local IP access to home network, and so on. 
     Step  804   b : the HSS  24  and the SGSN  23  supporting the S4 interface use the Diameter protocol to interact, the HSS  24  uses the update location acknowledgement message to send the user subscription data and the routing strategies to the SGSN  23 , and the SGSN  23  stores the received user subscription data and the routing strategies. 
     The routing strategies are for the user and might be the corresponding relationship between the packet destination address and either of the two routing options of the local IP access and the core network access; might also be the relationship between the local IP access type and the routing option, wherein the local IP access type might be the local IP access to Internet, or the local IP access to home network, and so on. 
     The routing strategies stored in the HSS  24  are for each user, and might be set by the operator and stored in the HSS  24 . 
     Step  805 : the SGSN  23  sends an attach accept message including the information such as temporary identifier assigned to the user to the user equipment  21  after completing the attachment of the user. 
     After the SGSN  23  obtains the routing strategies for the user, if the user&#39;s local IP access function is enabled, the routing strategies for users are required, and then the corresponding routing strategies can be sent to the radio side network element  22 , and the radio side network element  22  transmits the data of this user according to the routing strategies for the user. 
       FIG. 9  is a schematic diagram  2  of the procedure of acquiring the routing strategies when a user initiates an attachment process according to the present document, and as shown in  FIG. 9 , the procedure specifically comprises the following steps. 
     Step  901 : when powering on, the user equipment  31  initiates an attachment process to register to the core network, and the user equipment  31  sends an attach request message to the MME  33 . 
     Step  902 : the MME  33  receives the attach request message, and then authenticates the user, and after the user passes the authentication, step  903  is performed; if the user does not pass the authentication, the MME  33  rejects the attach request message of the user equipment  31 . 
     Step  903 : the MME  33  determines that the MME  33  itself does not store the user subscription data and sends an update location request message including information of the MME identifier, the user identifier, and the update type and so on to the HSS  34 . 
     Step  904 : the HSS  34  receives the update location request message, and then uses an update location acknowledgement message to send the user subscription data and the routing strategies to the MME  33 , and the MME  33  stores the received user subscription data and the routing strategies. 
     The routing strategies are for the user and might be the corresponding relationship between the packet destination address and either of the two routing options of the local IP access and the core network access; also might be the relationship between the local IP access type and the routing options, wherein the local IP access type might be the local IP access to Internet, or the local IP access to home network, and so on. 
     The routing strategies stored in the HSS  34  are for each user, and might be set by the operator and stored in the HSS  34 . 
     Step  905 : the MME  33  receives the update location acknowledgement message, and then the MME  33  establishes the default bearer at the core network side in order to support the users always online. After the default bearer at the core network side is established, the corresponding radio bearer is activated. 
     Step  906 : if the MME  33  decides to enable the local IP access function for the user based on the user&#39;s local IP access subscription or the network load, the MME  33  uses the initial context setup request message to send the bearer-related QoS parameter and the routing strategies to the radio side network element  32 , and the attach accept message can be encapsulated into the initial context setup request message which is sent to the radio side network element  32 . 
     The specific form of the routing strategies might be the corresponding relationship between the packet destination address and two routing options of the local IP access and the core network access; it might also be the relationship between the local IP access type and the routing option, wherein the local IP access type is the local IP access to Internet, or the local IP access to home network, and so on. 
     The routing strategies might be for the users or for the radio side network elements. If the routing strategies are for the users, the MME  33  can send the routing strategies obtained from the HSS  34  in step  904  to the radio side network element  32 ; if the routing strategies are for the radio side network elements, the MME  33  can locally configure the general routing strategies of the local IP access to send to the radio side network element  32 . 
     Step  907 : the radio side network element  32  receives the initial context setup request message, and then establishes the corresponding radio bearer according to the bearer information instructed by the core network, and stores the routing strategies. 
     Step  908 : the radio side network element  32  returns the initial context setup response message to the MME  33  after completing to establish the radio bearer to notify the core network that the radio bearer establishment is completed. 
       FIG. 10  is the schematic diagram  2  of the procedure of acquiring the routing strategies when a user initiates a service request process according to the present document, and as shown in  FIG. 10 , the process specifically comprises the following steps. 
     Step  1001 : the user equipment  41  establishes the radio resource control (RRC) connection with the radio side network elements before sending a non-access stratum message. 
     Step  1002 : if the user needs to execute the uplink service or the network side needs to execute the downlink service to page the user equipment  41 , the user equipment  41  initiates a service request process and sends a service request message to the SGSN  43 , and the service type contained in the service request message is signaling or data. 
     Step  1003 : the SGSN  43  receives the service request message, and then authenticates the user, and after the user passes the authentication, step  1004  is performed; if the user does not pass the authentication, the SGSN  43  rejects the service request message from the user equipment  41 . 
     Step  1004 : if the service type contained in the service request message is data, and the core network enables the local IP access function for the user, the SGSN  43  uses the radio access bearer (RAB) assignment request message to indicate the radio side to establish the bearer, and uses the RAB assignment request message to send the bearer-related QoS parameter and the routing strategies to the radio side network elements. 
     The specific form of the routing strategies might be the corresponding relationship between the packet destination address and either of the two routing options of the local IP access and the core network access; it might also be the relationship between the local IP access type and the routing option, wherein the local IP access type is the local IP access to Internet, or the local IP access to home network, and so on. 
     The routing strategies might be for users or for the radio side network elements. If the routing strategies are for the users, the SGSN  43  can send the routing strategies obtained from the HSS  44  to the radio side network element  42  via the user registration or location update process; if the routing strategies are for the radio side network elements, the SGSN  43  can locally configure the general routing strategies of the local IP access to send to the radio side network elements. 
     Step  1005 : the radio side network element  42  receives the RAB assignment request message, and then establishes the corresponding radio bearer according to the bearer information instructed by the core network, and stores the routing strategies. 
     Step  1006 : the radio side network element  42  returns the RAB assignment response message after completing to establish the radio bearer to the SGSN  43  to notify the core network that the radio bearer establishment is completed. 
     Step  1007 : if the service request process is initiated in the connection state, the SGSN  43  returns a service response message to the user equipment  41 ; if the service request process is initiated in the idle state, the user equipment  41  takes the safe mode control command message at the RRC layer as the reply of the service request. 
       FIG. 11  is a schematic diagram  2  of the procedure of acquiring the routing strategies when the user initiates a service request according to the present document, and as shown in  FIG. 11 , the process specifically comprises the following steps. 
     Step  1101 : the user equipment  51  establishes the RRC connection with the radio side network elements before sending the non-access stratum message. 
     Step  1102 : if the user needs to execute the uplink service or the network side needs to execute the downlink service to page the user equipment  51 , the user equipment  51  initiates a service request process to send the service request message to the MME  53 . 
     Step  1103 : the MME  53  receives the service request message, and then authenticates the user, and after the user passes the authentication, step  1104  is performed; if the user does not pass the authentication, the MME  53  rejects the service request message sent of the user equipment  51 . 
     Step  1104 : if the service request message received by the MME  53  does not distinguish the service type, then the bearers established by the core network are all re-established at the radio side. The MME  53  uses the initial context setup request message to send the bearer-related QoS parameter and the routing strategies to the radio side network elements. 
     The specific form of the routing strategies might be the corresponding relationship between the packet destination address and two routing options of the local IP access and the core network access; it might also be the relationship between the local IP access type and the routing option, wherein the local IP access type is the local IP access to Internet, or the local IP access to home network, and so on. 
     The routing strategies might be for the users or for the radio side network elements. If the routing strategies are for the users, the MME  53  can send the routing strategies obtained from the HSS to the radio side network element  52  via the user registration or the location update process; if the routing strategies are for the radio side network element  52 , the MME  53  can locally configure the general routing strategies of the local IP access to send to the radio side network element  52 . 
     Step  1105 : the radio side network element  52  receives the initial context setup request message, and then establishes the corresponding radio bearer according to the bearer information instructed by the core network, and stores the routing strategies. 
     Step  1106 : the radio side network element  52  returns an initial context setup response message to the MME  53  after completing to establish the radio bearer to notify the core network that the radio bearer establishment is completed. 
     Step  1107 : the MME  53  receives the initial context setup response message, and then uses the modify bearer request message to send the radio side network element identifier and the downlink tunneling identifier to the S-GW  54 . 
     Steps  1108 ˜ 1109 : if the radio access technology changes or the core network demands to report the user location information for charging, then the S-GW  54  uses the bearer update process to report the above information to the P-GW  55 . 
     Step  1110 : the S-GW  54  receives the modify bearer request message, and then returns a modify bearer response message to the MME  53 . 
       FIG. 12  is a schematic diagram of the procedure of acquiring the routing strategies when a user initiates a context activation procedure according to the present document, and as shown in  FIG. 12 , the process specifically comprises the following steps. 
     Step  1201 : if the user needs to access a certain PDN or request a certain service, the user equipment  61  initiates a packet data protocol (PDP) context activation procedure and sends the activate PDP context request message to the SGSN  63  to establish a connection between the user equipment  61  and the PDN. 
     Step  1202 : the SGSN  63  receives the activate PDP context request message, and then uses the access point names reported by the user to query to acquire the GGSN  64  to be accessed by the user via the DNS, and establishes the bearer connection between the SGSN  63  and the GGSN  64  with the create PDP context process. The SGSN  63  sends the information of the SGSN address, the bearer-related QoS parameter, and the bearer connection downlink tunneling identifier, and so on to the GGSN  64  by creating the PDP context request message. 
     Step  1203 : the GGSN  64  receives the create PDP context request message, and then generates the user context, and sends information of the IP address assigned to the user equipment  61 , the uplink tunneling identifier, the negotiated QoS parameter, and so on to the SGSN  63  with the create PDP context response message. 
     The above description is the related process when the SGSN  63  is a SGSN supporting the Gn/Gp interface, and if the SGSN  63  is a SGSN supporting the S4 interface, the SGSN  63  establishes a connection between the user equipment  61  and the PDN through a session establishment process. 
     Step  1204 : the SGSN  63  receives the create PDP context response message, and then uses the RAB assignment request message to indicate the radio side to establish the bearer, and uses the RAB assignment request message to send the bearer-related QoS parameter and the routing strategies to the radio side network elements. 
     The specific form of the routing strategies might be the corresponding relationship between the packet destination address and two routing options of the local IP access and the core network access; it might also be the relationship between the local IP access type and the routing option, wherein the local IP access type is the local IP access to Internet, or the local IP access to home network, and so on. 
     The routing strategies might be for the users or for the radio side network elements. If the routing strategies are for the users, the SGSN  63  can send the routing strategies obtained from the HSS to the radio side network element  62  via the user registration or location update process; if the routing strategies are for the radio side network elements, the SGSN  63  might locally configure the general routing strategies of the local IP access to send to the radio side network element  62 . 
     Step  1205 : the radio side network element  62  receives the RAB assignment request message, and then establishes the corresponding radio bearer according to the bearer information indicated by the core network. 
     Step  1206 : the radio side network element  62  returns the RAB assignment response message to the SGSN  63  after completing to establish the radio bearer to notify the core network that the radio bearer establishment is completed. 
     Step  1207 : the SGSN  63  receives the RAB assignment response message, and then returns a create PDP context response message to the user equipment  61  to notify the user equipment  61  that the connection between the user equipment  61  and the PDN is established. 
       FIG. 13  is a schematic diagram of the procedure of acquiring the routing strategies when a user initiates a routing area update according to the present document, and as shown in  FIG. 13 , the process specifically comprises the following steps. 
     Step  1301 : if the user moves to a new routing area outside the stored routing areas, the user equipment  71  initiates a routing update process, and the user equipment  71  uses the routing update request message to send information of the user temporary ID, the original routing area ID, and the user capability, and so on to the radio side network element  72 , wherein the routing update request message is a non-access stratum message. The radio side network element  72  selects a new SGSN  73  to be accessed for the user after receiving the non-access layer message, and sends a routing update request message to the new SGSN  73 . 
     Step  1302 : the new SGSN  73  receives the routing update request message, and then finds out the original SGSN/MME  74  based on the user temporary identifier and the original routing area identifier to obtain the user context information. 
     Step  1303 : the new SGSN  73  determines that the new SGSN  73  itself does not store the user subscription data, sends an update location request message including the information of the new SGSN identifier, the user identifier, and the update type and so on to the HSS  75 . 
     Steps  1304 ˜ 1305 : when the idle mode signaling reduction (ISR) function is not activated, the HSS  75  acquires that the user is registered in the new SGSN  73 , and sends a cancel location message to the original SGSN/MME  74  so that the original SGSN/MME  74  deletes the user context information stored in it and releases the signaling connection in the original radio side network element  72 . The original SGSN/MME  74  returns a cancel location acknowledgement message to the HSS  75 . 
     After the HSS  75  receives the update location request message, if the new SGSN  73  is a SGSN supporting the Gn/Gp interface, then step  1306   a  is performed; if the new SGSN  73  is a SGSN supporting the S4 interface, then step  1306   b  is performed. 
     Step  1306   a : the HSS  75  and the new SGSN  73  supporting the Gn/Gp interface use the MAP protocol to interact, the HSS  75  uses the insert subscriber data process to send the routing strategies and the user subscription data to the new SGSN  73 , and the new SGSN  73  stores the received user subscription data and the routing strategies. The new SGSN  73  returns an insert subscriber data acknowledgement message to the HSS  75 . 
     The routing strategies are for the user and might be the corresponding relationship between the packet destination address and two routing options of the local IP access and the core network access; it might also be the relationship between the local IP access type and the routing option, wherein the local IP access type is the local IP access to Internet, or the local IP access to home network, and so on. 
     Step  1306   b : the HSS  75  and the new SGSN  73  supporting the S4 interface use the Diameter protocol to interact, the HSS  75  uses the location update acknowledgement message to send the user subscription data and the routing strategies to the new SGSN  73 , and the new SGSN  73  stores the received user subscription data and the routing strategies. 
     The routing strategies are for the users, and it might be the corresponding relationship between the packet destination address and two routing options of the local IP access and the core network access; it might also be the relationship between the local IP access type and the routing option, wherein the local IP access type is the local IP access to Internet, or the local IP access to home network, and so on. 
     The routing strategies stored in HSS  75  are for each user, and can be set and stored in the HSS  75  by the operator. 
     Step  1307 : the new SGSN  73  sends the routing update accept message including the information of temporary identifier assigned to the user and so on to the user equipment  71  after completing the routing area update of the user. 
     After the new SGSN  73  acquires the user&#39;s routing strategies, if it needs the routing strategies for the user when the user&#39;s local IP access function is enabled, the new SGSN  73  sends the corresponding routing strategies to the radio side network element  72 , and the radio side network element  72  transmits the subscriber data based on the routing strategies for the user. 
     In addition, if the original SGSN/MME  74  has acquired the routing strategies for the user, the original SGSN/MME  74  might also provide the routing strategies for the user to the new SGSN  73 . 
       FIG. 14  is a schematic diagram of the procedure of acquiring the routing strategies when a user initiates a tracking area update process according to the present document, and as shown in  FIG. 14 , the process specifically comprises the following steps. 
     Step  1401 : if the user moves to a tracking area outside of the tracking area list, the user equipment  81  initiates a tracking area update process, and the user equipment  81  uses the tracking area update request message to send information of the user temporary identifier, the original tracking area identifier, the user capability and so on to the radio side network elements, and the tracking area update request message is a non-access stratum message. Besides, the user needs to send uplink data, and then sets an activation indication in the tracking area update request message to request the core network to establish a radio bearer in the tracking area update process. The radio side network element  82  receives the non-access stratum message, then selects a new MME  83  to be accessed for the user, and sends a routing update request message to the new MME  83 . 
     Step  1402 : the new MME  83  receives the tracking area update request message, and then finds out the original SGSN/MME  84  according to the user temporary identifier and the original tracking area identifier to acquire the user context information. 
     Step  1403 : the new MME  83  determines that the MME  83  itself does not store the user subscription data, and sends an update location request message including information of the new MME identifier, the user identifier, the update type, and so on to the HSS  85 . 
     Steps  1404 ˜ 1405 : when the ISR function is not activated, the HSS  85  knows that the user is registered in the new MME  83 , and sends a cancel location message to the original SGSN/MME  84  so that the original SGSN/MME  84  deletes the user context information stored in it, and releases the signaling connection in the original radio side network element  82 . The original SGSN/MME  84  returns a cancel location acknowledgement message to the HSS  85 . 
     Step  1406 : the HSS  85  sends the user subscription data and the routing strategies to the new MME  83  via the location update acknowledgement message, and the new MME  83  stores the received user subscription data and the routing strategies. 
     The specific form of the routing strategies might be the corresponding relationship between the packet destination address and two routing options of the local IP access and the core network access; it might also be the relationship between the local IP access type and the routing option, wherein the local IP access type is local IP access to Internet, or local IP access to home network, and so on. 
     The routing strategies might be for users or for the radio side network elements. If the routing strategies are for the users, the new MME  83  can send the routing strategies obtained from the HSS  85  to the radio side network elements; if the routing strategies are for the radio side network elements, the new MME  83  can locally configure the general routing strategies of the local IP access to send to the radio side network elements. 
     Step  1407 : since the tracking area update request message sent by the user contains the activation indication, the new MME  83  uses the initial context setup request message to send the bearer-related QoS parameter and the routing strategies to the radio side network elements, and the attach accept message might be also encapsulated into the initial context setup request message which is sent to the radio side network elements. 
     The specific form of the routing strategies might be the corresponding relationship between the packet destination address and two routing options of the local IP access or the core network access; it might also be the relationship between the local IP access type and the routing option, wherein the local IP access type is the local IP access to Internet, or the local IP access to home network, and so on. 
     The routing strategies might be for the users or for the radio side network elements. If the routing strategies are for the users, the MME can send the routing strategies obtained from the HSS  85  in step  904  to the radio side network elements; if the routing strategies are for the radio side network elements, the MME can locally configure and send the general routing strategies of the local IP access to the radio side network elements. 
     Step  1408 : the radio side network elements  82  receive the initial context setup request message, and then establish the corresponding radio bearer according to the bearer information indicated by the core network, and stores the routing strategies. 
     Step  1409 : the radio side network elements  82  return the initial context setup response message to the new MME  83  after completing to establish the radio bearer to notify the core network that the radio bearer establishment is completed. 
       FIG. 15  is a schematic diagram  1  of the destination radio side network element acquiring the routing strategies in the handover process according to the present document, and as shown in  FIG. 15 , the process specifically comprises the following steps. 
     Step  1501 : the user equipment  91  measures the radio signal condition in adjacent cells to report to the radio side network element that is serving the user equipment  91  currently in the form of measurement report. 
     Step  1502 : The radio side network element, namely the source network element  92 , that is currently serving the user equipment  91  finds out that the signal in the cell in which the user equipment  91  is currently located becomes poor according to the measurement report reported by the user equipment  91 , and it needs to perform handover to another radio side network element, the source radio side network element  92  selects another radio side network element to initiate handover. 
     Step  1503 : if the source radio side network element  92  determines that it needs to initiate the handover implemented by the core network according to the condition of the interface between the network elements or the location information of the destination radio side network element  93 , the source radio side network element  92  sends a handover required message including information of the indication of whether to support the tunnel direct forwarding and the destination radio network side identifier and so on to the original MME  94 . 
     Step  1504 : the original MME  94  receives the handover request message, and then judges whether it needs to reselect a MME according to the destination radio side network element  93  identifier, and if determines that the MME reselection should be performed, the original MME  94  sends the user&#39;s context information, the destination radio side network element identifier, the indication of whether it supports direct forwarding of the tunnel, and the routing strategies and so on to the new MME  95  via the relocation request message. 
     The specific form of the routing strategies might be the corresponding relationship between the packet destination address and two routing options of the local IP access and the core network access; it might also be the relationship between the local IP access type and the routing option, wherein the local IP access type is the local IP access to Internet, or the local IP access to home network, and so on. 
     The routing strategies might be for the users or for the radio side network elements. If the routing strategies are for the users, the original MME  94  might send the routing strategies obtained from the HSS to the new MME  95  via the user registration or location update process; if the routing strategies are for the radio side network elements, the original MME  94  might send the locally configured general routing strategies of the local IP access to the new MME  95 . 
     Step  1505 : the new MME  95  receives the relocation request message, and then sends a handover request message including information of the bearer establishment list, handover restriction list, a source to destination transport container, routing strategies, and so on to the destination radio side network element  93  to indicate the destination radio side network element  93  to reserve the handover resource. 
     Step  1506 : the destination radio side network element  93  receives the handover request message, and then establishes the radio bearer and stores the routing strategies, and after completing to establish the radio bearer, the destination radio side network element  93  returns a handover request acknowledgement message to the new MME  95 . 
     Step  1507 : the new MME  95  receives the handover request acknowledgement message, and then uses the relocation response message to notify the original MME  94  that the destination side is ready for the handover. 
     Steps  1508 ˜ 1509 : the original MME  94  uses a handover command to indicate the user equipment  91  to perform handover to the destination radio side network element  93 . 
     Steps  1510 ˜ 1511 : the user equipment  91  synchronizes to the destination radio side network element  93 , and then sends a handover confirmation message to the destination radio side network element  93 . The destination radio side network element  93  uses the handover notification message to notify the new MME  95  that the handover process is completed, and the handover notification message contains the destination radio side network element identifier and the downlink tunnel identifier. 
     If the source and destination radio side network elements  92 ,  93  provide a service by the same MME, the handover process is completed by the same MME, and the step  1504  and the step  1507  are not performed; and the routing strategies are sent by the same MME. 
       FIG. 16  is a schematic diagram of the destination radio side network element acquiring the routing strategies in the handover process according to the present document, and as shown in  FIG. 16 , the process specifically comprises the following steps. 
     Step  1601 : the user equipment  161  measures the radio signal condition in adjacent cells to report to the radio side network element  162  which is serving the user equipment  161  currently in the form of measurement report. 
     Step  1602 : The radio side network element, namely the source network element  162 , that is currently serving the user equipment  161  finds out that the signal in the cell in which the user equipment  161  is currently located becomes poor according to the measurement report reported by the user equipment  161 , and it needs to perform handover to another radio side network element, the source radio side network element  162  selects another radio side network element to initiate a handover. 
     Step  1603 : if the source radio side network element  162  determines that it needs to initiate the handover implemented by the core network according to the condition of the interface between the network elements or the location information of the destination radio side network element  163 , the source radio side network elements  162  sends a handover request message including information of the RRC context, the destination radio side network element identifier, the AS layer configuration, the bearer-related QoS parameter, the routing strategies, and so on to the original MME  164 . 
     The specific form of the routing strategies might be the corresponding relationship between the packet destination address and two routing options of the local IP access and the core network access; it might also be the relationship between the local IP access type and the routing option, the local IP access type is the local IP access to Internet, or the local IP access to home network, and so on. The routing strategies might be for the users or for the network elements. 
     Step  1604 : the original source radio side network element  162  receives the handover request message, and then stores the routing strategies and allocates the radio resource according to the information included in the handover request message and triggers the user equipment  161  to initiate the handover to the destination radio side network element  163  after completing the handover preparation, and sends a handover request acknowledgement message to the source radio side network element  162 . 
     Step  1605 : the source radio side network element  162  receives the handover request acknowledgement message, and then indicates the user equipment  161  to perform handover to the destination radio side network element  163  with a handover command. 
     Step  1606 : the user equipment  161  sends a handover confirmation message to the destination radio side network element  163  after synchronizing to the destination radio side network element  163  to indicate that the handover process is completed. At this point, the destination radio side network element  163  can start to send the cached downlink data to the user equipment  161 . 
     Step  1607 : the destination radio side network element  163  notifies the MME  164  that the user equipment  161  has changed the serving cell with a path switch request message. 
     Step  1608 : a user plane update process is implemented between the MME  164  and the S-GW  165 , and the destination radio side network element ID and the downlink tunnel ID are sent to the S-GW  165 , and at this point, sending the downlink data in the core network can also be started. 
     Step  1609 : the MME  164  returns a path switch request acknowledgement message to the destination radio side network element  163  to provide the aggregate maximum bit rate (AMBR) of the updated user equipment  161  or indicate which radio bearers fail to be established so that the radio side deletes the corresponding radio bearers. 
       FIG. 17  is a schematic diagram  1  of acquiring the routing strategies when updating the routing strategies according to the present document, and as shown in  FIG. 17 , the process specifically comprises the following steps. 
     Step  1701 : the user and the operator negotiate to modify the subscribed routing strategies of local IP access and the routing strategies are the routing strategies for the users. 
     The specific form of the routing strategies might be the corresponding relationship between the packet destination address and the two routing options of the local IP access and the core network access; might also be the relationship between the local IP access type and the routing options, wherein the local IP access type might be the local IP access to Internet, or the local IP access to home network, and so on. 
     Step  1702 : the HSS  173  sends the updated routing strategies to the MME  172  via the insert subscriber data process. 
     Step  1703 : the MME  172  receives the updated routing strategies and then returns an insert subscriber data acknowledgement message to the HSS  173 . 
     Step  1704 : if the user equipment is already in the connection state and has established a user plane, the MME  172  sends the updated routing strategies to the radio side network element  171  via the configuration update message. 
     Step  1705 : the radio side network element  171  receives the updated routing strategies, and then updates its own stored routing strategies for the user, and returns the configuration update acknowledgement message to the MME  172 . 
     In addition, if the routing strategies for the radio side network elements locally configured by the MME  172  change, the updated routing strategies are directly sent to the radio side network elements  171  with the process similar to steps  1704 ˜ 1705 . 
       FIG. 18  is a schematic diagram  2  of the procedure of acquiring the routing strategies when the routing strategies update according to the present document, and as shown in  FIG. 18 , the process specifically comprises the following steps: 
     Step  1801 : the user and the operator negotiate to modify the routing strategies of local IP access of the subscription, and the routing strategies are the routing strategies for the users. 
     The specific form of the routing strategies might be the corresponding relationship between the packet destination address and the two routing options of the local IP access and the core network access; might also be the relationship between the local IP access type and the routing options, wherein the local IP access type might be the local IP access to Internet, or the local IP access to home network, and so on. 
     Step  1802 : the HSS  183  sends the updated routing strategies to the SGSN  182  via the insert subscriber data process. 
     Step  1803 : the SGSN  182  receives the updated routing strategies, and then returns an insert subscriber data acknowledgement message to the HSS  183 . 
     Step  1804 : if the user equipment is already in the connection state and has established a user plane, the SGSN  182  sends the updated routing strategies to the radio side network element via an information transfer indication message. 
     Step  1805 : the radio side network element receives the updated routing strategies, and then updates its own stored routing strategies for the users, and returns the configuration update acknowledgement message to the SGSN  182 . 
     In addition, if the routing strategies for the radio side network element locally configured by the SGSN  182  change, the updated routing strategies are directly sent to the radio side network element with the process similar to steps  1804 ˜ 1805 . 
     If the radio side network element acquires both the routing strategies for the users and the routing strategies for the network elements, and when the radio side network elements transmit data to the user, it might select the routing strategies according to the configuration rules, for example, select the routing strategies with the high priority according to the priorities; and for another example, preferably select the routing strategies for the user for a particular type of users. 
     After the radio side network element acquires the routing strategies, it transmits the data according to the routing strategies. Specifically, the radio side network elements do not distinguish users, and uniformly send the data of each user according to the routing strategies for the corresponding radio side network elements; alternatively, transmit the corresponding subscriber data according to the routing strategies for each user. 
     The above description is the preferred embodiments of the present document, and it is not intended to limit the protection scope of the claims of the present document.