Abstract:
Disclosed are a method, device and system for establishing a connection. The method comprises the following steps: a source base station sending a message of requesting an opposite end to transmit an address through an S1 interface ( 101 ); the source base station receiving a response message of requesting the opposite end to transmit the address ( 102 ); and the source base station initiating an X2 interface establishment flow for a target base station according to the response message ( 103 ).

Description:
TECHNICAL FIELD 
       [0001]    The disclosure relates to the field of communication, and in particular to a method, device, and system for establishing a connection. 
       BACKGROUND 
       [0002]    A home eNB (HeNB) is defined in a Long Term Evolution (LTE) system by the third Generation Partnership Projects (3GPP) standard organization. In LTE release R10, there is only a direct interface X2 between two HeNBs, while no interface X2 is supported between a Macro Evolved NodeB (eNB) and an HeNB. In LTE R11, an X2 gateway (GW) is introduced. The X2 GW, like an HeNB GW, is an optional deployment. Between an eNB and an HeNB and/or between two HeNBs, a proxy interface X2 may be established via an X2 GW, or a direct interface X2 may be established directly via no X2 GW. An interface X2 established directly between an HeNB and a neighboring eNB is referred to as a direct X2 connection between the HeNB and the neighboring eNB. An interface X2 between an X2 GW and the neighboring eNB established via an X2 GW is referred to as an indirect X2 connection. 
         [0003]    At present, an eNB may discover a cell managed by a neighboring eNB using an Automatic Neighbor Relation (ANR) and establish an X2 connection with the neighboring eNB. After a user equipment (UE) camping on a cell managed by the eNB has measured a strong signal from a neighboring cell, the UE may send a measurement report to the eNB. Having acquired the measurement report for the neighboring cell, the eNB may determine, according to the measurement report, whether the neighboring cell is a Macro cell or an HeNB cell, acquire an eNB ID of an eNB managing the neighboring cell and a Tracking Area Indicator (TAI) (PLMN ID+Tracking Area Code, TAC) of the neighboring cell, and then initiate a process of discovering a Transport Network Layer (TNL) address to acquire a TNL address for establishing an X2 connection to the neighboring HeNB cell. 
         [0004]    However, during the connection establishment, there is no way for deciding a direct or indirect X2 connection mode between the eNBs via the TNL address discovering flow, failing to effectively enhance network performance. 
       SUMMARY 
       [0005]    To this end, embodiments herein provide a data processing method and terminal based on IPTV, and non-transitory computer-readable storage medium. 
         [0006]    The disclosure provides a method for establishing a connection, including: 
         [0007]    sending, by a source Evolved NodeB, eNB, via an interface S1, a request for a transport address of an opposite end; 
         [0008]    receiving, by the source eNB, a response to the request for the transport address; and 
         [0009]    initiating, by the source eNB according to the response, a flow of establishing an interface X2 to a target eNB. 
         [0010]    The request for the transport address of the opposite end may include: information on the target eNB; 
         [0011]    and/or, information on a type of the interface X2 to be established with the target eNB set by the source eNB; the type of the interface X2 including a direct X2 connection or an indirect X2 connection; 
         [0012]    and/or, information on a Transport Network Layer, TNL, address of the source eNB for establishing the interface X2; 
         [0013]    and/or, a request for an indicator of the type of the interface X2 to be established between the target eNB and the source eNB. 
         [0014]    The response may include: information on a Transport Network Layer, TNL, address of the target eNB for establishing the interface X2; 
         [0015]    and/or, information on a type of the interface X2 to be established with the source eNB set by the target eNB; 
         [0016]    and/or, information on a TNL address of an X2 GW connected to the target eNB for establishing the interface X2; 
         [0017]    and/or, an indicator of whether the target eNB accepts a type of the interface X2 proposed by the source eNB. 
         [0018]    The type of the interface X2 may include a direct X2 connection or an indirect X2 connection. 
         [0019]    The initiating, by the source eNB according to the response, a flow of establishing an interface X2 to a target eNB may include: determining, by the source eNB, a type of the interface X2 according to information on the type of the interface X2 between the target eNB and the source eNB, and information on a Transport Network Layer, TNL, address of an X2 GW for establishing the interface X2, and/or information on a TNL address for establishing the interface X2 included in the response; and initiating, by the source eNB, the flow of establishing the interface X2 to the target eNB. 
         [0020]    The method may further include: determining, by the source eNB according to the information on the TNL address of the X2 GW connected to the target eNB for establishing the interface X2, whether the interface X2 with the target eNB can be established via an X2 GW connected to the source eNB. 
         [0021]    The information on the TNL address of the X2 GW connected to the target eNB for establishing the interface X2 may be generated by the target eNB by: 
         [0022]    determining, according to the included information on the TNL address of the X2 GW for establishing the interface X2, whether it is possible to establish the interface X2 with the source eNB via the X2 GW connected to the target eNB, and generating a result of the determination as the information on the TNL address of the X2 GW connected to the target eNB for establishing the interface X2. 
         [0023]    The disclosure provides a method for establishing a connection, including: 
         [0024]    receiving, by a target Evolved NodeB, eNB, via an interface S1, a request for a transport address sent by an opposite end; and 
         [0025]    returning, by the target eNB via the interface S1, a response to the request for the transport address. 
         [0026]    The response may include: information on a Transport Network Layer, TNL, address of the target eNB for establishing the interface X2; 
         [0027]    and/or, information on a type of the interface X2 to be established with the source eNB set by the target eNB; 
         [0028]    and/or, information on a TNL address of an X2 GW connected to the target eNB for establishing the interface X2. 
         [0029]    The type of the interface X2 may include a direct X2 connection or an indirect X2 connection. 
         [0030]    The method may further include: deciding, by the target eNB according to information on a type of an interface X2 included in the request for the transport address as well as information on a type of the interface X2 to be established between the target eNB and a source eNB set by the target eNB, to establish a direct interface X2 or an indirect interface X2 between the target eNB and the source eNB, and initiating, by the target eNB according to the decision, a flow of establishing the interface X2 to the source eNB. 
         [0031]    The disclosure further provides a source Evolved NodeB, eNB, including a sending unit, a receiving unit, and a processing unit. 
         [0032]    The sending unit is configured for: sending, via an interface S1, a request for a transport address of an opposite end. 
         [0033]    The receiving unit is configured for: receiving a response to the request for the transport address. 
         [0034]    The processing unit is configured for: initiating, according to the response, a flow of establishing an interface X2 to a target eNB. 
         [0035]    The request for the transport address of the opposite end may include: information on the target eNB; and/or, information on a type of the interface X2 to be established with the target eNB set by the source eNB, the type of the interface X2 including a direct X2 connection or an indirect X2 connection; and/or, information on a Transport Network Layer, TNL, address of the source eNB for establishing the interface X2; and/or, a request for an indicator of the type of the interface X2 to be established between the target eNB and the source eNB. 
         [0036]    The response may include: information on a Transport Network Layer, TNL, address of the target eNB for establishing the interface X2; 
         [0037]    and/or, information on a type of the interface X2 to be established with the source eNB set by the target eNB; 
         [0038]    and/or, information on a TNL address of an X2 GW connected to the target eNB for establishing the interface X2; 
         [0039]    and/or, an indicator of whether the target eNB accepts a type of the interface X2 proposed by the source eNB. 
         [0040]    The type of the interface X2 may include a direct X2 connection or an indirect X2 connection. 
         [0041]    The processing unit may be configured for: determining a type of the interface X2 according to information on the type of the interface X2 between the target eNB and the source eNB, and information on a Transport Network Layer, TNL, address of an X2 GW for establishing the interface X2, and/or information on a TNL address for establishing the interface X2 included in the response; and initiating the flow of establishing the interface X2 to the target eNB. 
         [0042]    The processing unit may be configured for: determining, according to the information on the TNL address of the X2 GW connected to the target eNB for establishing the interface X2, whether the interface X2 with the target eNB can be established via an X2 GW connected to the source eNB. 
         [0043]    The information on the TNL address of the X2 GW connected to the target eNB for establishing the interface X2 may be generated by the target eNB by: determining, according to the included information on the TNL address of the X2 GW for establishing the interface X2, whether it is possible to establish the interface X2 with the source eNB via the X2 GW connected to the target eNB, and generating a result of the determination as the information on the TNL address of the X2 GW connected to the target eNB for establishing the interface X2. 
         [0044]    The disclosure further provides a target Evolved NodeB, eNB, including a receiving unit and a sending unit. 
         [0045]    The receiving unit is configured for: receiving, via an interface S1, a request for a transport address sent by an opposite end. 
         [0046]    The sending unit s configured for: returning, via the interface S1, a response to the request for the transport address. 
         [0047]    The response may include: information on a Transport Network Layer, TNL, address of the target eNB for establishing the interface X2, 
         [0048]    and/or, information on a type of the interface X2 to be established with a source eNB set by the target eNB, 
         [0049]    and/or, information on a TNL address of an X2 GW connected to the target eNB for establishing the interface X2. 
         [0050]    The type of the interface X2 may include a direct X2 connection or an indirect X2 connection. 
         [0051]    The eNB may further include a processing unit configured for: deciding, according to information on a type of an interface X2 included in the request for the transport address received by the receiving unit as well as information on a type of the interface X2 to be established between the target eNB and a source eNB set by the target eNB, to establish a direct interface X2 or an indirect interface X2 between the target eNB and the source eNB; the target eNB may initiate, according to the decision, a flow of establishing the interface X2 to the source eNB. 
         [0052]    The disclosure further provides a system for establishing a connection, including a source Evolved NodeB, eNB, and a target eNB. 
         [0053]    The source eNB is configured for: sending, from a network side via an interface S1, a request for a transport address of an opposite end; receiving, from the network side, a response to the request for the transport address sent by the target eNB; and initiating, according to the response, a flow of establishing an interface X2 to a target eNB. 
         [0054]    The target eNB is configured for: receiving, from the network side via the interface S1, the request for the transport address sent by the source eNB; and returning, from the network side via the interface S1, the response to the request for the transport address. 
         [0055]    With the method, device, and system for establishing a connection herein, a source eNB sends, via an interface S1, a request for a transport address of an opposite end; receives a response to the request for the transport address; and initiates, according to the response, a flow of establishing an interface X2 to a target eNB. Thus, the source eNB may determine, according to the acquired address response, a mode of connection with the target eNB, and initiate the flow of establishing the interface X2 with the target eNB, thereby effectively enhancing network performance. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0056]      FIG. 1  is a flowchart of a method for establishing a connection at a source-eNB side according to an Embodiment 1 herein. 
           [0057]      FIG. 2  is a flowchart of a method for establishing a connection at a target-eNB side according to an Embodiment 2 herein. 
           [0058]      FIG. 3  is a flowchart of a method for establishing a connection according to an Embodiment 3 herein. 
           [0059]      FIG. 4  is a flowchart of the method according to an Embodiment 4 herein. 
           [0060]      FIG. 5  is a flowchart of the method according to an Embodiment 5 herein. 
           [0061]      FIG. 6  is a diagram of a structure of an eNB according to an Embodiment 6 herein. 
           [0062]      FIG. 7  is a diagram of a structure of a system for establishing a connection according to an Embodiment 8 herein. 
           [0063]      FIG. 8  is HeNB network architecture under independent X2 GW deployment. 
       
    
    
     DETAILED DESCRIPTION 
       [0064]    According to an embodiment herein, a source eNB sends, via an interface S1, a request for a transport address of an opposite end; receives a response to the request for the transport address; and initiates, according to the response, a flow of establishing an interface X2 to a target eNB. 
         [0065]    The disclosure is further elaborated below with reference to the drawings and embodiments. 
       Embodiment 1 
       [0066]    As shown in  FIG. 1 , according to an embodiment herein, a flow of a method for establishing a connection at a source-eNB side includes steps as follows. 
         [0067]    In step  101 , a source eNB sends, via an interface S1, a request for a transport address of an opposite end. 
         [0068]    Here, the request for the transport address of the opposite end may be sent via a local configuration transport message. 
         [0069]    The request for the transport address of the opposite end may include information on the target eNB. The information on the target eNB may be an identifier of the target eNB. 
         [0070]    The request for the transport address of the opposite end may include information on a type of the interface X2 to be established with the target eNB set by the source eNB. 
         [0071]    The request for the transport address of the opposite end may include information on an IP address of the source eNB for establishing the interface X2. 
         [0072]    The request for the transport address of the opposite end may include a request for an indicator of the type of the interface X2 to be established between the target eNB and the source eNB. 
         [0073]    The type of the interface X2 may include a direct X2 connection or an indirect X2 connection. 
         [0074]    The information on the IP address of the source eNB for establishing the interface X2 may contain: information on one or more TNL addresses, such as when the source eNB is configured with information on an IP address of an X2 GW connected thereto for establishing the interface X2. 
         [0075]    When the source eNB is configured to be connected to multiple X2 GWs, the information on the IP address of the source eNB for establishing the interface X2 may contain information on IP addresses of the multiple X2 GWs for establishing the interface X2. Alternatively, the request for the transport address of the opposite end may include a request for an indicator of the type of the interface X2 to be established between the target eNB and the source eNB. 
         [0076]    In step  102 , the source eNB receives a response to the request for the transport address. 
         [0077]    Here, the response may include information on a Transport Network Layer, TNL, address of the target eNB for establishing the interface X2. 
         [0078]    The response may include information on a type of the interface X2 to be established with the source eNB set by the target eNB. 
         [0079]    When the target eNB is configured with the information on the IP address of an X2 GW connected thereto for establishing the interface X2, the response may include information on a TNL address of the X2 GW connected to the target eNB for establishing the interface X2. 
         [0080]    The type of the interface X2 may include a direct X2 connection or an indirect X2 connection. 
         [0081]    In step  103 , the source eNB initiates, according to the response, a flow of establishing an interface X2 to a target eNB. 
         [0082]    The source eNB may determine a type of the interface X2 according to information on the type of the interface X2 between the target eNB and the source eNB, and information on a TNL address of an X2 GW for establishing the interface X2, and/or information on a TNL address for establishing the interface X2 included in the response; and initiate the flow of establishing the interface X2 to the target eNB. 
         [0083]    Before step  103  is executed, the source eNB may determine, according to the information on the TNL address of the X2 GW connected to the target eNB for establishing the interface X2, whether the interface X2 with the target eNB can be established via an X2 GW connected to the source eNB. 
         [0084]    The information on the TNL address of the X2 GW connected to the target eNB for establishing the interface X2 may be generated as follows. The target eNB may determine, according to the included information on the TNL address of the X2 GW for establishing the interface X2, whether it is possible to establish the interface X2 with the source eNB via the X2 GW connected to the target eNB, and generate a result of the determination as the information on the TNL address of the X2 GW connected to the target eNB for establishing the interface X2. 
         [0085]    The source eNB may be an HeNB or a Macro eNB. When the source eNB is an HeNB connected to an HeNB GW, a message sent by the interface S1 has to be sent to the HeNB GW by the source eNB, and transferred transparently by the HeNB GW to the target eNB. Alternatively, a message sent by the interface S1 has to be transferred transparently by the HeNB GW to a core network, and forwarded by the core network to the target eNB. The core network may include a Mobility Management Entity (MME). 
       Embodiment 2 
       [0086]    As shown in  FIG. 2 , according to an embodiment herein, a flow of a method for establishing a connection at a target-eNB side includes steps as follows. 
         [0087]    In step  201 , a target eNB receives, via an interface S1, a request for a transport address sent by an opposite end. 
         [0088]    In step  202 , the target eNB returns, via the interface S1, a response to the request for the transport address. 
         [0089]    After receiving the request for the transport address of the opposite end, the target eNB may determine whether a response succeeds, and if so, return a successful response; otherwise return a failed response. 
         [0090]    Here, the response may include information on one or more IP addresses of the target eNB for establishing the interface X2. 
         [0091]    The successful response may include information on a type of the interface X2 to be established with the source eNB. When the target eNB is configured with information on an IP address of an X2 GW connected to the target eNB for establishing the interface X2, the successful response may include information on one or more IP addresses of X2 GW connected to the target eNB for establishing the interface X2. 
         [0092]    The interface X2 to be established with the source eNB may be of a direct X2 connection or an indirect X2 connection. 
         [0093]    When the target eNB is an HeNB connected to an HeNB GW, a message sent by the interface S1 has to be transferred transparently and forwarded via the HeNB GW connected to the target eNB. When the source eNB, also like the target eNB, is an HeNB connected to an HeNB GW, processing thereof may be the same. 
         [0094]    The target eNB may determine whether the response succeeds as follows. When a decision of the target eNB on the type of the interface X2 is inconsistent with that of the source eNB included in the request for the transport address, the target eNB may determine that the response fails. The target eNB may include, in the failed response, an indicator indicating an interface X2 type refusal. 
         [0095]    The target eNB may decide, according to information on a type of an interface X2 included in the request for the transport address as well as information on a type of the interface X2 to be established between the target eNB and a source eNB set by the target eNB, to establish a direct interface X2 or an indirect interface X2 between the target eNB and the source eNB. The target eNB may then initiate, according to the decision, a flow of establishing the interface X2 to the source eNB. the flow of establishing the interface X2 is known and thus is not repeated here. 
         [0096]    The target eNB may be a Macro eNB or an HeNB. 
       Embodiment 3 
       [0097]    As shown in  FIG. 3 , according to the embodiment for example, assuming that the eNB is the source eNB and the HeNB is the target eNB, a method for establishing a connection may include steps as follows. 
         [0098]    In step  301 , when a UE managed by the eNB detects a cell managed by the HeNB, the UE may notify the eNB that an X2 connection has to be established with the HeNB. 
         [0099]    In step  302 , the eNB may send, via a local eNB configuration transport message, the MME a request for a transport address of an opposite end. 
         [0100]    The request for the transport address of the opposite end may contain: information on the target HeNB, information on a type of the interface X2 to be established with the target HeNB set by the eNB. The type of the interface X2 may denote a direct X2 connection or an indirect X2 connection between the source eNB and the target eNB. The information on the type may be a 1-bit indicator of, for example, 0, denoting the direct X2 connection, or 1, denoting the indirect X2 connection. 
         [0101]    The request for the transport address of the opposite end may further include: information on one or more IP addresses of the eNB for establishing the interface X2, and/or information on one or more IP addresses of X2 GW connected to the eNB for establishing the interface X2; 
         [0102]    With the information on one or more IP addresses of X2 GW connected to the eNB for establishing the interface X2, the HeNB may determine whether the interface X2 with the eNB can be established via an X2 GW connected to the HeNB. 
         [0103]    In step  303 , the MME may determine whether the target HeNB is connected to the HeNB GW; when the target HeNB is connected to the HeNB GW, the MME may send, via a local MME configuration transport message, the HeNB GW the request for the transport address of the opposite end; the flow then goes to step  304 ; when the target HeNB is not connected to the HeNB GW, the flow goes to step  305 . 
         [0104]    In step  304 , the HeNB GW may deliver the request for the transport address of the opposite end to the HeNB; and the flow goes to step  306 . 
         [0105]    In step  305 , the MME may send, via a local MME configuration transport message, the HeNB the request for the transport address of the opposite end. 
         [0106]    In step  306 , after receiving the request for the transport address of the opposite end, when being connected to the HeNB GW, the HeNB may construct a response to send information on a TNL address of the HeNB for establishing the interface X2 to the HeNB GW, and the flow goes to step  307 ; otherwise the flow goes to step  308 . 
         [0107]    The response may include information on one or more IP addresses of the target HeNB for establishing the interface X2. 
         [0108]    The response may further include information on a type of the interface X2 to be established with the source eNB set by the target HeNB, and/or information on one or more IP addresses of X2 GW connected to the HeNB for establishing the interface X2. 
         [0109]    In step  307 , the HeNB GW may transfer the response transparently to the MME; and the flow goes to step  309 . 
         [0110]    In step  308 , the HeNB may construct a response to send information on a TNL address of the HeNB for establishing the interface X2 to the MME. 
         [0111]    In step  309 , the MME may deliver the response to the eNB via an MME configuration transport message. 
         [0112]    In step  310 , the eNB may establish the X2 connection according to the information on the TNL address of the HeNB for establishing the interface X2 included in the response, and/or the information on a TNL address of an X2 GW for establishing the interface X2, and the information on the type of the interface X2 between the target HeNB and the eNB. 
         [0113]    When an eNB is configured to be connected to multiple X2 GWs, the request and the response may contain information on IP addresses of the multiple X2 GWs for establishing the interface X2. 
         [0114]    When a decision of the target eNB on the type of the interface X2 is inconsistent with that of the source eNB included in the request for the transport address, the target eNB may include, in the response, an indicator such as indicating an interface X2 type acceptance or refusal. 
         [0115]    The source eNB may include, in the request, a request for an indicator of the type of the interface X2 to be established between the target eNB and the source eNB, such as a request for an interface X2 type indicator. The target eNB may include, in the response, according to the indicator, information on the type of the interface X2 to be established between the target eNB and the source eNB. 
       Embodiment 4 
       [0116]    As shown in  FIG. 4 , according to the embodiment, assuming that the HeNB is the source eNB and the eNB is the target eNB, a method for establishing a connection may include steps as follows. 
         [0117]    In step  401 , a UE managed by the HeNB may detect a cell managed by the eNB, and may have to establish an X2 connection with the eNB; when the HeNB is connected to the HeNB GW, the flow may go to step  402 ; otherwise when the HeNB is not connected to the HeNB GW, the flow may go to step  404 . 
         [0118]    In step  402 , the HeNB may send the HeNB GW an eNB configuration transport message to send a request for a transport address of an opposite end. 
         [0119]    The request for the transport address of the opposite end may contain information on the target eNB, and information on a type of the interface X2 to be established with the target eNB set by the HeNB. The type of the interface X2 may denote a direct X2 connection or an indirect X2 connection between the source eNB and the target eNB. The information on the type may be a 1-bit indicator of, for example, 0, denoting the direct X2 connection, or 1, denoting the indirect X2 connection. 
         [0120]    The request for the transport address of the opposite end may include: information on an IP address of the source HeNB for establishing the interface X2 (including information on one or more TNL addresses), information on an IP address of an X2 GW connected to the source HeNB for establishing the interface X2 (including information on one or more TNL addresses). With the information on the IP address of the X2 GW for establishing the interface X2 included therein, the eNB may establish the interface X2 with the X2 GW. 
         [0121]    In step  403 , the HeNB GW may deliver the request for the transport address of the opposite end to the MME via an eNB configuration transport message, and the flow may go to step  405 . 
         [0122]    In step  404 , the HeNB may send the MME an eNB configuration transport message to send a request for a transport address of an opposite end. 
         [0123]    The request may contain information on the target eNB, and information on a type of the interface X2 to be established with the target eNB set by the HeNB. The type of the interface X2 may denote a direct X2 connection or an indirect X2 connection between the source eNB and the target eNB. The information on the type may be a 1-bit indicator of, for example, 0, denoting the direct X2 connection, or 1, denoting the indirect X2 connection. The request may optionally include: information on an IP address of the source HeNB for establishing the interface X2 (including information on one or more TNL addresses). The request may optionally include information on an IP address of an X2 GW connected to the source HeNB for establishing the interface X2 (including information on one or more TNL addresses), when the source HeNB is configured with such information. With the information on the IP address of the X2 GW for establishing the interface X2 included therein, the eNB may establish the interface X2 with the X2 GW. 
         [0124]    In step  405 , the MME may forward the request to the target eNB according to the information on the target eNB included in the request. 
         [0125]    In step  406 , after receiving the MME configuration transport message, the eNB may construct an eNB configuration message to send information on a TNL address of the eNB for establishing the interface X2 to the MME. 
         [0126]    The response may include information on an IP address of the target eNB for establishing the interface X2 (including information on one or more TNL addresses). 
         [0127]    Optionally, the response may include information on a type of the interface X2 to be established with the source HeNB set by the target eNB. The type of the interface X2 may denote a direct X2 connection or an indirect X2 connection between the eNB and the HeNB is to be adopted. The information on the type may be a 1-bit indicator of, for example, 0, denoting the direct X2 connection, or 1, denoting the indirect X2 connection. The response to the request may optionally include information on an IP address of an X2 GW connected to the eNB for establishing the interface X2 (including information on one or more TNL addresses), when the eNB is configured with such information. With the information on the IP address of the X2 GW for establishing the interface X2 included therein, the HeNB may determine whether the interface X2 with the eNB can be established via an X2 GW connected to the HeNB. 
         [0128]    In step  407 , the MME may parse the received eNB configuration transport message; when the target HeNB is connected to the HeNB GW, the MME may transfer the eNB configuration transport message transparently to the HeNB GW, and the flow may go to step  408 ; otherwise when the target HeNB is not connected to the HeNB GW, the flow may go to step  409 . 
         [0129]    In step  408 , the HeNB GW may forward the eNB configuration transport message to the HeNB, and the flow may go to step  410 . 
         [0130]    In step  409 , the MME may deliver the response to the HeNB via an MME configuration transport message. 
         [0131]    In step  410 , the HeNB may establish the X2 connection between the source HeNB and the target eNB according to the information on the TNL address of the HeNB for establishing the interface X2 included in the response, and/or possibly the information on a TNL address of an X2 GW for establishing the interface X2, and the information on the type of the interface X2 between the target eNB and the HeNB. 
         [0132]    When an eNB is configured to be connected to multiple X2 GWs, the request and the response may contain information on IP addresses of the multiple X2 GWs for establishing the interface X2. 
         [0133]    When a decision of the target eNB on the type of the interface X2 is inconsistent with that of the source eNB included in the request for the transport address, the target eNB may include, in the response, an indicator such as indicating an interface X2 type acceptance or refusal. 
         [0134]    The source eNB may include, in the request, a request for an indicator of the type of the interface X2 to be established between the target eNB and the source eNB, such as a request for an interface X2 type indicator. The target eNB may include, in the response, according to the indicator, information on the type of the interface X2 to be established between the target eNB and the source eNB. 
       Embodiment 5 
       [0135]    As shown in  FIG. 5 , according to the embodiment, assuming that the HeNB1 is the source eNB and the HeNB2 is the target eNB, when the HeNB1 and the HeNB2 are connected to the same HeNB GW, a method for establishing a connection may include steps as follows. 
         [0136]    In step  501 , a UE managed by the HeNB1 may detect a cell managed by the HeNB2, and may have to establish an X2 connection with the HeNB2. 
         [0137]    In step  502 , the HeNB1 may send the HeNB GW an eNB configuration transport message requesting information on a TNL address of the target HeNB2 for establishing the interface X2. 
         [0138]    The request may include information on the target HeNB2, and information on a type of the interface X2 to be established with the target HeNB2 set by the HeNB1. The type of the interface X2 may denote a direct X2 connection or an indirect X2 connection between the source eNB and the target eNB. The information on the type may be a 1-bit indicator of, for example, 0, denoting the direct X2 connection, or 1, denoting the indirect X2 connection. The request may optionally include information on an IP address of the source HeNB1 for establishing the interface X2 (including information on one or more TNL addresses). The request may optionally include information on an IP address of an X2 GW connected to the source HeNB1 for establishing the interface X2 (including information on one or more TNL addresses), when the source HeNB1 is configured with such information. With the information on the IP address of the X2 GW for establishing the interface X2 included therein, the HeNB2 may determine whether the interface X2 with the HeNB1 can be established via an X2 GW connected to the HeNB2. 
         [0139]    In step  503 , the HeNB GW may deliver the request to the HeNB2 via an MME configuration transport message. 
         [0140]    In step  504 , after receiving the MME configuration transport message, the HeNB2 may construct an eNB configuration message to send information on a TNL address of the HeNB2 for establishing the interface X2 to MME. 
         [0141]    The response to the request may include information on an IP address of the target HeNB2 for establishing the interface X2 (including information on one or more TNL addresses). The response may optionally contain information on a type of the interface X2 to be established with the source HeNB1 set by the target HeNB2. The type of the interface X2 may denote a direct X2 connection or an indirect X2 connection between the HeNB1 and the HeNB2 to be adopted. The information on the type may be a 1-bit indicator of, for example, 0, denoting the direct X2 connection, or 1, denoting the indirect X2 connection. The response may optionally include information on an IP address of an X2 GW connected to the HeNB2 for establishing the interface X2 (including information on one or more TNL addresses), when the HeNB2 is configured with such information. With the information on the IP address of the X2 GW for establishing the interface X2 included therein, the HeNB1 may determine whether the interface X2 with the HeNB2 can be established via an X2 GW connected to the HeNB1. 
         [0142]    In step  505 , the HeNB GW may parse the received eNB configuration transport message and transfer the eNB configuration transport message transparently to the HeNB1. 
         [0143]    In step  506 , the HeNB1 may establish the X2 connection between the source HeNB1 and the target HeNB2 according to the information on the TNL address of the HeNB2 for establishing the interface X2 included therein, and/or possibly the information on a TNL address of an X2 GW for establishing the interface X2, and the information on the type of the interface X2 between the target HeNB2 and the HeNB1. 
         [0144]    When an eNB is configured to be connected to multiple X2 GWs, the request and the response may contain information on IP addresses of the multiple X2 GWs for establishing the interface X2. 
         [0145]    When a decision of the target eNB on the type of the interface X2 is inconsistent with that of the source eNB included in the request for the transport address, the target eNB may include, in the response, an indicator such as indicating an interface X2 type acceptance or refusal. 
         [0146]    The source eNB may include, in the request, a request for an indicator of the type of the interface X2 to be established between the target eNB and the source eNB, such as a request for an interface X2 type indicator. The target eNB may include, in the response, according to the indicator, information on the type of the interface X2 to be established between the target eNB and the source eNB. 
       Embodiment 6 
       [0147]    As shown in  FIG. 6 , the disclosure may further provide an eNB, including a sending unit  61 , a receiving unit  62 , and a processing unit  63 . 
         [0148]    The sending unit  61  is configured for: sending, via an interface S1, a request for a transport address of an opposite end. 
         [0149]    The receiving unit  62  is configured for: receiving a response to the request for the transport address. 
         [0150]    The processing unit  63  may be configured for: sending the request for the transport address to the sending unit  61 , and deciding a type of an interface X2 according to the response received by the receiving unit  62 . 
         [0151]    The request for the transport address of the opposite end may include information on the target eNB. 
         [0152]    The request for the transport address of the opposite end may include information on a type of the interface X2 to be established with the target eNB set by the source eNB. The type of the interface X2 may include a direct X2 connection or an indirect X2 connection. 
         [0153]    The request for the transport address of the opposite end may include information on an IP address of the source eNB for establishing the interface X2. 
         [0154]    The request for the transport address of the opposite end may include a request for an indicator of the type of the interface X2 to be established between the target eNB and the source eNB. 
         [0155]    The response may include information on an IP address of the target eNB for establishing the interface X2. 
         [0156]    The response may include information on a type of the interface X2 to be established with the source eNB set by the target eNB. 
         [0157]    The response may include information on an IP address of an X2 GW connected to the target eNB for establishing the interface X2. 
         [0158]    The type of the interface X2 may include a direct X2 connection or an indirect X2 connection. 
         [0159]    The processing unit  63  may be configured for: determining a type of the interface X2 according to information on the type of the interface X2 between the target eNB and the source eNB, and information on a Transport Network Layer, TNL, address of an X2 GW for establishing the interface X2, and/or information on a TNL address for establishing the interface X2 included in the response. 
         [0160]    The processing unit  63  may be configured for: determining, according to the information on the TNL address of the X2 GW connected to the target eNB for establishing the interface X2, whether the interface X2 with the target eNB can be established via an X2 GW connected to the source eNB. 
         [0161]    The information on the TNL address of the X2 GW connected to the target eNB for establishing the interface X2 may be generated as follows. The target eNB may determine, according to the included information on the TNL address of the X2 GW for establishing the interface X2, whether it is possible to establish the interface X2 with the source eNB via the X2 GW connected to the target eNB, and generate a result of the determination as the information on the TNL address of the X2 GW connected to the target eNB for establishing the interface X2. 
         [0162]    Both the sending unit  61  and the receiving unit  62  may be implemented by hardware such as an antenna and a CPU, or an antenna and a DSP. The processing unit  63  may be implemented by hardware such as a DSP or a CPU. 
       Embodiment 7 
       [0163]    An eNB according to an embodiment herein may further serve as the target eNB, including a receiving unit and a sending unit. 
         [0164]    The receiving unit is configured for: receiving, via an interface S1, a request for a transport address sent by an opposite end. 
         [0165]    The sending unit is configured for: returning, via the interface S1, a response to the request for the transport address. 
         [0166]    The response may include information on an IP address of the target eNB for establishing the interface X2. 
         [0167]    The response may include information on a type of the interface X2 to be established with the source eNB set by the target eNB. 
         [0168]    The response may include information on an IP address of an X2 GW connected to the target eNB for establishing the interface X2. 
         [0169]    The type of the interface X2 may include a direct X2 connection or an indirect X2 connection. 
         [0170]    The eNB may further include a processing unit configured for: deciding, according to information on a type of an interface X2 included in the request for the transport address received by the receiving unit as well as information on a type of the interface X2 to be established between the target eNB and a source eNB set by the target eNB, to establish a direct interface X2 or an indirect interface X2 between the target eNB and the source eNB, and initiating, according to the decision, a flow of establishing the interface X2 to the source eNB. 
         [0171]    The eNB according to the embodiment may serve as the target eNB, with a structure as shown in  FIG. 6 . 
       Embodiment 8 
       [0172]    As shown in  FIG. 7 , a system herein include a source eNB  71  and a target eNB  72 . 
         [0173]    The source eNB  71  is configured for: sending, from a network side via an interface S1, a request for a transport address of an opposite end; receiving, from the network side, a response to the request for the transport address sent by the target eNB; and deciding a type of an interface X2 according to the response. 
         [0174]    The target eNB  72  is configured for: receiving, from the network side via the interface S1, the request for the transport address sent by the source eNB; and returning, from the network side via the interface S1, the response to the request for the transport address. 
         [0175]    For example, as shown in  FIG. 8 , a system according to an embodiment herein may be HeNB network architecture under independent X2 GW deployment. 
         [0176]    What described are merely embodiments herein and are not intended for limiting the protection scope of the disclosure.