A method, system and device for processing the service in the circuit switching domain

FIELD OF THE TECHNOLOGY

0001The present invention relates to the field of mobile communication technologies, and more particularly to a method, system and device for processing Circuit Switched (CS) domain service.

BACKGROUND OF THE INVENTION

0002The existing 3^rd Generation Partnership Project (3GPP) protocol specifies that all service flows in a data plane of a Circuit Switched (CS) domain need to be switched through a Media Gateway (MGW).

0003<figref idref="f0001">FIG. 1</figref> is a schematic view of service flows in a data plane of a CS domain in the prior art. The network system includes a Mobile Switching Center (MSC) and an MGW located in a core network (CN), base station controllers (e.g. Radio Network Controllers, RNCs), and a plurality of base stations (e.g. NodeBs). Generally, NodeB0, NodeB1, NodeB2, NodeB3, NodeB4, and NodeB5 are base stations that directly communicate with a User Equipment (UE), and an aggregation base station (HUB NodeB) is a base station used for aggregating the transmission of lower-level cascaded NodeBs. As shown in <figref idref="f0001">FIG. 1</figref>, solid lines represent physical connections, and dashed lines represent service flows in the data plane. As can be seen from <figref idref="f0001">FIG. 1</figref>, all service flows in the data plane that are processed by the NodeBs need to be switched through the MGW.

0004In the prior art, the RNCs exchange data with the devices in the CN through an lu interface, and exchange data with the NodeBs through an lub interface.

0005The prior art has at least the following problems. After the data processing manner shown in <figref idref="f0001">FIG. 1</figref> is adopted, since the MSC needs to process CS data services of all subordinate RNCs, and each RNC needs to process CS data services of all subordinate NodeBs, the transmission bandwidth requirements for the lub and lu interfaces are increased. In addition, since the service flows need to be transmitted through a plurality of devices, the transmission delay of the service flows is increased.

0006<patcit id="pcit0001" dnum="WO2007069229A"><text>WO 2007/069229</text></patcit><b>discloses the set up of calls between subscribers on the same base transceiver station by means of a proxy connected to the base transceiver station and controlled by a base station controller.</b>

0007<patcit id="pcit0002" dnum="WO2006126923A1"><text>WO 2006/126923 A I</text></patcit> relates to a telecommunication system, to a radio base station and to a radio network controller for set-up, release and control of local calls in the telecommunication system. The telecommunication system comprises a core network and at least a radio access network, an MSC server, a central media gateway having a point of interconnection to the public switched telecommunication network and at least a radio access gateway to each respective radio access network. At least a local MGW provided with switch means and geographically separated from the central MGW. The radio access gateway and the MSC server are provided with control logic for set-up and release of local calls in the respective radio access networks using the local MGW as switch. The local MGW is located in each radio access gateway of in base stations or in a RBS aggregation site, thereby reducing costs and trombone effects.

SUMMARY OF THE INVENTION

0008The present invention is directed to a method, system and device for processing CS domain service, which can lower the requirements for bandwidth and shorten the transmission delay of service flows.

0009The technical solutions of the present invention are implemented as follows.

0010According to one aspect of the present invention, a method for processing CS domain service is provided, which includes: <ul id="ul0001" list-style="none"><li>receiving a local loop back instruction sent by a base station controller after the base station controller determines that a calling UE and a called UE are served by a same base station or in a same aggregation base station;</li><li>switching the communication mode between the calling UE and the called UE to the local loop back mode according to the local loop back instruction;</li><li>wherein the switching the communication mode between the calling UE and the called UE to the local loop back mode according to the local loop back instruction comprises: <ul id="ul0002" list-style="none"><li>establishing, by the base station or the aggregation base station, an internal transmission channel of the called UE in the base station or the aggregation base station;</li><li>removing, by the base station or the aggregation base station, a calling CS channel in a calling UE channel established with the base station controller, and establishing an internal transmission channel of the calling UE in the base station or aggregation base station, wherein the calling CS channel in the calling UE channel is established after the calling UE initiates a CS call and removed according to the local loop back instruction; and</li><li>establishing, by the base station or aggregation base station, a switching relation between the internal transmission channel of the called UE and the internal transmission channel of the calling UE to enable the calling UE and the called UE to communicate in the local loop back mode.</li></ul></li></ul>

0011According to another aspect of the present invention, a method for processing CS domain service is provided, which includes: <ul id="ul0003" list-style="none"><li>determining, by a base station controller, that a calling user equipment, UE, and a called UE are served by a same base station or a same aggregation base station; and</li><li>sending, by the base station controller, a local loop back instruction to the base station or aggregation base station, for switching the communication mode between the calling UE and the called UE to the local loop back mode;</li><li>wherein the for switching the communication mode between the calling UE and the called UE to the local loop back mode comprises: <ul id="ul0004" list-style="none"><li>for establishing, by the base station or the aggregation base station, an internal transmission channel of the called UE in the base station or the aggregation base station;</li><li>for removing, by the base station or the aggregation base station, a calling CS channel in a calling UE channel established with the base station controller, and establishing an internal transmission channel of the calling UE in the base station or aggregation base station, wherein the calling CS channel in the calling UE channel is established after the calling UE initiates a CS call and removed according to the local loop back instruction; and</li><li>for establishing, by the base station or aggregation base station, a switching relation between the internal transmission channel of the called UE and the internal transmission channel of the calling UE to enable the calling UE and the called UE to communicate in the local loop back mode.</li></ul></li></ul>

0012According to another aspect of the present invention, a device for processing CS domain service is provided, which includes: a receiving unit and a switching unit, where <ul id="ul0005" list-style="none"><li>the receiving unit is configured to receive a local loop back instruction from a base station controller; and</li><li>the switching unit is configured to switch the communication mode between a calling UE and a called UE to the local loop back mode according to the local loop back instruction;</li><li>wherein the switching unit comprises: an establishment subunit (210) and a communication subunit, wherein,</li><li>the establishment subunit is configured to establish an internal transmission channel of the called UE in the device, and remove a calling CS channel established with the base station controller, and establish an internal transmission channel of the calling UE in the device, and establish a switching relation between the internal transmission channel of the called UE and the internal transmission channel of the calling UE, wherein the calling CS channel is established after the calling UE initiates a CS call and removed according to the local loop back instruction; and</li><li>the communication subunit is configured to enable the calling UE and the called UE to communicate in the local loop back mode according to the internal transmission channels established by the establishment subunit.</li></ul>

0013According to another aspect of the present invention, a system for processing CS domain service is provided, which includes the above-said device and a base station controller, wherein the base station controller is configured to determine that the calling user equipment, UE, and the called UE are served by the device, and send a local loop back instruction to the device.

0014As can be seen, through the technical solutions of the present invention, a base station controller determines that a calling UE and a called UE are served by a same base station or a same aggregation base station, and sends a local loop back instruction to the base station or aggregation base station, and the base station or aggregation base station switches the communication mode between the calling UE and the called UE to the local loop back mode according to the received local loop back instruction.

0015Compared with the prior art, in the solutions of the present invention, the communication mode between the calling UE and the called UE served by a same base station or a same aggregation base station is switched to the local loop back mode, so that the participation of an MGW is not required, thereby lowering the bandwidth requirements and shortening the transmission delay of service flows.

BRIEF DESCRIPTION OF THE DRAWINGS

0016<ul id="ul0006" list-style="none"><li><figref idref="f0001">FIG. 1</figref> is a schematic view of service flows in a data plane of a CS domain in the prior art;</li><li><figref idref="f0001">FIG. 2</figref> is a flow chart of a method according to a first embodiment of the present invention;</li><li><figref idref="f0002">FIG. 3</figref> is a flow chart of a method according to a second embodiment of the present invention</li><li><figref idref="f0003">FIG. 4</figref> is a schematic view of data flows before and after switching to the local loop back mode according to the second embodiment of the present invention;</li><li><figref idref="f0004">FIG. 5</figref> is a flow chart of implementing switching to the non-local loop back mode according to the second embodiment of the present invention;</li><li><figref idref="f0005">FIG. 6</figref> is a schematic view of data flows before and after switching to the non-local loop back mode according to the second embodiment of the present invention;</li><li><figref idref="f0006">FIG. 7</figref> is a flow chart of a method according to a third embodiment of the present invention;</li><li><figref idref="f0007">FIG. 8</figref> is a schematic view of data flows before and after switching to the local loop back mode according to the third embodiment of the present invention;</li><li><figref idref="f0008">FIG. 9</figref> is a flow chart of implementing re-switching to the local loop back mode according to the third embodiment of the present invention;</li><li><figref idref="f0009">FIG. 10</figref> is a schematic view of data flows before and after re-switching to the local loop back mode according to the third embodiment of the present invention;</li><li><figref idref="f0010">FIG. 11</figref> is a flow chart of implementing switching to the non-local loop back mode according to the third embodiment of the present invention;</li><li><figref idref="f0011">FIG. 12</figref> is a schematic view of data flows before and after switching to the non-local loop back mode according to the third embodiment of the present invention;</li><li><figref idref="f0011">FIG. 13</figref> is a schematic structural view of a system according to an embodiment of the present invention; and</li><li><figref idref="f0012">FIG. 14</figref> is a schematic structural view of a device according to an embodiment of the present invention.</li></ul>

DETAILED DESCRIPTION OF THE EMBODIMENTS

0017In the present invention, a base station controller determines that a calling UE and a called UE are served by a same base station or a same aggregation base station, and sends a local loop back instruction to the base station or aggregation base station, and the base station or aggregation base station switches the communication mode between the calling UE and the called UE to the local loop back mode according to the received local loop back instruction.

0018In the following embodiments of the present invention, the solutions of the present invention are described by taking a NodeB defined by the 3GPP standard as an example of the base station, taking a HUB NodeB defined by the 3GPP standard as an example of the aggregation base station, and taking an RNC defined by the 3GPP standard as an example of the base station controller. In the embodiments of the present invention, the control plane always exists at lu and lub interfaces, and switching is merely performed for the data plane.

0019In order to make the objectives, technical solutions, and advantages of the present invention more comprehensible, the present invention is described in further detail below with reference to some exemplary embodiments and the accompanying drawings.

0020<figref idref="f0001">FIG. 2</figref> is a flow chart of a method according to a first embodiment of the present invention. As shown in <figref idref="f0001">FIG. 2</figref>, the method includes the following steps.

0021In step 201, an RNC determines that a calling UE and a called UE are served by a same NodeB or a same HUB NodeB, and sends a local loop back instruction to the NodeB or HUB NodeB.

0022When the callingUE and the called UE are served by a same NodeB, before step 201, the method further includes the following process: The calling UE initiates a call and accesses a CN, and the CN sends a calling UE channel establishment instruction message to the RNC; the RNC establishes a calling UE channel with the CN and with a NodeB that serves the calling UE, and instructs the NodeB to establish a calling UE radio bearer with the callingUE; the CN sends a called UE channel establishment instruction message to the RNC. and the RNC establishes a called UE channel with the CN.

0023The RNC determines that the calling UE and the called UE are served by a same NodeB according to calling UE location information carried in the calling UE channel establishment instruction message received from the CN and called UE location information carried in the called UE channel establishment instruction message received from the CN. Then, the RNC instructs through an instruction message the NodeB to establish a called UE radio bearer with the called UE, specifies in the instruction message sent by the RNC to the NodeB that the calling UE and the called UE use the local loop back mode for communication, and notifies the HUB NodeB of a calling UE radio bearer corresponding to the called UE radio bearer.

0024When the calling UE and the called UE are served by different NodeBs but are served by a same HUB NodeB, before step 201, the method further includes: the calling UE initiates a call and accesses a CN, and the CN sends a calling UE channel establishment instruction message to the RNC; the RNC establishes a calling UE channel with the CN and with a NodeB that serves the calling UE, and instructs the NodeB to establish a calling UE radio bearer with the calling UE; the RNC instructs the HUB NodeB corresponding to the NodeB that serves the calling UE to establish a calling UE channel with the NodeB that serves the calling UE; the CN sends a called UE channel establishment instruction message to the RNC. and the RNC establishes a called UE channel with the CN, and instructs a NodeB that serves the called UE to establish a called UE radio bearer with the called UE.

0025The RNC determines that the calling UE and the called UE are served by a same HUB NodeB according to calling UE location information carried in the calling UE channel establishment instruction message received from the CN and called UE location information carried in the called UE channel establishment instruction message received from the CN. Then, the RNC instructs through an instruction message the HUB NodeB to establish a called UE channel with the NodeB that serves the called UE, specifies in the instruction message sent by the RNC to the HUB NodeB that the calling UE and the called UE use the local loop back mode for communication, and notifies the HUB NodeB of a calling UE channel corresponding to the called UE channel.

0026In step 202, the NodeB or HUB NodeB switches the communication mode between the calling UE and the called UE to the local loop back mode according to the received local loop back instruction.

0027When the calling UE and the called UE are served by a same NodeB, this step may be specifically implemented as follows: The NodeB establishes an internal transmission channel of the called UE in the NodeB; the NodeB removes a calling CS channel in a calling UE channel established with the RNC, and establishes an internal transmission channel of the calling UE in the NodeB; the NodeB establishes a switching relation between the internal transmission channel of the called UE and the internal transmission channel of the calling UE, that is, connects the internal transmission channel of the calling UE and the internal transmission channel of the called UE to form one channel, and enables the calling UE and the called UE to communicate in the local loop back mode.

0028When the calling UE and the called UE are served by different NodeBs but are served by a same HUB NodeB, this step may be specifically implemented as follows: The HUB NodeB establishes an internal transmission channel of the called UE in the HUB NodeB; the HUB NodeB removes a calling CS channel in a calling UE channel established with the RNC, and establishes an internal transmission channel of the calling UE in the HUB NodeB; the HUB NodeB establishes a switching relation between the internal transmission channel of the called UE and the internal transmission channel of the calling UE, that is, connects the internal transmission channel of the calling UE and the internal transmission channel of the called UE to form one channel, and enables the calling UE and the called UE to communicate in the local loop back mode.

0029As can be seen, through the technical solutions of the embodiment of the present invention, when UEs at two ends of the CS call are served by a same RNC, it is determined whether the two UEs are located within the service coverage of a same NodeB or a same HUB NodeB, and if one of the conditions is satisfied, the two UEs served by the same RNC are switched to a local switching mode, that is, the local loop back mode. If one of the UEs is moved later, the switching mode may also be reset.

0030The technical solutions of the present invention are described in further detail below through other embodiments.

0031<figref idref="f0002">FIG. 3</figref> is a flow chart of a method according to a second embodiment of the present invention. In this embodiment, a calling UE and a called UE are served by a same NodeB. The calling UE accesses a NodeB3 shown in <figref idref="f0001">FIG 1</figref>, and the called UE also accesses the NodeB3 shown in <figref idref="f0001">FIG. 1</figref>. An RNC determines that the calling UE and the called UE can implement local loop back, and when establishing a called UE radio bearer, the RNC specifies in a radio link establishment request sent to the NodeB3 that the calling UE and the called UE use the local loop back mode for communication. As shown in <figref idref="f0002">FIG. 3</figref>, the method includes the following steps.

0032In step 301, the calling UE initiates a CS call and accesses a CN, and the CN sends a calling UE channel establishment instruction message to the RNC.

0033In this step, the CN sends the calling UE channel establishment instruction message to the RNC; and a calling UE channel is established between the RNC and the CN, including a 3.4K signaling channel in the control plane and a CS channel in the data plane.

0034The calling UE channel establishment instruction message carries a calling UE ID, configured to identify location information of the calling UE, and the RNC receives and stores the location information of the calling UE.

0035In step 302. the RNC sends a calling UE radio bearer establishment instruction message to the NodeB.

0036In this step, the RNC sends the calling UE radio bearer establishment instruction message to the NodeB that serves the calling UE and the called UE, that is, the NodeB3 as described in this embodiment. After receiving the message, the NodeB establishes a calling UE channel with the RNC, including a 3.4K signaling channel in the control plane and a CS channel in the data plane, and establishes a calling UE radio bearer with the calling UE.

0037In step 303, the NodeB returns a calling UE radio bearer establishment response message to the RNC.

0038In step 304, the RNC returns a calling UE channel establishment response message to the CN.

0039In step 305, the CN sends a called UE channel establishment instruction message to the RNC.

0040In this step, the CN sends the called UE channel establishment instruction message to the RNC, and a called UE channel is established between the RNC and the CN, including a 3.4K signaling channel in the control plane and a CS channel in the data plane.

0041The called UE channel establishment instruction message carries a called UE ID, configured to identify location information of the called UE, and the RNC receives and stores the location information of the called UE.

0042In step 306, the RNC determines that the calling UE and the called UE can use the local loop back mode for communication.

0043In this step, the RNC determines that the calling UE and the called UE are served by a same NodeB according to the stored location information of the calling UE and the called UE, and thus determines that the calling UE and the called UE can use the local loop back mode for communication.

0044In steps 307 to 308, the RNC sends a called UE radio bearer establishment instruction message to the NodeB, and specifies in the message that the local loop back mode is used for communication and specifies the calling UE radio bearer corresponding to a called UE radio bearer; and the NodeB establishes the local loop back mode as the communication mode of the calling UE and the called UE.

0045In this step, the RNC sends the called UE radio bearer establishment instruction message to the NodeB, requesting the NodeB to establish a called UE radio bearer with the called UE. The NodeB establishes a 3.4K signaling channel to the RNC for the called UE, but does not establish any CS channel, and instead, establishes an internal transmission channel for the called UE. Then, the NodeB removes a calling UE CS channel between the NodeB and the RNC and establishes an internal transmission channel of the calling UE, and establishes a switching relation between the internal transmission channel of the calling UE and the internal transmission channel of the called UE, that is, connects the internal transmission channel of the calling UE and the internal transmission channel of the called UE to form one channel.

0046In step 309, the NodeB returns a called UE radio bearer establishment response message to the RNC.

0047In step 310, the RNC returns a called UE channel establishment response message to the CN.

0048After the above process, the calling UE and the called UE can communicate in the local loop back mode.

0049<figref idref="f0003">FIG. 4</figref> is a schematic view of data flows before and after switching to the local loop back mode according to the second embodiment of the present invention. As shown in <figref idref="f0003">FIG. 4</figref>, a thin line represents a 3.4K signaling channel, and a thick line represents a CS channel. It can be seen that, the solutions of the present invention are merely directed to the data plane, so that before and after the switching, the 3.4K signaling channel does not change, but the CS channel changes after the switching, and service flows sent from the calling UE and the called UE are transmitted to the peer end through the NodeB, without requiring participation of an RNC or an MGW.

0050Based on the embodiment shown in <figref idref="f0002">FIG. 3</figref>, at a time when the calling UE or the called UE is moved out of the service coverage of the NodeB3 and enters the service coverage of a new NodeB, if the new NodeB and the NodeB3 are served by different HUB NodeBs, the RNC, while deleting an original radio link for the moved UE and establishing a new radio link, needs to send a radio link reconfiguration message to the NodeB3 to request the NodeB3 to establish a radio link bearer of a CS channel of the UE that is still resident in the service coverage of NodeB3 to an RNC channel, that is, switch the communication mode of the resident UE to the non-local loop back mode. <figref idref="f0004">FIG. 5</figref> is a flow chart of implementing the switching to the non-local loop back mode according to the second embodiment of the present invention. As shown in <figref idref="f0004">FIG. 5</figref>, the process includes the following steps.

0051In steps 501 to 502, the RNC sends a moved UE radio bearer deletion message to the NodeB; and the NodeB deletes a radio bearer corresponding to the moved UE, and returns a moved UE radio bearer deletion response message to the RNC.

0052In steps 503 to 504, the RNC determines that the communication mode of the resident UE is the local loop back mode, sends a resident UE radio bearer reconfiguration message to the NodeB, and specifies that switching to the non-local loop back mode.

0053In step 505, the NodeB switches the communication mode of the resident UE from the local loop back mode to the non-local loop back mode, deletes the internal transmission channel, and establishes a CS channel between the resident UE and the RNC.

0054In step 506, the NodeB sends a resident UE radio bearer reconfiguration response message to the RNC.

0055<figref idref="f0005">FIG. 6</figref> is a schematic view of data flows before and after switching to the non-local loop back mode according to the second embodiment of the present invention. As shown in <figref idref="f0005">FIG. 6</figref>, a thin line represents a 3.4K signaling channel, and a thick line represents a CS channel. It can be seen that, after the switching, the resident UE communicates through the RNC according to the existing manner.

0056<figref idref="f0002 f0003 f0004 f0005">FIGs. 3 to 6</figref> introduce a process for implementing the solutions of the present invention, when the calling UE and the called UE are served by a same NodeB. A process for implementing the solutions of the present invention when the calling UE and the called UE are served by different NodeBs but are served by a same HUB NodeB is described below through a third embodiment.

0057<figref idref="f0006">FIG. 7</figref> is a flow chart of a method according to a third embodiment of the present invention. In this embodiment, a calling UE and a called UE are served by a same HUB NodeB. The calling UE accesses a NodeB4 shown in <figref idref="f0001">FIG. 1</figref>, and the called UE accesses a NodeB5 shown in <figref idref="f0001">FIG. 1</figref>. An RNC determines that the calling UE and the called UE can implement local loop back, and when establishing a called UE radio bearer, the RNC specifies in a transmission channel configuration message sent to the HUB NodeB that the calling UE and the called UE use the local loop back mode for communication. As shown in <figref idref="f0006">FIG. 7</figref>, the method includes the following steps.

0058In step 701, the calling UE initiates a CS call and accesses a CN, and the CN sends a calling UE channel establishment instruction message to the RNC.

0059In this step, the CN sends the calling UE channel establishment instruction message to the RNC; and a calling UE channel is established between the RNC and the CN, including a 3.4K signaling channel in the control plane and a CS channel in the data plane.

0060The calling UE channel establishment instruction message carries a calling UE ID, configured to identify location information of the calling UE, and the RNC receives and stores the location information of the calling UE.

0061In step 702, the RNC sends a calling UE radio bearer establishment instruction message to the NodeB4.

0062In this step, the RNC sends the calling UE radio bearer establishment instruction message to the NodeB that serves the calling UE, that is, the NodeB4 as described in this embodiment. After receiving the message, the NodeB4 establishes a calling UE radio bearer with the calling UE.

0063In step 703, the NodeB4 returns a calling UE radio bearer establishment response message to the RNC.

0064In step 704, the RNC returns a calling UE channel establishment response message to the CN.

0065In steps 705 to 706, the RNC sends a calling UE channel establishment instruction message to the HUB NodeB; and the HUB NodeB establishes a calling UE channel with the RNC and with the NodeB4, and returns a calling UE channel establishment response message to the RNC.

0066In step 707, the CN sends a called UE channel establishment instruction message to the RNC.

0067In this step, the CN sends the called UE channel establishment instruction message to the RNC, and a called UE channel is established between the RNC and the CN, including a 3.4K signaling channel in the control plane and a CS channel in the data plane.

0068The called UE channel establishment instruction message carries a called UE ID, configured to identify location information of the called UE, and the RNC receives and stores the location information of the called UE.

0069In step 708, the RNC sends a called UE radio bearer establishment instruction message to the NodeB5.

0070In step 709, the NodeB5 establishes a called UE radio bearer with the called UE, and returns a called UE radio bearer establishment response message to the RNC.

0071In step 710, the RNC determines that the calling UE and the called UE can use the local loop back mode.

0072In this step, the RNC determines that the calling UE and the called UE are served by a same HUB NodeB according to the pre-stored location information of the calling UE and the called UE, and thus determines that the calling UE and the called UE can use the local loop back mode for communication.

0073In step 711, the RNC sends a called UE channel establishment instruction message to the HUB NodeB, and specifies in the message that the local loop back mode is used for communication and specifies a calling UE transmission bearer corresponding to a called UE transmission bearer, that is, the CS channel.

0074In this step, the HUB NodeB establishes a called UE channel with the Node5 and establishes a 3.4K signaling channel between the HUB NodeB and the RNC for the called UE, but does not establish any CS channel between the HUB NodeB and the RNC.

0075In step 712, the HUB NodeB establishes a loop back transmission channel, and deletes a transmission bearer between the calling UE and the RNC.

0076In this step, the HUB NodeB establishes an internal transmission channel of the called UE, removes a calling UE CS channel between the HUB NodeB and the RNC and establishes an internal transmission channel of the calling UE, and establishes a switching relation between the internal transmission channel of the calling UE and the internal transmission channel of the called UE.

0077In step 713, the HUB NodeB returns a called UE channel establishment response message to the RNC.

0078In step 714, the RNC returns a called UE channel establishment response message to the CN.

0079After the above process, the calling UE and the called UE can communicate in the local loop back mode.

0080<figref idref="f0007">FIG. 8</figref> is a schematic view of data flows before and after switching to the local loop back mode according to the third embodiment of the present invention. As shown in <figref idref="f0007">FIG. 8</figref>, a thin line represents a 3.4K signaling channel, and a thick line represents a CS channel. It can be seen that, after the switching, service flows sent from the calling UE and the called UE are transmitted to the peer end through the HUB NodeB, without requiring participation of an RNC or an MGW.

0081Based on the embodiment shown in <figref idref="f0007">FIG 8</figref>, it is assumed that at a time, the called UE is moved out of the service coverage of the NodeB5, and enters the service coverage of the NodeB3 shown in <figref idref="f0001">FIG. 1</figref>. Since the NodeB3 and the NodeB4 are still served by the same HUB NodeB, the RNC needs to reconfigure a local loop back relation while deleting an original UE channel for the called UE and establishing a new UE channel. <figref idref="f0008">FIG. 9</figref> is a flow chart of implementing re-switching to the local loop back mode according to the third embodiment of the present invention. As shown in <figref idref="f0008">FIG. 9</figref>, the process includes the following steps.

0082In steps 901 to 902, the RNC sends a called UE radio bearer deletion message to the NodeB5; and the NodeB5 deletes a radio bearer corresponding to the called UE, and returns a called UE radio bearer deletion response message to the RNC.

0083In steps 903 to 904, the RNC sends a called UE channel deletion message to the HUB NodeB; and the HUB NodeB performs a corresponding operation, and returns a called UE channel deletion response message to the RNC.

0084Steps 905 to 910 are similar to steps 708 to 713 shown in <figref idref="f0006">FIG. 7</figref>, except that the step of deleting the transmission bearer between the calling UE and the RNC as shown in step 712 does not need to be performed in step 909. The remaining steps are substantially same as those shown in <figref idref="f0006">FIG. 7</figref>, so the details will not be described herein again.

0085<figref idref="f0009">FIG. 10</figref> is a schematic view of data flows before and after re-switching to the local loop back mode according to the third embodiment of the present invention. As shown in <figref idref="f0009">FIG. 10</figref>, a thin line represents a 3.4K signaling channel, and a thick line represents a CS channel. It can be seen that, the communication mode is the local loop back mode before and after the switching, and the difference lies in that the NodeB that serves the called UE is changed.

0086It is assumed that at a time, the called UE is continuously moved out of the service coverage of the NodeB3, and enters the service coverage of the NodeB1 shown in <figref idref="f0001">FIG 1</figref>. Since the NodeB1 and the NodeB4 are served by different HUB NodeBs, the RNC needs to switch the communication mode from the local loop back mode to the non-local loop back mode while deleting an original UE channel for the called UE and establishing a new UE channel. <figref idref="f0010">FIG. 11</figref> is a flow chart of implementing switching to the non-local loop back mode according to the third embodiment of the present invention. As shown in <figref idref="f0010">FIG. 11</figref>, the process includes the following steps.

0087In steps 1101 to 1102, the RNC sends a called UE radio bearer deletion message to the NodeB3; and the NodeB3 deletes a radio bearer corresponding to the called UE, and returns a called UE radio bearer deletion response message to the RNC.

0088In steps 1103 to 1104, the RNC sends a called UE channel deletion message to the HUB NodeB; and the HUB NodeB performs a corresponding operation, and returns a called UE channel deletion response message to the RNC.

0089Insteps 1105 to 1106, the RNC sends a called UE radio bearer establishment instruction message to the NodeB1; and the NodeB1 establishes a called UE radio bearer with the called UE, and returns a called UE radio bearer establishment response message to the RNC.

0090In steps 1107 to 1108, the RNC determines that the calling UE and the called UE can no longer use the local loop back mode for communication, but the calling UE is still set as the local loop back mode, and thus sends a calling UE channel reconfiguration message to the HUB NodeB, and specifies that switching to the non-local loop back mode.

0091In step 1109, the HUB NodeB deletes the original internal transmission channel, and restores the CS channel between the calling UE and the RNC.

0092In step 1110, the HUB NodeB returns a calling UE channel reconfiguration response message to the RNC.

0093<figref idref="f0011">FIG. 12</figref> is a schematic view of data flows before and after switching to the non-local loop back mode according to the third embodiment of the present invention. As shown in <figref idref="f0011">FIG. 12</figref>, a thin line represents a 3.4K signaling channel, and a thick line represents a CS channel. It can be seen that, since the NodeB1 and the NodeB4 are served by different HUB NodeBs, the communication mode between the calling UE and the called UE after the switch is the existing non-local loop back mode, and service flows between the calling UE and the called UE still need to be transmitted through an MGW.

0094It can be seen from the above introduction that, through the technical solutions of the embodiments of the present invention, the communication mode between the calling UE and the called UE that are served by a same NodeB or a same HUB NodeB may be switched to the local loop back mode, thereby lowering the bandwidth requirements and shortening the transmission delay of service flows.

0095It should be understood that, the above embodiments are described by way of examples only, but are not intended to limit the technical solutions of the present invention. For instance, the above embodiments are merely described through an example that the called UE is moved, but persons skilled in the art can easily understand from the above description that the process is similar when the calling UE is moved, so the details will not be described herein again.

0096It should be noted that, through the technical solutions of the embodiments of the present invention, adaptive adjustment needs to be performed for some specific implementations of the existing CS domain services. Since the CS domain services are generally voice services, the voice services are described as an example below.

0097Since the NodeB does not have a voice playing function, that is, the function of playing a ring back tone, the voice playing function is implemented by the CN in the prior art. That is to say, when the calling UE initially establishes a link, a CS voice channel is inevitably established to the CN. After the technical solutions of the embodiments of the present invention are used, the CN still plays the ring back tone for the calling UE, and after the NodeB or HUB NodeB switches the communication mode between the calling UE and the called UE to the local loop back mode, the established CS voice channel is released, so that normal communication is carried out in the local loop back mode.

0098In practical applications, it is generally required that adaptive multi-rates (AMRs) of two UEs capable of implementing local loop back match one another. Since the NodeB cannot directly obtain the AMRs of the UEs, in the embodiments of the present invention, after determining that the calling UE and the called UE are served by a same NodeB or a same HUB NodeB according to a message sent from the CN, the RNC needs to further determine whether AMRs of the calling UE and the called UE match one another, and sends the local loop back instruction to the NodeB or HUB NodeB if AMRs of the calling UE and the called UE match one another; if AMRs of the calling UE and the called UE do not match one another, the non-local loop back mode is adopted for communication.

0099In the above embodiments, the RNC may further carry voice packet encryption/decryption parameters in the calling UE radio bearer establishment instruction message or called UE radio bearer establishment instruction message sent to the NodeB that serves the calling UE or the called UE; during communication in the local loop back mode, the NodeB that serves the calling UE or the called UE parses an uplink Frame Protocol (FP) packet carrying CS voice, decrypts the uplink CS voice packet according to the voice packet encryption/decryption parameters, and converts the uplink CS voice packet into a downlink FP packet format; and for the downlink FP packet obtained after conversion, the converted downlink CS voice packet is encrypted according to the voice packet encryption/decryption parameters, and then sent out through an air interface.

0100Moreover, the technical solutions of the embodiments of the present invention can realize a soft handover function. For example, when the RNC determines that all links of the calling UE or the called UE are connected to a same NodeB, the RNC instructs the NodeB to execute a soft handover function; the NodeB selects from different soft handover links, and each time selects an uplink FP packet in a soft handover link having the best signal quality from more than one received soft handover link, and converts and sends the uplink FP packet: if the local loop back is implemented by the NodeB, the FP packet is processed according to the encryption/decryption manner described above and then transmitted; and if the local loop back is not implemented by the NodeB, the selected FP packet is sent to an lub interface according to an existing process. When the RNC determines that the soft handover occurs in a plurality of NodeBs, but the NodeBs are served by a same HUB NodeB, the RNC instructs each NodeB to operates in the same manner as that when the RNC determines that all links of the calling UE or the called UE are connected to a same NodeB, and instructs the HUB NodeB to complete the soft handover link processing between the NodeBs. The soft handover link operation specifically includes the following process: The HUB NodeB selects an uplink FP packet in a soft handover link having the best signal quality from the soft handover links that are connected to different NodeBs but belong to a same UE, performs CS voice packet decryption, converts the uplink FP packet into a downlink FP packet format, and then loops back the FP packet to a link of a NodeB for downlink processing. Since the soft handover technology belongs to the prior art, the details will not be described herein.

0101Accordingly, <figref idref="f0011">FIG. 13</figref> is a schematic structural view of a system according to an embodiment of the present invention, and <figref idref="f0012">FIG. 14</figref> is a schematic structural view of a device according to an embodiment of the present invention. In the two embodiments, description is also given by taking a NodeB defined by the 3GPP standard as an example of the base station, taking a HUB NodeB defined by the 3GPP standard as an example of the aggregation base station, and taking an RNC defined by the 3GPP standard as an example of the base station controller.

0102<figref idref="f0011">FIG. 13</figref> is a schematic structural view of a system according to an embodiment of the present invention. As shown in <figref idref="f0011">FIG. 13</figref>, the system includes an RNC and a NodeB, or an RNC and a HUB NodeB.

0103The RNC is configured to determine that a calling UE and a called UE are served by a same NodeB or a same HUB NodeB, and send a local loop back instruction to the NodeB or HUB NodeB.

0104The NodeB or HUB NodeB is configured to switch the communication mode between the calling UE and the called UE to the local loop back mode according to the received local loop back instruction.

0105The system may further include a CN.

0106The CN is configured to send a calling UE channel establishment instruction message and a called UE channel establishment instruction message to the RNC when the calling UE initiates a call. The RNC determines that the calling UE and the called UE are served by a same NodeB or a same HUB NodeB according to calling UE location information carried in the calling UE channel establishment instruction message and called UE location information carried in the called UE channel establishment instruction message.

0107The RNC may be further configured to determine whether AMRs of the calling UE and the called UE match one another, and send the local loop back instruction to the NodeB or HUB NodeB, if AMRs of the calling UE and the called UE match one another.

0108<figref idref="f0012">FIG. 14</figref> is a schematic structural view of a device according to an embodiment of the present invention. As shown in <figref idref="f0012">FIG. 14</figref>, the device includes a receiving unit 10 and a switching unit 20.

0109The receiving unit 10 is configured to receive a local loop back instruction from an RNC.

0110The switching unit 20 is configured to switch the communication mode between a calling UE and a called UE to the local loop back mode according to the local loop back instruction.

0111The receiving unit 10 further includes: a first receiving subunit 110 and a second receiving subunit 120.

0112The first receiving subunit 110 is configured to receive a calling UE radio bearer establishment instruction message from the RNC, and establish a calling UE radio bearer with the calling UE according to the instruction message.

0113The second receiving subunit 120 is configured to receive a called UE radio bearer establishment instruction message from the RNC, and establish a called UE radio bearer with the called UE according to the instruction message, where the instruction message carries the local loop back instruction, and calling UE radio bearer information corresponding to the called UE radio bearer.

0114Or, the first receiving subunit 110 is configured to receive a calling UE channel establishment instruction message from the RNC, and establish a calling UE channel with a NodeB that serves the calling UE according to the instruction message.

0115The second receiving subunit 120 is configured to receive a called UE channel establishment instruction message from the RNC, and establish a called UE channel with a NodeB that serves the called UE according to the instruction message, where the instruction message carries the local loop back instruction, and calling UE channel information corresponding to the called UE channel.

0116The switching unit 20 further includes: an establishment subunit 210 and a communication subunit 220.

0117The establishment subunit 210 is configured to establish an internal transmission channel of the called UE in the device, and remove a calling CS channel previously established with the RNC, and establish an internal transmission channel of the calling UE in the device, and establish a switching relation between the internal transmission channel of the called UE and the internal transmission channel of the calling UE.

0118The communication subunit 220 is configured to enable the calling UE and the called UE to communicate in the local loop back mode according to the internal transmission channels established by the establishment subunit 210.

0119When the device is a NodeB, the receiving unit 10 further includes: a third receiving subunit 130, configured to, when the calling UE or the called UE is moved out of the service coverage of the NodeB, delete a radio bearer corresponding to the moved UE according to an instruction received from the RNC, and instruct the switching unit 20 to switch the communication mode of the locally-resident UE to the non-local loop back mode; the establishment subunit 210 establishes a CS channel between the NodeB and the RNC; and the communication subunit 220 communicates in the non-local loop back mode.

0120When the device is a HUB NodeB, the receiving unit 10 further includes: a third receiving subunit 130 and a fourth receiving subunit 140. The third receiving subunit 130 is configured to, when the calling UE or the called UE is moved to the service coverage of a new NodeB, and the calling UE and the called UE are still served by the same HUB NodeB after the movement, instruct a NodeB corresponding to the moved UE to delete a radio bearer corresponding to the moved UE according to an instruction received from the RNC, and delete a CS channel with the NodeB corresponding to the moved UE, and receive a new local loop back instruction sent by the RNC; and the switching unit 20 reestablishes a local loop back communication mode between the calling UE and the called UE for communication. The fourth receiving subunit 140 is configured to, when the calling UE or the called UE is moved to the service coverage of a new NodeB, and the calling UE and the called UE are located within the service coverage of different HUB NodeBs after the movement, instruct a NodeB corresponding to the moved UE to delete a radio bearer corresponding to the moved UE according to an instruction received from the RNC, and delete a CS channel with the NodeB corresponding to the moved UE, and instruct the switching unit 20 to switch the communication mode of the locally-resident UE to the non-local loop back mode; the establishment subunit 210 establishes a CS channel between the NodeB corresponding to the resident UE and the RNC; and the communication subunit 220 communicates in the non-local loop back mode.

0121As for specific work flows of the embodiments of the system and the device shown in <figref idref="f0011">FIGs. 13</figref> and <figref idref="f0012">14</figref>, reference is made to the description in the part corresponding to the method, and the details will not be described herein again.

0122Based on the above description, by using the technical solutions of the embodiments of the present invention, the transmission bandwidth requirements for the lub and lu interfaces are lowered and the data transmission delay is shortened. In addition, the ideas of the embodiments of the present invention are equally applicable to Global System for Mobile Communication (GSM), Code Division Multiple Access (CDMA) or like scenarios.

0123Through the descriptions of the preceding embodiments, those skilled in the art may understand that the present invention may be implemented by hardware only or by software and a necessary universal hardware platform. Based on such understandings, the technical solution under the present invention may be embodied in the form of a software product. The software product may be stored in a nonvolatile storage medium, which can be a Compact Disk Read-Only Memory (CD-ROM), USB flash drive, or a removable hard drive. The software product includes a number of instructions that enable a computer device (personal computer, server, or network device) to execute the methods provided in the embodiments of the present invention.

0124Although the present invention has been described through several exemplary embodiments, the invention is not limited to such embodiments. Any modification, equivalent replacement, or improvement made without departing from the principle of the present invention should fall within the scope of the present invention as defined by the appended claims.