WO2017201694A1

WO2017201694A1 - Csfb implementation method and access network device

Info

Publication number: WO2017201694A1
Application number: PCT/CN2016/083357
Authority: WO
Inventors: 许莉; 刘雪红; 张振宇; 章健
Original assignee: 华为技术有限公司
Priority date: 2016-05-25
Filing date: 2016-05-25
Publication date: 2017-11-30

Abstract

Disclosed in the embodiments of the present invention are a CSFB implementation method and an access network device, which relate to the field of communications, solving the problem of a large time delay when the voice service of a UE falls back from an LET network/5G network to a 2G/3G network by using a redirection-based CSFB technique. The specific solution is: a first access network device in a first network receiving position information of a UE with respect to a second access network device in a second network, sent by the second access network device, the UE requiring the voice service to fall back from the second network the UE is currently residing on to the first network; the first access network device determining, according to the position information, a search range; and the first access network device searching according to the search range, and after finding the UE, establishing a connection with the UE, so as to provide the voice service for the UE by means of the first network. The embodiments of the present invention are used in the process of the redirection-based CSFB implementation.

Description

CSFB implementation method and access network device

Technical field

The embodiments of the present invention relate to the field of communications, and in particular, to a CSFB implementation method and an access network device.

Background technique

With the continuous development of mobile communication technologies and mobile bandwidth services, users can provide long-term evolution (Long Term Evolution, LTE for short) and fifth-generation mobile communication technologies (English: fifth generation, Abbreviation: 5G) The network came into being. Because this high-speed network focuses on providing data services to users, it does not support voice services in the initial stage of network deployment. When the user equipment (English: User Equipment, UE for short) needs to perform voice services on such a high-speed network, the voice service of the UE can usually be dropped by adopting Circuit Switched Fallback (CSFB) technology. To the second generation mobile communication technology (English: Second Generation, 2G) / third generation mobile communication technology (English: 3rd Generation, referred to as: 3G) network, thus using 2G / 3G network to achieve voice services.

In the prior art, the voice service of the UE may be dropped from the LTE network/5G network to the 2G/3G network by using the redirection-based CSFB technology. For example, to reduce the voice service of the UE from the LTE network to the 3G network, the fallback process is specifically: when the UE needs to perform voice service in the LTE network, the UE moves to the mobility management entity (English: Mobility Management Entity, referred to as: The MME) initiates a CSFB access request, and after receiving the request, the MME sends an S1-AP UE context modification request to an evolved base station (English: evolutional Node B, eNodeB for short) (English: S1-AP UE Context Modification Request) In order to inform the eNodeB that the UE needs to fall back to the 3G network due to the voice service, the eNodeB may send a radio resource control (English: Radio Resource Control, RRC) connection release message to the UE to indicate that the UE will Voice service falls back to the 3G network when the UE After the connection is released in the LTE network, the connection can be re-established in the 3G network to perform voice services over the 3G network. When the UE re-establishes the connection in the 3G network, the base station (English: NodeB) in the 3G network needs to perform a search in the entire cell covered by itself to search for the UE, thereby establishing a connection with the UE. However, by searching through the entire cell to search for the UE, the time that the NodeB searches for the UE is long, so that the delay of the UE to drop the voice service from the LTE network to the 3G network is large.

Summary of the invention

The embodiment of the invention provides a CSFB implementation method and an access network device, which solves the problem that when the voice service of the UE is dropped from the LTE network/5G network to the 2G/3G network by using the CSFB technology based on the redirection, the delay is large. problem.

To achieve the above objective, the embodiment of the present invention adopts the following technical solutions:

A first aspect of the embodiments of the present invention provides a CSFB implementation method, including:

The first access network device in the first network receives, by the second access network device in the second network, the UE that needs to drop the voice service from the currently camped second network to the first network in the second access network. Position information under the device, then, the first access network device may determine the search range according to the received location information, and finally perform a search according to the determined search range, and after searching for the UE, establish a connection with the UE, so as to pass the A network provides voice services for the UE.

The CSFB implementation method provided by the embodiment of the present invention, the first access network device receives the location information of the UE sent by the second access network device under the second access network device, and determines the search range according to the received location information, and then Searching according to the determined search range, and after searching for the UE, establishing a connection with the UE to provide voice services for the UE through the first network. The search is performed according to the search range of the received location of the UE under the second access network device, indicating that the UE is located in the cell where the first access network device is located, compared to the first connection. The search is performed in the entire cell where the network access device is located, which reduces the search range, thereby reducing the delay when the voice service of the UE is dropped from the second network to the first network by using the CSFB technology based on the redirection.

With reference to the first aspect, in a possible implementation manner, the determining, by the first access network device, the search range according to the location information may include: the first access network device Determining, according to the location information, a distance between the UE and the second access network device, that is, a first distance a, and then according to the first distance a and a distance between the first access network device and the second access network device, that is, The second distance b determines a reference range of the distance between the UE and the first access network device, the reference range is |ab| to (a+b), and finally according to the reference range and the cell search radius r of the first access network device Determine the scope of your search.

With reference to the first aspect and the foregoing possible implementation manner, in another possible implementation manner, if the cell search radius r of the first access network device is greater than or equal to |ab|, the search range is |ab| to min{ r, (a+b)}, where min{r, (a+b)} represents the minimum value in r and (a+b).

With reference to the first aspect and the foregoing possible implementation manner, in another possible implementation manner, if the cell search radius r of the first access network device is less than |ab|, considering the measurement error, the UE is located at the first connection. At the edge of the cell where the network access device is located, the cell may be searched from the edge of the cell where the first access network device is located to the inner side of the cell to shorten the search time.

In conjunction with the first aspect and the foregoing possible implementation manners, in another possible implementation manner, the first network may be a Universal Mobile Telecommunications System (UMTS) network.

When the first network is a UMTS network, the determining, by the first access network device, the first distance a according to the location information may include: determining, by the first access network device, the transmission delay according to the location information (English: Transport Propagation Delay) , abbreviated as: Tp) and the strongest path position, and then the first distance a is determined according to the Tp and the strongest path position.

With reference to the first aspect and the foregoing possible implementation manner, in another possible implementation manner, the first network is a Global System for Mobile Communications (GSM) network.

When the first network is a GSM network, the determining, by the first access network device, the first distance a according to the location information may include: determining, by the first access network device, the first time advance according to the location information (English: Timing) Advance, abbreviated as: TA), then determines a first distance a according to the first TA, where the first TA is a timing advance of the UE to send data under the first access network device.

With reference to the first aspect and the foregoing possible implementation manners, in another possible implementation manner, the second network may be an LTE network, and the location information may include at least one of the following: loopback time (English: Round Trip Time, referred to as: RTT), second TA, the strongest path delay. The second TA is a timing advance of the UE sending data under the second access network device.

With reference to the first aspect and the foregoing possible implementation manner, in another possible implementation, the first access network device receives, by the second access network device, a location of the UE under the second access network device. The information may include: the first access network device receives the radio access network carrying the location information sent by the second access network device by using the second core network device in the second network (English: Radio Access Network, referred to as: RAN) ) Information request.

A second aspect of the embodiments of the present invention provides a CSFB implementation method, including:

The second access network device in the second network sends, to the first access network device in the first network, the UE that needs to drop the voice service from the currently camped second network to the first network in the second access network device. After the location information is sent to the first access network device, the radio resource control (Radio Resource Control, RRC for short) connection release message is sent to the UE, so that the UE releases the current resident The connection of the two networks.

The CSFB implementation method provided by the embodiment of the present invention, the second access network device sends the location information of the UE under the second access network device to the first access network device, and after sending the location information to the first access network device, Sending an RRC Connection Release message to the UE, so that the UE releases the connection with the currently camped second network. The second access network device sends the location information of the UE under the second access network device to the first access network device, so that the first access network device can determine, according to the location information, that the UE is in the first access. The search range of the possible location in the cell where the network device is located, and then searching according to the determined search range, the search is reduced compared to the entire cell in which the first access network device is located, thereby reducing the search range, thereby reducing the search range. The delay when the UE's voice service is dropped from the second network to the first network by using the redirection-based CSFB technology.

With reference to the second aspect, in a possible implementation manner, the second access network The device may send the location information of the UE to the second access network device to the first access network device, where the second access network device carries the location information in the RAN information request through the second core in the second network. The network device sends to the first access network device.

With reference to the second aspect and the foregoing possible implementation manner, in another possible implementation manner, the second network may be an LTE network, and correspondingly, the location information includes at least one of the following: RTT, second. TA, the strongest path delay. The second TA is a timing advance of the UE sending data under the second access network device.

A third aspect of the embodiments of the present invention provides a first access network device, including:

a receiving unit, configured to receive location information of the user equipment UE sent by the second access network device under the second access network device; the UE needs to return the voice service from the currently camped second network to the first network The first access network device is an access network device in the first network, and the second access network device is an access network device in the second network;

a determining unit, configured to determine a search range according to the location information received by the receiving unit;

a searching unit, configured to perform searching according to the search range determined by the determining unit;

And a establishing unit, configured to establish a connection with the UE after the searching unit searches for the UE, to provide a voice service for the UE by using the first network.

For a specific implementation manner, reference may be made to the behavior function of the first access network device in the CSFB implementation method provided by the first aspect or the possible implementation manner of the first aspect.

A fourth aspect of the embodiments of the present invention provides a second access network device, including:

a sending unit, configured to send, to the first access network device, location information of the user equipment UE under the second access network device, and send a radio resource control RRC connection release message to the UE, so that the UE releases the a connection of the second network; the UE is a UE that needs to drop the voice service from the currently camped second network to the first network, and the second access network device is an access network device in the second network, The first access network device is an access network device in the first network.

For a specific implementation, reference may be made to the second aspect or the possible implementation of the second aspect. The behavior of the second access network device in the CSFB implementation method provided by the method.

A fifth aspect of the embodiments of the present invention provides a first access network device, including: a radio frequency unit and a baseband processing unit.

The radio frequency unit is configured to perform the CSFB implementation method provided by the first aspect or the possible implementation manner of the first aspect to implement the function of the receiving unit in the third aspect.

The baseband processing unit is used in the CSFB implementation method provided by the first aspect or the possible implementation of the first aspect to implement the functions of the determining unit, the searching unit and the establishing unit in the third aspect.

A sixth aspect of the embodiments of the present invention provides a second access network device, including: a radio frequency unit.

The radio frequency unit is configured to perform the CSFB implementation method provided by the second aspect or the possible implementation manner of the second aspect to implement the function of the sending unit in the fourth aspect.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any inventive labor.

1 is a simplified schematic diagram of a system architecture to which an embodiment of the present invention is applied according to an embodiment of the present invention;

2 is a flowchart of a method for implementing CSFB according to an embodiment of the present invention;

3 is a flowchart of another CSFB implementation method according to an embodiment of the present invention;

4 is a flowchart of still another CSFB implementation method according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a location relationship between a first access network device, a second access network device, and a UE according to an embodiment of the present disclosure;

FIG. 6 is a schematic diagram of a location relationship between another first access network device, a second access network device, and a UE according to an embodiment of the present disclosure;

FIG. 7 is a schematic diagram of a positional relationship between a first access network device, a second access network device, and a UE according to an embodiment of the present disclosure;

FIG. 8 is a schematic diagram of a search range according to an embodiment of the present invention;

FIG. 9 is a schematic structural diagram of a first access network device according to an embodiment of the present invention;

FIG. 10 is a schematic structural diagram of a second access network device according to an embodiment of the present invention;

FIG. 11 is a schematic diagram showing the composition of another first access network device according to an embodiment of the present invention;

FIG. 12 is a schematic structural diagram of another second access network device according to an embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments.

Among them, the character "/" in this article generally indicates that the contextual object is an "or" relationship.

When the UE needs to perform voice services in a high-speed network such as an LTE network or a 5G network (the network does not support the voice service temporarily), the voice service of the UE can be dropped back to the 2G/3G network by using the CSFB technology, thereby utilizing the 2G/ The 3G network implements voice services. The CSFB technology includes two types of redirection and packet-switched (PS-switched). In the CSFB technology based on PS handover, the UE has previously established PS services in the 2G/3G network. Therefore, the location information of the UE exists in the 2G/3G network. When the UE needs to fall back to the 2G/3G network for voice service, the access network device in the 2G/3G network can search according to the existing location information. In order to access in a 2G/3G network, the voice service is implemented by using a 2G/3G network. However, in the CSFB technology based on redirection, since the UE does not establish any service in the 2G/3G network before, the access network device in the 2G/3G network needs to search in the entire cell, which may result in access. The network device searches for the UE for a long time, so that the delay of the UE's voice service falling back to the 2G/3G network is large.

In order to solve the problem that the delay of the UE's voice service from the LTE network and the 5G network to the 2G/3G network is large, the embodiment of the present invention provides a CSFB implementation method. The basic principle of the specific embodiment of the present invention is: The first access network device in the network is connected Receiving, by the second access network device in the second network, location information that needs to be dropped from the second network that currently camps on the voice service to the UE in the first network, and then first, The network access device can determine the search range according to the received location information, and finally reduces the search range by performing search according to the determined search range, thereby reducing the use of the redirection-based CSFB technology to the UE's voice service from the second. The delay when the network falls back to the first network.

Embodiments of the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in FIG. 1, FIG. 1 shows a simplified schematic diagram of a system architecture to which embodiments of the present invention may be applied. The system architecture may include: a first access network device 101, a second access network device 102, a UE 103, a first core network device 104, and a second core network device 105.

The first access network device 101 is an access network device in the first network, and the first core network device 104 is a core network device in the first network.

In the embodiment of the present invention, the first network may be a 2G/3G network. Specifically, in one implementation, the first network is a UMTS network, and correspondingly, the first access network device 101 is a NodeB, and the first core network device 104 is a radio network controller (English: Radio Network Controller, referred to as: RNC) And GPRS service support node (English: Service GPRS Supporting Node, referred to as: SGSN). In another implementation, the first network is a GSM network, and correspondingly, the first access network device 101 is a base transceiver station (English: Base Transceiver Station, BTS for short), and the first core network device 104 is controlled by a base station. (English: Base Station Controller, referred to as: BSC).

The second access network device 102 is an access network device in the second network, and the second core network device 105 is a core network device in the second network.

In the embodiment of the present invention, the second network may be an LTE/5G network. Specifically, in an implementation, the second network is an LTE network, and correspondingly, the second access network device 102 is an eNodeB, and the second core network device 105 is an MME.

The first access network device 101 and the second access network device 102 belong to the same coverage.

The UE 103 currently resides in the second network.

FIG. 2 is a flowchart of a method for implementing CSFB according to an embodiment of the present invention, such as As shown in FIG. 2, the method can include:

201. The first access network device receives location information of the UE sent by the second access network device under the second access network device.

The UE is a UE that needs to drop the voice service from the currently camped second network to the first network, the first access network device is an access network device in the first network, and the second access network device is the An access network device in the second network. The first network is a network that supports voice services, and the second network is a network that does not support voice services. Specifically, when the UE is in the second network that currently camps, voice services are required (for example, the UE needs to initiate a voice call on the second network). Or receiving a voice call, the voice service needs to be dropped from the currently camped second network to the first network, and the first connection in the first network is before the voice service of the UE falls back from the second network to the first network. The network access device may receive location information of the UE sent by the second access network device in the second network under the second access network device.

202. The first access network device determines a search range according to the location information.

Wherein, in the CSFB technology, the first access network device and the second access network device belong to the same coverage, so the first access network device may be configured by the second access network device according to the second access network device. The lower position to approximate the location of the UE under the first access network device, that is, the first access network device receives the location of the UE sent by the second access network device under the second access network device After the information, the first access network device can determine the search range according to the received location information.

203. The first access network device performs a search according to the search range, and after searching for the UE, establishes a connection with the UE, so as to provide a voice service for the UE by using the first network.

After the first access network device determines the search range according to the location information, the search may be performed according to the determined search range, and after determining to search for the UE, establish a connection with the UE, and then use the first network as the UE. Provide voice services. Exemplarily, the first access network device may perform a multi-path search manner according to the determined search range.

The CSFB implementation method provided by the embodiment of the present invention can be applied to the CSFB technology based on redirection.

The CSFB implementation method provided by the embodiment of the present invention, the first access network device receives the first The location information of the UE sent by the second access network device under the second access network device, and determining the search range according to the received location information, and then searching according to the determined search range, and after searching the UE, with the UE A connection is established to provide voice services to the UE over the first network. The search is performed according to the search range of the received location of the UE under the second access network device, indicating that the UE is located in the cell where the first access network device is located, compared to the first connection. The search is performed in the entire cell where the network access device is located, which reduces the search range, thereby reducing the delay when the voice service of the UE is dropped from the second network to the first network by using the CSFB technology based on the redirection.

FIG. 3 is a flowchart of another CSFB implementation method according to an embodiment of the present invention. As shown in FIG. 3, the method may include:

301. The second access network device sends, to the first access network device, location information of the UE under the second access network device.

The UE is a UE that needs to drop the voice service from the currently camped second network to the UE in the first network, and the second access network device is the access network device in the second network, and the first access network device is the first Access network equipment in the network. The first network is a network that supports voice services, and the second network is a network that does not support voice services. Specifically, in the CSFB technology, the first access network device and the second access network device belong to the same coverage, so The small UE uses the CSFB technology to delay the delay of the voice service from the second network to the first network. When the UE needs to perform voice service on the second network currently camped, the second access network device in the second network may The location parameter information of the UE in the current cell, that is, the second access network device, is sent to the first access network device in the first network, so that the first access network device can be sent according to the UE sent by the second access network device. The location under the second access network device approximates the location of the UE under the first access network device.

302. The second access network device sends an RRC connection release message to the UE.

After the second access network device sends the location information of the UE to the second access network device to the first access network device, the RRC connection release message may be sent to the UE, so that the UE can release the second network. The connection, in which the first access network device searches for the UE according to the location information of the UE under the second access network device, can re-establish a connection with the UE, thereby providing voice service for the UE through the first network.

FIG. 4 is a flowchart of still another method for implementing CSFB according to an embodiment of the present invention. As shown in FIG. 4, the method may include:

In the embodiment of the present invention, the CSFB implementation method provided by the embodiment of the present invention is specifically introduced by using the first network as the UMTS network and the second network as the LTE network, where no IP is deployed in the LTE network. Multimedia Subsystem (English: IP Multimedia Subsystem, IMS for short), that is, the LTE network does not support voice services. When the first network is a UMTS network, specifically, the first access network device is a NodeB, and when the second network is an LTE network, specifically, the second access network device is an eNodeB.

401. The second access network device sends, to the first access network device, location information of the UE under the second access network device.

The UE is a UE that needs to drop the voice service from the currently camped second network to the UE in the first network, and the second access network device is the access network device in the second network, and the first access network device is the first Access network equipment in the network. The first network is a network that supports voice services, and the second network is a network that does not support voice services. Specifically, in the CSFB technology, the first access network device and the second access network device belong to the same coverage, so When the small UE uses the CSFB technology to drop the voice service from the second network to the delay of the first network, when the UE needs to perform the voice service on the second network currently camped, the second access network device in the second network may be in the Before the UE sends an RRC Connection Release message, the UE is in the Dang The location parameter information in the pre-cell, that is, the second access network device, is sent to the first access network device in the first network, so that the UE that is sent by the first access network device according to the second access network device is in the second The location under the access network device approximates the location of the UE under the first access network device.

Exemplarily, when the UE needs to perform voice service in the currently camped LTE network, if the voice call needs to be initiated or the voice call is received, since the LTE network does not support the voice service, the UE can use the CSFB technology to transmit the voice service from the LTE. The network falls back to the UMTS network. In this case, in order to reduce the delay of the UE to use the CSFB technology to drop the voice service from the LTE network to the UMTS network, the eNodeB may send the UE to the NodeB under the eNodeB before sending the RRC connection release message to the UE. location information. The location information may include at least one of the following: an RTT, a second TA, where the second TA is a time advance amount and a strongest path delay for the UE to send data under the eNodeB.

In a specific implementation, the second access network device may send the location information of the UE to the second access network device to the first access network device by using a RIM process. Specifically, the second access network device sends the location information in the RAN information request to the first access network device by using the second core network device; the second core network device is the core network device in the second network.

Exemplarily, when the second network is an LTE network, specifically, the second core network device is an MME, and the eNodeB carries the location information in the RAN information request first to the MME, and then the MME sends the core network to the first network. The device finally sends the location information to the NodeB by the core network device of the first network. Specifically, the MME sends the RAN information request carrying the location information to the SGSN, and then the SGSN sends the RAN information request carrying the location information to the SGSN. RNC, finally the location information is sent by the RNC to the NodeB.

402. The first access network device receives location information of the UE sent by the second access network device under the second access network device.

After the second access network device sends the location information of the UE to the second access network device to the first access network device, the first access network device can receive the UE sent by the second access network device. Location information under the second access network device.

In a specific implementation, the first access network device may receive, by using a RIM process, location information of the UE sent by the second access network device under the second access network device. Specifically, the first access network device may receive the RAN information request that carries the location information that is sent by the second access network device by using the second core network device.

403. The second access network device sends an RRC connection release message to the UE.

After the second access network device sends the location information of the UE to the second access network device to the first access network device, the second access network device may send an RRC connection release message to the UE, so that the UE The connection with the second network is released, thereby facilitating the UE to access the first network. Further, when the UE uses the CSFB technology based on the RIM process to implement the fallback of the voice service from the second network to the first network, the RRC connection release message sent by the second access network device to the UE may carry the target cell, that is, the first A system message of a cell in which the access network device is located, the system message of the cell where the first access network device is located is pre-stored in the second access network device.

Exemplarily, the eNodeB sends an RRC connection release message to the UE, so that the UE releases the connection with the LTE network, where the eNodeB sends the UE to the UE when the UE uses the CSFB technology based on the RIM process to implement the fallback of the voice service from the LTE network to the UMTS network. The RRC connection release message sent may carry the target cell, that is, the system message of the cell where the NodeB is located.

When the UE accesses the first network, the first access network device may determine whether the UE is a UE redirected from the second network by determining whether the location information of the UE is received, and if yes, the first The access network device determines the search range according to the received location information of the UE. Specifically, the first access network device may determine the search range by performing the following steps 404-406.

404. The first access network device determines the first distance a according to the location information.

The first distance a is a distance between the UE and the second access network device. The first access network device may determine the distance between the UE and the second access network device according to the location information of the UE under the second access network device, that is, the first distance a.

When the first network is a UMTS network, the first access network device determines the first distance a according to the location information, and the first access network device determines the location information according to the location information. Tp and the strongest path position, the first distance a is determined according to the Tp and the strongest path position.

Of course, the first network can also be a GSM network. When the first network GSM network is used, the first access network device determines the first distance a according to the location information, including: the first access network device determines the first TA according to the location information; and the first TA is the UE in the first access network. The timing advance of transmitting data under the device; then determining the first distance a according to the first TA.

405. The first access network device determines, according to the first distance a and the second distance b, a reference range of a distance between the UE and the first access network device.

The second distance b is the distance between the first access network device and the second access network device (the second distance b is pre-configured in the first access network device), and the reference range is |ab| to (a +b). Specifically, the location relationship between the first access network device, the second access network device, and the UE may be as shown in FIG. 5-7. Therefore, the distance between the UE and the first access network device is The reference range may be: greater than or equal to |ab|, and less than or equal to (a+b), where the first access network device is a NodeB and the second access network device is an eNodeB, where c represents the distance between the UE and the first access network device, that is, the distance between the UE and the NodeB.

406. The first access network device determines a search range according to the reference range and a cell search radius r of the first access network device.

After the first access network device determines the reference range of the distance between the UE and the first access network device, the search range may be determined according to the reference range and the cell search radius r of the first access network device, where If the cell search radius r of the first access network device is greater than or equal to |ab|, the search range is |ab| to min{r, (a+b)}, where min{r, (a+b) } represents the minimum value in r and (a+b). If the cell search radius r of the first access network device is smaller than |ab|, considering the measurement error, it indicates that the UE is located at the edge of the cell where the first access network device is located, and may be from the edge of the cell where the first access network device is located. Search inside the cell.

407. The first access network device performs a search according to the search range, and after searching for the UE, establishes a connection with the UE, so as to provide a voice service for the UE by using the first network.

After the first access network device determines the search range, the search may be performed according to the determined search range, because the cell search radius r in the first access network device When the value is greater than or equal to |ab|, the search range is |ab| to min{r, (a+b)}, and the first access network device and the second access network device belong to the same coverage, so b may be relatively small. Then, as shown in FIG. 8 (the first access network device is a NodeB in FIG. 8 and the second access network device is an eNodeB as an example), the search range of the first access network device is as shown in the figure. Partially) is a very narrow ring area, ie searching for UEs in the range of 0 to r compared to the first access network device, which greatly reduces the search time and, in the cell of the first access network device When the search radius r is smaller than |ab|, it indicates that the UE is located at the edge of the cell where the first access network device is located. Therefore, searching from the edge of the cell where the first access network device is located to the inner side of the cell can also shorten the search time and shorten the adoption. The delay of the CSFB technology based on the redirection of the UE's voice service from the second network to the first network.

FIG. 9 is a schematic diagram of a composition of a first access network device according to an embodiment of the present invention. As shown in FIG. 9, the method includes: a receiving unit 51, a determining unit 52, a searching unit 53, and an establishing unit 54.

The receiving unit 51 is configured to receive location information of the user equipment UE sent by the second access network device under the second access network device, where the UE needs to return the voice service from the currently camped second network to The UE of the first network, the first access network device is an access network device in the first network, and the second access network device is an access network device in the second network.

The determining unit 52 is configured to determine a search range according to the location information received by the receiving unit 51.

The searching unit 53 is configured to perform a search according to the search range determined by the determining unit 52.

The establishing unit 54 is configured to establish a connection with the UE after the searching unit 53 searches for the UE, to provide voice service for the UE by using the first network.

In the embodiment of the present invention, the determining unit 52 is specifically configured to determine the first distance a according to the location information, where the first distance a is the UE and the second access network device. a distance between the UE and the first access network device according to the first distance a and the second distance b; the second distance b is the first access network a distance between the device and the second access network device, the reference range is |ab| to (a+b); and determining according to the reference range and a cell search radius r of the first access network device Search range.

In the embodiment of the present invention, if the cell search radius r of the first access network device is greater than or equal to |ab|, the search range determined by the determining unit 52 is |ab| to min. {r, (a+b)}, where min{r, (a+b)} represents the minimum of r and (a+b).

In the embodiment of the present invention, the first network is a universal mobile communication system UMTS network; the determining unit 52 is specifically configured to determine a transmission delay Tp and a strongest path position according to the location information; The Tp and the most strong path position determine the first distance a.

In the embodiment of the present invention, the first network is a global mobile communication system GSM network; the determining unit 52 is specifically configured to determine a first timing advance TA according to the location information; the first TA And a time advance amount for the UE to send data under the first access network device; determining the first distance a according to the first TA.

In the embodiment of the present invention, the second network is a long-term evolution LTE network, and the location information received by the receiving unit 51 includes at least one of the following: an RTT, a second TA, and a strongest path delay. .

It should be noted that the specific working process of each functional module in the first access network device provided by the embodiment of the present invention may refer to a specific description of the corresponding process in the method embodiment. The embodiments of the present invention are not described in detail herein.

The first access network device provided by the embodiment of the present invention is configured to execute the foregoing CSFB implementation method, so that the same effect as the CSFB implementation method described above can be achieved.

FIG. 10 is a schematic structural diagram of a second access network device according to an embodiment of the present invention. As shown in FIG. 10, the method includes: a sending unit 61.

The sending unit 61 is configured to send, to the first access network device, location information of the user equipment UE under the second access network device, and send a radio resource control RRC connection release message to the UE, so that the UE releases and a connection of the second network; the UE is a UE that needs to drop a voice service from a currently camped second network to a first network, and the second access network device is an access in the second network. The network device, where the first access network device is an access network device in the first network.

In the embodiment of the present invention, the sending unit 61 is specifically configured to carry the location information in the radio access network RAN information request to the first access network device by using the second core network device. The second core network device is a core network device in the second network.

In the embodiment of the present invention, the second network is a long-term evolution LTE network, and the location information sent by the sending unit 61 includes at least one of the following: an RTT, a second TA, and a strongest path delay. .

The second TA is a timing advance of the UE sending data under the second access network device.

It should be noted that the specific working process of each functional module in the second access network device provided by the embodiment of the present invention may be referred to the specific description of the corresponding process in the method embodiment, and details are not described in detail herein.

The second access network device provided by the embodiment of the present invention is configured to execute the foregoing CSFB implementation method, so that the same effect as the CSFB implementation method described above can be achieved.

FIG. 11 is a schematic diagram of another first access network device according to an embodiment of the present invention. As shown in FIG. 11, the method includes: a radio frequency unit 71 and a baseband processing unit 72.

In a specific implementation, the radio frequency unit 71 is configured to implement the CSFB implementation method provided in FIG. 2 or FIG. 4 to implement the function of the receiving unit 51 in the first access network device shown in FIG. 9.

For example, the radio frequency unit 71 can be used to perform step 201 in the CSFB implementation method provided in FIG. 2 to implement the function of the receiving unit 51 in the first access network device shown in FIG. The radio frequency unit 71 can also be used to perform step 402 in the CSFB implementation method provided in FIG. 4 to implement the function of the receiving unit 51 in the first access network device shown in FIG.

The baseband processing unit 72 is configured to perform the CSFB implementation method provided in FIG. 2 or FIG. 4 to implement the functions of the determining unit 52, the searching unit 53, and the establishing unit 54 in the first access network device shown in FIG. 9.

For example, baseband processing unit 72 may be operable to perform step 202 of the CSFB implementation method provided in FIG. 2 to implement the functionality of determining unit 52 in the first access network device illustrated in FIG. The baseband processing unit 72 can also be used to perform step 203 in the CSFB implementation method provided in FIG. 2 to implement the functions of the search unit 53 and the establishing unit 54 in the first access network device shown in FIG. For example, the baseband processing unit 72 can be used to perform step 404, step 405, and step 406 in the CSFB implementation method provided in FIG. 4 to implement the function of the determining unit 52 in the first access network device shown in FIG. 9. The baseband processing unit 72 can also be used to perform step 407 in the CSFB implementation method provided in FIG. 4 to implement the functions of the search unit 53 and the establishing unit 54 in the first access network device shown in FIG.

It should be noted that, the specific working process of each functional module in the first access network device provided by the embodiment of the present invention may be referred to the specific description of the corresponding process in the method embodiment, and details are not described in detail herein.

FIG. 12 is a schematic diagram showing the composition of another second access network device according to an embodiment of the present invention. As shown in FIG. 12, the method includes: a radio frequency unit 81.

The radio frequency unit 81 is configured to implement the CSFB implementation method provided in FIG. 3 or FIG. 4 to implement the function of the sending unit 61 in the first access network device shown in FIG. 10.

For example, the radio frequency unit 81 can be used to perform

steps

301 and 302 in the CSFB implementation method provided in FIG. 3 to implement the functions of the transmitting unit 61 in the second access network device shown in FIG. The radio frequency unit 81 can also be used to implement the CSFB provided in FIG. Step 401 and step 403 in the current method to implement the function of the transmitting unit 61 in the second access network device shown in FIG.

Of course, as shown in FIG. 12, the second access network device may further include a baseband processing unit 82 for performing processing of the baseband signal.

Through the description of the above embodiments, those skilled in the art can clearly understand that for the convenience and brevity of the description, only the division of the above functional modules is illustrated. In practical applications, the above functions can be allocated according to needs. It is completed by different functional modules, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above.

In the several embodiments provided by the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be used. The combination may be integrated into another device, or some features may be ignored or not performed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.

The units described as separate components may or may not be physically separated, and the components displayed as units may be one physical unit or multiple physical units, that is, may be located in one place, or may be distributed to multiple different places. . Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or may be two or two. The upper unit is integrated in one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a standalone product, may be stored in a readable storage medium. Based on such understanding, the technical solution of the present invention may contribute to the prior art or all or part of the technical solution may be embodied in the form of a software product stored in a storage medium. A number of instructions are included to cause a device (which may be a microcontroller, chip, etc.) or a processor to perform all or part of the steps of the methods described in various embodiments of the present invention. The foregoing storage medium includes: a U disk, a mobile hard disk, a read only memory (English: Read-Only Memory, abbreviated as: ROM), a random access memory (English: Random Access Memory, abbreviated as: RAM), a magnetic disk or an optical disk, and the like. A variety of media that can store program code.

The above is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the appended claims.

Claims

A circuit domain fallback CSFB implementation method, comprising:

The first access network device receives location information of the user equipment UE sent by the second access network device under the second access network device; the UE needs to return the voice service from the currently camped second network to a UE of the first network, where the first access network device is an access network device in the first network, and the second access network device is an access network device in the second network;

Determining, by the first access network device, a search range according to the location information;

The first access network device performs a search according to the search range, and after searching for the UE, establishes a connection with the UE, so as to provide the voice service to the UE by using the first network.
The method according to claim 1, wherein the first access network device determines a search range according to the location information, including:

Determining, by the first access network device, the first distance a according to the location information; the first distance a is a distance between the UE and the second access network device;

Determining, by the first access network device, a reference range of a distance between the UE and the first access network device according to the first distance a and the second distance b; the second distance b is the a distance between an access network device and the second access network device, the reference range is |ab| to (a+b);

The first access network device determines a search range according to the reference range and a cell search radius r of the first access network device.
The method according to claim 2, wherein if the cell search radius r of the first access network device is greater than or equal to |ab|, the search range is |ab| to min{r, (a +b)}, where min{r, (a+b)} represents the minimum of r and (a+b).
The method according to claim 2 or 3, wherein the first network is a universal mobile communication system UMTS network;

Determining, by the first access network device, the first distance a according to the location information, including:

Determining, by the first access network device, a transmission delay Tp and a maximum according to the location information Strong path position

The first access network device determines the first distance a according to the Tp and the most strong path position.
The method according to claim 2 or 3, wherein the first network is a Global System for Mobile Communications (GSM) network;

Determining, by the first access network device, the first distance a according to the location information, including:

Determining, by the first access network device, the first timing advance TA according to the location information; the first TA is a timing advance of the UE sending data under the first access network device;

The first access network device determines the first distance a according to the first TA.
The method according to any one of claims 1 to 5, wherein the second network is a Long Term Evolution (LTE) network, and the location information includes at least one of the following: a loopback time RTT, a second TA, and a most Strong path delay

The second TA is a timing advance of the UE sending data under the second access network device.
A circuit domain fallback CSFB implementation method, comprising:

The second access network device sends, to the first access network device, location information of the user equipment UE under the second access network device; the UE needs to return the voice service from the currently camped second network to the first a UE of the network, the second access network device is an access network device in the second network, and the first access network device is an access network device in the first network;

The second access network device sends a radio resource control RRC connection release message to the UE.
The method according to claim 7, wherein the second access network device sends the location information of the user equipment UE under the second access network device to the first access network device, including:

The second access network device carries the location information in the radio access network RAN information request to the first access network device through the second core network device; the second core network device is the The core network device in the second network.
The method according to claim 7 or 8, wherein the second network is a long term evolution LTE network, and the location information includes at least one of the following: a loopback time RTT, a second timing advance TA, and a strongest Trail delay

The second TA is a timing advance of the UE sending data under the second access network device.
A first access network device, comprising:

a receiving unit, configured to receive location information of the user equipment UE sent by the second access network device under the second access network device; the UE needs to return the voice service from the currently camped second network to the first a UE of a network, the first access network device is an access network device in the first network, and the second access network device is an access network device in the second network;

a determining unit, configured to determine a search range according to the location information received by the receiving unit;

a searching unit, configured to perform searching according to the search range determined by the determining unit;

And a establishing unit, configured to establish a connection with the UE after the searching unit searches for the UE, to provide the voice service to the UE by using the first network.
The first access network device according to claim 10, wherein the determining unit is specifically configured to:

Determining, according to the location information, a first distance a; the first distance a is a distance between the UE and the second access network device;

Determining, according to the first distance a and the second distance b, a reference range of a distance between the UE and the first access network device; the second distance b is the first access network device and the The distance between the second access network devices, the reference range is |ab| to (a+b);

And determining a search range according to the reference range and a cell search radius r of the first access network device.
The first access network device according to claim 11, wherein if the cell search radius r of the first access network device is greater than or equal to |a-b| The search range determined by the determining unit is |a-b| to min{r, (a+b)}, where min{r, (a+b)} represents the minimum value of r and (a+b).
The first access network device according to claim 11 or 12, wherein the first network is a universal mobile communication system UMTS network;

The determining unit is specifically configured to:

Determining a transmission delay Tp and a strongest path position according to the location information;

The first distance a is determined according to the Tp and the most strong path position.
The first access network device according to claim 11 or 12, wherein the first network is a global mobile communication system GSM network;

The determining unit is specifically configured to:

Determining, according to the location information, a first timing advance TA; the first TA is a timing advance of the UE sending data under the first access network device;

The first distance a is determined according to the first TA.
The first access network device according to any one of claims 10 to 14, wherein the second network is a long term evolution LTE network, and the location information received by the receiving unit includes at least one of the following Species: loopback time RTT, second TA, strongest path delay.
A second access network device, comprising:

a sending unit, configured to send, to the first access network device, location information of the user equipment UE under the second access network device, and send a radio resource control RRC connection release message to the UE; The service is dropped from the currently camped second network to the UE of the first network, the second access network device is the access network device in the second network, and the first access network device is the An access network device in a network.
The second access network device according to claim 16, wherein the sending unit is specifically configured to:

Carrying the location information in the radio access network RAN information request to the first access network device by using the second core network device; the second core network device is the core network device in the second network .
A second access network device according to claim 16 or 17, wherein The second network is a long-term evolution LTE network, and the location information sent by the sending unit includes at least one of the following: a loopback time RTT, a second timing advance TA, and a strongest path delay;

The second TA is a timing advance of the UE sending data under the second access network device.
A first access network device, comprising:

a radio unit, configured to receive location information of the user equipment UE sent by the second access network device under the second access network device; the UE needs to return the voice service from the currently camped second network to the first a UE of a network, the first access network device is an access network device in the first network, and the second access network device is an access network device in the second network;

a baseband processing unit, configured to determine a search range according to the location information received by the radio frequency unit, perform a search according to the search range, and establish a connection with the UE after searching the UE, so as to pass the The first network provides the voice service to the UE.
A second access network device, comprising:

a radio unit, configured to send, to the first access network device, location information of the user equipment UE under the second access network device, and send a radio resource control RRC connection release message to the UE; The service is dropped from the currently camped second network to the UE of the first network, the second access network device is the access network device in the second network, and the first access network device is the An access network device in a network.