WO2008148313A1

WO2008148313A1 - Handover method, mobile station and switch device

Info

Publication number: WO2008148313A1
Application number: PCT/CN2008/070601
Authority: WO
Inventors: Shengqiang Yang
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2007-06-04
Filing date: 2008-03-27
Publication date: 2008-12-11
Also published as: CN101321380B; CN101321380A

Abstract

A handover method includes the following steps: a mobile station judging whether initiating a handover to a second base station according to the search and measure results from each transceiver; if the handover requires being initiated, initiating a new call to the second base station through a second transceiver of the mobile station, and the new call taking address information of the opposite end; building a second service link between the mobile station and the second base station through the second transceiver of the mobile station. And a method of a handover method, mobile station and switch device judging whether a handover requires being initiated by using a MS and performing handover process by use of the MS initiating a new call, which avoids the troubles of developing inter-operation interface and protocol for supporting trans-network handover among kinds of wireless networks; by use of the handover method provided in the implement in the present invention, the operation is simple and universal well, and the handover could be applied within kinds of wireless network systems and among different network systems.

Description

Switching method, mobile station and switching device

The present application claims priority to Chinese Patent Application No. 200710111729.6, entitled "Switching Method, Mobile Station, and Switching Equipment", which is incorporated by reference in its entirety. in.

Technical field

The present invention relates to the field of mobile station handover, and more particularly to a handover method, a mobile station (MS), and a switching device. Background technique

The wireless cellular network system mainly includes a mobile station (MS), a base station (BS), a mobile switching center (MSC), an external network, and functional entities responsible for mobility management. The main function of the MS is to terminate the propagation path of the radio wave at the user end, and to ensure that the user can obtain the service through the network, which is connected with the BS through the Um interface; the main function of the BS is to end the radio wave propagation path and connect to the MSC. The interface between the MSC and the MSC is the A interface; the MSC is responsible for the conversion of the service between the wireless network user and the wired network or other wireless network; the functional entity responsible for the mobility management mainly performs the mobility management of the MS, which mainly includes the home location. The register (HLR), the visitor location register (VLR), and the authentication center (AC), etc.; and the external network mainly refers to the Public Switched Telephone Network (PSTN) and the Integrated Services Digital Network (ISDN) and the like.

Among the above functional entities, the BS is often split and installed in a base station controller (BSC) and a base transceiver station (BTS). Wherein, the BTS is composed of one or more transceivers arranged at the same location, which end the radio wave propagation path at the network end, and the BSC is a system for managing and controlling one or more BTSs, between the BTS and the BSC The interface is an Abis interface. Under normal circumstances, a BSC and one or more BTSs managed and controlled by it form a base station (BS).

In a wireless cellular mobile network, the MS can roam freely. During the user's call, the MS moves beyond the original base station (BS) coverage and enters the other second BS coverage. It is necessary to make the mobile station communicate with the second BS through the handover process, and keep the user's conversation uninterrupted.

Currently, wireless cellular mobile networks offer two switching technologies: hard handover and soft handover.

Hard handover: When the MS moves, it detects that the first BS signal has deteriorated to a certain threshold or detects a stronger and better signal of the second BS, and then reports it to the mobile switching center (MSC). The method decides to perform a hard handover, instructs the MS to perform handover, interrupts communication with the first BS, and attempts to establish a service connection with the second BS.

Soft handoff: In a code division multiple access (CDMA) system wireless cellular mobile network, the CDMA MS is equipped with a rake-like RAKE multipath receiver that can simultaneously support multiple signal path reception. When the MS moves, after detecting a strong signal of the second BS, a branch of the RAKE multipath receiver can be used to establish a service connection with the second BS without interrupting the service link with the first BS.

The above two switching methods use the cooperative work between the first BS and the second BS to complete the switching process with the MS. When the span of the network devices involved in the handover is relatively large, an interoperation interface needs to be designed on each related network device, and a protocol for communication between the related network devices is established to support the normal handover process; When the wireless network belongs to different network systems, it is more necessary to design an interoperation interface between network devices in different network systems, and establish a communication protocol between network devices in different network systems to support the normal process of switching between networks. If a new wireless network system is added in the future, it is also necessary to design an interoperability interface between the existing network system and the network device in the newly added network system, and between the establishment of the existing network system and the network device in the newly added network system. The communication protocol to support the normal process of switching between the newly added networks. At present, this switching design is complicated, the scalability is not strong, and the design difficulty and implementation cost are high.

Summary of the invention

The embodiments of the present invention provide a handover method, an MS, and a switching device, simplify the handover process, improve the versatility of the handover process, and reduce the design difficulty and implementation cost of the network.

An embodiment of the present invention provides a handover method, in which a first service link is established between a first transceiver and a peer end of a mobile station, and the method includes the following steps:

The mobile station determines, according to the results of the search and measurement of each transceiver, whether to initiate a handover to the second base station;

If the handover needs to be initiated, the second transceiver of the mobile station sends a new call to the second base station, where the new call carries the address information of the opposite end;

Establishing, by the second transceiver of the mobile station, a second service link between the mobile station and the second base station;

The mobile station switches the first service link to a second service link.

The embodiment of the invention further provides a handover method, where the first transceiver and the opposite end of the mobile station have been established. The first service link, the method includes the following steps:

Receiving, after the second base station receives a new call of the second transceiver of the mobile station, a service connection command from the second base station, where the new call is determined by the mobile station according to a result of the search and measurement a call initiated after the handover of the second base station, where the new call carries the address information of the peer end;

And establishing, according to the service connection command, a second service link with the second base station; switching the first service link to a second service link with the second base station; The mobile station transmits a handover command instructing the mobile station to switch to a second service link with the second base station.

An embodiment of the present invention further provides a mobile station, including: a determining unit, two or more transceivers, and a switching unit, where

The determining unit is configured to determine, according to a result of the frequency signal search and measurement by the two or more transceivers, whether to initiate a handover, send a control signal, and switch a signal;

The two or more transceivers are respectively configured to perform frequency signal search and measurement, and establish a service link with the base station according to the control signal from the determining unit;

The switching unit is configured to control the service to be connected to the service link of the designated transceiver according to the switching signal from the determining unit.

The embodiment of the invention further provides a switching device, including:

a receiving unit, configured to receive a service connection command, where the service connection command carries address information of the peer end;

a determining unit, configured to determine, according to the service connection command received by the receiving unit, whether the mobile station and the opposite end have established a service connection through the device;

The control unit is configured to establish a service link between the mobile station and the opposite end according to the judgment result of the determining unit, or switch the existing service link.

The MS is used to determine whether a handover needs to be initiated, and the handover process is performed by adopting a method for the MS to initiate a new call, thereby effectively avoiding the trouble that various wireless networks need to develop an interoperation interface and protocol for supporting inter-network handover; The switching mode provided by the embodiment is simple in operation and strong in versatility, and is suitable for switching between various wireless network systems and different wireless network systems.

DRAWINGS 1 is a schematic diagram of a network structure of a handover in an embodiment of the present invention;

2 is a schematic flow chart of switching in an embodiment of the present invention;

3 is a schematic flow chart of switching in another embodiment of the present invention;

4 is a schematic structural diagram of a system for switching in an embodiment of the present invention.

detailed description

The embodiment of the present invention proposes a handover method of MS control, which simplifies the handover process, and effectively avoids the trouble of developing interoperation interfaces and protocols between various wireless networks to support inter-network handover.

In the first embodiment, a first service link is established between the first transceiver and the peer end of the MS, including the following steps:

Each transceiver of the MS performs frequency signal search and measurement;

The result of the MS search and measurement determines whether it is necessary to initiate a handover to the second base station;

If the handover needs to be initiated, the second transceiver of the MS initiates a new call to the second BS, and the new call carries the address information of the opposite end;

And establishing, by the second transceiver of the MS, a second industry path between the MS and the second BS; and the MS switching the first service link to the second service link.

The peer end is a terminal that establishes a service link with the MS, and may be a mobile station or a fixed user equipment. The service established between the MS and the peer end may be a call, a data transmission, or the like. In this embodiment, a call service is established between the MS and the peer end.

In the step 2, the address information of the peer that is carried may be the identifier of the peer end, such as the telephone number and the IP address of the peer end. The address information of the peer end is also different according to different service types. In this embodiment, The address information of the peer is the phone number of the peer.

The MS uses the MS to determine whether it is necessary to initiate a handover, and performs a handover process by using the MS to initiate a new call, thereby effectively avoiding the trouble of developing interoperable interfaces and protocols between various wireless networks to support inter-network handover.

In the second embodiment, referring to FIG. 1 and FIG. 2, the first service link is established between the MS and the peer end, and the following steps are included:

1. The MS determines that a handover to the second BS needs to be initiated;

2. The MS sends a call connection request to the second BS, and carries the address information of the peer end, and requests the network to which the second BS belongs to establish a second service link between the MS and the opposite end; After the second service link is set up, the switching device determines that the new call is a handover, and switches the service link between the MS and the peer to the second service link, where the switching device is the first service link and the second. A switching device through which a service link passes.

The switching device determines that the new call is actually a handover, so that the operation of establishing a new call is not performed, but the original service link between the switching device and the opposite end is switched to the second service link, thereby completing the handover of the MS. Simple and versatile, it is suitable for switching between various wireless network systems and different wireless network systems.

There may be multiple switching devices on the first service link between the MS and the peer end of the call, and multiple switching devices may also be in the second service link. The switching device is the first service link and the second service link. The switching device that the path passes through may be any network connection device on the network side, such as a PSTN switch, an MSC mobile switching center, or a base station device. If a new one of the network connection devices that the first service link and the second service link pass through receives the new call signal without determining, the new call signal is forwarded to the next switching device, if the exchange After receiving the new call signal, the device detects that the service is established between the MS and the peer end, and determines that the new call is actually a handover, thereby switching the service link between the MS and the peer end to the second service chain. On the way, the call signal is no longer forwarded to the next switching device. In this embodiment, the switching device is preferably the first switching device located on the MS side of the switching device that the first service link and the second service link pass together, and can complete the handover quickly without forwarding the call signal.

In the foregoing step 3, the switching device determines that the handover is required, except that the switching device detects that the MS has established a service with the peer, thereby determining that the new call is actually a handover; Carrying the handover indication, the switching device detects the handover indication, and then detecting whether a service link has been established between the MS and the opposite end, and if yes, determining that the new call is a handover, so that the normal new call and the handover can be effectively performed. The new call is distinguished. If the handover indication is not detected, it is not necessary to detect whether a service link has been established between the MS and the peer, and the normal new call is not detected, thereby improving the efficiency of the ordinary new call.

The construction of the second service link includes the following steps:

The second BS establishes a front-end link of the second industry road between the MS and the MS;

The second BS sends a service connection command to the switching device, and carries the address information of the peer end to establish a back-end link of the second service link. The service connection command also has different commands according to different service types. In this embodiment, since the call service is established between the MS and the peer end, the service connection command sent is a call connection command.

The step of switching the service link between the MS and the peer end to the second service link includes: after the switching device switches to the second service link, sending a handover command to the MS;

The MS receives the handover command and switches to the second service link.

The first service link is specifically configured between the peer end and the first transceiver of the MS.

The front-end link is specifically built between the second BS and the second transceiver of the MS.

The modes of the first transceiver and the second transceiver may be the same, and the modes of the first transceiver and the second transceiver are the same, for example, all of the GSM can be switched in the GSM system; or both are CDMA, and the CDMA can be used in CDMA. Switching within the system; or both WCDMA, can be switched within the WCDMA system.

The modes of the first transceiver and the second transceiver can also be different, and switching can be implemented in various systems to further improve the versatility of mobile station switching. For example, the first transceiver is a second generation CDMA transceiver, and the second transceiver is a third generation CDMA transceiver, which can implement hard handover between the second generation CDMA and the third generation CDMA system; if the first transceiver is CDMA The transceiver, the second transceiver is a GSM transceiver, and can implement hard handover between the CDMA and GSM systems; if the first transceiver is a CDMA transceiver and the second transceiver is a WCDMA transceiver, the CDMA and WCDMA systems can be implemented. Hard switching between.

The handover command may be sent to the MS only through the first service link, or may be sent to the MS only through the second service link, or may be sent to the MS through the first service link and the second service link simultaneously, and simultaneously through the first The manner in which the service link and the second service link are sent to the MS can improve the reliability of the message relative to the manner of transmitting to the MS only through the first service link, or the manner of sending to the MS only through the second service link. Sex.

Before step 1, the following steps are also included:

Each transceiver of the MS performs frequency signal search and measurement, and the MS judges that it is necessary to trigger the handover to the second BS based on the results of the search and measurement.

The MS can use the first transceiver for frequency signal search and measurement, and the MS can also perform frequency signal search and measurement with other transceivers than the first transceiver, such as the second transceiver, avoiding one. Transceivers must maintain the current call at a certain frequency, and switch to another frequency at the appropriate time for signal measurement conflicts, thereby improving the quality of the user's call.

In the second step, the second transceiver of the MS sends an initial call connection request message to the second BS, and carries the address information of the opposite end, requesting the second BS to belong to the second service between the second transceiver and the opposite end of the MS. Link

Step 3 also includes the following steps:

4. After the switching of the switching device is completed, the link between the switching device and the MS in the first service link is cleared.

Step 4 specifically includes the following steps:

After the switching of the switching device is completed, the release message is sent to the first BS, and the link between the switching device and the mobile station is cleared.

The transceivers in the above MS are in the working state at the same time, and are independent of each other, and the first transceiver is in a service connection state with the first BS. In this embodiment, the first transceiver is in a call with the first BS. State, other transceivers perform signal search and measurement in real time. When the MS finds that the measured signal strength reported by the transceiver is stronger than the source BS, then one cell carrier frequency is selected as the switching target, and another transceiver is used. For example, the second transceiver) initiates a new call to the second BS corresponding to the selected cell carrier frequency.

Embodiment 3 Referring to FIG. 3, an MS equipped with a first transceiver and a second transceiver is taken as an example. The modes of the first transceiver and the second transceiver are both CDMA, equipped with other mode transceivers and equipment. The case where there are more than two transceivers can be obtained based on the principle of the present embodiment. Taking the call between the MS and the peer as an example, another type of service switching between the MS and the peer can be established, or based on the implementation. The principle of the example is obtained. The method for implementing the handover in this embodiment includes the following steps:

301. The MS determines, according to the signal measurement result, a hard handover initiated to the second BS, and sends an originating call connection request message to the second BS.

302. The second BS receives the originating call connection request message, and establishes a service link between the second BS and the MS as a front-end link of the second service link of the MS.

303. The second BS sends a call connection command to the switching device, carries the telephone number of the opposite end, and establishes a back-end link of the second service link.

304. The switching device determines whether the new call is a handover, and if it is a handover, sends a handover command. 305. ~ 305' The switching device simultaneously sends a handover command on the first service link and the second service link. Obviously, sending a handover command message from multiple channels at the same time will increase the likelihood that the MS will receive the message. For these 305 and 305, the two steps are parallel. Subsequent messages can be sent on both service links at the same time, improving the reliability of the message.

306. ~ 306' The first BS and the second BS send an extended or general handover command message to the MS over the air interface.

307. ~ 307' The MS sends an MS acknowledgment command to the first BS or the second BS.

308. The control unit of the ~308' MS switches the call link from the first transceiver to the second transceiver, and simultaneously sends a handover complete message to the first BS and the second BS.

309. ~ 309' The first BS or the second BS sends a BS acknowledgment command to the MS.

310. ~ 310' The first BS or the second BS receiving the handover complete message sends a handover complete message to the switching device, notifying the switching device that the MS has successfully completed the handover.

311. The switching device switches the service connection to the second service link, and the mobile station and the opposite end talk on the second service link. After the switching of the switching device is completed, a clear command message is sent to the first BS.

312. After releasing the first service link between the first transceiver of the MS and releasing its own terrestrial circuit and resources, the first BS sends a clear complete message to the switching device to notify the switching device that the clearing process has been completed.

Referring to FIG. 4, for the method in the second embodiment, a corresponding switching system is set on the hardware, and a first service link is established between the MS and the peer end, including:

The MS is configured to determine that a handover to the BS needs to be initiated, initiate a new call to the BS, and carry the address information of the opposite end;

a BS, configured to establish a second service link between the MS and the peer end;

The switching device is configured to determine that the new call is a handover, and switch the service link between the MS and the peer end to the second service link.

Where MS includes:

a determining unit, configured to determine, according to a result of the frequency signal search and measurement, whether to initiate a handover, send a control signal, and switch a signal;

Two or more transceivers for performing frequency signal search and measurement, respectively, and establishing a service link with the BS according to the control signal; The switching unit is configured to control the service to be connected to the service link of the designated transceiver according to the switching signal. In the MS, the judgment unit can be directly used as the input/output device, or the user interface can be additionally provided to provide input and output devices. The user can set the working mode and search frequency parameters of each transceiver through the user interface, select the current call or perform other services. Transceiver. The control bus transmits signaling messages and control commands; the data bus transmits service data, such as voice packets, data packets.

The switching equipment includes:

The receiving unit receives the service connection command, and the service connection command carries the address information of the peer end; the determining unit determines, according to the service connection command, whether the service connection has been established between the MS and the peer end through the device;

The control unit establishes a service link between the MS and the peer according to the judgment result of the judgment unit; or switches the existing service link.

It will be understood by those skilled in the art that the above various units in the MS and the switching device may be provided by software, hardware or a combination of both, although the above various components are given as discrete units in the figure, but actually They may be implemented by a microprocessor containing input and output ports and running software code, or by custom or hybrid chips, or by discrete components, or by a combination of the above. For example, multiple transceivers in the MS can be implemented in one processor, and each transceiver is integrated into the processor as a software module.

The judging unit of the MS can control the multi-transceiver to perform frequency signal search and measurement respectively according to the terminal setting or the BS indication. When one transceiver is used for a service such as a call, other transceivers can continue to perform frequency signal search and measurement.

The MS can set up a separate antenna for each transceiver, or a single antenna for multiple transceivers. Signal separation and synthesis can be accomplished by providing a splitter/combiner between the transceiver and the antenna.

Through the description of the above embodiments, those skilled in the art can clearly understand that the present invention can be implemented by means of software plus a necessary hardware platform, and of course, all can be implemented by hardware. Based on such understanding, all or part of the technical solution of the present invention contributing to the background art may be embodied in the form of a software product, which may be stored in a storage medium such as a ROM/RAM, a magnetic disk, an optical disk, or the like. A number of instructions are included to cause a computer device (which may be a personal computer, server, or network device, etc.) to perform the methods described in various embodiments of the present invention or portions of the embodiments. The above is only a specific embodiment of the present invention, and it should be noted that those skilled in the art can also make some improvements and retouching without departing from the principles of the present invention. It is considered as the scope of protection of the present invention.

Claims

Rights request

A handover method, characterized in that a first service link is established between a first transceiver and a peer end of the mobile station, and the method comprises the following steps:

The mobile station switches the first service link to a second service link.

2. The handover method according to claim 1, further comprising the step of: clearing the first service link.

A handover method, characterized in that a first service link between a first transceiver of a mobile station and a peer end is established, the method comprising the following steps:

The handover method according to claim 3, further comprising the step of: clearing the first service link.

The handover method according to claim 3, wherein the step of switching the first service link to the second service link with the second base station comprises:

Determining that the new call is a handover, switching the first service link to a second service link with the second base station.

6. The handover method according to claim 5, wherein said determining said new call The steps for switching include:

If it is detected that a service connection is established between the mobile station and the opposite end, determining that the new call is a handover; or

Detecting a handover indication carried in the new call, detecting whether a service connection has been established between the mobile station and the opposite end, and if yes, determining that the new call is a handover.

7. The handover method according to claim 3, wherein the step of transmitting a handover command to the mobile station comprises:

Transmitting the handover command to the mobile station by using a first service link; or

Transmitting the handover command to the mobile station by using a second service link; or

The handover command is sent to the mobile station through a first service link and a second service link.

A mobile station, comprising: a determining unit, two or more transceivers and a switching unit, wherein

9. A switching device, comprising:

The switching device according to claim 9, wherein the switching device is integrated in a network that is newly established between the mobile station and the opposite end and the existing service link Connect the first device on the mobile station side of the device.