WO2007124677A1

WO2007124677A1 - Method and device for switch controlling

Info

Publication number: WO2007124677A1
Application number: PCT/CN2007/001309
Authority: WO
Inventors: Hao Wu; Liyan Yin
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2006-04-21
Filing date: 2007-04-20
Publication date: 2007-11-08

Abstract

A method and device for switch controlling, which control the switching on the basis of determining the performance needs of scheduled switching time. The method concludes step of when it needs to switch cells during the source cell receiving or sending data, determining the interrupting time from the source cell to the target cell on the basis of the transmitting time and delay time need by correlative operation data unit; after receiving or sending correlative operation data unit, if the terminal connecting to the target cell, then ending the switch operation. The device concludes: judgement unit, which judges whether the terminal connects the target cell in schedule time; switch control unit, which starts and controls the process of switching according to the switch command. As the exact interrupt situation of data stream and interrupt time are determined, the accuracy and flexibility of the process of switching control are improved.

Description

Switching control method and device The present application claims to be submitted to the Chinese Patent Office on April 21, 2006, respectively, and the application numbers are 200610074594.6, 200610074511.3, respectively, and the invention names are "a long-term evolution system switching control method", "a switching The priority of the Chinese Patent Application, which is incorporated herein by reference. Technical field

The present invention relates to the field of wireless communication technologies, and in particular, to a handover technique in a wireless communication system, and more particularly to a handover control method and apparatus. Background technique

In order to make the wireless access technology of the 3rd Generation 3GPP (The 3rd Generation Partnership Project) still have strong competitiveness in the next 10 years or more, 3GPP wireless access needs to be considered. Long Term Evolution of Technology (LTE, Long Term Evolution). The goal of LTE is to develop a framework for wireless access technologies with features such as high data rates, low response times, and optimal packet access. Therefore, important parts of LTE include shorter response times, higher user data rates, greater system capacity and wider coverage, and reduced operator cost.

The general process of LTE handover is described as follows: When the wireless condition changes, the terminal measures the neighboring cell, then sends a measurement report, the network makes a decision according to the measurement report, and notifies the target cell to prepare for handover, and then the network sends a handover command to the terminal. Instructing to switch to the target cell. At this time, the terminal disconnects from the source cell and starts to synchronize to the target cell. After the synchronization, the terminal notifies the network side of the handover confirmation, and starts to send and receive user data on the target cell, and finally the source cell. Release resources.

During the LTE handover execution process, the terminal disconnects from the source cell and then synchronizes to the target cell before establishing connection with the target cell. Therefore, due to the process of disconnecting and then connecting, the terminal is interrupted when receiving or transmitting data.

The terminal uses the foregoing process to perform the handover. After the terminal receives the handover command, it needs to pass a certain handover delay. The handover delay includes the processing delay of the network side of the 3GPP system, and the delay of waiting for the activation time to arrive. a user data transfer block, After obtaining synchronization with the target cell, the terminal starts to send and receive user data in the target cell. In the current 3GPP system, the handover delay time is defined as: the time between the transmission time interval ( ΤΉ ) of the last source cell containing the transport block and the start of transceiving user data on the target cell. The time between when the terminal sends or receives the last complete SDU (Service Data Unit) on the source cell to transmit or receive the first complete upper SDU on the target cell is defined as the handover interruption time.

When the terminal switches from a frequency division duplex (FDD) cell to an FDD cell, different handover delay times can be determined under different conditions:

The terminal performs the inter-frequency measurement in the compressed mode or the compressed mode, and the network side of the 3GPP system does not indicate that the terminal does not perform any synchronization process, and the process of completing the frame timing synchronization, the process of the physical channel synchronization, and the pair in the handover delay time The process of re-confirming the target cell system timing information or/and the process of the unknown target cell search, and the synchronization of the transmission timing of the transport block in the target cell are known.

The terminal does not use the compressed mode for inter-frequency measurement when switching, and the 3GPP system network side does not indicate that the terminal does not perform any synchronization process, or the terminal uses the compressed mode for inter-frequency measurement when switching, and the 3GPP system network side instructs the terminal not to perform any synchronization process. The process of re-confirming the system timing information re-confirmation of the known target cell or/and the unknown target cell search, and the synchronization of the transmission timing of the transport block in the target cell during the handover delay time.

The process of decoding the known target cell system timing information or/and the unknown target cell search, and the transmission timing synchronization of the transport block in the target cell are completed within the handover delay time.

When the terminal switches from the FDD cell to the time division duplex (TDD) cell, the terminal completes the process of frame synchronization, the process of waiting for the uplink access time slot to appear, and the re-confirmation of the known target cell system timing information. And a process of decoding a known target cell system timing information or an unknown cell search, and a transmission timing of a transport block in the target cell.

The network side of the 3GPP system determines the handover delay time according to the different handover procedures of the terminal. When the terminal receives the handover command, it performs timing, and determines whether the terminal starts to send and receive user data in the target cell within the determined handover delay time. If yes, the terminal The switch is successful. Otherwise, the terminal switches abnormally this time. Switching an exception can cause the switch to fail or initiate the switch process again.

However, since the physical layer frame structure of the 3GPP system and the LTE system are completely different, The operation performed during the change process will be different, so the process of determining the handover delay time is currently not applicable to the LTE system. In addition, since the LTE system adopts flexible bandwidth technology, this will result in more handover scenarios than the current 3GPP system, and the current process of determining the handover delay time is not applicable to the LTE system; the system timing information decoding and the cell of the LTE system The process of searching and the like is different from the current 3GPP system, and the process of determining the handover delay time is not applicable to the LTE system; since the transmission time interval of the LTE system and the use of the physical channel are different from the current 3GPP system, the current determination is made. The process of switching delay time is not applicable to LTE systems.

In addition, due to the different services provided by the system, there are some differences in the performance requirements of the outage time. In the prior art, the interrupt time is defined as the time between the user equipment (UE, User Equipment) expecting to receive the next SDU and the UE actually receiving the next non-repeating SDU. Perform performance analysis on different data forwarding methods, and assume that the SDU transmission interval is equivalent to the handover execution time. There are usually two handover control methods: (1) Bi-casting method: After the connection between the target cell and the upper-layer gateway is established in the handover preparation phase, the data packet is simultaneously sent by the gateway to the source cell and the target cell, until the UE establishes and targets. The connection of the cell.

As shown in Figure 1, for real-time services, the technique proposes a maximum interruption time of twice the SDU arrival time interval for the handover execution time.

As shown in Figure 2, for non-real-time services, the technology proposes that the maximum interruption time is the handover execution time plus several times the SDU arrival interval, where several times the SDU arrival interval is because a duplicate SDU is received. The received SDU is buffered in the target cell.

(2) Forwarding method: Establish a data tunnel between the target cell and the source cell in the handover preparation phase. For real-time services, data forwarding starts after the tunnel is established. For non-real-time services, data forwarding starts after the UE side handover execution, and only forwards. The SDU that the UE failed to receive on the source cell.

As shown in Figure 3, for real-time services, the technique proposes that the maximum interruption time is twice the switching execution time plus the SDU arrival time interval.

As shown in Figure 4, for non-real-time services: This technique proposes that the interrupt time is equal to the switch execution. Time.

However, due to the inaccurate setting of the interrupt location and the inappropriate setting of the interrupt time, the technique can only be based on the fact that the handover execution time is close to the SDU Arrival Time (ISAT). Therefore, the result of the technology's analysis of the interruption time performance of the real-time service is not a performance requirement; in addition, since the technology does not take into account the repeated SDUs that may be received in the non-real-time service, the accuracy is not high.

Another solution in the prior art is: defining an interruption time for the UE to receive the last downlink Media Access Control Protocol Data Unit (DL MAC PDU) to the UE on the source cell. The time between receiving the first DL MAC PDU on the target cell. The specific process is shown in Figure 5.

However, in this solution, since the technology does not consider the interruption time according to the type of service, there is no flexibility, and the same interruption time for different service types also affects the accuracy of the handover.

In practical applications, the last MAC PDU received on the source cell cannot be guaranteed to be valid, and it is difficult to reorganize into a complete SDU, further reducing the accuracy. Summary of the invention

Embodiments of the present invention provide a handover control method and apparatus for determining a start position and an interruption time of a data flow interruption according to actual conditions to determine a performance requirement of an interruption time, thereby more accurately controlling a handover process.

The embodiment of the invention provides a handover control method, including:

Receiving or transmitting data in the source cell, and starting to switch according to the received switching command;

It is judged whether the terminal is connected to the target cell within a predetermined interruption time, and if so, the handover execution is completed.

Another handover control method provided by an embodiment of the present invention includes:

Receiving a switching command;

Starting to switch according to the switching command;

It is judged whether the handover is completed within the preset handover delay time or the handover execution time, and if so, it is determined that the handover is successful. The embodiment of the present invention provides a handover control method for an LTE system, where the method includes: after the terminal transmits and receives the last transmission block of the source cell, determining whether the source cell switches to the target cell within the set handover execution time, If yes, the handover is successful; the handover execution time includes starting from the end of the transmission and reception of the last transport block of the source cell, re-confirming the target cell system timing information or decoding the target cell system timing information or/and the target cell search, the physical channel The time required to synchronize the transmission time synchronization process of the transport block in the target cell.

An embodiment of the present invention provides a handover control apparatus, including:

The determining unit determines whether the terminal is connected to the target cell within a predetermined interruption time; the switching control unit is configured to start and control the switching process according to the switching command; and the switching control unit controls to perform normal switching.

Another embodiment of the present invention provides a handover control apparatus, where the apparatus includes:

The determining unit determines whether the switching is completed in the preset switching delay time or the switching execution time, and if yes, determines that the switching is successful;

a switching control unit, configured to start and control a switching process according to the switching command;

If the determining unit determines that the terminal completes the handover within the handover delay time or the handover execution time, the handover control unit controls to perform the normal handover.

In the technical solution provided by the embodiment of the present invention, for each handover process of the terminal in the LTE system, various processes that the terminal needs to complete during handover and time required for each process are proposed, thereby determining handover delay of different handover processes of the terminal. Time or switch execution time. Therefore, the method provided by the present invention determines the handover delay time and the handover execution time in the handover process of the LTE system, thereby completing the handover control process.

In the technical solution provided by the present invention, since the exact start and end positions of the data stream interruption are determined, the accuracy of determining the performance requirement of the handover interruption time in the handover process is improved, which is advantageous for accurately controlling the handover process;

Secondly, before determining the exact location of the interrupt and the handover interruption time, the service information used by the terminal user is analyzed, and the performance requirements of different handover interruption times in each case are determined according to the corresponding relationship, and the handover interruption time is also determined. Can be the downlink interruption time, It can also be the uplink interrupt time, which gives a more comprehensive performance requirement for switching interruption time, thereby improving the accuracy of the handover control;

From the perspective of the SDU, compared with the prior art, from the perspective of the MAC PDU, the validity of the data is ensured, and the accuracy of the switching interruption time performance requirement is further improved, thereby further improving the precision of the control switching process. Sex. DRAWINGS

1 is a flow chart of processing a real-time service in the prior art;

2 is a flow chart of processing a non-real time service in the prior art;

FIG. 3 is a flow chart of another process for real-time services in the prior art; FIG.

4 is a flow chart of another process for non-real time services in the prior art;

5 is a flow chart of a prior art handover control method;

6 is a flowchart of a method in an embodiment of the present invention;

7 is a flowchart of a method for handover of a terminal in a first embodiment of the present invention;

FIG. 8 is a flowchart of a method for handover of a terminal according to a second embodiment of the present invention; FIG.

9 is a schematic structural diagram of a system in an embodiment of the present invention;

FIG. 10 is a schematic structural diagram of a system according to an embodiment of the present invention; FIG.

FIG. 11 is a flowchart of a method for handover of a terminal according to still another embodiment of the present invention. detailed description

The present invention will be further described in detail below with reference to the accompanying drawings, in which FIG.

Referring to FIG. 6, a handover control method provided in an embodiment of the present invention includes the following steps:

5101. The terminal receives/transmits data in the source cell, and includes receiving a handover command sent by the original cell, and receiving or sending user data on the source cell.

S102: After receiving/transmitting on the source cell, the terminal starts to receive/send the data packet on the target cell.

5103. If the terminal connects to the target cell during the interruption time, that is, the terminal sends an access signal or/and control signaling, receives or sends user data on the target cell, the handover execution is completed.

Referring to FIG. 9, the system in the embodiment of the present invention includes: The terminal 100 is configured to receive/transmit a data packet on the source cell and the target cell and perform handover. The source cell control unit 200 is configured to send a data packet to or receive a data packet from the terminal before the handover; the target cell control unit 300, It is used to send a data packet to or receive a data packet from the terminal after the handover.

Referring to FIG. 10, the system further includes: a time setting unit 400, configured to establish and store a correspondence between an interruption time and a service type. The terminal 100 is further configured to: initiate a handover request; the source cell control unit 200 is further configured to receive a handover request initiated by the terminal, and send a handover preparation notification to the target cell control unit; the target cell control unit 300 is further configured to receive the source. The handover preparation notification sent by the cell control unit completes the handover preparation.

Referring to FIG. 7, in another embodiment of the present invention, the handover process includes the following steps:

Step 201, the terminal 100 sends a measurement report to the source cell control unit 200;

When the terminal 100 detects that the wireless network condition changes, the terminal 100 sends a measurement report to the source cell control unit 200.

The change of the wireless network condition may be that the terminal 100 moves from the service coverage of one cell to the service coverage of another cell, or may be the edge of the source cell service coverage of the terminal 100. If the number of users in the target cell is small, the terminal 100 will provide services for the target cell to achieve resource balance.

Step 202: The source cell control unit 200 sends a handover decision after receiving the measurement ^= report; Step 203: The source cell control unit 200 sends a handover preparation notification to the target cell control unit 300, requesting that it prepare for the handover;

Step 204, the target cell control unit 300 feeds back the handover preparation reply to the source cell control unit 200;

Step 205: The terminal 100 sends/receives the last valid transport block in the source cell control unit 200.

An effective transport block means that the transport block can be reassembled at the receiving end into a complete and non-repetitive high-level SDU.

Step 206: After receiving the handover preparation reply sent by the target cell control unit 300, the source cell control unit 200 sends a handover command to the terminal 100. The terminal 100 disconnects from the source cell control unit 200 after transmitting/receiving the transport block.

Step 207: Receive/send an invalid transport block.

Step 208: Receive/send the last transport block.

Step 209, the terminal 100 starts to switch to the target cell;

If the terminal fails to receive/send the first valid transmission block on the target cell within the interruption time, the handover exception processing is performed.

The handover exception processing may be to indicate that the handover fails and end the handover, return to the state before the handover, or may automatically re-switch, or may be another manner of exception processing. The downlink interruption time refers to that the terminal receives the last valid transmission block containing the data on the downlink physical channel carrying the data of the source and the area, and the terminal starts receiving the first effective transmission block on the downlink physical channel carrying the data of the target cell. Between the time.

The uplink interruption time refers to that the terminal sends the first valid transport block on the uplink physical channel of the source d and the area carrying the data on the uplink physical channel containing the data effective transport block until the terminal starts to transmit the data on the uplink physical channel of the target cell bearer data. Between the time.

The interruption time T _Intoupt is a fixed time of curing in the device, and the determination methods are as follows:

a, T _{Interrupt is} determined by the number of service data unit SDUs included in the handover execution time and the time required for the SDU to be completely transmitted at the physical layer.

Tinterrupt ⁼ N*T _SDU or T _Interrupt = ( N- l ) *T _SDU .

The T _SDU is a time required for the high-level service data unit SDU to be completely transmitted on the physical channel after being multiplexed into a transport block.

The N is the maximum value of the number of SDUs included in the handover execution time.

b. T _Intemipt is confirmed by the network to delay the disconnection with the terminal, the data forwarding delay, the time required to switch the execution process, the time required to receive the repeated SDU, and the delay between the completion of the handover execution and the reception/transmission of the first transport block by the terminal. determine.

That is, T _Int errupt ⁼ MAX ( TExec_Time , Df _orwarding + Ddetect ) + M* TSDU + Dn;.

C, T _Interrupt delay by switching start position, delay of network acknowledgment and terminal disconnection, number The delay between the forwarding delay, the time required to switch the execution process, the time required to receive the repeated SDU, and the delay between the reception and transmission of the first transport block to the terminal after completion of the handover execution.

Interrupt ⁼ TRJ + MAX( T _Ex ec_Time , Dforwarding+ Ddetect )+ M* T _SDU + Di _Uo d, T _Int , _pt Delayed by the network to confirm disconnection with the terminal, data forwarding delay, time required for switching execution and switching The delay determination between the first transport block is received/transmitted to the terminal 100 after execution is completed.

That is T _IntelTupt = MAX ( T Exec - Time , Df _onv arding + Ddetect ) + I3⁄4u.

Wherein, the Τπ; is due to the delay of switching the execution start point position, the maximum is

TsDU.

The T _SDU is a time required for the high-level SDU to be completely transmitted on the physical channel after being multiplexed into a transport block.

The D _f . _Ding is the network side data forwarding delay.

The D _detect is a delay in which the network confirms disconnection from the terminal.

The T _Exec — _Time is the terminal switching execution time.

The MAX ( T _Exec Time ' Df _{orwar (} jing + Ddetect ) table ⁷ ^ takes TE _xe c_Time and ( Dforwarding

+ D _de tect ) The maximum value.

The M is the number of duplicate SDUs received or transmitted by the terminal.

The _Dm is a delay between when the handover execution is completed and when the terminal 100 receives/transmits the first transport block.

The DKJ includes a signaling retransmission delay, a processing delay or a retransmission delay, and the like.

The method for determining the switching time in the foregoing embodiment is completed by giving an expression form, and can also be completed by a method for giving a constant value by a system simulation result.

Step 210: The terminal 100 sends signaling to the target cell control unit 300.

The terminal 100 sends a signaling to the target cell control unit 300 to indicate that the handover has been completed.

Step 211, generating a delay;

The delay includes a signaling retransmission delay, a processing delay, or a retransmission delay.

Step 212: The target cell control unit 300 starts an interaction with the terminal 100. The terminal 100 starts to transmit/receive the first valid transport block. Step 213: The target cell control unit 300 notifies the source cell control unit 200 that the handover ends; Step 214, dry resources.

The source cell control unit 200 releases the resource allocated to the terminal 100 after receiving the notification message of the handover end sent by the target cell control unit 300.

Another embodiment of the present invention, referring to FIG. 8, the handover process includes the steps of:

Step 301, the time setting unit 400 establishes a correspondence relationship between the interruption time and the service type;

The time setting unit 400 may be integrated in the terminal 100, may be integrated in the source cell control unit 200, and may be integrated in other units.

The time setting unit 400 establishes a correspondence relationship between the interruption time T _Interrupt and the service type, and the specific establishment method is as follows:

1. If the terminal is currently using real-time services, T _{IntOTUpt is} determined by the number of service data unit SDUs included in the handover execution time and the time required for the SDU to be completely transmitted at the physical layer.

La. If the upper layer does not indicate the control plane and user plane coordination processing, then T _Intemipt = N*T _SDU ; lb. If the upper layer indicates the control plane and the user plane coordinate processing, then T _IntOTUpt = ( N-1 ) * T _SDU ; The T _SDU is the time required for the high-level service data unit SDU to be completely transmitted on the physical channel after being multiplexed into a transport block.

2. If the terminal is currently using non-real-time services:

2a. If the SDU is sent as a whole:

2al. If the upper layer does not indicate that the control plane and the user plane coordinate processing, the T _IntOTUpt is interrupted by the switching start position, the network acknowledgement and the terminal disconnection delay, the data forwarding delay, the time required to switch the execution process, and the received SDU. The required time and the delay between the completion of the handover execution and the reception/transmission of the first transport block by the terminal are determined:

That is, Ti _n terrupt = T _LY + MAX ( TE _xec _Time , Dforwarding + Ddetect ) + M * TSDU + D _{I ( J} ;

2a2. If the upper layer instructs the control plane and the user plane to coordinate processing, the T _IntOTUpt is confirmed by the network to delay the disconnection from the terminal, the data forwarding delay, the time required to switch the execution process, and the repeated reception.

The time required by the SDU and the delay between the completion of the handover execution and the first transport block of the terminal are determined: That is, Tinterrupt ⁼ MAX (TExec_Time, Dforwarding + ^detect ) + M* TsDU + DlU; 2b. If the SDU is sent in segments, the data is not received completely, but the terminal 100 exchanges the last received SDU with the network. Segmentation information, and only need to resend the segment of the SDU that did not send successfully. Then, T _IntOTUpt is confirmed by the network to delay the disconnection with the terminal, the data forwarding delay, the time required for the handover execution process, and the delay determination between the reception/transmission of the first transport block by the terminal 100 after the completion of the handover execution.

That is, Tinterrupt ⁼ MAX (TE _xec _Time , Dforwarding + Dd _e t _ec t ) + Diu.

Wherein, the T is a delay due to the uncertainty of the location of the handover execution start point, and the maximum is

TsDU.

The D _fOTWal . _ding is a network side data forwarding delay.

The D _detect is a delay generated by the network side detecting a connection lost to the terminal.

The T _Exec — _Time is the terminal switching execution time.

The MAX (T _Exe c_Time , Dforwarding + D _detect ) indicates that TE _xec _Time and (Dforwarding) are taken.

The maximum value of + D _d etect ).

The M is the number of duplicate SDUs received or transmitted by the terminal.

The DKJ is a delay between the completion of the handover execution and the reception/transmission of the first transport block by the terminal.

The D _m includes a signaling retransmission delay, a processing delay or a retransmission delay, and the like.

Wherein, for the non-real-time services, if the user plane gateway method using simultaneously transmits packets to the source cell and the target cell, need not be considered 0 _{¾ (^} and _{_{0 (1 ^ 1, MAX (}} T Exec _ Time,

Dforwarding + D _detect ) can be expressed directly as T Exec Time.

For non-real-time services, if the system QoS specifies that duplicate SDUs are not allowed to be received in non-real-time services, then the above M is 0.

For non-real-time services, if the system QoS has been specified to allow the maximum value of the repeated SDUs to be received in the non-real-time service, then the above M takes the maximum value.

For non-real-time services, if the last received SDU sequence number is exchanged between the terminal and the network, then the above M is 0. The form is completed, it is understandable that it can also be done by the method of system simulation to give a constant value.

The terminal 100 must complete the following operations during the interruption time:

1. Receiving, from the source cell, an SDU segment transport block that is incomplete before the handover is performed;

2. The network confirms the delay caused by the disconnection of the terminal and the data forwarding, or the switching execution process;

3. After the handover execution is completed, the terminal and the target cell perform signaling exchange and signaling processing, or a retransmission process;

4. Receiving an incomplete SDU segment transmission block or a duplicate after the handover is performed from the target cell.

SDU segmentation transport block.

Step 302, the terminal 100 sends a measurement report to the source cell control unit 200;

Step 303: The source cell control unit 200 sends a handover decision after receiving the measurement report. Step 304: The source cell control unit 200 sends a handover preparation notification to the target cell control unit 300, and requests it to prepare for the handover.

Step 305, the target cell control unit 300 feeds back the handover preparation reply to the source cell control unit 200;

According to 306, the corresponding interrupt time is queried;

The terminal 100 queries the corresponding relationship according to the currently used service type, and obtains a corresponding interruption time.

Step 307: The terminal 100 sends/receives the last valid transport block from the source cell control unit 200. An effective transport block means that the transport block can be reassembled at the receiving end into a complete and non-repeating high-level SDU.

Step 308: After receiving the switch preparation reply sent by the target cell control unit 300, the source cell control unit 200 sends a handover command to the terminal 100.

The terminal 100 disconnects the source cell control unit 200 after transmitting/receiving the transport block. Step 309, receiving/sending an invalid transport block;

Step 310, receiving/sending the last transport block;

Step 311: The terminal 100 starts to switch to the target cell.

If the terminal fails to receive/send the first valid transport block on the target cell within the interruption time, the handover abnormality processing is performed.

The switching abnormality processing may be a method of indicating that the handover fails and ending the handover, returning to the state before the handover, or automatically re-switching, or other abnormal processing.

Step 312: The terminal 100 sends signaling to the target cell control unit 300.

Step 313, generating a delay;

Step 314, the target cell control unit 300 starts interaction with the terminal 100; wherein, the terminal 100 starts to transmit/receive the first valid transport block.

Step 315, the target cell control unit 300 notifies the source cell control unit 200 that the handover ends; Step 316, release the resource.

In summary, when the radio condition changes, the terminal 100 reports the measurement report to the source cell control unit 200, and the source cell control unit 200 notifies the target cell control unit 300 to perform handover preparation. After the target cell control unit 300 completes the handover preparation, the source The cell control unit 200 sends a handover command to the terminal 100. After receiving the handover command, the terminal 100 performs handover, and completes the handover within the interruption time. Otherwise, the handover fails. After the handover is completed, the target cell control unit 300 is completed. The handover end message is sent to the source cell control unit 200, and the source cell control unit 200 releases the resources.

In the alternative, before the terminal 100 reports the measurement report to the source cell control unit 200, the time setting unit 400 establishes a correspondence between the interruption time and the service type. Before the source cell control unit 200 sends the handover command to the terminal 100, The time setting unit 400 queries the corresponding interrupt time according to the currently used service type, and the terminal 100 completes the handover according to the interruption time.

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

The determining unit determines whether the terminal is connected to the target cell within a predetermined interruption time; the switching control unit is configured to start and control the switching process according to the switching command; and the switching control unit performs the normal processing.

If the determining unit determines that the target cell is not connected within the interruption time, the switching control unit performs handover exception processing;

The handover exception processing includes indicating that the handover fails and ending the handover, returning to the state before the handover; or automatically re-switching.

The system further includes a storage unit configured to store a correspondence between the set interruption time and the service type;

The determining unit acquires an interruption time corresponding to the service type from the storage unit.

The working process of the device is the same as that described in the foregoing embodiment, and details are not described herein again. Referring to FIG. 9 and FIG. 10, the handover control system provided by the present invention includes: a terminal 100, configured to receive/transmit a data packet on a source cell and a target cell and perform handover; and a source cell control unit 200, configured to The terminal sends a data packet or receives a data packet from the terminal. The target cell control unit 300 is configured to send a data packet to the terminal or receive the data packet from the terminal after the handover.

The system further includes: a time setting unit 400, configured to establish a correspondence between the interrupt time and the service type and store the corresponding relationship.

The terminal 100 is further configured to initiate a handover request. The source cell control unit 200 is further configured to receive a handover request initiated by the terminal, and send a handover preparation to the target cell control unit. The target cell control unit 300 is further configured to receive a handover preparation notification sent by the source cell control unit and complete handover preparation.

When the radio condition changes, the terminal 100 reports the measurement report to the source cell control unit 200, and the source cell control unit 200 sends a handover preparation notification to the target cell control unit 300 after receiving the measurement report, and the feedback is performed after the target cell control unit 300 completes the handover preparation. The acknowledgment message is sent to the source cell control unit 200. After receiving the feedback message, the source cell control unit 200 sends a handover command to the terminal 100. After receiving the handover command, the terminal 100 performs handover, and completes the handover within the interruption time. Otherwise, the handover fails, and after the handover is completed. Then, the target cell control unit 300 transmits a handover end message to the source cell control unit 200, and the source cell control unit 200 releases the resource.

In the alternative, the correspondence between the interruption time and the service type may be established by the time setting unit 400 before the terminal 100 reports the measurement report to the source cell control unit 200, and the feedback confirmation message is sent to the source after the target cell control unit 300 completes the handover preparation. The cell control unit 200 then queries the time setting unit 400 for the corresponding interrupt time according to the currently used service type, and the terminal 100 completes the handover at the interruption time.

In summary, when the radio condition changes, the terminal 100 reports the measurement report to the source cell control unit 200, and after receiving the measurement report, the source cell control unit 200 sends a handover preparation notification to the target cell control unit 300, when the target cell control unit 300 After the handover preparation is completed, the feedback confirmation message is sent to the source cell control unit 200. After receiving the feedback message, the source cell control unit 200 sends a handover command to the terminal 100. After receiving the handover command, the terminal 100 performs handover, and if the handover is not completed within the interruption time, The handover fails. If the handover is completed within the interruption time, the target cell control unit 300 transmits a handover end message to the source cell control unit 200, and the source cell control unit 200 releases the resource.

In another embodiment of the present invention, a method for performing handover by a terminal is as shown in FIG. 11. The handover delay time or the handover execution time is set in advance in the terminal, and the handover delay time is based on a process and a delay time that the terminal passes during the handover process. Determining, the handover execution time is determined according to a process to be performed by the terminal in the handover process, and the network entity involved in the method includes a terminal, a cell where the terminal is currently located, that is, a source cell, a cell to which the terminal is handed over, that is, a target cell, and On the network side of the LTE system, the specific steps are as follows:

Step 400 to step 401, the radio condition of the area where the terminal is located changes, and the terminal moves to the source cell. Report the measurement report.

Step 402 - Step 403: The source cell determines to switch the terminal according to the measurement report reported by the terminal, and sends a handover preparation request of the terminal to the target cell.

Step 404 - Step 405: The target cell that receives the handover preparation request prepares for handover through the network side of the LTE system, and after the handover preparation is completed, sends a handover preparation confirmation to the source cell.

Step 406: The source cell that receives the handover preparation confirmation sends a handover command to the terminal.

Step 407: After receiving the handover command, the terminal performs timing and starts handover, and after the handover to the target cell, the target cell sends a handover complete message of the terminal to the source cell.

The process of switching includes: switching the delay process and switching the execution process.

The process of switching may also include only the handover execution process.

The handover delay process includes: receiving a handover command start, an LTE processing delay or waiting activation time delay, transmitting and receiving of a last transmission block of a source cell, re-confirming a target cell system timing information, or decoding target cell system timing information or/and a target cell The process of searching, synchronizing the physical channel to the transmission time of the upper transport block.

The handover execution process includes: starting from the end of the transmission and reception of the last transport block of the source cell, re-confirming or decoding the target cell system timing information or/and the target cell search, and the physical channel synchronization to the transport block in the target cell. The process of sending time synchronization.

Step 408: The terminal determines whether the handover is completed within the set handover delay time or the handover execution time. If yes, step 409 is performed; otherwise, the source cell confirms that the handover process of the terminal is abnormal, and ends (not shown).

An abnormality in the switching process may cause the handover to fail or re-initiate the handover process.

Step 409: The handover process of the terminal is successful, and the source cell releases the resources occupied by the terminal in the source cell through the network side of the LTE system, and ends.

In the present invention, the handover delay time is defined as: the time between the completion of reception of the last transmission data block containing the handover command on the source cell to the time when the terminal starts transmitting and receiving user data on the physical channel of the target cell.

The handover delay time also includes the handover execution time of the terminal, and the handover execution time is defined as: the terminal completes the transmission and reception of the last transmission data block containing the data on the source cell until the terminal starts to send and receive user data on the physical channel of the target cell. time. If the handover command sent by the source cell to the terminal includes an activation time and indicates that the activation time is greater than the processing delay time of the terminal, the handover delay time includes an activation time included in the handover command and a handover execution time; if the source cell sends a handover command to the terminal The activation time is included and the indicated activation time is the current time or is not greater than the processing delay time of the terminal, or the switching time sent by the source cell to the terminal does not include the activation time, and the handover delay time includes the processing delay time of the terminal and the handover. execution time.

The following describes in detail how to determine the handover execution time of the terminal for different handover procedures. The terminal is switched from FDD cell handover to FDD cell

When the terminal does not need to change the operating frequency during the handover process, the terminal completes the process of re-confirming the identified target cell system timing information or/and the unidentified target cell search, the process of physical channel synchronization, and the transport block in the target cell. The process of sending time synchronization. Therefore, when determining the handover execution time of the terminal, it is required to include the process time of the identified target cell system timing information re-confirmation and/or the unidentified target cell search, the process time of the physical channel synchronization, and the transmission time synchronization of the transport block in the target cell. Process time.

When the terminal needs to change the operating frequency during the handover process, the terminal completes the process of decoding the identified target cell system timing information or/and the unidentified target cell search, the process of physical channel synchronization, and the transmission of the transport block in the target cell. The process of time synchronization. Therefore, when determining the handover execution time of the terminal, it is required to include decoding the identified target cell system timing information or/and the process time of the unidentified target cell search, the process time of the physical channel synchronization, and the transmission time synchronization of the transport block in the target cell. Process time.

The terminal is switched from the FDD cell to the TDD cell.

The terminal can support two modes, FDD and TDD.

When the target cell is the identified cell and the terminal obtains the target cell system timing information, the terminal completes the frame timing synchronization process, the process of waiting for the uplink access time slot to appear, the process of re-confirming the target cell system timing information, and The process of transmitting timing synchronization of transport blocks in the target cell. Therefore, when determining the handover execution time of the terminal, the process time including the completion of the frame timing synchronization, the process time of waiting for the uplink access slot to appear, the process time of the re-confirmation of the target cell system timing information, and the transport block in the target cell are required. The process time for sending timing synchronization. When the target cell is an identified cell and the terminal does not obtain the target cell system timing information, the terminal completes the frame timing synchronization process, the process of waiting for the uplink access time slot to appear, the process of decoding the target cell system timing information, and the process of decoding the target cell system timing information. The process of transmitting timing synchronization of transport blocks in the target cell. Therefore, when determining the handover execution time of the terminal, the process time including the completion of the frame timing synchronization, the process time of waiting for the uplink access slot to appear, the process of decoding the target cell system timing information, and the transmission of the transport block on the target cell are required. Timing synchronization process time.

When the target cell is an unidentified cell, the terminal completes the process of frame timing synchronization, the process of waiting for the uplink access slot to appear, the process of searching for the unidentified target cell, and the transmission timing synchronization of the transport block in the target cell. the process of. Therefore, when determining the handover execution time of the terminal, the process time including frame timing synchronization, the process time of waiting for the uplink access slot to appear, the process time for searching for the unidentified target cell, and the transmission timing of the transport block in the target cell are required. Synchronization process time.

In the embodiment of the present invention, the frame timing synchronization process may be a process in which a channel required for synchronization is present, and therefore, the frame timing synchronization process time may be a process time in which a channel required for synchronization is present.

The process time at which the terminal performs frame timing synchronization, that is, the process time required for the channel waiting for synchronization to occur is 5 milliseconds (ms) times, instead of 10 ms in the prior art, so it can be determined that the process time of the frame timing synchronization can be set. Set to 5ms.

Waiting for the uplink access slot to appear in the process time is 5ms, instead of the prior art

10ms, so it can be determined that the waiting time for waiting for the uplink access slot to occur is 5ms.

In the embodiment of the present invention, the process time of the unknown cell search or the system timing information confirmation of the known cell is different from the time used by the prior art, mainly because the frame structure of the LTE system and the frame structure of the 3GPP system are not the same.

In the embodiment of the present invention, the process timing of the transmission timing synchronization of the transport block in the target cell may be determined to be an integer multiple of 0.675 ms or 0.5 ms or 0.5 ms, which is also different from the prior art 10 ms.

In summary, considering the system characteristics of LTE, the performance requirements of handover delay time and handover execution time in different handover procedures are given for different handover procedures of the terminal. Improved switching control performance.

The description of the above embodiments is only for helping to understand the method of the present invention and its core ideas; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in specific embodiments and applications. In summary, the content of the specification should not be construed as limiting the invention.

Claims

Rights request

A switching control method, comprising:

In the process of receiving or transmitting data in the source cell,

Start switching according to the received switching command;

The handover control method according to claim 1, further comprising: performing handover exception processing if the terminal fails to receive or transmit the first valid transport block on the target cell within the interruption time;

The handover exception processing includes indicating that the handover fails and ends the handover, returns to the state before the handover, or automatically re-switches.

3. The handover control method according to claim 1, wherein:

The interruption time is a downlink interruption time or an uplink interruption time;

The downlink interruption time is a time between when the terminal completes receiving of the last valid transmission block of the source cell and when the terminal starts receiving the first valid transmission block in the target cell;

The uplink interruption time is a time between when the terminal completes transmission of the last valid transmission block of the source cell and when the terminal starts transmitting the first valid transmission block in the target cell.

The handover control method according to claim 1, wherein the interruption time of the handover from the source cell to the target cell is determined by the following steps:

The interruption time from the source cell to the target cell is determined according to the time required for the service data unit SDU and SDU involved in the handover process to be transmitted at the physical layer.

5. The handover control method according to claim 1, wherein the interruption time is determined by the following steps:

The network acknowledges the delay with the terminal disconnection, the data forwarding delay, the time required for the handover execution process, the time required to receive the repeated SDU, and the delay between the completion of the handover execution and the reception or transmission of the first transport block by the terminal. The interruption time to the target cell.

6. The handover control method according to claim 1, wherein the interruption time is determined by the following steps:

Delay based on switching start position, delay of network acknowledgment and terminal disconnection, data forwarding The delay, the time required to switch the execution process, the time required to receive the repeated SDU, and the delay between the completion of the handover execution and the reception or transmission of the first transport block by the terminal determine the interruption time.

The interruption time is determined according to the delay of the network acknowledgment with the terminal disconnection, the data forwarding delay, the time required for the handover execution process, and the delay between the completion of the handover execution and the reception or transmission of the first transport block by the terminal.

The handover control method according to claim 1, further comprising: before the cell handover is performed, the terminal sends a handover request to the source cell;

The source cell sends a handover preparation notice to the target cell;

The target cell sends a handover preparation confirmation to the source cell;

After receiving the acknowledgement, the source cell sends a handover command to the terminal.

The handover control method according to claim 1, further comprising: determining, before the cell handover is performed, determining a required transmission time of the relevant service data unit and a related cell wireless communication parameter according to the type of service used, to determine The interruption time.

10. A handover control method, the method comprising:

Receiving a switching command;

According to the switching command, the switching starts;

It is judged whether the handover is completed within the preset handover delay time or the handover execution time, and if so, it is determined that the handover is successful.

The switching control method according to claim 10, further comprising:

If the terminal fails to complete the handover within the handover delay time or the handover execution time, the handover exception processing is performed;

12. The switching control method according to claim 10, wherein

When the activation time of the handover command is not greater than the processing delay time of the terminal, the handover delay time includes a handover execution time and a processing delay time of the terminal; When the activation time of the handover command is greater than the processing delay time of the terminal, the handover delay time includes the handover execution time and the activation time.

The method according to claim 10, wherein when the source cell and the target cell are both frequency division duplex FDD cells and the terminal does not need to change the frequency, the handover execution time includes:

The process time of the target cell system timing information re-acknowledgment or/and the unidentified target cell search, the process time of the physical channel synchronization, and the process time of the transmission time of the transport block in the target cell are identified; or

When the source cell and the target cell are both frequency division duplex FDD cells and the terminal needs to change the frequency, the handover execution time includes:

Decoding the identified target cell system timing information or/and the process time of the unidentified target cell search, the process time of the physical channel synchronization, and the process time of the transmission time synchronization of the transport block in the target cell.

14. The method of claim 10, wherein

The source cell is an FDD cell, and the target cell is a time division duplex TDD cell and is an identified cell, and the terminal has obtained target cell system timing information, where the handover execution time includes:

The process time of the channel waiting for synchronization, the process time of waiting for the uplink access time slot, the process time of the re-confirmation of the target cell system timing information, and the process time of the transmission timing of the transmission block in the target cell; or

The source cell is an FDD cell, and the target cell is a time division duplex TDD cell and is an identified cell, and the terminal does not obtain target cell system timing information, where the handover execution time includes:

The process time of the channel waiting for synchronization, the process time of waiting for the uplink access time slot, the process time of decoding the target cell system timing information, and the process time of the transmission timing of the transmission block in the target cell; or

The source cell is an FDD cell, and the target cell is a time division duplex TDD cell and is an unidentified cell, and the handover execution time includes:

Process time for waiting for the channel required for synchronization, waiting for uplink access slot The current process time, the process time for searching for the unidentified target cell, and the transmission timing synchronization process time of the transport block in the target cell.

The method according to claim 14, wherein the process time at which the channel required to wait for synchronization occurs is a process time of frame timing synchronization.

A handover control method for an LTE system, the method comprising: determining, after the terminal transmits and receives the last transmission block of the source cell, whether the source cell switches to the target cell within the set handover execution time. If yes, the switch is successful;

The handover execution time includes starting from the end of the transmission and reception of the last transmission block of the source cell, re-confirming or decoding the target cell system timing information or/and the target cell search, and the physical channel synchronization to the target cell in the target cell. The time required to send the time synchronization process.

The method according to claim 16, wherein, when both the source cell and the target cell are frequency division duplex FDD cells and the terminal does not need to change the frequency, the target cell system timing information re-confirm or decode the target. The process of cell system timing information or/and target cell search includes:

The steps of re-confirming the target cell system timing information or/and unidentified target cell search are identified; or

When the source cell and the target cell are both frequency division duplex FDD cells and the terminal needs to change the frequency, the process of re-confirming or decoding the target cell system timing information or/and the target cell search by the target cell system timing information includes:

The steps of decoding the identified target cell system timing information or/and the unidentified target cell search are decoded.

The method according to claim 16, wherein the source cell is an FDD cell, the target cell is a time division duplex TDD cell, and is an identified cell, and the terminal has obtained target cell system timing information, The process of re-confirming or decoding the target cell system timing information or/and the target cell search by the target cell system timing information includes: a step of re-confirming the target cell system timing information;

The handover execution time further includes: a process time for waiting for a channel required for synchronization and a process time for waiting for an uplink intrusion slot to occur.

The method according to claim 16, wherein the source cell is an FDD cell, the target cell is a time division duplex TDD cell and is an identified cell, and the terminal does not obtain target cell system timing information, The process of re-confirming or decoding the target cell system timing information or/and the target cell search by the target cell system timing information includes: a step of decoding the target cell system timing information;

The handover execution time further includes: a process time for waiting for a channel required for synchronization and a process time for waiting for an uplink time slot to occur.

The method according to claim 17, wherein the source cell is an FDD cell, the target cell is a time division duplex TDD cell, and is an unidentified cell, and the target cell system timing information re-confirms or decodes the target cell. The process of system timing information or/and target cell search is: searching for a process of not identifying a target cell;

The handover execution time further includes: a process time for waiting for a channel required for synchronization and a process time for waiting for an uplink i3⁄4 wife to enter a time slot.

The method according to claim 18 or 19, characterized in that the process time of the channel required to wait for synchronization is the process time of the frame timing synchronization.

22. A switching control device, comprising:

The determining unit determines whether the terminal is connected to the target cell within a predetermined interruption time; the switching control unit is configured to start and control the switching process by the switching command; and the switching control unit controls to perform the normal switching.

23. Apparatus according to claim 22 wherein:

The device according to claim 22, further comprising:

a storage unit, configured to store a correspondence between the set interrupt time and the service type;

25. A switching control device, the device comprising: The determining unit determines whether the switching is completed in the preset switching delay time or the switching execution time, and if yes, determines that the switching is successful;

The switching control unit is configured to start and control the switching process according to the switching command; when the switching is performed, the switching control unit controls to perform normal switching.

The handover control method according to claim 25, further comprising:

If the determining unit determines that the terminal fails to complete the handover within the handover delay time or the handover execution time, performing handover exception processing;