CN106937338B

CN106937338B - Link reconstruction method and system

Info

Publication number: CN106937338B
Application number: CN201511021363.4A
Authority: CN
Inventors: 许森; 孙震强; 张光辉
Original assignee: China Telecom Corp Ltd
Current assignee: China Telecom Corp Ltd
Priority date: 2015-12-31
Filing date: 2015-12-31
Publication date: 2020-01-10
Anticipated expiration: 2035-12-31
Also published as: CN106937338A

Abstract

The invention provides a link reselection method and a link reselection system, and relates to the field of wireless communication. The link reconstruction method comprises the following steps: a base station receives an RRC reestablishment request message from a terminal, wherein the RRC reestablishment request message comprises extension carrier information for indicating that the terminal has radio link failure in an extension carrier; the base station adds the extension carrier information in the switching report information sent to the base station to which the cell with the radio link failure belongs, so that the base station to which the cell with the radio link failure belongs determines the radio link failure condition of the extension carrier of the cell with the radio link failure. By the method, when the terminal generates the radio link failure in the extension carrier, the base station to which the cell generating the radio link failure belongs can determine the carrier type generating the radio link failure, thereby providing a data basis for executing adjustment to reduce the probability of the radio link failure.

Description

Link reconstruction method and system

Technical Field

The present invention relates to the field of wireless communications, and in particular, to a link reestablishment method and system.

Background

In the current LTE/LTE-a protocol, the LTE single carrier bandwidth only supports several configurations such as 1.4MHz,3MHz,5MHz,10MHz,15MHz, and 20MHz, but in the actual LTE frequency re-cultivation process, an operator finds that the sum of carrier bandwidths of multiple frequency points of a 2G/3G system (such as GSM/WCDMA/CDMA2000) is not an integral multiple of the bandwidth defined by LTE, so that this situation inevitably causes a waste of frequency resources in the hands of the operator.

In order to solve the above problems, some GSM/WCDMA companies and operators in the standardization work of 3GPP R13 propose a concept of "flexible bandwidth", and hope that the operators can use the existing frequency resources more flexibly without affecting the compatibility of the network and the terminal, and push the frequency re-cultivation work of 2G/3G. These companies are currently pushing the work of "flexible bandwidth" technology throughout the 3 GPP.

The principle of "flexible bandwidth" is shown in fig. 1. For a downlink 7MHz bandwidth, the base station side transmits signals in the whole 7MHz, and for a traditional terminal which does not support 'flexible bandwidth', the base station side can only work on the traditional 5MHz bandwidth, and the rest 2MHz bandwidth resource is not available for the traditional terminal. For terminals supporting "flexible bandwidth", it is possible to operate above the conventional 5MHz and 5MHz extension. Therefore, the new and old terminals can work on different 5MHz frequencies, thereby solving the problem of carrier compatibility. We call the flexible bandwidth non-supported terminal access carrier the primary carrier on which the relevant common, user specific signals and the relevant channel information are transmitted as specified in 3GPP R12 and earlier releases. We call a carrier that cannot be accessed by a terminal that does not support flexible bandwidth as an extension carrier, where in a non-overlapping area of the extension carrier, as shown in fig. 2, a base station does not transmit a conventional downlink Common control Signal, a PBCH (Physical broadcast channel), a synchronization Signal, etc., but still transmits a CRS (Common Reference Signal). When the terminal works in the extended carrier, the scheduling information and the feedback information of the base station side are obtained by reading an enhanced Physical downlink control Channel (ePDCCH).

Once a radio link failure occurs in a terminal, first, cell reselection is required to select a suitable cell for camping, and an RRC connection reestablishment procedure is sent on the suitable cell, where a reestablishment request message carries the following information for identifying a user identity:

RRCConnectionReestablishmentRequest message

as can be seen from the above information, the identification information of the terminal includes the C-RNTI of the user, the cell identity of the radio link failure, and the encryption authentication information ShortMAC-I.

According to the notification of the reconstruction condition, the reconstruction cell utilizes the X2 Handover information Handover Report to the failed cell of the radio link, and the failed cell can adjust radio parameters according to the statistical result so as to realize the optimization of radio performance.

TABLE 1Handover Report message

According to the above messages, it can be known that, when an extension carrier is introduced into a network, a network side cannot determine a carrier type of a radio link failure, that is, in RRC connection reestablishment and an MRO process of SON, interactive information only includes an identifier (such as PCI or ECGI information) of a failed cell, and since the extension carrier and a main carrier may use the same PCI and ECGI information from a planning angle and a pilot pattern, the network and a target cell cannot distinguish whether a failure is generated on the main carrier or the extension carrier, and since the extension carrier is close to other systems and is easily interfered by other systems, a higher call drop probability may be generated.

Disclosure of Invention

An object of the present invention is to provide a scheme in which a base station knows a carrier type of a radio link failure.

According to an aspect of the present invention, a link reestablishing method is provided, including: a base station receives a Radio Resource Control (RRC) reestablishment request message from a terminal, wherein the RRC reestablishment request message comprises extension carrier information which indicates that the terminal has radio link failure in an extension carrier; the base station judges whether the radio link failure occurs in the reestablished cell according to the RRC reestablishment request message; if the radio link failure does not occur in the reestablished cell, the base station adds the extension carrier information in the switching report information sent to the base station to which the cell with the radio link failure belongs so that the base station to which the cell with the radio link failure belongs determines the radio link failure condition of the cell with the radio link failure; and if the radio link failure occurs in the reestablished cell, the base station determines the radio link failure condition of the expanded carrier of the reestablished cell according to the expanded carrier information in the RRC reestablishment request message.

Optionally, the method further comprises: and the terminal residing in the extended frequency band tries to perform a cell reconstruction process under the condition of radio link failure, selects a reconstruction cell according to reselection configuration information in the broadcast message, and sends an RRC reconstruction request message to the reconstruction cell.

Optionally, the reselection configuration information includes unidirectional reselection configuration information that the extension carrier is reselected to the main carrier, and when a radio link failure occurs to a terminal residing in the extension frequency band, the terminal configures the extension carrier residing in the terminal as the lowest priority and starts a reselection timer to time according to the unidirectional reselection configuration information, and selects a suitable target cell according to the frequency priority within a preset time range; if the target cell suitable for residing is found, reselecting the terminal to reside in the target cell; and if the terminal cannot find the target cell suitable for residing in the preset time range, the terminal selects the suitable target cell to reside in by executing a cell search process.

Optionally, the method further comprises: the base station to which the cell with the radio link failure occurs counts the radio link failure information of the cell with the radio link failure according to the RRC reestablishment request message from the terminal or the switching report information from the base station to which the cell with the radio link failure occurs, wherein the radio link failure information comprises the time for the radio link failure to occur, the carrier type, the reestablishment cell identification and the failure cell identification; and if the RRC reestablishment request message or the switching report message comprises the information of the extension carrier, determining that the radio link failure occurs in the extension carrier.

Optionally, the base station to which the cell in which the radio link failure occurs counts the number of radio link failures occurring in the main carrier and the number of radio link failures occurring in the extension carrier within a predetermined time according to the radio link failure information; calculating the radio link failure proportion of the cell in the extended carrier by the base station to which the cell with the radio link failure occurs, wherein the radio link failure proportion of the cell in the extended carrier is the proportion of the radio link failure times in the extended carrier to the total failure times; and the base station of the cell with the radio link failure reports the radio link failure ratio of the cell in the extension carrier and the radio link failure times of the cell in the extension carrier to the network management system.

Optionally, the method further comprises: the network management system judges whether the radio link failure ratio of the cell in the extension carrier exceeds a preset failure threshold according to the radio link failure ratio of the extension carrier acquired from the base station; if the radio link failure exceeds the preset failure threshold, sending scheduling information to the base station of the cell with the radio link failure, so as to adjust the switching parameters or control the base station to avoid scheduling the cell edge users to the extension carrier wave through the scheduling information.

Optionally, the handover parameters include a main carrier handover parameter and an extension carrier handover parameter; the main carrier switching parameter is a decision threshold of the terminal for switching from the main carrier of the cell of the base station to the main carrier of the adjacent cell; the switching parameter of the extension carrier is a decision threshold of the terminal for switching from the extension carrier of the cell of the base station to the extension carrier or the main carrier of the adjacent cell; and the network management system controls the base station to adjust the extended carrier switching parameters of the base station through the scheduling information.

Optionally, the method further comprises: the network management system starts the mobile performance optimization function and sends an indication message to the base station; the base station starts a mobility optimization function according to the indication message, and issues an RRC configuration message to a terminal working in an extension carrier or needing to be switched to the extension carrier, wherein the RRC configuration message comprises mobility optimization configuration information; the terminal executes extended carrier measurement operation according to the mobility optimization configuration information, and measures Reference Signal Receiving Quality (RSRQ) and Reference Signal Receiving Power (RSRP) of an extended carrier of a cell where the terminal is located; when a terminal working on an extended carrier wave has a radio link failure, the terminal reports the RSRQ and the RSRP of a cell with the radio link failure to a base station through an RRC reestablishment request message.

Optionally, the mobility optimization configuration information includes: the extended carrier measurement instruction is that a terminal working on an extended carrier or needing to be switched to the extended carrier measures the parameters of the extended carrier of a cell according to the extended carrier measurement instruction; a measurement reporting instruction, wherein a terminal working in an extension carrier or needing to be switched to the extension carrier reports a measurement result through an RRC reestablishment request message when a radio link failure occurs according to the measurement reporting instruction; a measurement quantity comprising RSRP and/or RSRQ.

Optionally, the method further comprises: a base station reports the extended carrier RSRQ and the RSRP of a cell where a terminal is located to a network management system; if the network management system judges that the radio link failure ratio of the cell in the extension carrier exceeds a preset failure threshold, the network management system compares the RSRQ information with the RSRQ threshold and compares the RSRP information with the preset RSRP threshold; if the RSRQ information is lower than a preset RSRQ threshold and the RSRP information is higher than the preset RSRQ threshold, the network management system controls the base station to avoid dispatching the cell edge users to the extension carrier through the dispatching information; and if the RSRQ information is higher than the preset RSRQ threshold and the RSRP information is lower than the preset RSRQ threshold, the network management system controls the base station to adjust the expanded carrier switching parameters through the scheduling information.

Optionally, the RRC configuration message further includes a neighbor cell list supporting extended carrier measurement; the terminal measures extension carriers RSRP and RSRQ of adjacent cells in an adjacent cell list supporting extension carrier measurement of the RRC configuration message, main carriers RSRP and RSRQ of the adjacent cells, and main carriers RSRP and RSRQ of other adjacent cells are measured; when a terminal working on an extended carrier wave has a radio link failure, the terminal reports the RSRP and the RSRQ of the adjacent cell, the carrier wave type and the cell identification to a base station through an RRC reestablishment request message.

Optionally, the method further comprises: the base station judges whether to execute carrier switching or not based on the extended carrier switching parameters according to the RSRQ and the RSRP of the cell where the terminal is located and acquired from the terminal; and the base station determines a cell and a carrier type to which the terminal is switched according to the RSRP, the RSRQ and the carrier type of the neighbor cell of the cell in which the terminal is located in the cell list of the RRC configuration message acquired from the terminal.

Optionally, the mobility optimization configuration information further includes: and if the terminal working on the extension carrier or needing to be switched to the extension carrier measures that the RSRP and/or the RSRQ of the adjacent cell reaches the configuration parameter of the adjacent cell, the terminal reports the RSRP and/or the RSRQ of the adjacent cell to the base station through an RRC reestablishment request message when the radio link failure occurs in the terminal.

Optionally, the extension carrier information is 1-bit identification.

By the method, when the terminal generates the radio link failure in the extension carrier, the terminal can insert the extension carrier information for identifying the radio link failure of the terminal in the extension carrier into the RRC reestablishment request sent to the base station, and the base station can add the extension carrier information in the switching report information sent to the base station to which the cell generating the radio link failure belongs, so that the base station to which the cell generating the radio link failure belongs determines the carrier type generating the radio link failure.

According to another aspect of the present invention, a link reestablishment system is provided, which includes a base station and a terminal, wherein the base station includes: the message receiving module is used for receiving an RRC reestablishment request message from the terminal, wherein the RRC reestablishment request message comprises extension carrier information, and the extension carrier information indicates that the terminal has radio link failure in an extension carrier; the judging module is used for judging whether the radio link failure occurs in the reestablished cell according to the RRC reestablishment request message; and the switching module is used for adding the extension carrier information into the switching report information sent to the base station to which the cell with the radio link failure belongs under the condition that the radio link failure does not occur in the reconstructed cell so that the base station to which the cell with the radio link failure belongs determines the radio link failure condition of the cell with the radio link failure.

Optionally, the terminal is configured to select a reestablished cell according to reselection configuration information in the broadcast message when attempting to perform a cell reestablishment process in a case where a radio link fails in a state of residing in the extended frequency band, and send an RRC reestablishment request message to the reestablished cell.

Optionally, the message obtaining module is further configured to obtain handover report information from a base station to which the terminal reestablishes the cell belongs, when the base station fails in the radio link; the base station further comprises: the storage module is used for counting the radio link failure information of the cell according to the RRC reestablishment request message from the terminal or the switching report information from the base station to which the reestablishment cell belongs, wherein the radio link failure information comprises the time of radio link failure, the carrier type, the reestablishment cell identification and the failure cell identification; the judging module is further configured to determine that a radio link failure occurs in an extension carrier according to the extension carrier information included in the RRC reestablishment request message or the handover report information.

Optionally, the base station further includes: the statistical module is used for counting the wireless link failure times of the main carrier and the wireless link failure times of the extension carrier within the preset time according to the wireless link failure information; the calculating module is used for calculating the radio link failure proportion of the cell in the extension carrier, wherein the radio link failure proportion of the cell in the extension carrier is the proportion of the radio link failure times in the extension carrier to the total failure times; and the reporting module is used for reporting the radio link failure ratio of the cell in the extension carrier and the radio link failure times of the cell in the extension carrier to the network management system.

Optionally, the method further comprises: the network management system is used for judging whether the radio link failure ratio of the cell in the extension carrier exceeds a preset failure threshold or not according to the radio link failure ratio of the extension carrier acquired from the base station; if the radio link failure exceeds the preset failure threshold, sending scheduling information to the base station of the cell with the radio link failure, so as to adjust the switching parameters or control the base station to avoid scheduling the cell edge users to the extension carrier wave through the scheduling information.

Optionally, the handover parameters include a main carrier handover parameter and an extension carrier handover parameter; the main carrier switching parameter is a decision threshold of the terminal for switching from the main carrier of the cell of the base station to the main carrier of the adjacent cell; the switching parameter of the extension carrier is a decision threshold of the terminal for switching from the extension carrier of the cell of the base station to the extension carrier or the main carrier of the adjacent cell; the network management system is also used for controlling the base station to adjust the extended carrier switching parameters of the base station through the scheduling information.

Optionally, the network management system is further configured to start a mobility performance optimization function, and issue an indication message to the base station; the base station is also used for starting a mobility optimization function according to the indication message and issuing an RRC configuration message to a terminal working in the extension carrier or needing to be switched to the extension carrier, wherein the RRC configuration message comprises mobility optimization configuration information; the terminal is also used for executing the measurement operation of the extension carrier according to the mobility optimization configuration information, and measuring the Reference Signal Received Quality (RSRQ) and the Reference Signal Received Power (RSRP) of the extension carrier of the cell where the terminal is located; when a terminal working on an extended carrier wave has a radio link failure, the terminal reports the RSRQ and the RSRP of a cell with the radio link failure to a base station through an RRC reestablishment request message.

Optionally, the mobility optimization configuration information includes: the extended carrier measurement identifier is used for measuring the parameters of the extended carrier of the cell according to the extended carrier measurement identifier by a terminal which works on the extended carrier or needs to be switched to the extended carrier; reporting an indication mark, and reporting a measurement result through an RRC reestablishment request message when a radio link failure occurs according to the reporting indication mark by a terminal which works in an extended carrier or needs to be switched to the extended carrier; and the terminal working on the extension carrier or needing to be switched to the extension carrier determines a measurement RSRP and/or an RSRQ value according to the measurement quantity identifier.

Optionally, the reporting module is further configured to report, to the network management system, an RSRQ and an RSRP of an extended carrier of a cell in which the terminal is located; the network management system is also used for comparing the RSRQ information with a preset RSRQ threshold and comparing the RSRP information with the preset RSRQ threshold under the condition that the radio link failure ratio of the cell in the extension carrier wave is judged to exceed the preset failure threshold; if the RSRQ information is lower than a preset RSRQ threshold and the RSRP information is higher than the preset RSRQ threshold, the network management system controls the base station to avoid dispatching the cell edge users to the extension carrier through the dispatching information; and if the RSRQ information is higher than the preset RSRQ threshold and the RSRP information is lower than the preset RSRQ threshold, the network management system controls the base station to adjust the expanded carrier switching parameters through the scheduling information.

Optionally, the RRC configuration message further includes a cell list of extension carriers applicable to the neighboring cell of the cell in which the terminal is located; the terminal is also used for measuring the extension carriers RSRP and RSRQ of the adjacent cells in the cell list of the RRC configuration message, the main carriers RSRP and RSRQ, and measuring the main carriers RSRP and RSRQ of other adjacent cells; when a terminal working on an extended carrier wave has a radio link failure, the terminal reports the RSRP and the RSRQ of the adjacent cell, the carrier wave type and the cell identification to a base station through an RRC reestablishment request message.

Optionally, the base station further includes: the extended carrier switching module is used for judging whether to execute carrier switching or not based on the extended carrier switching parameters according to the RSRQ and the RSRP of the cell where the terminal is located, which are acquired from the terminal; and the base station determines a cell and a carrier type to which the terminal is switched according to the RSRP, the RSRQ and the carrier type of the neighbor cell of the cell in which the terminal is located in the cell list of the RRC configuration message acquired from the terminal.

Optionally, the RRC configuration information further includes: and if the terminal working on the extension carrier or needing to be switched to the extension carrier measures that the RSRP and/or the RSRQ of the adjacent cell reaches the configuration parameter of the adjacent cell, the terminal reports the RSRP and/or the RSRQ of the adjacent cell to the base station through an RRC reestablishment request message when the radio link failure occurs in the terminal.

Optionally, the extension carrier information is 1-bit identification.

In such a system, the terminal can insert extension carrier information identifying that the terminal has a radio link failure in an extension carrier in an RRC reestablishment request message sent to the base station, and the base station can add the extension carrier information in handover report information sent to the base station to which the cell having the radio link failure belongs, so that the base station to which the cell having the radio link failure belongs can determine the type of the carrier having the radio link failure.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

fig. 1 is a schematic diagram of a flexible bandwidth.

Fig. 2 is a schematic diagram of frequency division of a flexible bandwidth.

Fig. 3 is a flowchart of an embodiment of a link reestablishment method according to the present invention.

Fig. 4 is a flowchart of another embodiment of a link reestablishment method according to the present invention.

Fig. 5 is a flowchart of an embodiment of processing an RRC reestablishment request message or handover report information by a base station to which a cell with a radio link failure belongs in the link reestablishment method of the present invention.

Fig. 6 is a flowchart of another embodiment of processing an RRC reestablishment request message or handover report information by a base station to which a cell with a radio link failure occurs in the link reestablishment method according to the present invention.

Fig. 7 is a flowchart of an embodiment of information processing performed by the network management system on the radio link failure rate of the extension carrier in the link reestablishment method of the present invention.

Fig. 8 is a flowchart of another embodiment of the information processing performed by the network management system on the radio link failure rate of the extension carrier in the link reestablishment method according to the present invention.

Fig. 9 is a flowchart of an embodiment of adjusting an extension carrier switching parameter by a base station in the link reestablishment method of the present invention.

Fig. 10 is a diagram illustrating an embodiment of a link reestablishment system according to the present invention.

Fig. 11 is a diagram illustrating another embodiment of a base station in a link reestablishment system according to the present invention.

Fig. 12 is a diagram illustrating a base station in a link reestablishment system according to still another embodiment of the present invention.

Fig. 13 is a schematic diagram of a link reestablishment system according to still another embodiment of the present invention.

Detailed Description

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

A flow chart of an embodiment of the link reestablishment method of the present invention is shown in fig. 3.

In step 301, when the terminal has a radio link failure and is reestablished to a cell, an RRC reestablishment request message is sent to the base station. The base station receives an RRC reestablishment request message from the terminal. If the terminal has a radio link failure in the extension carrier, the RRC reestablishment request message includes extension carrier information to identify that the terminal has a radio link failure in the extension carrier. In one embodiment, the extension carrier information is a 1-bit identification.

In step 302, the base station determines whether the radio link failure occurs in the cell being reestablished according to the RRC reestablishment request message. The RRC reestablishment request message includes a failed cell identifier, and the base station may determine a cell in which a radio link failure occurs according to the identifier. If the radio link failure occurs in the re-established cell, step 303 is executed; if the radio link failure does not occur in the re-established cell, step 304 is performed.

In step 303, the base station determines that a radio link failure occurs in the extension carrier of the reestablished cell, and determines the radio link failure of the extension carrier of the reestablished cell according to the extension carrier information in the RRC reestablishment request message.

In step 304, the base station adds extension carrier information to the handover report information sent to the base station to which the cell with the radio link failure occurs, so that the base station to which the cell with the radio link failure occurs determines that the cell with the radio link failure occurs.

By the method, when the terminal has the radio link failure in the extension carrier, the terminal can insert extension carrier information for identifying the radio link failure of the terminal in the extension carrier into the RRC reestablishment request message sent to the base station, and the base station can add the extension carrier information into the switching report information sent to the base station to which the cell with the radio link failure belongs, so that the base station to which the cell with the radio link failure belongs determines the carrier type with the radio link failure.

A flow chart of another embodiment of the link reestablishment method of the present invention is shown in fig. 2.

In step 401, a radio link failure occurs in a terminal residing in an extended frequency band. The terminal attempts cell re-establishment. In one embodiment, a terminal selects a reconstruction cell according to reselection configuration information in a broadcast message, wherein the reselection configuration information includes unidirectional reselection configuration information reselected from an extension carrier to a main carrier, and when a terminal residing in an extension frequency band fails to have a radio link, the terminal configures the extension carrier residing in the terminal to have the lowest priority and starts a reselection timer to time according to the unidirectional reselection configuration information, and selects a suitable target cell according to frequency priority within a preset time range; if the target cell suitable for residing is found, reselecting the terminal to reside in the target cell; and if the terminal cannot find the target cell suitable for residing in the preset time range, the terminal selects the suitable target cell to reside in by executing a cell search process.

In step 402, the terminal sends an RRC reestablishment request message to the base station to which the cell selected for reestablishment belongs. The RRC reestablishment request message comprises extension carrier information and identifies that the terminal has radio link failure in the extension carrier.

In step 403, the base station determines whether the radio link failure occurs in the cell being reestablished by the terminal according to the RRC reestablishment request message. If the radio link failure occurs in the re-established cell, go to step 404; if the radio link failure does not occur in the re-established cell, step 405 is executed.

In step 404, the base station determines that a radio link failure occurs in the extension carrier of the reestablished cell, and determines the radio link failure of the extension carrier of the reestablished cell according to the extension carrier information in the RRC reestablishment request message.

In step 405, the base station adds extension carrier information to the handover report information sent to the base station to which the cell with the radio link failure occurs, so that the base station to which the cell with the radio link failure occurs determines the radio link failure condition of the cell extension carrier with the radio link failure.

By the method, the terminal can select a proper cell to camp on according to the reselection configuration information after the radio link failure occurs. The terminal can insert extension carrier information for identifying that the terminal has radio link failure in an extension carrier in an RRC reestablishment request message sent to the base station, and the base station can add the extension carrier information in handover report information sent to the base station to which the cell having the radio link failure belongs, so that the base station to which the cell having the radio link failure belongs determines the type of the carrier having the radio link failure.

Fig. 5 shows a flowchart of an embodiment of processing an RRC reestablishment request message or handover report information by a base station to which a cell with a radio link failure belongs in the link reestablishment method according to the present invention.

In step 501, the base station to which the cell in which the radio link failure occurs belongs counts radio link failure information. If the cell in which the radio link failure occurs and the terminal reconstruction cell are the same cell, the base station acquires and counts radio link failure information according to an RRC reconstruction request message from the terminal; and if the cell with the radio link failure is not the same cell as the cell reconstructed by the terminal, the base station to which the cell with the radio link failure belongs acquires and counts the radio link failure information according to the switching report information acquired from the base station to which the cell reconstructed is to belong. The radio link failure information includes a type of occurrence of a radio link failure, a carrier type, a reestablishment cell identity, and a failed cell identity.

In step 502, the base station determines the carrier type in which the radio link failure occurs according to whether the RRC reestablishment request message or the handover report message includes the extension carrier information. If the extended carrier information is included, a radio link failure occurs at the extended carrier; if the extension carrier information is not included, a radio link failure occurs in the primary carrier.

By the method, the base station to which the cell with the radio link failure belongs can count the radio link failure information generated in the cell with the radio link failure and judge the type of the failed carrier, so that the base station can adjust according to the radio link failure information conveniently.

In one embodiment, if the terminal has a radio link failure in the extension carrier of the cell PCI1 and performs link reestablishment in the same cell PCI1, the terminal sends an RRC reestablishment request message to the base station to which the PCI1 belongs, where the RRC reestablishment request message includes extension carrier information indicating that the terminal has a radio link failure in the extension carrier. The PCI1 determines that the terminal has a radio link failure in the cell according to the failed cell identifier in the RRC reestablishment request message, and determines that the terminal has a radio link failure in the extension carrier according to the extension carrier information, thereby counting the radio link failure information.

If the terminal has a radio link failure in the extension carrier of the cell PCI1 and link reestablishment is realized in the cell PCI2, the terminal sends an RRC reestablishment request message to the base station to which the PCI2 belongs, wherein the RRC reestablishment request message includes extension carrier information indicating that the terminal has a radio link failure in the extension carrier. And the base station to which the PCI2 belongs determines that the cell with the radio link failure is PCI1 according to the failed cell identifier in the RRC reestablishment request message, sends switching report information to the base station to which the PCI2 belongs, and adds extension carrier information in the switching report information. The PCI1 determines that the terminal has a radio link failure in the extension carrier according to the extension carrier information in the handover report information, thereby counting the radio link failure information.

By the method, the base station to which the cell with the radio link failure belongs can determine the carrier type with the radio link failure, thereby providing a data basis for pertinently adjusting and reducing the radio link failure probability of the expanded carrier.

Fig. 6 shows a flowchart of another embodiment of processing an RRC reestablishment request message or handover report information by a base station to which a cell with a radio link failure occurs in the link reestablishment method according to the present invention.

In step 601, the base station to which the cell in which the radio link failure occurs counts the number of radio link failures occurring in the primary carrier and the number of radio link failures occurring in the extension carrier within a predetermined time according to the counted radio link failure information.

In step 602, the base station to which the cell in which the radio link failure occurs belongs calculates the radio link failure ratio of the cell in the extension carrier. The radio link failure rate of the cell on the extension carrier is equal to the radio link failure rate of the cell on the extension carrier/(the radio link failure rate on the extension carrier + the radio link failure rate on the primary carrier).

In step 603, the base station reports the radio link failure rate of the cell on the extension carrier and the number of times of radio link failure occurring on the extension carrier within a predetermined time to the network management system.

By the method, the base station can calculate the radio link failure conditions of the extension carrier and the main carrier, and the radio link failure proportion of the extension carrier and report the radio link failure proportion to the network management system, so that the network management system can analyze and judge conveniently and adjust correspondingly.

Fig. 7 shows a flowchart of an embodiment of information processing performed by the network management system on the radio link failure ratio of the extension carrier in the link reestablishment method according to the present invention.

In step 701, the network management system obtains the radio link failure ratio of the extension carrier of the cell from the base station.

In step 702, it is determined whether the radio link failure rate of the cell on the extension carrier exceeds a predetermined threshold. If the threshold is exceeded, go to step 703; if the predetermined threshold is not exceeded, no processing is performed.

In step 703, the network management system sends scheduling information to the base station to which the radio link failure cell belongs, and controls the base station to perform adjustment, so as to reduce the service failure rate.

By the method, the network management system can acquire the radio link failure proportion from the base station, further judge the radio link failure condition of the cell in the extension carrier, and schedule the base station to adjust when the radio link failure condition of the extension carrier exceeds the threshold so as to reduce the service failure rate of the extension carrier.

In one embodiment, the network management system determines whether the radio link failure frequency of the extension carrier exceeds the frequency threshold while determining that the radio link failure ratio of the extension carrier exceeds the threshold. When both of the two signals exceed the threshold, the adjustment is carried out, so that misadjustment is avoided under the condition that the radio link failure ratio of the expanded carrier is high but the times are few, the adjustment times are reduced, and the network regulation and control burden is reduced.

In one embodiment, the handover parameters of the base station include two types: a primary carrier switching parameter and an extension carrier switching parameter. The base station configures the extended carrier switching parameters independently of the main carrier switching parameters. When a terminal is switched to a main carrier of an adjacent cell from a main carrier of a connected base station cell, taking a main carrier switching parameter as a decision threshold; when the terminal is switched to the extension carrier or the main carrier of the adjacent cell from the extension carrier of the cell, the extension carrier switching parameter is used as a decision threshold. The specific data of the main carrier switching parameter and the extended carrier switching parameter may be different and may be separately managed and controlled.

By the method, the base station has different switching parameters aiming at the main carrier and the extension carrier, and can be respectively used as a judgment threshold for switching the main carrier and the extension carrier to the adjacent cell by the terminal, so that the switching parameters can respectively accord with the use conditions of the main carrier and the extension carrier, the switching parameters are more targeted, and the user experience is improved. In addition, when the network management system needs to adjust the extension carrier of the base station, only the switching parameter of the extension carrier can be adjusted, and the switching parameter of the main carrier is not influenced, so that the adjustment aiming at the extension carrier is more targeted, and the influence on the terminal connected with the main carrier is avoided.

In one embodiment, the network management system may start the mobility optimization function according to the needs of the operator or the configuration of the technician, and issue an indication message to the base station. The indication message may include an identifier indicating the base station to start a mobility optimization function, and optimization information for the extension carrier of the base station supporting the flexible bandwidth capability. The optimization information may specifically include an identifier indicating that the terminal performs flexible bandwidth measurement and reporting, an indication that the terminal needs to report RSRP and/or RSRQ, and a period that the base station needs to report to the network management system. The indication message may further include various threshold values, including a handover parameter threshold, a timer threshold, and the like.

By the method, the network management system can start the mobility optimization function of the base station and issue optimization information and various threshold values to the base station, so that the controllability of the base station and the terminal is enhanced.

In one embodiment, the base station starts the mobility optimization function according to the indication message, and issues an RRC configuration message to the terminal operating in the extension carrier or needing to be switched to the extension carrier. The RRC configuration message includes mobility optimization configuration information.

In an embodiment, the mobility optimization configuration information of the RRC configuration message includes a plurality of parameters, where according to the extension carrier measurement identifier, a terminal operating on the extension carrier or needing to be switched to the extension carrier determines whether to measure an extension carrier parameter of a cell where the terminal is located, for example, when the extension carrier measurement identifier is 1, the terminal measures the extension carrier parameter of the cell where the terminal is located, otherwise, the terminal does not perform the extension carrier parameter measurement operation. And according to the reporting indication mark, reporting the measurement result through an RRC reestablishment request message when the radio link failure occurs in the terminal working in the extension carrier or needing to be switched to the extension carrier. The measurement quantity identity may indicate that the terminal measures an RSRP or an RSRQ value, or both.

By the method, the base station can configure the operation performed by the terminal through the RRC configuration message, so that the measurement of the terminal on the extension carrier is more controllable.

The terminal working on the extension carrier or needing to be switched to the extension carrier can measure the RSRP and RSRQ information of the cell according to the mobility optimization configuration information; and when the terminal has radio link failure, sending the RSRP and RSRQ information of the cell to which the terminal belongs to the base station of the reestablished cell through an RRC reestablishment request message. The base station to which the cell is reestablished can report the RSRP and RSRQ information of the cell to the network management system, so that the network management system can accurately analyze the extended carrier state of the cell with the radio link failure according to the acquired information, and the adjustment is more targeted.

Fig. 8 shows a flowchart of another embodiment of the information processing performed by the network management system on the radio link failure ratio of the extension carrier in the link reestablishment method according to the present invention.

In step 801, the network management system obtains the radio link failure ratio of the extension carrier of the cell, and RSRQ and RSRP information of the extension carrier from the base station.

In step 802, the network management system determines whether the radio link failure rate of the cell in the extension carrier exceeds a predetermined threshold. If the predetermined threshold is exceeded, go to step 803; if the predetermined threshold is not exceeded, step 807 is performed.

In step 803, the network management system compares the RSRQ and RSRP information with predetermined RSRQ and RSRP thresholds, respectively. If the RSRQ information is lower than the predetermined RSRQ threshold but the RSRP information is higher than the predetermined RSRP threshold, go to step 804; otherwise, step 805 is performed.

In step 804, the network management system sends scheduling information to the base station, and controls the base station to avoid scheduling cell edge users to the extension carrier.

In step 805, the network management system compares the RSRQ and RSRP information with predetermined RSRQ and RSRP thresholds, respectively. If the RSRQ information is higher than the predetermined RSRQ threshold but the RSRP information is lower than the predetermined RSRP threshold, go to step 806; otherwise, step 807 is performed.

In step 806, the network management system controls the base station to adjust the handover parameters according to the scheduling information, so as to reduce the occurrence of radio link failure in the extension carrier.

In step 807, the network management system ignores the radio link failure ratio reported this time, and does not perform the operation of regulating and controlling the base station.

By the method, after acquiring the radio link failure proportion of the extension carrier, the network management system can judge which regulation and control is performed on the base station according to the RSRQ and RSRP conditions, so that targeted adjustment is performed, and the service failure probability of the extension carrier of the base station is reduced better.

Fig. 9 shows a flowchart of an embodiment of adjusting the extended carrier switching parameter by the base station in the link reestablishment method according to the present invention.

In step 901, the base station issues an extended carrier measurement configuration message to the terminal, where the extended carrier measurement configuration message includes an object to be measured by the terminal, a cell list, a reporting mode, a measurement identifier, and/or an event parameter.

In step 902, the terminal performs a measurement operation on the extension carrier and reports an extension carrier measurement report to the base station.

In step 903, the base station determines whether to perform carrier switching based on the extension carrier switching parameter according to the extension carrier measurement report, and determines to switch the terminal from the extension carrier of the cell where the terminal is located to the extension carrier of the neighboring cell or the primary carrier of the neighboring cell.

By the method, the base station can analyze the extended carrier measurement report fed back by the terminal by taking the extended carrier switching parameter as a judgment basis, and judge whether the terminal is switched from the extended carrier of the cell to the extended carrier or the main carrier of the adjacent cell, so that the extended carrier switching independent of the main carrier switching is realized, and the extended carrier service is more perfect.

In one embodiment, the RRC configuration message sent by the base station to the terminal further includes a cell list of applicable extension carriers in neighboring cells of the cell in which the terminal is located. The terminal may measure the extension carriers RSRP, RSRQ, primary carriers RSRP, RSRQ of the neighbor cells included in the cell list of the RRC configuration message, and may also measure the primary carriers RSRP, RSRQ of other neighbor cells not included in the cell list of the RRC configuration message. When a radio link failure occurs in a terminal working on an extended carrier, the terminal reports the RSRP and the RSRQ of the adjacent cell, the corresponding carrier type and the corresponding cell identifier to the base station through an RRC reestablishment request message.

By the method, the base station can acquire the RSRP and the RSRQ, the carrier types and the cell identifiers of the adjacent cells of the cell with the radio link failure, so that the expanded carrier switching parameters can be used as the switching threshold, and the RSRP and the RSRQ of the adjacent cells are compared to select the proper switching cell and the proper carrier type for the terminal working on the expanded carrier.

In one embodiment, the mobility optimization configuration information further includes a neighbor cell configuration parameter. If the RSRP and the RSRQ of the adjacent cell are measured by the terminal working on the extension carrier or needing to be switched to the extension carrier, the signal quality of the cell is better, and the cell can be used as an alternative cell for terminal switching, and when the radio link failure occurs in the terminal, the terminal reports the RSRP and/or the RSRQ of the adjacent cell to the base station through an RRC reestablishment request message; if the RSRP and the RSRQ of the adjacent cells do not reach the configuration parameters of the adjacent cells, the RSRP and the RSRQ do not need to be reported to the base station.

By the method, the terminal can be configured to perform screening work of part of adjacent cells and carriers, so that the burden of the base station is reduced, and the network burden of interaction between the terminal and the base station is also reduced.

A schematic diagram of one embodiment of a link re-establishment system of the present invention is shown in fig. 10. Here, 1001 is a terminal, and 1002 is a base station. The base station 1002 includes a message receiving module 1012 that can receive an RRC reestablishment request message from the terminal. When the terminal is switched to a base station due to radio link failure, an RRC reestablishment request message is sent to the base station. The RRC reestablishment request message comprises extension carrier information and identifies that the terminal has radio link failure in the extension carrier. In one embodiment, the extension carrier information is a 1-bit identification. The determining module 1022 can determine whether the radio link failure occurs in the cell being reestablished according to the RRC reestablishment request message. The handover module 1032 can send handover report information to the cell with the radio link failure when the terminal does not have the radio link failure in the cell to be reestablished, and add extension carrier information to the handover report information, so that the base station to which the cell with the radio link failure belongs determines the radio link failure of the cell with the radio link failure.

In such a system, the terminal can insert extension carrier information for identifying that the terminal has a radio link failure in an extension carrier in the RRC reestablishment request sent to the base station, and the base station can add the extension carrier information to the handover report information sent to the base station to which the cell having the radio link failure belongs, so that the base station to which the cell having the radio link failure belongs can determine the type of the carrier having the radio link failure.

In one embodiment, a terminal residing in the extended frequency band experiences a radio link failure. The terminal attempts cell re-establishment. In one embodiment, a terminal selects a reconstruction cell according to reselection configuration information in a broadcast message, wherein the reselection configuration information includes unidirectional reselection configuration information reselected from an extension carrier to a main carrier, and when a terminal residing in an extension frequency band fails to have a radio link, the terminal configures the extension carrier residing in the terminal to have the lowest priority and starts a reselection timer to time according to the unidirectional reselection configuration information, and selects a suitable target cell according to frequency priority within a preset time range; if the target cell suitable for residing is found, reselecting the terminal to reside in the target cell; and if the terminal cannot find the target cell suitable for residing in the preset time range, the terminal selects the suitable target cell to reside in by executing a cell search process. And the terminal sends an RRC reestablishment request message to the base station to which the selected cell belongs. The RRC reestablishment request message comprises extension carrier information and identifies that the terminal has radio link failure in the extension carrier.

In such a system, the terminal can select a suitable cell to camp on according to the reselection configuration information after a radio link failure occurs. The terminal can insert extension carrier information for identifying that the terminal has a radio link failure in an extension carrier in an RRC reestablishment request sent to the base station, and the base station can add the extension carrier information in handover report information sent to the base station to which the cell having the radio link failure belongs, so that the base station to which the cell having the radio link failure belongs determines the type of the carrier having the radio link failure.

Fig. 11 is a schematic diagram of another embodiment of a base station in the link reestablishment system according to the present invention. The message receiving module 1101, the judging module 1102 and the switching module 1103 have a structure and a function similar to those of the embodiment of fig. 10. The message receiving module 1101 can receive an RRC reestablishment request from the terminal, and can also obtain handover report information from another base station. When the terminal fails in the radio link in the cell belonging to the base station, if the reconstructed cell of the terminal does not belong to the base station, the base station will obtain the switching report information from the base station to which the terminal reconstructs the cell belongs. The base station also includes a memory module 1104. If the cell in which the radio link failure occurs and the terminal reestablishment cell are the same cell, the storage module 1104 counts radio link failure information according to an RRC reestablishment request message from the terminal; if the cell in which the radio link failure occurs is not the same cell as the terminal reestablishment cell, the storage module 1104 counts the radio link failure information according to the handover report information obtained from the base station to which the reestablishment cell belongs. The radio link failure information includes a type of occurrence of a radio link failure, a carrier type, a reestablishment cell identity, and a failed cell identity.

In the system, the base station to which the cell with the radio link failure belongs can count the radio link failure information generated in the cell with the radio link failure and judge the type of the failed carrier, so that necessary information is provided for subsequent optimization processing, and the base station can conveniently adjust according to the radio link failure information.

Fig. 12 is a schematic diagram of another embodiment of a base station in the link reestablishment system according to the present invention. The message receiving module 1201, the determining module 1202, the switching module 1203 and the storing module 1204 have similar structures and functions as those of the embodiment of fig. 11. The base station further includes a counting module 1205, which is capable of counting the number of radio link failures occurring in the primary carrier and the number of radio link failures occurring in the extension carrier within a predetermined time according to the counted radio link failure information. The calculation module 1206 can calculate a radio link failure ratio of the cell on the extension carrier. The radio link failure rate of the cell on the extension carrier is equal to the radio link failure rate of the cell on the extension carrier/(the radio link failure rate on the extension carrier + the radio link failure rate on the primary carrier). The reporting module 1207 can report the radio link failure frequency of the cell occurring in the extension carrier within the radio link failure proportion of the extension carrier and the predetermined time to the network management system.

The base station can calculate the radio link failure conditions of the extension carrier and the main carrier, and the radio link failure proportion of the extension carrier, and reports the radio link failure proportion to the network management system, so that the network management system can analyze and judge conveniently and perform corresponding adjustment.

A schematic diagram of yet another embodiment of the link re-establishment system of the present invention is shown in fig. 13. The base stations are connected with the network management system and can report the radio link failure proportion and times of the expanded carriers to the network management system. The network management system acquires the radio link failure ratio of the cell from the base station, and then judges whether the radio link failure ratio of the cell in the extension carrier exceeds a preset threshold. If the radio link failure rate exceeds the preset threshold, the scheduling information is sent to the base station of the radio link failure cell, and the base station is controlled to adjust so as to reduce the service failure probability of the extended carrier.

In the link reconstruction system, the network management system can acquire the radio link failure proportion from the base station, further judge the radio link failure condition of the cell in the extension carrier, and schedule the base station for adjustment when the radio link failure condition of the extension carrier exceeds a threshold so as to reduce the service failure rate.

In one embodiment, the reporting module of the base station can also report RSRQ and RSRP information of the cell extension carrier to the network management system. The network management system can acquire the RSRQ and RSRP information of the cell extension carrier from the base station. And under the condition that the radio link failure ratio of the cell in the extension carrier wave is judged to exceed a preset threshold, the network management system compares the RSRQ and the RSRP information with the preset RSRQ and the RSRP threshold respectively. And if the RSRQ information is lower than a preset RSRQ threshold but the RSRP information is higher than the preset RSRQ threshold, sending scheduling information to the base station, and controlling the base station to avoid scheduling the cell edge users to the extension carrier. If the RSRQ information is higher than the preset RSRQ threshold but the RSRP information is lower than the preset RSRQ threshold, the base station is controlled to adjust the switching parameters through the scheduling information so as to reduce the occurrence of radio link failure of the extension carrier.

In the link reconstruction system, after acquiring the radio link failure proportion of the extension carrier, the network management system can judge which regulation and control is performed on the base station according to the conditions of RSRQ and RSRP, so that targeted adjustment is performed, and the service failure probability of the extension carrier of the base station is reduced better.

In one embodiment, the handover parameters of the base station include two types: a primary carrier switching parameter and an extension carrier switching parameter. The base station configures the extended carrier switching parameters independently of the main carrier switching parameters. When the terminal is switched from the main carrier of the cell of the base station to the main carrier of the adjacent cell, the main carrier switching parameter is used as a judgment threshold; when the terminal is switched to the extension carrier or the main carrier of the adjacent cell from the extension carrier of the cell, the extension carrier switching parameter is used as a decision threshold. The specific data of the main carrier switching parameter and the extended carrier switching parameter may be different and may be separately managed and controlled.

The base station has different switching parameters aiming at the main carrier and the extension carrier, and can be respectively used as a judgment threshold for switching the main carrier and the extension carrier to the adjacent cell by the terminal, so that the switching parameters can respectively accord with the use conditions of the main carrier and the extension carrier, the switching parameters are more targeted, and the user experience is improved. In addition, when the network management system needs to schedule the extension carrier of the base station, only the switching parameter of the extension carrier can be adjusted, and the switching parameter of the main carrier is not influenced, so that the adjustment aiming at the extension carrier is more targeted, and the influence on the terminal connected with the main carrier is not caused.

In one embodiment, the base station further includes an extension carrier switching module, which is capable of issuing an extension carrier measurement configuration message to the terminal, where the extension carrier measurement configuration message includes an object to be measured by the terminal, a cell list, a reporting mode, a measurement identifier, and/or an event parameter; acquiring an extended carrier measurement report from a terminal and reporting the extended carrier measurement report; and judging whether to execute carrier switching or not based on the extended carrier switching parameters according to the extended carrier measurement report, and judging whether to switch the terminal from the extended carrier of the cell where the terminal is located to the extended carrier of the adjacent cell or the main carrier of the adjacent cell.

The base station can analyze the extended carrier measurement report fed back by the terminal by taking the extended carrier switching parameter as a judgment basis, and judge whether to switch the terminal from the extended carrier of the cell to the extended carrier or the main carrier of the adjacent cell, thereby realizing the extended carrier switching independent of the main carrier switching and improving the extended carrier service.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention and not to limit it; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art will understand that: modifications to the specific embodiments of the invention or equivalent substitutions for parts of the technical features may be made; without departing from the spirit of the present invention, it is intended to cover all aspects of the invention as defined by the appended claims.

Claims

1. A method for link re-establishment, comprising:

a base station receives a Radio Resource Control (RRC) reestablishment request message from a terminal, wherein the RRC reestablishment request message comprises extended carrier information, and the extended carrier information indicates that the terminal has radio link failure in an extended carrier;

the base station judges whether the radio link failure occurs in a reestablished cell according to the RRC reestablishment request message;

if the radio link failure does not occur in the reestablished cell, the base station adds extension carrier information in the switching report information sent to the base station to which the cell with the radio link failure belongs, so that the base station to which the cell with the radio link failure belongs determines the radio link failure condition of the cell with the radio link failure;

and if the radio link failure occurs in the reestablished cell, the base station determines the radio link failure condition of the expanded carrier of the reestablished cell according to the expanded carrier information in the RRC reestablishment request message.

2. The method of claim 1, further comprising:

and the terminal which resides in the extended frequency band tries to perform a cell reconstruction process under the condition of radio link failure, selects a reconstruction cell according to reselection configuration information in the broadcast message and sends an RRC reconstruction request message to the reconstruction cell.

3. The method according to claim 2, wherein the reselection configuration information includes unidirectional reselection configuration information reselected from an extension carrier to a main carrier, and when a terminal residing in an extension frequency band fails to have a radio link, the terminal configures the extension carrier residing in the terminal to have a lowest priority and starts a reselection timer to time according to the unidirectional reselection configuration information, and selects a suitable target cell according to a frequency priority within a preset time range;

if the target cell suitable for residing is found, reselecting the terminal to reside in the target cell;

and if the terminal cannot find the target cell suitable for residing in the preset time range, the terminal selects the suitable target cell to reside in by executing a cell search process.

4. The method of claim 1 or 2, further comprising:

the base station to which the cell with the radio link failure occurs counts the radio link failure information of the cell with the radio link failure according to the RRC reestablishment request message from the terminal or the switching report information from the base station to which the cell with the radio link failure occurs, wherein the radio link failure information comprises the time of the radio link failure, the carrier type, the reestablishment cell identifier and the failed cell identifier;

and if the RRC reestablishment request message or the switching report message comprises extension carrier information, determining that the radio link failure occurs in an extension carrier.

5. The method according to claim 4, wherein the base station to which the cell in which the radio link failure occurs belongs counts the number of radio link failures occurring in the primary carrier and the number of radio link failures occurring in the extension carrier within a predetermined time according to the radio link failure information;

the base station to which the cell with the radio link failure belongs calculates the radio link failure proportion of the cell in the extension carrier, wherein the radio link failure proportion of the cell in the extension carrier is the proportion of the radio link failure times in the extension carrier to the total failure times;

and the base station to which the cell with the radio link failure belongs reports the radio link failure proportion of the cell in the extension carrier and the radio link failure times of the cell in the extension carrier to a network management system.

6. The method of claim 5, further comprising:

the network management system judges whether the radio link failure ratio of the cell in the extension carrier exceeds a preset failure threshold or not according to the radio link failure ratio of the extension carrier acquired from the base station;

if the radio link failure exceeds the preset failure threshold, sending scheduling information to the base station to which the cell with the radio link failure belongs so as to adjust switching parameters or control the base station to avoid scheduling cell edge users to the extension carrier wave through the scheduling information.

7. The method of claim 6, wherein the handover parameters comprise primary carrier handover parameters and extended carrier handover parameters; the main carrier switching parameter is a decision threshold of a terminal for switching from a main carrier of a cell of a base station to a main carrier of an adjacent cell; the switching parameter of the extension carrier is a decision threshold of the terminal for switching from the extension carrier of the cell of the base station to the extension carrier or the main carrier of the adjacent cell;

and the network management system controls the base station to adjust the extended carrier switching parameters of the base station through the scheduling information.

8. The method of claim 6, further comprising:

the network management system starts a mobile performance optimization function and issues an indication message to the base station;

the base station starts a mobility optimization function according to the indication message and issues an RRC configuration message to a terminal working in an extension carrier or needing to be switched to the extension carrier, wherein the RRC configuration message comprises mobility optimization configuration information;

the terminal executes extended carrier measurement operation according to the mobility optimization configuration information, and measures Reference Signal Received Quality (RSRQ) and Reference Signal Received Power (RSRP) of an extended carrier of a cell where the terminal is located;

when a terminal working on an extended carrier wave has a radio link failure, the terminal reports the RSRQ and the RSRP of a cell with the radio link failure to a base station through an RRC reestablishment request message.

9. The method of claim 8, wherein the mobility optimization configuration information comprises:

an extended carrier measurement instruction, wherein a terminal working on an extended carrier or needing to be switched to the extended carrier measures the extended carrier parameter of a cell according to the extended carrier measurement instruction;

a measurement reporting instruction, wherein a terminal working in an extension carrier or needing to be switched to the extension carrier reports a measurement result through an RRC reestablishment request message when a radio link failure occurs according to the measurement reporting instruction;

a measurement quantity comprising RSRP and/or RSRQ.

10. The method of claim 9, further comprising:

the base station reports the extended carrier RSRQ and the RSRP of the cell where the terminal is located to a network management system;

if the network management system judges that the radio link failure ratio of the cell in the extension carrier exceeds the preset failure threshold,

the network management system compares the RSRQ information with an RSRQ threshold and compares the RSRP information with a preset RSRP threshold;

if the RSRQ information is lower than a preset RSRQ threshold and the RSRP information is higher than the preset RSRQ threshold, the network management system controls the base station to avoid dispatching the cell edge users to the extension carrier waves through the dispatching information;

and if the RSRQ information is higher than a preset RSRQ threshold and the RSRP information is lower than the preset RSRQ threshold, the network management system controls the base station to adjust the expanded carrier switching parameters through the scheduling information.

11. The method according to claim 9 or 10, wherein the RRC configuration message further includes a neighbor cell list supporting extended carrier measurement;

the terminal measures extension carriers RSRP and RSRQ of adjacent cells in an adjacent cell list supporting extension carrier measurement of the RRC configuration message, main carriers RSRP and RSRQ, and main carriers RSRP and RSRQ of other adjacent cells;

when a terminal working on an extended carrier wave has a radio link failure, the terminal reports the RSRP and the RSRQ of the adjacent cell, the carrier wave type and the cell identification to a base station through an RRC reestablishment request message.

12. The method of claim 11, further comprising:

the base station judges whether to execute carrier switching or not based on the extended carrier switching parameters according to the RSRQ and the RSRP of the cell where the terminal is located, which are acquired from the terminal; and the base station determines a cell and a carrier type to which the terminal is switched according to the RSRP, the RSRQ and the carrier type of the adjacent cell of the cell in which the terminal is located in the cell list of the RRC configuration message acquired from the terminal.

13. The method of claim 10, wherein the mobility optimization configuration information further comprises:

and if the terminal working on the extension carrier or needing to be switched to the extension carrier measures that the RSRP and/or the RSRQ of the adjacent cell reaches the configuration parameter of the adjacent cell, the terminal reports the RSRP and/or the RSRQ of the adjacent cell to the base station through an RRC reestablishment request message when the radio link failure occurs in the terminal.

14. The method of claim 9, wherein the extension carrier information is a 1-bit identity.

15. A link reestablishment system, comprising a base station and a terminal, wherein the base station comprises:

a message receiving module, configured to receive an RRC reestablishment request message from a terminal, where the RRC reestablishment request message includes extension carrier information, and the extension carrier information indicates that a radio link failure occurs in an extension carrier in the terminal;

a judging module, configured to judge whether a radio link failure occurs in a reestablished cell according to the RRC reestablishment request message;

and the switching module is used for adding extension carrier information in switching report information sent to the base station to which the cell with the radio link failure belongs under the condition that the radio link failure does not occur in the reestablished cell, so that the base station to which the cell with the radio link failure belongs determines the radio link failure condition of the cell with the radio link failure.

16. The system of claim 15,

the terminal is used for selecting a reestablishing cell according to reselection configuration information in the broadcast message and sending an RRC reestablishment request message to the reestablishing cell when a cell reestablishing process is attempted under the condition that a radio link fails in the state of residing in the extended frequency band.

17. The system according to claim 16, wherein the reselection configuration information includes unidirectional reselection configuration information reselected from an extension carrier to a primary carrier, and when a terminal residing in an extension frequency band fails to perform a radio link, the terminal configures the extension carrier residing in the terminal to have a lowest priority and starts a reselection timer to time according to the unidirectional reselection configuration information, and selects a suitable target cell according to a frequency priority within a preset time range;

18. The system of claim 15 or 16,

the message acquisition module is also used for acquiring switching report information from the base station to which the terminal reestablishes the cell under the condition that the base station fails in the wireless link;

the base station further comprises:

a storage module, configured to count radio link failure information of a cell according to the RRC reestablishment request message from the terminal or handover report information from a base station to which the reestablished cell belongs, where the radio link failure information includes time when a radio link failure occurs, a carrier type, a reestablished cell identifier, and a failed cell identifier;

the determining module is further configured to determine that the radio link failure occurs in an extension carrier according to extension carrier information included in the RRC reestablishment request message or the handover report message.

19. The system of claim 18, wherein the base station further comprises:

the statistical module is used for counting the radio link failure times of the main carrier and the radio link failure times of the extension carrier within the preset time according to the radio link failure information;

the calculating module is used for calculating the radio link failure proportion of a cell in an extended carrier, wherein the radio link failure proportion of the cell in the extended carrier is the proportion of the number of radio link failures occurring in the extended carrier to the total number of failures;

and the reporting module is used for reporting the radio link failure ratio of the cell in the extension carrier and the radio link failure times of the cell in the extension carrier to the network management system.

20. The system of claim 19, further comprising: the network management system is used for judging whether the radio link failure ratio of the cell in the extension carrier exceeds a preset failure threshold or not according to the radio link failure ratio of the extension carrier acquired from the base station;

21. The system of claim 20,

the switching parameters comprise main carrier switching parameters and extension carrier switching parameters; the main carrier switching parameter is a decision threshold of a terminal for switching from a main carrier of a cell of a base station to a main carrier of an adjacent cell; the switching parameter of the extension carrier is a decision threshold of the terminal for switching from the extension carrier of the cell of the base station to the extension carrier or the main carrier of the adjacent cell;

the network management system is also used for controlling the base station to adjust the extended carrier switching parameters of the base station through the scheduling information.

22. The system according to claim 20, wherein said network management system is further configured to start a mobility optimization function and send an indication message to said base station;

the base station is also used for starting a mobility optimization function according to the indication message and issuing an RRC configuration message to a terminal working in an extension carrier or needing to be switched to the extension carrier, wherein the RRC configuration message comprises mobility optimization configuration information;

the terminal is also used for executing extended carrier measurement operation according to the mobility optimization configuration information, and measuring Reference Signal Received Quality (RSRQ) and Reference Signal Received Power (RSRP) of an extended carrier of a cell where the terminal is located; when a terminal working on an extended carrier wave has a radio link failure, the terminal reports the RSRQ and the RSRP of a cell with the radio link failure to a base station through an RRC reestablishment request message.

23. The system of claim 22, wherein the mobility optimization configuration information comprises:

the extended carrier measurement identifier is used for measuring the parameters of the extended carrier of the cell according to the extended carrier measurement identifier by a terminal which works on the extended carrier or needs to be switched to the extended carrier;

reporting an indication mark, and reporting a measurement result through an RRC reestablishment request message when a radio link failure occurs according to the reporting indication mark by a terminal working in an extended carrier or needing to be switched to the extended carrier;

and the terminal working on the extension carrier or needing to be switched to the extension carrier determines a measurement RSRP and/or an RSRQ value according to the measurement quantity identifier.

24. The system of claim 23,

the reporting module is further configured to report, to the network management system, the RSRQ and the RSRP of the extension carrier of the cell in which the terminal is located;

the network management system is also used for comparing the RSRQ information with a preset RSRQ threshold and comparing the RSRP information with the preset RSRQ threshold under the condition that the radio link failure ratio of the cell in the extension carrier wave is judged to exceed the preset failure threshold;

25. The system of claim 23 or 24,

the RRC configuration message also comprises a cell list of applicable extension carriers in a cell adjacent to the cell in which the terminal is positioned;

the terminal is further configured to measure extension carriers RSRP and RSRQ of neighboring cells in the cell list of the RRC configuration message, main carriers RSRP and RSRQ, and measure main carriers RSRP and RSRQ of other neighboring cells; when a terminal working on an extended carrier wave has a radio link failure, the terminal reports the RSRP and the RSRQ of the adjacent cell, the carrier wave type and the cell identification to a base station through an RRC reestablishment request message.

26. The system of claim 25, wherein the base station further comprises:

the extended carrier switching module is used for judging whether to execute carrier switching or not based on extended carrier switching parameters according to the RSRQ and the RSRP of the cell where the terminal is located, which are acquired from the terminal; and the base station determines a cell and a carrier type to which the terminal is switched according to the RSRP, the RSRQ and the carrier type of the adjacent cell of the cell in which the terminal is located in the cell list of the RRC configuration message acquired from the terminal.

27. The system according to claim 24, wherein the RRC configuration information further comprises:

28. The system of claim 23, wherein the extension carrier information is a 1-bit identity.