CN102711171B - Method and device for deleting branch - Google Patents

Abstract

The invention relates to a method and device for deleting a branch. The method includes: receiving a pilot strength measurement message sent by a mobile terminal, where the pilot strength measurement message carries indication information for deleting at least one branch; determining the branch activation set of the mobile terminal except the at least one branch Whether the quality of the reverse link of a branch in other branches meets the preset threshold value, if yes, then determine to delete the at least one branch; if not, then further determine the reverse link of the at least one branch Whether the quality of the method satisfies a preset threshold value, if yes, it is determined to keep the at least one branch, and if not, it is determined to delete the at least one branch. The invention realizes whether to delete a branch according to the quality of the forward link and the reverse link of each branch, and reduces the call drop caused by deleting the branch.

Description

Method and device for deleting branch

technical field

The invention relates to the field of wireless communication, in particular to a method and device for deleting a branch.

Background technique

The Code Division Multiple Access (CDMA) communication system has a soft handover function. Soft handover means that when the mobile station enters another cell from one cell, it first establishes communication with the new base station until it receives a signal lower than the original base station. A switching method that cuts off the communication link with the original base station after a threshold value is reached. The soft handover process ensures the continuity of information transmission during the handover process. The soft handover function makes it possible that there may be multiple forward and reverse unbalanced branches in the branch activation set of the CDMA network, that is, the forward link of the branch is good but the reverse link is not good, or the forward link of the branch is not good but the reverse link is not good. Good link. In this scenario, if the handover process is not performed well, it is likely to cause branch overload and call drop of the mobile station, which greatly reduces network quality. The so-called branch refers to the wireless link (including the forward link and the direction link) between the base station and the mobile terminal, and the English name of the branch is leg.

Under the existing technology, the addition and deletion of branches in the CDMA system is based on the Ec/Io (Pilot energy accumulated over one PN chip period to the total power spectral desity in the received bandwidth, The signal-to-noise ratio of the pilot signal), regardless of the quality of its reverse link. When the quality of the forward link and reverse link of multiple branches in the active set is unbalanced, it is possible to delete the branch with bad forward link but good reverse link only according to the Ec/Io of the forward link , which will cause the remaining branch reverse links to be too poor and cause call drops.

Contents of the invention

Embodiments of the present invention provide a method and device to determine whether to delete a certain branch based on the quality of the reverse link in the scenario where the terminal requests to delete the branch, effectively reducing the The call is dropped due to the good branch of the link.

On the one hand, an embodiment of the present invention provides a method for deleting a branch, the method comprising:

receiving a pilot strength measurement message sent by the mobile terminal, where the pilot strength measurement message carries indication information for deleting at least one branch;

Determining whether the quality of the reverse link of a branch in other branches except the at least one branch in the branch active set of the mobile terminal meets a preset threshold value, and if so, determining to delete the at least one branch ;

If not, then further determine whether the quality of the reverse link of the at least one branch meets the preset threshold value, if yes, then determine to keep the at least one branch; if not, then determine to delete the at least one branch a branch.

On the other hand, an embodiment of the present invention provides a device for deleting a branch, and the device includes:

a receiver, configured to receive a pilot strength measurement message sent by the mobile terminal, where the pilot strength measurement message carries indication information for deleting at least one branch;

A first processor, configured to determine whether the quality of the reverse link of a branch in other branches except the at least one branch in the branch active set of the mobile terminal satisfies a preset threshold value, if yes, then Determining to delete the at least one branch; if not, further determining whether the quality of the reverse link of the at least one branch meets the preset threshold value, if yes, then determining to retain the at least one branch; if If not, then determine to delete the at least one branch.

In the embodiment of the present invention, in the soft handover scenario, after receiving the pilot strength measurement message reported by the mobile terminal indicating to delete at least one branch, the base station controller first determines that the at least one branch is removed from the branch activation set of the mobile terminal. Whether the quality of the reverse link of a branch in the other branches meets the preset threshold value, if yes, then determine to delete the at least one branch; if not, then further determine the reverse link of the at least one branch Whether the quality of the link satisfies the preset threshold value, if so, determine to keep the at least one branch, or determine to delete the at least one branch. Therefore, the embodiment of the present invention realizes that when the terminal requests to delete at least one branch, it can be determined whether to delete the at least one branch according to the quality of the reverse link of each branch, effectively reducing The call is dropped due to the good branch of the link.

Description of drawings

FIG. 1 is a schematic diagram of an application scenario of a method for deleting a branch provided by an embodiment of the present invention;

FIG. 2 is a flowchart of a method for deleting a branch provided by an embodiment of the present invention;

Fig. 3 is a schematic diagram of an apparatus for deleting a branch provided by an embodiment of the present invention.

Detailed ways

In the following description, for purposes of illustration rather than limitation, specific details such as specific system architectures, interfaces, and techniques are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the invention may be practiced in other embodiments without these specific details. In other instances, detailed descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

FIG. 1 is a schematic diagram of an application scenario of a method for deleting a branch provided by an embodiment of the present invention. The method and device for deleting a branch provided by the embodiments of the present invention can be used as a new method for deleting a branch in all soft handover or softer handover scenarios during practical application. Assuming that there are two or more branches with unbalanced forward links and reverse links in the branch activation set of the mobile terminal, the mobile terminal may need to delete branches in such a scenario. The embodiment of the present invention provides a method for a base station controller to make a decision to delete a branch in a soft handover scenario. As shown in Figure 1, the mobile terminal is in the state of preparing to switch from branch B to branch A. Assuming that the solid line indicates that the link quality is good, and the dotted line indicates that the link quality is poor, then it can be seen from Figure 1 that the connection between the mobile terminal and base station A The forward link quality of branch A is good but the reverse link quality is not good, and the forward link quality of branch B between the mobile terminal and base station B is not good but the reverse link quality is good. When the pilot strength of the forward link of branch B is lower than the soft handoff deletion threshold, the mobile terminal reports a PilotStrength Measurement Message (PSMM) to the base station controller BSC through base station A and base station B to request deletion For the branch B, after receiving the PSMM message, the BSC will judge whether to delete the branch B according to the quality of the reverse link between the branch A and the branch B.

The technology described in this article can be used in wireless communication systems with soft handover and softer handover, such as Code Division Multiple Access (CDMA, Code Division Multiple Access) system, Wideband Code Division Multiple Access (WCDMA, Wideband Code Division Multiple Access Wireless), and other such communication systems or some evolutionary systems based on such systems.

Various aspects are described herein in connection with mobile terminals, base stations, and base station controllers.

The above-mentioned mobile terminal can be a personal communication service (PCS, Personal Communication Service) phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL, Wireless Local Loop) station, a personal digital assistant (PDA, Personal Digital Assistant) and other equipment. The mobile terminal can also be a subscriber unit (Subscriber Unit), a subscriber station (Subscriber Station), a mobile station (Mobile Station), a remote station (Remote Station), an access point (Access Point), a remote terminal (Remote Terminal), an access terminal (AccessTerminal), User Agent (User Agent), User Device (User Device), or User Equipment (User Equipment), etc.

The base station can be a base station (BTS, Base Transceiver Station) in GSM or CDMA, or a base station (NodeB) in WCDMA, or an evolved base station (NodeB or eNB or e-NodeB, evolutional NodeB) in E-UTRA B), the present invention is not limited.

The base station controller can be a base station controller (BSC, base station controller) in GSM or CDMA, or a radio network controller (RNC, Radio Network Controller) in WCDMA, etc., and the present invention is not limited.

Embodiments of the present invention provide a method and device for deleting a branch. In the soft handover scenario, after receiving the pilot strength measurement message reported by the mobile terminal indicating to delete at least one branch, the base station controller first determines whether any other branches in the branch activation set of the mobile terminal except the at least one branch The quality of the reverse link of a branch meets the preset threshold value, if yes, then determine to delete the at least one branch; if not, further determine whether the quality of the reverse link of the at least one branch satisfies If the preset threshold value is yes, it is determined to keep the at least one branch, otherwise it is determined to delete the at least one branch. Therefore, the embodiment of the present invention realizes that when the terminal requests to delete at least one branch, it can be determined whether to delete the at least one branch according to the quality of the reverse link of each branch, effectively reducing The call is dropped due to the good branch of the link.

FIG. 2 is a flowchart of a method for deleting a branch provided by an embodiment of the present invention. The execution body of this embodiment may be the base station controller, which describes in detail the method for the base station controller to determine whether to delete the branch requested by the terminal according to the quality of the reverse link of each branch. As shown in Figure 2, this embodiment includes the following steps:

Step 201, the base station controller receives a pilot strength measurement message sent by a mobile terminal, and the pilot strength measurement message carries instruction information for deleting at least one branch.

The pilot strength measurement message is sent when the mobile terminal detects that the pilot strength of the forward link of the at least one branch is lower than the pilot discarding threshold. For example, assuming that there are two or more unbalanced branches in the branch activation set of the mobile terminal, and when the pilot strength of the forward link of one of the branches is less than the pilot drop threshold value T_DROP, the mobile terminal starts The drop timer of this branch, when the timing of the drop timer exceeds the threshold T_TDROP specified by the drop timer, the mobile terminal will send a pilot strength measurement message PSMM to the base station to request to delete the branch, and the base station forwards the received PSMM to base station controller.

The pilot strength of each branch can be represented by Ec/Io (the ratio of the energy Ec of a bit to the received total spectral density—noise plus signal).

Step 202, the base station controller determines whether the quality of the reverse link of a branch in the branches other than the at least one branch in the branch active set of the terminal meets the preset threshold value, and if so, determines to delete The at least one branch; if not, go to step 203 .

The PSMM message gives the pilot strength of the forward link of each branch and the value of the branch reservation indication information KEEP. The KEEP value of 1 indicates that the corresponding branch is reserved, and the branch with the KEEP value of 1 includes the pilot of the forward link. The branch whose strength is greater than or equal to T_DROP, or the branch whose pilot strength of the forward link is less than T_DROP but whose duration does not exceed the threshold T_TDROP specified by the drop timer; a KEEP value of 0 indicates that the corresponding branch needs to be deleted, and a branch with a KEEP value of 0 It includes branches whose pilot strength of the forward link is less than T_DROP and whose duration exceeds the threshold T_TDROP specified by the drop timer.

The detailed embodiments of the present invention are mainly described in detail for the situation that the PSMM message carries indication information for deleting at least one branch. If the mobile terminal requests to delete at least one branch through a PSMM message, the base station controller first determines whether the quality of the reverse link of one branch in the branch activation set of the mobile terminal whose KEEP value is 1 meets the preset threshold value, that is, whether the quality of the reverse link is relatively good, and if so, the at least one branch may be deleted.

Before performing the operation in this step, the base station controller can also set the threshold value, which is used to measure the quality of the reverse link of each branch. If the quality of the reverse link of the branch is greater than or equal to the threshold value, it indicates that the quality of the reverse link of the branch is relatively good; otherwise, it indicates that the quality of the reverse link of the branch is too poor.

The quality of the reverse link of the branch can be specifically reflected by evaluating the parameters of the link quality, and the parameters of the evaluating link quality can include one or more of parameters such as frame error rate, pilot strength value, signal-to-noise ratio, etc. All kinds of parameter data that can be used by those skilled in the art to evaluate the link quality are within the protection scope of the present invention. For example, when the parameters for evaluating the link quality are pilot strength and frame error rate, the threshold may include the pilot strength threshold and the frame error rate threshold, if the reverse link pilot strength If the value is greater than or equal to the pilot strength threshold value, and its frame error rate is also smaller than the frame error rate threshold value, it means that the quality of the link in this direction meets the threshold value, that is, the link quality comparison good. The data for evaluating the link quality can be monitored by the corresponding base station and sent to the base station controller.

In addition to the branch that the mobile terminal requests to delete, there may be one or more other branches in the branch activation set of the mobile terminal. When there are multiple other branches, the base station controller will judge whether there is at least one branch in the other branches The quality of the reverse link meets the preset threshold value, if so, the base station controller deletes at least one branch that the mobile terminal requests to delete, that is, sends an extended handover indication message to the mobile terminal for Instructing the mobile terminal to delete the at least one branch that the mobile terminal requests to delete; if not, perform step 203 .

Step 203, the base station controller further determines whether the quality of the reverse link of the at least one branch satisfies the preset threshold value, if yes, then determines to retain the at least one branch; if not, then determines to delete the at least one branch.

When the base station controller determines that the qualities of the reverse links of other branches except the at least one branch requested to be deleted by the mobile terminal are all less than a preset threshold value, it will continue to determine the at least one branch requested to be deleted by the mobile terminal. Whether the quality of the reverse link of the branch meets the preset threshold value, if yes, it means that the quality of the reverse link of at least one branch requested by the mobile terminal to be deleted is better, and the base station controller makes a decision not to delete the at least one branch The decision of one branch is to send an extended handover instruction message to the mobile terminal, which is used to instruct the mobile terminal not to delete the at least one branch requested to be deleted by the mobile terminal.

If the base station controller determines that the quality of the reverse link of the at least one branch requested by the mobile terminal to be deleted is less than the threshold value, it means that the quality of the reverse link of the at least one branch requested by the mobile terminal to be deleted is also not good, At this time, the base station controller may delete the at least one branch, that is, send an extended handover instruction message to the mobile terminal, instructing the mobile terminal to delete the at least one branch from the branch activation set.

In the embodiment of the present invention, after receiving the pilot strength measurement message reported by the mobile terminal indicating to delete at least one branch, the base station controller first determines whether the other branches in the branch activation set of the mobile terminal except the at least one branch Whether the quality of the reverse link judged by a branch meets the preset threshold value, if yes, then determine to delete the at least one branch; if not, then further determine the quality of the reverse link of the at least one branch Whether the preset threshold value is met, if so, determine to keep the at least one branch, otherwise determine to delete the at least one branch. Therefore, the embodiment of the present invention realizes that when the terminal requests to delete at least one branch, it can be determined whether to delete the at least one branch according to the quality of the reverse link of each branch, effectively reducing The call is dropped due to the good branch of the link.

Correspondingly, the embodiment of the present invention also provides a device for deleting a branch. Fig. 3 is a schematic diagram of an apparatus for deleting a branch provided by an embodiment of the present invention. The main body of this embodiment is the base station controller, which describes in detail the process of each functional module in the base station controller determining whether to delete at least one branch requested by the terminal according to the quality of the reverse link of each branch. As shown in Figure 3, this embodiment includes the following units:

The receiver 301 is configured to receive a pilot strength measurement message sent by a mobile terminal, where the pilot strength measurement message carries instruction information for deleting at least one branch.

The pilot strength measurement message is sent when the mobile terminal detects that the pilot strength of the forward link of the at least one branch is lower than the pilot discarding threshold. For example, assuming that there are two or more unbalanced branches in the branch activation set of the mobile terminal, and the pilot strength of the forward link of one of the branches is less than the pilot discarding threshold value T_DROP, the mobile terminal starts The drop timer of this branch, when the timing of the drop timer exceeds the threshold T_TDROP specified by the drop timer, the mobile terminal will send a pilot strength measurement message PSMM to the base station to request to delete the branch, and the base station forwards the received PSMM to The base station controller, whereby the base station controller can receive PSMM messages.

The first processor 302 is configured to determine whether the quality of the reverse link of a branch in other branches except the at least one branch in the branch active set of the terminal satisfies a preset threshold value, and if so, then Determining to delete the at least one branch; if not, further determining whether the quality of the reverse link of the at least one branch meets the preset threshold value, if yes, then determining to retain the at least one branch; if If not, then determine to delete the at least one branch.

If the mobile terminal requests to delete at least one branch, the first processor 302 first determines whether the quality of the reverse link of one branch in the branch activation set of the mobile terminal other than the at least one branch meets the preset quality. The threshold value, that is, whether the quality of the reverse link of the branch whose KEEP value is 1 meets the preset threshold value, if yes, it means that the quality of the reverse link of other branches is relatively good, and the mobile The at least one branch requested by the terminal to be deleted.

Preferably, the embodiment of the present invention further includes: a second processor 303, configured to set the threshold.

The threshold value is used to measure the quality of the reverse link of each branch. If the quality of the reverse link of the branch is greater than or equal to the threshold value, it indicates that the quality of the reverse link of the branch is relatively good; otherwise, it indicates that the quality of the reverse link of the branch is too poor.

The quality of the reverse link of the branch can be specifically reflected by evaluating the parameters of the link quality, and the parameters of the evaluating link quality can include one or more of parameters such as frame error rate, pilot strength value, signal-to-noise ratio, etc. All the parameters that can be used by those skilled in the art to evaluate the link quality are within the protection scope of the present invention. For example, when the parameters for evaluating the link quality are pilot strength and frame error rate, the threshold may include the pilot strength threshold and the frame error rate threshold, if the reverse link pilot strength If the value is greater than or equal to the pilot strength threshold value, and its frame error rate is also smaller than the frame error rate threshold value, it means that the quality of the link in this direction meets the threshold value. The quality is better. The data for evaluating the link quality can be monitored by the corresponding base station, sent to the base station controller, and received by the receiver 301 of the base station controller.

In addition to the branch that the mobile terminal requests to delete, there may be one or more other branches in the branch activation set of the mobile terminal. When there are multiple other branches, the first processor 302 will judge whether there is at least one of the other branches. The quality of the reverse link of a branch satisfies a preset threshold value, if yes, the first processor 302 determines to delete the at least one branch; if not, the first processor 302 further determines that the quality of the at least one branch Whether the quality of the reverse link of the at least one branch satisfies the preset threshold value, if yes, retain the at least one branch; if not, determine to delete the at least one branch.

The device in this embodiment of the present invention may further include: a sender 304, specifically configured to: after the first processor 302 determines to reserve the at least one branch, send an extended handover instruction message to the mobile terminal, for instructing the mobile terminal The terminal does not delete the at least one branch requested to be deleted by the mobile terminal.

or,

The sender 304 is specifically configured to: after the first processor 302 determines to delete the at least one branch, send an extended handover indication message to the mobile terminal, for instructing the mobile terminal to delete the branch that the mobile terminal requests to delete. at least one branch.

When the first processor 302 of the base station controller determines that the quality of the reverse link of the at least one branch that the mobile terminal requests to delete is less than or equal to a preset threshold value, it will continue to determine the reverse link of the at least one branch. Whether the quality of the link is greater than or equal to the preset threshold value, if yes, it means that the quality of the reverse link of the at least one branch requested by the mobile terminal to be deleted is better, and the first processor 302 determines to keep the at least one branch One branch is to send an extended switching instruction message to the mobile terminal through the transmitter 304, which is used to instruct the mobile terminal not to delete the at least one branch that the mobile terminal requests to delete.

If the first processor 302 of the base station controller determines that the quality of the reverse link of the at least one branch requested by the mobile terminal to be deleted is less than the preset threshold value, it indicates that the reverse link of the branch requested by the mobile terminal to be deleted The quality of the link is bad. At this time, the first processor 302 determines to delete the at least one branch, that is, sends an extended handover indication message to the mobile terminal through the transmitter 304, instructing the mobile terminal to delete the branch from the active set.

In the embodiment of the present invention, after receiving the pilot strength measurement message reported by the mobile terminal indicating to delete at least one branch, the base station controller first determines whether the other branches in the branch activation set of the mobile terminal except the at least one branch If the quality of the reverse link of one branch meets the preset threshold, if yes, then determine to delete the at least one branch; if not, then further determine whether the quality of the reverse link of the at least one branch satisfies the If the preset threshold value is yes, it is determined to keep the at least one branch, otherwise it is determined to delete the at least one branch. Therefore, the embodiment of the present invention realizes that when the terminal requests to delete at least one branch, it can determine whether to delete the at least one branch according to the quality of the reverse link of each branch, effectively reducing A call drop caused by a branch with a good link.

Professionals should further realize that the units and algorithm steps described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the relationship between hardware and software Interchangeability. In the above description, the composition and steps of each example have been generally described according to their functions. Whether these functions are executed by hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present invention.

The steps of the methods or algorithms described in connection with the embodiments disclosed herein may be implemented by hardware, software modules executed by a processor, or a combination of both. Software modules can be placed in random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other Any other known storage medium.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the scope of the present invention. Protection scope, within the spirit and principles of the present invention, any modification, equivalent replacement, improvement, etc., shall be included in the protection scope of the present invention.

Claims (6)

1. A method for deleting a branch, characterized in that the method comprises: receiving a pilot strength measurement message sent by the mobile terminal, where the pilot strength measurement message carries indication information for deleting at least one branch; Determining whether the quality of the reverse link of a branch in other branches except the at least one branch in the branch active set of the mobile terminal meets a preset threshold value, and if so, determining to delete the at least one branch ; If not, then further determine whether the quality of the reverse link of the at least one branch meets the preset threshold value, if yes, then determine to keep the at least one branch; if not, then determine to delete the at least one branch a branch; After the determining to delete the at least one branch, it further includes: sending an extended handover instruction message to the mobile terminal, for instructing the mobile terminal to delete the at least one branch; After the determining to retain the at least one branch, the method further includes: sending an extended handover indication message to the mobile terminal to instruct the mobile terminal not to delete the at least one branch. 2. The method according to claim 1, wherein the determination of whether the quality of the reverse link of a branch in other branches except the at least one branch in the branch active set of the mobile terminal satisfies the predetermined Before the threshold value is set, the method further includes: setting the threshold value. 3. The method according to any one of claims 1-2, characterized in that, the quality of the reverse link is specifically reflected by evaluating link quality parameters, and the evaluating link quality parameters include frame error One or more of rate, pilot strength value, and signal-to-noise ratio. 4. A device for deleting a branch, characterized in that the device comprises: a receiver, configured to receive a pilot strength measurement message sent by the mobile terminal, where the pilot strength measurement message carries indication information for deleting at least one branch; A first processor, configured to determine whether the quality of the reverse link of a branch in other branches except the at least one branch in the branch active set of the mobile terminal satisfies a preset threshold value, if yes, then Determining to delete the at least one branch; if not, further determining whether the quality of the reverse link of the at least one branch meets the preset threshold value, if yes, then determining to retain the at least one branch; if No, then determine to delete the at least one branch; The device further includes: a sender, configured to send an extended handover instruction message to the mobile terminal after the first processor determines to delete the at least one branch, for instructing the mobile terminal to delete the at least one branch branch; The device further includes: a sender, configured to send an extended handover instruction message to the mobile terminal after the first processor determines to retain the at least one branch, for instructing the mobile terminal not to delete the at least one branch a branch. 5. The device according to claim 4, further comprising: a second processor, configured to set the threshold value. 6. The device according to any one of claims 4-5, wherein the quality of the reverse link is specifically reflected by parameters for evaluating link quality, and the parameters for evaluating link quality include frame error One or more of rate, pilot strength value, and signal-to-noise ratio.