CN1753554A - Implementing method of relay switchover judging process - Google Patents

Abstract

The invention discloses a method for realizing a relay handover judgment process. RNC first judges whether the signal quality or strength of the UE's current serving cell has declined and is lower than a threshold value, and if so, locates the UE, and if the UE's location information can be obtained , then according to the location information of the UE, determine the adjacent cells related to the location of the UE, and then select several cells with high signal strength from the related adjacent cells as candidate cells for relay handover; and then sequentially Make an admission judgment on the candidate cell, select a candidate cell that is allowed to be admitted as the target cell of the UE's relay handover, and start the execution process of the relay handover. The method of the invention can accurately judge whether the UE meets the condition of the relay handover, and select a target cell for the relay handover, so as to ensure that the UE can reliably execute the relay handover process.

Description

A Realization Method of Relay Handover Judgment Process

technical field

The invention relates to a TD-SCDMA (Time Division Synchronous Code Division Multiple Access) mobile communication system, in particular to a method for realizing a relay switching judgment process in the system.

Background technique

Baton Handover is one of the core technologies of TD-SCDMA mobile communication system. Its design idea is to use technologies such as smart antennas and uplink synchronization to locate the distance and orientation of the UE (mobile terminal), and use the orientation and distance of the UE as auxiliary information to determine whether the current UE has moved to a place where handover can be performed. The vicinity of adjacent base stations. If the UE enters the handover area, the RNC (Radio Network Controller) notifies the base station to prepare for the handover, so as to achieve the purpose of fast, reliable and efficient handover. This process is like passing the baton in a relay race in a track and field competition, so it is vividly called relay switching.

Relay handover is a new handover method between hard handover and soft handover. Compared with soft handover, both have the advantages of higher handover success rate, lower call drop rate, and less uplink interference. The difference between them is that relay handover does not require multiple base stations to provide services for a mobile terminal at the same time, so it can overcome the need to occupy more channel resources for soft handover, the complexity of signaling leads to increased system burden, and the increase in downlink interference, etc. shortcoming. Compared with hard handover, both have advantages such as high resource benefit rate, relatively simple algorithm, and relatively light signaling load of the system. The difference is that relay handover disconnects the original base station and establishes a communication link with the target base station almost at the same time, thus overcoming the disadvantages of high call drop rate and low handover success rate of traditional hard handover.

Therefore, through the organic combination of smart antenna and uplink synchronization technology, relay handover skillfully combines the high success rate of soft handover and the high channel benefit rate of hard handover, which is a handover method with better system performance.

The relay switching is divided into three processes: measurement process, judgment process and execution process.

In the measurement process of relay handover, traditional soft handover and hard handover are performed without knowing the exact location of the UE, so it is necessary to measure all adjacent cells, and then make handover decisions based on given handover algorithms and criteria and target cell selection. In the case of the relay handover, the handover measurement is performed under the condition that the position of the UE is accurately known, including the measurement of the positioning of the UE and the measurement of the signal strength of the candidate cell. The conditions for the RNC to obtain the accurate position of the UE are the key technologies of TD-SCDMA, the smart antenna technology and the synchronization technology.

In the judgment process of the relay handover, in the relay handover process, it is necessary to judge whether the UE should be handed over and how to perform the handover according to certain criteria and algorithms based on various measurement information and integrated system information.

In the execution process of the relay handover, after the relay handover is started, the terminal receives downlink data from the source cell and sends uplink data to the target cell.

In essence, the measurement process and the judgment process of the handover are an interactive process, and the measurement process can be considered as a link in the judgment process, and the judgment result of the handover depends on the accuracy of the measurement. However, in the existing standards or other public documents, the specific implementation of the decision process of the relay handover (such as the decision condition, etc.) has not been involved.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for realizing the judgment process of the relay handover. According to the method, the RNC can judge whether the UE meets the condition of the relay handover, and determine a target cell for the relay handover.

In order to solve the above-mentioned technical problems, the present invention provides a method for implementing a relay handover judgment process, comprising the following steps:

(a) The radio network controller judges whether the signal quality or strength of the current serving cell of the mobile terminal has declined and is lower than the threshold value, and if so, executes the next step, otherwise, does not perform relay handover;

(b) The radio network controller locates the mobile terminal, if the location information of the mobile terminal can be obtained, the next step is performed, otherwise the relay handover is not performed;

(c) The radio network controller determines the adjacent cells related to the location of the mobile terminal according to the location information of the mobile terminal;

(d) The radio network controller selects several cells with higher signal strength from the relevant adjacent cells as candidate cells for the relay handover;

(e) The radio network controller sequentially makes admission judgments on the candidate cells, and selects a candidate cell that is allowed to be admitted as a target cell for the handover of the mobile terminal, and starts the execution process of the handover.

Further, the above method can also have the following characteristics: when the radio network controller locates the mobile terminal in the step (b), it initiates the positioning measurement of the mobile terminal; obtained from the location information of .

Further, the above method may also have the following features: the step (d) radio network controller instructs the mobile terminal to measure the signal strength of the relevant adjacent cell through a measurement control message, and obtains the signal strength according to the measurement report of the mobile terminal Several cells with higher signal strength are used as the candidate cells; or the radio network controller selects several cells with higher signal strengths as the candidate cells from the stored measurement reports of related neighboring cells.

Further, the above-mentioned method may also have the following characteristics: said step (c) the wireless network controller predicts the area to which the mobile terminal may move according to the current position of the mobile terminal, and uses the adjacent cell whose coverage includes the area as the mobile terminal related neighboring areas.

Further, the above method may also have the following characteristics: in the step (b) when the radio network controller locates the mobile terminal, if the switching time allows, then initiate multiple positioning measurements of the mobile terminal, and according to the multiple measurement results Calculate the moving speed and moving direction of the mobile terminal, and in step (c), consider the position, moving speed, moving direction and switching time of the mobile terminal comprehensively to determine the area that the mobile terminal may move to.

Further, the above method may also have the following characteristics: the threshold value in the step (a) refers to a good quality threshold of the mobile terminal signal.

Further, the above method may also have the following characteristics: the threshold value in the step (a) refers to the good threshold of the signal strength of the mobile terminal.

Further, the above method can also have the following characteristics: in the step (e), the radio network controller performs admission judgments in sequence according to the order of the signal strength of the candidate cells, and uses this cell as a handover after finding an acceptable candidate cell target area.

Further, the above method may also have the following features: when the radio network controller instructs the mobile terminal to measure the signal strength of the relevant adjacent cell through a measurement control message, the mobile terminal is designated to report a measurement report by means of event reporting, And configure the threshold of signal strength as the trigger condition for event reporting.

Further, the above method may also have the following features: when the radio network controller instructs the mobile terminal to measure the signal strength of the relevant adjacent cell through a measurement control message, the mobile terminal is designated to report the measurement report in a periodic reporting manner , and the radio network controller finds a cell with higher signal strength according to the reported measurement result.

As can be seen from the above, the present invention can accurately determine whether the UE satisfies the conditions for the relay handover through the judgment process before the execution of the relay handover, including the measurement and judgment interaction process of the relay handover, and can accurately select a UE for the relay handover. The target cell, so as to ensure that the UE can reliably perform the relay handover process.

Description of drawings

FIG. 1 is a flow chart of the relay handover decision process in the first embodiment of the present invention.

Fig. 2 is a schematic diagram of interaction between UE and RNC in the judgment process according to the first embodiment of the present invention.

Fig. 3 is a schematic diagram of the RNC selecting a candidate cell according to the current location and moving direction of the UE according to the embodiment of the present invention.

Detailed ways

first embodiment

Fig. 1 shows the flow process of the relay handover judging process of the present embodiment, please refer to Fig. 2 simultaneously, this judging process includes the following steps:

Step 110, the UE simultaneously measures the signal strength of the serving cell and the adjacent cell (the measurement quantity is the received signal code power of the main common control channel) or signal quality (the measurement quantity is the block error rate of the downlink transmission channel), and reports to the RNC;

Step 120, the RNC monitors the measurement results of the UE's current serving cell, and judges whether its signal quality or strength has declined and is lower than the threshold value (relay handover condition 1), if so, the RNC judges that the UE enters the ready handover state, and executes the next step, otherwise Exit the switching judgment process;

In this step, if the signal quality or strength is good enough, it is decided not to carry out the handover; if the signal quality is between the good quality threshold and the service requirement threshold or lower than the service requirement threshold, or its signal strength is If the signal strength is between good and the set minimum signal strength threshold or is lower than the set signal strength minimum threshold, the RNC believes that the current serving cell cannot provide good services to the UE, and needs to start the related measurement process of handover.

Step 130, the RNC initiates the positioning measurement of the UE, if the location information of the UE is obtained (relay handover condition 2), the next step is performed, otherwise, the execution process of the hard handover is started;

In this step, the location information of the UE includes distance and direction. If the signal quality provided by the serving cell is very poor at this time (for example, it is lower than the threshold of service requirements), it is necessary to complete the handover between cells as soon as possible, and only one measurement can be performed; threshold), the RNC can also initiate multiple positioning measurements to obtain multiple UE location information, and then calculate the UE's moving speed and moving direction. Moving speed v=(S1-S2)/t, wherein: S1 measures the position this time, S2 measures the position last time, and t is the time difference between these two measurements. In order to ensure the accuracy of the speed, the RNC may take an average value of the speeds calculated multiple times as the moving speed of the UE.

Step 140, the RNC determines the neighboring cell related to the current location of the UE according to the location information of the UE;

There can be up to 6 cells in the adjacent cell list of the UE. In order to reduce the measurement of the UE during the relay handover, the RNC first bases on the current location of the UE, as well as the moving speed and direction of the UE (if any), according to the mobile The current location of the terminal predicts the area it may move to, and the adjacent cells whose coverage range includes this area are taken as the relevant adjacent cells of the mobile terminal. Judging in combination with the moving speed and direction of the UE helps to accurately predict the area to which the UE may move.

As shown in Figure 3, the RNC can judge that the area that the UE may move to is the shaded area in the figure according to the UE's position, moving speed, moving direction, and handover time (predicted value), which is the overlapping area of cells A, B, and C , therefore, the RNC selects three cells, including cell A, cell B, and cell C, as adjacent cells for UE measurement, which reduces the range for the UE to search and measure adjacent cells.

Step 150, the RNC instructs the UE to measure the signal strength of the adjacent cell related to its location through a measurement control message;

Step 160, the RNC receives the measurement report reported by the UE, and uses several cells with higher signal strength (relay handover condition 3) in the relevant adjacent cells as candidate cells for the relay handover;

In steps 150 and 160, the RNC may order the UE to report the measurement report by means of event reporting or periodic reporting through a measurement control message. When the event reporting method is used, the RNC configures the threshold of signal strength as the trigger condition for event reporting, and the UE only reports the result of "neighboring cells with high signal strength"; when using periodic reporting, the UE periodically reports all According to the measurement result, the RNC finds out the cell with higher signal strength according to the measurement result.

In Figure 3, the UE measures the signal strength of cells A, B, and C. Considering that there is an allowable error redundancy when the RNC calculates and predicts the UE's mobile location, and considering that some cells in the adjacent cell list have low signal strength, and considering that some candidate cells may not require UE admission due to load reasons , so it is necessary to select multiple adjacent cells for measurement and as candidate cells.

Step 170, the RNC performs admission judgment on the candidate cells in sequence according to the priority order, and selects a candidate cell that is allowed to be admitted (relay handover condition 4) as the target cell of the UE relay handover;

Only the cell that the UE is allowed to accept may become the target cell of the relay handover. In order to admit the UE to the cell with the best quality, the RNC forms a priority list for admission control according to the signal strength of the candidate cells. Then make an admission judgment on the candidate cells in this order, stop the admission judgment after finding a cell that allows admission, and take the candidate cell as the target cell; or you can find multiple candidate cells that allow admission, and then select one of them as the target cell .

In step 180, the judging process of the relay handover ends, and the execution process of the relay handover begins.

As can be seen from the above flow process, the prerequisites for the RNC in the present embodiment indicated in Fig. 2 to carry out relay handover include the following four:

Relay handover condition 1, the signal quality or strength of the current serving cell drops and falls below the threshold;

Relay handover condition 2, the RNC can obtain the accurate location information of the UE;

Relay handover condition 3, the signal strength of the adjacent cell related to the UE location is relatively high, that is, there is a candidate cell with high signal strength;

Batter handover condition 4, the candidate cell allows the UE to accept.

Correspondingly, the target cell as a relay handover must meet three basic conditions: 1) the coverage of the target cell is related to the distance and direction of the UE; 2) the signal strength of the target cell is high enough; 3) the target cell allows the UE to admit.

second embodiment

The difference between the process of this embodiment and the first embodiment lies in the following two points:

First, in this embodiment, the RNC obtains the UE location information from the stored UE location information (generally stored in a database related to the location service), rather than by initiating UE location measurement.

Second, the way for the RNC to select a cell with a higher signal strength is obtained from the stored measurement reports of the relevant neighboring cells, rather than by instructing the UE to measure the relevant neighboring cells.

Other processing methods are the same.

Claims (10)

1, a kind of implementation method of relay switchover judging process may further comprise the steps:

(a) radio network controller judges whether the signal quality of portable terminal current service cell or intensity descend and be lower than threshold value, if carry out next step, otherwise do not carry out baton handover;

(b) radio network controller positions this portable terminal, if can access the positional information of this portable terminal, carries out next step, otherwise does not carry out baton handover;

(c) radio network controller is determined the neighbor cell relevant with this mobile terminal locations according to the positional information of this portable terminal;

(d) radio network controller is selected the higher sub-district of several signal strength signal intensities from described relevant neighbor cell, as the candidate cell that is used for baton handover;

(e) radio network controller carries out acceptance judging to described candidate cell successively, and selects a Target cell that allows the candidate cell of admittance as this relay mobile terminal switching, the implementation of beginning baton handover.

2, implementation method as claimed in claim 1 is characterized in that, when described step (b) radio network controller is located this portable terminal, is the location survey of initiating this portable terminal; Perhaps radio network controller is to obtain from the positional information of this portable terminal of having stored.

3, implementation method as claimed in claim 1 or 2, it is characterized in that, described step (d) radio network controller is by measuring control messages, indicate this portable terminal to measure the signal strength signal intensity of described relevant neighbor cell, and obtain the higher sub-district of several signal strength signal intensities as described candidate cell according to the measurement report of this portable terminal; Perhaps radio network controller is to select the higher sub-district of several signal strength signal intensities as described candidate cell from the measurement report of relevant neighbor cell of storage.

4, implementation method as claimed in claim 1, it is characterized in that, described step (c) radio network controller is to predict the zone that it may move to according to the current location of this portable terminal, and coverage is comprised the relevant neighbor cell of this regional neighbor cell as this portable terminal.

5, implementation method as claimed in claim 4, it is characterized in that, when described step (b) radio network controller is located this portable terminal, if allow switching time, then initiate repeatedly location survey to this portable terminal, and calculate the translational speed and the moving direction of this portable terminal according to measurement result repeatedly, determine the zone that this portable terminal may move to position, translational speed, moving direction and the switching time of in step (c), taking all factors into consideration this portable terminal.

6, implementation method as claimed in claim 1 is characterized in that, the threshold value in the described step (a) is meant the good thresholding of portable terminal quality of signals.

As claim 1 or 6 described implementation methods, it is characterized in that 7, the threshold value in the described step (a) is meant the good thresholding of the intensity of portable terminal signal.

8, implementation method as claimed in claim 1, it is characterized in that, radio network controller is to carry out acceptance judging successively according to the order of described candidate cell signal strength signal intensity in the described step (e), finds behind the candidate cell that can admit with the Target cell of this sub-district as baton handover.

9, implementation method as claimed in claim 3, it is characterized in that, when described radio network controller moves this portable terminal and measures the signal strength signal intensity of described relevant neighbor cell by measuring the control messages indication, specify the mode reporting measurement reports of this portable terminal employing reporting events, and the thresholding of configuration signal intensity is as the trigger condition of reporting events.

10, implementation method as claimed in claim 3, it is characterized in that, when described radio network controller moves this portable terminal and measures the signal strength signal intensity of described relevant neighbor cell by measuring the control messages indication, specify this portable terminal to adopt the mode reporting measurement reports that periodically reports, radio network controller is found out the higher sub-district of signal strength signal intensity according to the measurement result that reports again.

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