Background technology
System of broadband wireless communication, as 3G (Third Generation) Moblie (being called for short 3G), 3GPP Long Term Evolution (Long-Term Evolution, hereinafter to be referred as LTE) and the 4th Generation Mobile Communication System (being called for short 4G), be the beehive net mode based on many residential quarters, for mobile terminal provides seamless Mobile Communication Service.
The minizone is switched and to be referred to that mobile terminal is completed be connected the migration that Radio Link connects from the cell-of-origin with Target cell under the control of wireless access network.Switching is the basic fundamental means that mobile communication system guarantees seamless Mobile Communication Service.But, complete switching and need to consume a large amount of Internet resources, and if the reception requirement that the wireless link signals power before and after switching or quality can not satisfy mobile terminal, the quality level of wireless traffic will directly be affected, produce service disconnection, even cause the user terminal can't access network, cause radio link failure (Radio Link Failure is hereinafter to be referred as RLF).
The base station of network side (particularly source base station) can be by obtaining the latter's measurement report to the measurement of mobile terminal configuration, and then understand current service cell that mobile terminal can receive and signal power and the quality of other residential quarter.Source base station can judge accordingly whether mobile terminal is in the overlapping region of current service cell and other residential quarter, and whether corresponding Radio Link situation meets the requirement of switching, and then correctly complete the minizone switching, also can avoid unnecessary switching simultaneously and reduce the probability that produces mobile terminal side RLF.
The prior art relevant to the application mainly comprises following three lists of references:
[1]TS?36.300,“(E-UTRAN);Overall?description;Stage?2”,3GPP.
[2]R3-102058,“Rapid?HO”,RAN3#69,Huawei.
[3]R3-100384,“Finalization?of?too?early?handovers?by?UE?measurements”,RAN3#66bis,Alcatel-Lucent.
Due to the complexity of wireless propagation environment, the otherness that becomes when the Radio Link coverage condition of overlapping region, minizone certainly exists.It is abnormal that these complicated covering scene may cause the switching behavior of mobile communication system to produce, as pingpang handoff (Ping-pong Handover), handoff failure (Handover Failure), and the problem such as RLF even.Document [1] has defined three kinds of problem handoff scenario:
-switch too early (Too Early Handover);
-spending evening switches (Too Late Handover);
-wrong cell is switched (Handover to Wrong Cell).
Document [1] is pointed out, under these three kinds of problem handoff scenario, mobile terminal can detect RLF, and when setting up thereafter with being connected of base station, report the Radio Link measurement result relevant to radio link failure, make network side whether can detect the current wireless connection failure because aforementioned three kinds of problems cause.Subsequently, can hold consultation and optimize relevant handoff parameter by negotiation mechanism between the base station in relevant base station, finally eliminate above-mentioned three kinds of problem handoff scenario.But document [1] is not considered some other scene, although for example switching has obtained success, these switchings may not be necessary.If can avoid unnecessary switching, can reduce the consumption of Internet resources when providing the service of equal quality for mobile terminal, realize the lifting of overall performance of network and capacity.
The problem handoff scenario that document [2] has proposed a kind of " switching fast " (Rapid Handover), as shown in Figure 1.In this scene, 3 neighbor cells exist overlapping covered.During along certain track high-speed mobile, very short at the residence time of residential quarter B when mobile terminal, therefore will produce the quick continuous switching of residential quarter A to residential quarter B, residential quarter B to residential quarter C.During regional when mobile terminal between twice switching, under given conditions, the actual wireless communication environments may allow mobile terminal to receive simultaneously residential quarter A to be connected wireless signal and set up two-way connection with residential quarter C.In this case, the above-mentioned switching continuously fast is unnecessary, also should avoid.Document [2] has proposed to detect this by residential quarter B and " has switched fast " problem, and notifies the cell-of-origin A that switches for the first time; Subsequently, cell-of-origin A can select and the Target cell C of switching for the second time carries out the negotiation that moving parameter arranges, and manages to eliminate " switching fast ".Yet, document [2] also reckons without, when the Target cell C of the cell-of-origin A that switches for the first time and switching does not for the second time have enough information, can't know that namely mobile terminal during the wireless link condition in the overlapping region, just can't correctly judge whether to avoid " switching fast " and consult corresponding moving parameter setting between twice switching.
A kind of scene of similarly " switching fast " also has been discussed in document [3], namely the neighbor cell overlay area in the network is interlaced, thereby when forming the scene of so-called " area covered ", may form " covering isolated island " (Coverage Island).When mobile terminal moves and pass through this " isolated island " along certain track, just may produce " switching fast ", as shown in Figure 2.Document [3] has provided a kind of method, make the cell-of-origin A of initiation " switch fast " can be after the problem of learning produces, can require mobile terminal to carry out within a certain period of time periodic measurement before switch occuring, and with the Target cell B of this this switching of advisory; Even again switch, move to residential quarter C as mobile terminal from residential quarter B, by residential quarter B notifying cell C relevant information, guarantee that with this above-mentioned periodic measurement configuration still can keep until the timer expiry of appointment.After measurement is completed, mobile terminal reports current service cell (for example residential quarter C) with measurement result, then the handover relevant information when entering this residential quarter by current service cell according to this mobile terminal returns to Serving cell (for example residential quarter B) before mobile terminal with measurement result.So analogize, final measurement will be returned to the initiator cell-of-origin A of this periodic measurement.This cell-of-origin A is by the analysis to measure result, can make relevant " switching fast " correct judgement and and residential quarter B or C carry out the negotiation of moving parameter setting.The shortcoming of said method is:
-except residential quarter that initiate to measure instruction, the operation that other follow-up related cell can not be modified or stop the periodic measurement that has been configured, this has seriously limited the management of other residential quarter to the mobile terminal wireless connections;
-because time and the position span of this periodic measurement are large, need each related cell to extend memory time to the mobile terminal relevant configuration information of having switched away from own coverage, thereby increased resource take and process load;
-mobile terminal needs more resource to record configuration information and the measurement result of this periodic measurement;
RLF may occur in-mobile terminal within the time of this periodic measurement, cause measuring accordingly and report operation to complete.
To sum up, in existing moving parameter commonly used arranged optimisation technique, for want of multi-cell cooperating obtained the means of wireless measurement result, may cause moving parameter to arrange unreasonable, and then caused the unnecessary problem of switching behavior generation in mobile communication system.
Therefore, the present invention has designed in a kind of mobile communication system the cooperation of many minizones and has measured and switch the method that optimization is set, efficiently solve above-mentioned technical problem, improved between judgement switching problem scene and base station and consulted accuracy and the reliability of moving parameter, thereby improved the stability that wireless communication system is supported locomotive function.
Summary of the invention
The present invention proposes in mobile communication system the cooperation of many minizones measures and switches a kind of method that optimization is set.The method requires a plurality of cell coordinations of network side to control mobile terminals to complete at the Radio Link of its designated cell overlay area and measure, and this zone is the target area that the minizone handover optimization is attempted to carry out in a plurality of residential quarters.The minizone cooperation measurement mechanism of the present invention's proposition makes the cell-of-origin of initiating to measure can obtain from other residential quarter the measurement result of mobile terminal, the reasonability that the necessity that help cell-of-origin detection is switched and moving parameter arrange.If it is unreasonable that the cell-of-origin finds to exist unnecessary switching or moving parameter to arrange between cooperation cell, it can with this information notice cooperation cell, trigger the process that moving parameter arranges optimization thus.Finally, a plurality of cooperation cell can be revised parameter, avoid irrational switching, thereby the integrated moving function that reaches network is optimized, and realizes the lifting of performance of mobile communication system and capacity.
In the method that the present invention proposes, can measure the information that the residential quarter notifies the relevant mobile terminal of cooperation cell to measure task in handoff procedure by initiation, also can be by mobile terminal after switching to cooperation cell, the information of the relevant measurement task of proactive notification cooperation cell.Above-mentioned two kinds of effects that realize that approach can reach are identical.
The below illustrates main performing step of the present invention with the double example (scene that can have continuous several times to switch in real network) that switches to, as shown in Figure 3:
(1) residential quarter is provided for judging some timers of the normal residence time lower limit of mobile terminal, corresponds respectively to different translational speed scopes.The covering radius Radius of the classification of timer and value and current areaCellAnd mobile terminal translational speed UESpeedThe sorting technique that adopts is relevant.
For example, in the LTE system, UESpeedBe divided three classes: low speed moves, middling speed moves and high-speed mobile.Therefore, normal residence time lower limit timer T can be set respectivelyLow_speed_stayedCorresponding low speed mobile terminal, TMedium_speed_stayedCorresponding medium speed's mobile terminal and THigh_speed_stayedCorresponding high speed mobile terminal;
(2) in order to realize the detection to switching problem, reply following scenario-related information in residential quarter carries out record: the mobile terminal that it was once served to certain when cell detection first enters into scope under this residential quarter by switching, of short durationly switches to again next residential quarter after resident.The residence time T that should comprise at least mobile terminal in the information of recordUe_stayed, translational speed UESpeed, mobile terminal enters Target cell that the switching historical information, mobile terminal of the source Serving cell before this residential quarter switch etc.
As cell detection to the mobile terminal that occurs to switch fast continuously, with utilization record mobile terminal translational speed UESpeedInformation is carried out scene analysis.For example, compare mobile terminal residence time T in the residential quarterUe_stayedSet point with the normal residence time lower limit of the corresponding mobile terminal of translational speed type timer, if the former is less than the latter, can judge handover event has fast occured between the neighbor cell that relates in this handoff procedure continuously, and can determine that current area is the middle residential quarter in continuous fast handover procedures;
(3) after this, when the neighbor cell that occurs to switch fast sent handover preparation request message as the handover source residential quarter to it again, in the middle of this, residential quarter can in the handoff request acknowledgment message of returning, provide the measurement configuration information for mobile terminal.Measurement can be periodic measurement, also can be based on the periodic measurement of Event triggered etc.
In measurement configuration information, can include but not limited to following content:
-measuring object: mainly show the neighbor cell of deciding frequency range, be designated as cellList.Middle residential quarter should require mobile terminal at least several residential quarters that continuous fast handover procedures is correlated with to be measured;
-trigger condition: can threshold value be set for the measurement result of some measuring objects, measure so that mobile terminal can start this when condition satisfies, be used for the periodic measurement process based on Event triggered.Take the LTE system as example, the homologous ray A1-A5 of its normalized definition, different system B1-B2 event can be used as the condition of measuring that triggers.This measurement parameter can be made as option, when configure trigger condition not represents that mobile terminal should start the measurement task immediately;
-measurement result: the measurement result type of configuration mobile terminal is designated as measResult.Take the LTE system as example, can comprise Reference Signal Received Power (Reference Signal Receiving Power, hereinafter to be referred as RSRP) and Reference Signal Received Quality (Reference Signal Receiving Quality is hereinafter to be referred as RSRQ);
-measuring period: the configuration mobile terminal carries out the time interval of periodic measurement, is designated as measPeriod;
-to measure the duration: the configuration mobile terminal carries out the total time length of periodic measurement, is designated as measDuration.Or adopt the mode of measuring total degree to express, be designated as measAmount;
-measurement result postpones to report the interval: the configuration mobile terminal postpones the time interval of reporting measurement result, is designated as TDelayMobile terminal need stores it heretofore between the interval arrive and just to report this result.Need the regular hour expense because measurement result reports, so this setting is applicable to, residential quarter urgent when switching time and may have time enough to obtain the scene of the reporting message of mobile terminal.This measurement parameter can be made as option.If the no this item configuration, mobile terminal according to normal reporting measurement result measuring period, can not produce TDelayOvertime event;
-velocity factor: mobile terminal can utilize velocity factor that measuring period, measurement duration and measurement result are postponed to report the interval to process (weighting of for example multiplying each other), and get result as measuring configuration according to the translational speed of self, is designated as S.The UE of velocity factor and mobile terminal translational speedSpeedSorting technique is corresponding.Take the LTE system as example, velocity factor S can be setMediumAnd SHigh, the corresponding middling speed of difference and high-speed mobile classification, low speed moves can corresponding constant 1.
According to information such as the translational speed of the coverage (radius of society) of current area, terminal and the normal minimum residence times of mobile terminal, can be to measuring period, measure the duration (or measuring total degree) and the measurement result delay report the interval to be optimized.Without loss of generality, the length that can be set measuring period guarantees that the measurement result of mobile terminal is abundant, makes the coverage condition of analyzing wireless link signals by statistical method become possibility; And for example can be set longer the time interval of measuring more double quick switching of duration so that the measurement that mobile terminal is done can twice switching of complete embodiment mobile terminal between wireless link signals situation of change on movement locus;
(4) above-mentioned measurement configuration information will be carried in the handover source residential quarter in the switching command that sends to mobile terminal.After mobile terminal receives measurement configuration information, complete corresponding processing procedure, also adjust accordingly measuring period, measurement duration and measurement result comprising selected applicable velocity factor and postpone to report the interval.Then, mobile terminal is carried out switching command, residential quarter in the middle of being connected to.In the middle of this moment, the residential quarter becomes the current service cell of mobile terminal.Meanwhile, the measurement action that in the middle of mobile terminal starts, the residential quarter configures;
(5) during residential quarter, the resident centre of mobile terminal, following adjustment is made in the measurement configuration that carry out before can occuring aforementioned switching middle residential quarter:
-increase or the deletion measuring object;
Other content in configuration is measured in-adjustment;
-postpone to report interval T in measurement resultDelayStop this measurement before not overtime.
Be adjusted into example with the configuration of the measurement in the LTE system, can reshuffle signaling procedure by the air-link resources between residential quarter and mobile terminal and complete;
(6) during middle residential quarter resident according to mobile terminal, whether measurement result occuring postpones to report interval TDelayOvertime event is divided into following two kinds of situations:
(6.1) T has occuredDelayOvertime event, carry out according to the following steps:
(6.1.1) mobile terminal stops measuring.Implementation method can be that this measurement of mobile terminal proactive notification current service cell is completed, and its measurement result of storing has to be reported; Or the configuration information that records by inside of middle residential quarter, find that this mobile terminal measurement result postpones to report interval TDelayOvertime, expression is measured and is completed, and can require the mobile terminal reporting measurement result.Two kinds of effects that realize approach are identical.Mobile terminal is completed measurement result measResult by measurement report message and is reported, and wherein can comprise the value of the velocity factor that mobile terminal is selected, so that the residential quarter is analyzed more accurately;
(6.1.2) receive the measurement result of mobile terminal reporting after, middle residential quarter is analyzed this mobile terminal partly or entirely continuously fast switch the metrical information of overlapping region, the minizone wireless signal of related cell on its motion track.If middle residential quarter is thought after analyzing above-mentioned data, can guarantee also that even do not switch mobile terminal keeps and the wireless connections of these residential quarters, handoff parameter in the middle of can judging between residential quarter and related cell arranges existing problems, has caused unnecessary " switching fast " to occur.Correspondingly, the optimization range that moving parameter arranges will be assessed in middle residential quarter;
(6.1.3), the problem existence " is switched " fast by handover report message informing neighbor cell in the residential quarter, and can provide measurement result so that the neighbor cell analysis.Subsequently, the minizone can start movement renewal process is set, and consults respectively the moving parameter setting and completes Optimization Work, eliminates " switching fast " problem;
(6.2) T does not occurDelayOvertime event, carry out according to the following steps:
(6.2.1) postpone to report interval T in measurement resultDelayBefore not overtime, middle residential quarter may need aforementioned mobile terminal is switched to Target cell, sends handover preparation request to Target cell.Subsequently, middle residential quarter receives Target cell return to handoff request acknowledgment message after, send switching command to mobile terminal.Mobile terminal carry out to switch and to be connected to Target cell, and stops the cell-of-origin when switching completing, namely in the middle of the measurement action that configures of residential quarter.At this moment, Target cell becomes the current service cell of mobile terminal.For Target cell, have following two kinds of possible approach to obtain the not information of reporting measurement result of mobile terminal:
● approach one: middle residential quarter informs that this mobile terminal of Target cell still has the measurement result that does not report in the handover preparation request order;
● approach two: mobile terminal still has by handoff completion message notification target residential quarter the measurement result that does not report after completing switching;
(6.2.2) Target cell learns that mobile terminal still has the measurement result that does not report, and after mobile terminal is completed switching, as the new Serving cell of this terminal, inquires about signaling procedure by end message and requires the mobile terminal reporting measurement result:
1. new Serving cell to mobile terminal transmitting terminal information inquiring request message, requires the terminal to report measurement result;
2. mobile terminal transmitting terminal information answer message, wherein comprised measurement result.Measurement result should comprise the value of the selected velocity factor of mobile terminal, so that the residential quarter is analyzed more accurately;
After (6.2.3) Target cell obtained measurement result, cell-of-origin (residential quarter namely) the transmission handover report message at place, indicated the type not reporting measurement result of aforementioned mobile terminal for this reason before this mobile terminal, and measurement result incidentally;
(6.2.4), the residential quarter receives handover report, and after extracting measurement result, analyzes and switch fast continuously related cell in the radio signal quality of overlapping region, minizone.If the judgement of middle residential quarter can not guarantee that still mobile terminal keeps and the wireless connections of these residential quarters even do not switch, can judge that " switching fast " problem exists, and the optimization range of assessment moving parameter setting.Middle residential quarter sends handover report message to the cell-of-origin of switching for the first time, and " switching fast " problem of having informed occurs, and the portability measurement result is for the relevant Radio Link situation of its analysis and evaluation;
The cell-of-origin (residential quarter A) of (6.2.5) switching for the first time or the Target cell (residential quarter B) that switches for the first time all can start moving parameter renewal process is set, consult in twos the moving parameter setting and complete Optimization Work in three related minizones, eliminating " switching fast " problem.So far, the step of branch two is finished.The residential quarter can enter the switching problem testing process of a new round;
(7) so far, this switching problem testing process is finished.The residential quarter can enter new round process.
Further, the negotiation that the minizone moving parameter arranges can for different moving velocity of terminal classification, be distinguished ground applicationization parameter.
Further, abovely only be illustrated with the double example that switches to fast.In addition, following two kinds of situations also may appear in real network:
1. same mobile terminal continuous several times (more than twice) between a plurality of residential quarters is switched fast:
2. double switching occurs in many mobile terminals simultaneously between two or more residential quarters.
Method provided by the invention is still applicable to above-mentioned two situations.For example, the quick switching of same mobile terminal continuous several times (more than twice) can be decomposed on time domain as a basic processing unit by every double quick switching.When a plurality of mobile terminals between two or more residential quarters, double switching occur simultaneously, provide cooperation measurement and the switching of the related cell of handed over service optimizing process to be set, the process that is independently, can walks abreast and carry out for each mobile terminal.In the case, although the upper residential quarter number corresponding increase thereupon that participates in switching cooperation of macroscopic view, because each collaborative process process is completed in different residential quarter pairings, therefore can not cause single subdistrict itself to process the significantly increase of complexity.
Further, method proposed by the invention does not limit the cooperation measurement of many minizones or switches the number of times that optimizing process is set.Simultaneously, method proposed by the invention does not limit the quantity of being responsible for carrying out the mobile terminal of measuring yet, and the residential quarter can specify one or more mobile terminals to carry out cooperation measurement task.
Further, in mobile communication system proposed by the invention, the cooperation of many minizones is measured and is switched optimization method is set, and does not limit cooperation cell and whether belongs to different base stations.When the cooperation cell that communicates when needs belongs to same base station, the aforementioned interaction message of mentioning will transmit in the mode of inside of base station signaling, but the information content of wherein carrying is with described in the invention consistent.
Further, method proposed by the invention also goes for the interval situation switched fast continuously of occuring of double small, namely for the first time the handover source residential quarter and for the second time switching target small area be same residential quarter.This scene particularly can be comparatively common in the actual deployment of heterogeneous wireless network at next generation wireless network.Take the LTE system as example, as shown in Figure 4, be positioned at the coverage of a macrocell when a picocell (Picocell), when mobile terminal is along the direction high-speed mobile shown in figure, may cause from macrocell to picocell, again to twice of macrocell " switching fast ".After adopting method of the present invention to optimize, can avoid this twice " to switch fast ".
To sum up, basic characteristics of the present invention and advantage are:
-by being provided for judging the timer of the normal residence time lower limit of mobile terminal for the residential quarter, and corresponding different translational speed scopes respectively, the accuracy that switching problem detects improved;
-cooperation by the minizone, the handover source residential quarter can obtain the mobile terminal measurement result from switching target small area.This measurement result can reflect mobile terminal from enter into leave in the middle of the process of residential quarter, the wireless signal situation on motion track.Can this can be avoided because there is no enough Radio Link metrical informations (being the Radio Link situation in the zone of mobile terminal between twice switching), can't make to avoid the correct judgement of " switching fast " and corresponding moving parameter that negotiation is set.
-configuration mobile terminal postpones the time interval of reporting measurement result, makes measurement can be applicable to when switching time urgent, and the residential quarter may not have time enough to obtain the situation of the reporting message of mobile terminal.
-mobile terminal can utilize velocity factor that measuring period, measurement duration and measurement result are postponed to report the interval to process according to self translational speed, makes and self can adjust adaptively according to speed speed situation frequency and total duration of measurement.For example:
● when the mobile terminal translational speed was 10 meter per second, be 1 second measuring period, and measuring the duration is 30 seconds, and the velocity factor value is 1.The adjacent measurement points spacing is 10 meters, and it is 30 points that overall measurement is counted, and corresponding total displacement is 300 meters;
● when the mobile terminal translational speed is 20 meter per second, access speed factor values 0.5,
-weighted measurement cycle=1 * 0.5=1.5 (second);
-weighted measurement duration=30 * 0.5=15 (second);
After-weighting was adjusted, the adjacent measurement points spacing still remained 10 meters, overall measurement count also remain 30 constant.This measurement that has just guaranteed that mobile terminal is done can intactly, as one man embody the wireless link signals situation of change on movement locus between twice switching of mobile terminal;
The measurement configuration that carry out mobile terminal-handover source residential quarter, after can not affecting mobile terminal and moving to other residential quarter, the required follow-up measurement configuration of carrying out in other residential quarter namely can not limit other residential quarter to the management of these mobile terminal wireless connections.
-this method is propose in the scene that double quick switching occurs and set forth, but also can easily this thought be generalized in the scene of repeatedly switching fast.
Embodiment
General mobile communication system network framework comprises core net, wireless access network and three parts of mobile terminal.A plurality of residential quarters can be controlled in the base station, and there is certain overlapping region usually in the coverage of neighbor cell.Neighbor cell can be the co-frequency cell of same wireless access technology, can be also alien-frequency district, can also be the residential quarter of different access technologies.The base station can be controlled mobile terminal and switches in the minizone that belongs to identical or different base station; Mobile terminal can be in cell coverage area or in the neighbor cell overlapping region with one or more base station communications, and the cell downlink signal is carried out the measurement of signal received power or quality.
The below illustrates a specific embodiment of the present invention take the LTE system as example.
The residential quarter that the wireless access network of LTE system is controlled by base station and base station forms, and can carry out interacting message by X2 interface or S1 interface between the base station, as shown in Figure 5.Fig. 6 has provided the typical scene of a switching, and its small area A, residential quarter B and residential quarter C are neighbor cells, belong to respectively different base stations.The motion track of mobile terminal X and can switch at the cell coverage area intersection as shown in Fig. 5 cathetus direction of arrow, the position A that namely in figure, " * " indicates and position B.Below the processing procedure of the present embodiment, as shown in Figure 7:
Step 101: residential quarter A makes handover decisions according to the wireless connections situation of existing handoff parameter configuration and mobile terminal X, prepares terminal X is switched to residential quarter B;
Step 102: residential quarter A sends handover preparation request message to residential quarter B;
Step 103: the handover preparation request of B acceptance area, residential quarter A, and select mobile terminal X is measured configuration.Suppose that this is measured as periodic measurement, its parameter arranges as follows:
-measuring object: neighbor cell list cellList comprises residential quarter A, residential quarter B and residential quarter C;
-trigger condition: without (namely requiring mobile terminal to trigger at once the measurement task);
-measurement result: measurement result measResult type configuration is reference signal receiving intensity (RSRP);
-measuring period: periodic measurement time interval measPeriod value is 1 second (1s);
-to measure the duration: overall measurement time span measDuration value is 30s;
-measurement result postpones to report the interval: postpone to report time interval TDelayValue is 30s;
-velocity factor: velocity factor SMediumValue is 0.5, SHighValue is 0.25;
Step 104: residential quarter B returns to handoff request acknowledgment message to residential quarter A, comprising the measurement configuration information to mobile terminal X;
Step 105: residential quarter A prepares to extract residential quarter B to the measurement configuration information of mobile terminal X response message from the switching that receives, and sends to mobile terminal X by switching command message;
Step 106: after mobile terminal X received measurement configuration information, according to self translational speed, the selection velocity factor was SMedium, and it is as follows that measuring period, measurement duration and measurement result are postponed to report the interval to adjust:
Value after adjusting=residential quarter B Configuration Values * velocity factor SMediumMobile terminal X adjusts radio port, is connected to switching target small area B.
Step 107 hypothesis handover success, mobile terminal X completes response message by switching and informs that residential quarter B switches and complete, and starts simultaneously the periodic measurement that configures;
Step 108: residential quarter B is after 20s, and according to existing handoff parameter configuration, discovery need to switch to mobile terminal X residential quarter C.Residential quarter B makes handover decisions;
Step 109: residential quarter B sends handover preparation request message to residential quarter C, informs that this mobile terminal of Target cell still has the measurement result (being the approach one of abovementioned steps (6.2.1)) that does not report;
Step 110: residential quarter C returns to handoff request acknowledgment message to residential quarter B, and expression can be switched;
Step 111: residential quarter B sends switching command message to mobile terminal X, and mobile terminal X adjusts radio port, is connected to switching target small area C;
Step 112: suppose handover success, mobile terminal X completes response message by switching and informs that residential quarter C switches and complete, and mobile terminal X stops the measurement task that residential quarter B configures simultaneously;
Step 113: residential quarter C indicates the terminal to report measurement result to mobile terminal X transmitting terminal information inquiring request (UEInformationRequest) message;
Step 114: mobile terminal X responds end message and replys (UEInformationResponse) message, wherein carries to comprise velocity factor SMediumIn interior measurement result;
Step 115: after residential quarter C obtains measurement result, send handover report (Handover Report) message to residential quarter B, indicating type is the not reporting measurement result of mobile terminal X, and carries this measurement result;
Step 116: after residential quarter B receives handover report and extracts measurement result, can analyze on the movement locus of mobile terminal X from position A to position B the situation of change of residential quarter A, residential quarter B and the descending wireless Reference Signal Received Power RSRP of residential quarter C.Can guarantee that still mobile terminal X keeps the wireless connections with these residential quarters, judges that " switching fast " problem exists, and further assesses the optimization range that moving parameter arranges even suppose that residential quarter B not thinks to switch.
Step 117: residential quarter B sends handover report (Handover Report) to residential quarter A, and " switching fast " problem of having informed occurs, and carries measurement result for the relevant Radio Link situation of its analysis and evaluation;
Step 118: residential quarter A and residential quarter B all initiate moving parameter modification (Mobility Setting Change) process are set.Residential quarter B consults with residential quarter A and residential quarter C, heightens the handoff threshold value, for example 3dB; Residential quarter A and residential quarter C consult to turn down handoff threshold value, for example 3dB.Moving parameter arranges modification process can carry out repeatedly, finally eliminates between residential quarter A and residential quarter B and the unnecessary switching between residential quarter B and residential quarter C.Contrast before and after optimizing as shown in Figure 8.
The above is only one embodiment of the present of invention, is not limited to the present invention.The present invention can have various suitable changes and variation.All any modifications of doing within the spirit and principles in the present invention, be equal to replacement, improvement etc., within protection scope of the present invention all should be included in.