CN103997763A - Cell handover method and base station controller - Google Patents

Abstract

The invention discloses a cell handover method and a base station controller. When a terminal needs to carry out cell handover, a base station controller obtains M candidate target cells; for each candidate target cell, the respective processing is as follows: according to all recorded historical handover quality evaluation results of the candidate target cell, an average historical handover quality evaluation result of the candidate target cell is determined; on the basis of the obtained level intensity of the candidate target cell, the handover quality prediction result of the candidate target cell this time is determined; a final evaluation result of the candidate target cell is determined based on the average historical handover quality evaluation result and the handover quality prediction result this time of the candidate target cell; and according to the descending order of the values of the final evaluation results, sorting of all candidate target cells is carried out and the candidate target cell ranking the first after sorting is determined as the target cell, and the handover flow is executed. According to the scheme, the handover quality is improved.

Description

A kind of cell switching method and a kind of base station controller

Technical field

The present invention relates to wireless technology, particularly a kind of cell switching method and a kind of base station controller.

Background technology

In prior art, in the time that terminal need to be carried out community switching, under it, base station controller (BSC, Base Station Controller) will carry out following processing:

1) determine candidate target cells, be generally multiple;

2) according to each candidate target cells in the past the handover success rate in scheduled duration level punishment is carried out in each candidate target cells, according to handover success rate, the level intensity of each candidate target cells is carried out to reduction in various degree, to reach the priority that reduces the candidate target cells that handover failure rate is higher, and then promote the object of handover success rate;

3) sorted according to level intensity order from high to low in each candidate target cells of carrying out after level punishment, after sorting in primary candidate target cells as Target cell, and carry out switching flow.

But, can there is in actual applications certain problem in aforesaid way, as: when the select target community, only consider the factor such as current level intensity and handover success rate of candidate target cells, and do not consider more the factors such as historical quality of handoff, as time delay, the link-quality of user in can the handoff procedure of perception, and whether there will be call drop etc. after completing with switching in handoff procedure, thereby may make Target cell perception for user of electing very poor, be not optimum, thereby reduced quality of handoff.

Summary of the invention

In view of this, the invention provides a kind of cell switching method and a kind of base station controller, can improve quality of handoff.

For achieving the above object, technical scheme of the present invention is achieved in that

A kind of cell switching method, comprising:

In the time that a definite terminal need to be carried out community switching, base station controller obtains M candidate target cells, and M is greater than 1 positive integer;

For each candidate target cells, described base station controller carries out respectively following processing:

According to the each historical quality of handoff assessment result of this recorded candidate target cells, determine the averaged historical quality of handoff assessment result of this candidate target cells;

According to the level intensity of this candidate target cells getting, this quality of handoff of determining this candidate target cells predicts the outcome;

Predict the outcome according to the averaged historical quality of handoff assessment result of this candidate target cells and this quality of handoff, determine the final assessment result of this candidate target cells;

Described base station controller sorts to each candidate target cells according to the descending order of the value of final assessment result, will after sequence, be defined as Target cell in primary candidate target cells, and carries out switching flow.

A kind of base station controller, comprising:

The first processing module, for need to carry out when a definite terminal community switch time, obtain M candidate target cells, M is greater than 1 positive integer;

The second processing module, for for each candidate target cells, carry out respectively following processing:

According to the each historical quality of handoff assessment result of this recorded candidate target cells, determine the averaged historical quality of handoff assessment result of this candidate target cells; According to the level intensity of this candidate target cells getting, this quality of handoff of determining this candidate target cells predicts the outcome; Predict the outcome according to the averaged historical quality of handoff assessment result of this candidate target cells and this quality of handoff, determine the final assessment result of this candidate target cells;

The order descending according to the value of final assessment result sorts to each candidate target cells, will after sequence, be defined as Target cell in primary candidate target cells, and carries out switching flow.

Visible, adopt scheme of the present invention, in the time of select target community, level intensity and the historical quality of handoff assessment result etc. of each candidate target cells are considered, i.e. comprehensive above factor, from each candidate target cells, select optimum community as Target cell, thereby improved quality of handoff, and promoted user's experience etc.

Brief description of the drawings

Fig. 1 is the flow chart of cell switching method embodiment of the present invention.

Fig. 2 is the implication schematic diagram of the each bit in quality of handoff instruction of the present invention.

Fig. 3 is the value mode schematic diagram that the present invention works as Target cell and occur the each bit in quality of handoff instruction when resource congestion.

Fig. 4 is the value mode schematic diagram of the each bit in the quality of handoff instruction in the present invention's one example.

Embodiment

For the problems of the prior art, a kind of Hou community handover scheme that improves is proposed in the present invention, can improve quality of handoff.

For make technical scheme of the present invention clearer, understand, referring to the accompanying drawing embodiment that develops simultaneously, scheme of the present invention is described in further detail.

Fig. 1 is the flow chart of cell switching method embodiment of the present invention.As shown in Figure 1, comprising:

Step 11: in the time that a definite terminal need to be carried out community switching, base station controller obtains M candidate target cells, and M is greater than 1 positive integer.

Whether base station controller how to confirm terminal needs to carry out community switching, and a how to confirm M candidate target cells is prior art.In addition, the concrete value of M can be decided according to the actual requirements.

Step 12: for each candidate target cells x, base station controller is processed according to mode shown in step 13～15 respectively.

For ease of statement, in the present embodiment, represent each candidate target cells with candidate target cells x.

Step 13: base station controller, according to the each historical quality of handoff assessment result of recorded candidate target cells x, is determined the averaged historical quality of handoff assessment result of candidate target cells x.

In this step, for ensureing the ageing of result of calculation, first base station controller can be determined in the each historical quality of handoff assessment result of recorded candidate target cells x the rise time and be positioned at T and whether be greater than N to the number of this time period of T-Tmax, N is greater than 1 positive integer, concrete value can be decided according to the actual requirements, and T represents current time.

If so, can utilize rise time N the historical quality of handoff assessment result nearest apart from current time to calculate the averaged historical quality of handoff assessment result of candidate target cells x otherwise, utilize the rise time to be positioned at T and calculate to the each historical quality of handoff assessment result of this time period of T-Tmax

Wherein, for arbitrary historical quality of handoff assessment result, far away apart from current time, less on the impact of the averaged historical quality of handoff assessment result calculating.

Preferably, ${\stackrel{\‾}{H}}_{1-N^{\′}}=H_1.e^{-\frac{a}{T_{\max }}\·{\mathrm{\Δt}}_1}+...+H_{N^{\′}}\·e^{-\frac{a}{T_{\max }}\·{\mathrm{\Δt}}_{N^{\′}}}=\underset{i=1}{\overset{N^{\′}}{\mathrm{\Σ}}}{H}_i\·e^{-\frac{a}{T_{\max }}\·{\mathrm{\Δt}}_i};$

Wherein, N' represents to calculate time historical quality of handoff assessment result used number, Δ t _irepresent the duration at interval between rise time of i historical quality of handoff assessment result and current time, represent N' historical quality of handoff assessment result, be illustrated in the switching occurring before Tmax and reduce to e for the factor of influence of this result of calculation ^-a, a represents the positive integer of predetermined value.The concrete value of Tmax and a all can be decided according to the actual requirements, such as, a can value be 3.

Whether why base station controller will determine in the each historical quality of handoff assessment result of recorded candidate target cells x that the rise time is positioned at T is greater than N to the number of this time period of T-Tmax, the number that is mainly the historical quality of handoff assessment result in order to prevent participation calculating is too much, thereby increase the complexity of calculating, certainly, if do not processed like this, also be fine, directly utilize the rise time to be positioned at T and calculate to the each historical quality of handoff assessment result of this time period of T-Tmax

Step 14: base station controller is according to the level intensity of the candidate target cells x getting, and this quality of handoff of determining candidate target cells x predicts the outcome.

In this step, base station controller is determined the affiliated span of level intensity of candidate target cells x;

If belong to the first span >-A,, this quality of handoff that calculates candidate target cells x H that predicts the outcome ₀: H ₀=16-0*2;

If belong to the second span (B ,-A], this quality of handoff that calculates candidate target cells x H that predicts the outcome ₀: H ₀=16-1*2;

If belong to the 3rd span (C ,-B], this quality of handoff that calculates candidate target cells x H that predicts the outcome ₀: H ₀=16-2*2;

If belong to the 4th span (D ,-C], this quality of handoff that calculates candidate target cells x H that predicts the outcome ₀: H ₀=16-3*2;

Wherein, A, B, C and D are positive integer, and D>C>B>A.

The concrete value of A, B, C and D all can be decided according to the actual requirements, and conventionally, the value that the value that the value that the value of A is 60, B is 75, C is 90, D is 110.

Different spans is the different link-quality of correspondence respectively, such as, link-quality corresponding to the first span is " excellent ", link-quality corresponding to the second span is " good ", link-quality corresponding to the 3rd span is " normally ", and link-quality corresponding to the 4th span is " poor ".

Different span corresponding different R0 value respectively, 0,1,2 or 3, why R0 to be multiplied by 2, be to mate in order to carry out weights with the bit1～bit2 in the quality of handoff instruction of follow-up introduction.

Step 15: base station controller predicts the outcome according to the averaged historical quality of handoff assessment result of candidate target cells x and this quality of handoff, determines the final assessment result of candidate target cells x.

In this step, base station controller can calculate the final assessment result of candidate target cells x

${\stackrel{\‾}{H}}_{0-N^{\′}}=K\·(H_0+\underset{i=1}{\overset{N^{\′}}{\mathrm{\Σ}}}{H}_i\·e^{-\frac{a}{T_{\max }}\·{\mathrm{\Δt}}_i});$ Wherein, $K=1/\underset{i=0}{\overset{N^{\′}}{\mathrm{\Σ}}}{e}^{-\frac{a}{T_{\max }}\·{\mathrm{\Δt}}_i},$ For normalization factor.

Step 16: base station controller sorts to each candidate target cells according to the descending order of the value of final assessment result, will be defined as Target cell in primary candidate target cells after sequence, and carries out switching flow.

Distinguishingly, for two consistent candidate target cells of final assessment result, before candidate target cells larger level intensity can being come.

How carrying out switching flow is prior art.

In addition, in embodiment illustrated in fig. 1, also can further comprise: generate and switch corresponding quality of handoff assessment result with this, the line item of going forward side by side, a historical quality of handoff assessment result while being next time defined as candidate target cells by base station controller as Target cell, it is implemented as follows 1)～5) shown in.

1), in the time that definite terminal need to be carried out community switching, base station controller generates the quality of handoff instruction of a 5bit.

Fig. 2 is the implication schematic diagram of the each bit in quality of handoff instruction of the present invention.As shown in Figure 2, bit4 is congested indicating bit, and bit3 is call drop indicating bit, and bit2 and bit1 are the poor indicating bit of matter, and bit0 is handoff failure indicating bit; Initially, the value of each indicating bit is all set to 0; Bit0～bit3, for switching perception indicating bit, depends on wireless environment, and bit4 is congested indicating bit, depends on system resource.

2) base station controller determines whether Target cell resource congestion occurs, if so, the value of congested indicating bit is set to 1, and the binary numeral of 5bit is converted to 10 system numerical value, with the 16 10 system numerical value that deduct after conversion, obtain this and switch corresponding quality of handoff assessment result; Otherwise the value of congested indicating bit is set to 0.

In existing normal switching flow, base station controller is to Target cell request channel resource, confirm to send switching command after the reserved resource in Target cell, start switching flow, but when urgent switching occurs former link degradation, resource bid step will be left in the basket, and be directly switch to Target cell, in this case, easily switch unsuccessfully because of Target cell resource congestion.

In order to improve handover success rate, in scheme of the present invention, can in quality of handoff instruction, a congested indicating bit be set, with the resource congestion situation of recording cell, reduce the priority of the congested candidate target cells that causes handoff failure.

In actual applications, if base station controller is determined Target cell, resource congestion occurs, channel activates unsuccessfully, and value that can congested indicating bit is set to 1, and seeks out this and switch corresponding quality of handoff assessment result.

Fig. 3 is the value mode schematic diagram that the present invention works as Target cell and occur the each bit in quality of handoff instruction when resource congestion.As shown in Figure 3, binary numeral 10000 is converted to 10 system numerical value 16, then uses 16-16, obtain this and switch corresponding quality of handoff assessment result 0, this situation belongs to the poorest situation of quality of handoff.

Otherwise, if determining Target cell, base station controller there is not resource congestion, value that can congested indicating bit is set to 0, and continues subsequent treatment.

Wherein, if former community (community, terminal place before switching) and Target cell belong to same base station controller, activate while denying (Channel Activation NACK) message when base station controller receives the channel that sends Target cell, can think that resource congestion has occurred in Target cell; If being less than, former community and target do not belong to same base station controller, when base station controller receives the (MSC of mobile switching centre, Mobile Switching Center) send switching refusal (Handover Reject) message time, can think that resource congestion has occurred in Target cell.

3) base station controller determines whether this switches successful, and if so, the value of handoff failure indicating bit is set to 0, otherwise the value of handoff failure indicating bit is set to 1.

In actual applications, if former community and Target cell belong to same base station controller, in the time that base station controller receives the switching of sending Target cell and completes (Handover Complete) message, can think this handover success; If former community and Target cell do not belong to same base station controller, receive the clear command (Clear Command) that MSC sends when base station controller, when former because handover success (Handover Success), can think this handover success.

If base station controller receives handoff failure (Handover Failure) message of self terminal, or send after switching command (Handover Command) message self T3103 timer expired to terminal before, do not receive Handover Complete message or Clear Command message, can think this handoff failure.

If determine this handover success, the value that base station controller can handoff failure indicating bit is set to 0, otherwise, be set to 1.

4) base station controller is determined the affiliated span of level intensity of Target cell;

If belong to the first span >-A,, the value of the poor indicating bit of matter is set to 00;

If belong to the second span (B ,-A], the value of the poor indicating bit of matter is set to 01;

If belong to the 3rd span (C ,-B], the value of the poor indicating bit of matter is set to 10;

If belong to the 4th span (D ,-C], the value of the poor indicating bit of matter is set to 11;

Wherein, A, B, C and D are positive integer, and D>C>B>A; As previously mentioned, conventionally, the value that the value that the value that the value of A is 60, B is 75, C is 90, D is 110.

The values of the R0 introducing in integrating step 14 etc., can obtain following table:

R0	Level intensity	bit2	bit1	Link-quality
					0	>-60	0	0	Excellent
1	(-75,-60]	0	1	Good
					2	(-90,-75]	1	0	Normally
3	(-110,-90]	1	1	Poor

Relation between the each parameter of table one

5) base station controller determines whether to have occurred one of following situation: call drop after call drop, handover success in handoff procedure, handover delay are overtime, if, the value of call drop indicating bit is set to 1, otherwise, the value of call drop indicating bit is set to 0, and the binary numeral of 5bit is converted to 10 system numerical value, with the 16 10 system numerical value that deduct after conversion, obtain this and switch corresponding quality of handoff assessment result.

In actual applications, if before determining and need to be switched to and receive Handover Complete message or Clear Command message from base station controller, receive removing request (Clear Request) message of terminal to report, or, after handoff failure, terminal attempts returning former Traffic Channel (TCH, Traffic Channel) failure, (Idle) state that enters the free time, or, before timer T3103 is overtime, do not receive any message, former community link discharges, and can think call drop in handoff procedure has occurred.

If receive the Clear Request message that terminal reports in Target cell in the scheduled duration T3 after having switched, can think terminal at successful switch behind Target cell, because call drop has occurred link reason immediately; This rule is applicable to the situation that former community and Target cell belong to same base station controller, do not belong to the situation of same base station controller for former community and Target cell, consider and switch user's face of causing to interrupt time delay conventionally very long, therefore can assess to carry out equivalent analysis by time delay.

Specifically, base station controller obtains the handover delay in handoff procedure: receive Handover Complete message or Clear Command message～the send duration at interval between Handover Command message, if handover delay is greater than predetermined threshold, can think that handover delay has occurred is overtime; The concrete value of described threshold value can be decided according to the actual requirements, and conventionally, can be taken at terminal and attempt between the maximum trial access number of times of the timing duration of access timer (T3124) × terminal and the timing duration of timer T3103.

If switched in process after call drop, handover success call drop or handover delay overtime, the value that base station controller can call drop indicating bit is set to 1, otherwise, be set to 0.

Illustrate:

Fig. 4 is the value mode schematic diagram of the each bit in the quality of handoff instruction in the present invention's one example.As shown in Figure 4, the instruction of this quality of handoff represents: there is not resource congestion, handover success in Target cell, have call drop or handover delay is overtime, the level intensity of Target cell in (90 ,-75] span in; Corresponding quality of handoff assessment result is: 16-12=4.

It should be noted that base station controller and MSC under above introduced base station controller and MSCJun Zhiyuan community.

So far, completed the introduction about the inventive method embodiment.

Based on above-mentioned introduction, the present invention discloses a kind of base station controller, comprising:

The first processing module, for need to carry out when a definite terminal community switch time, obtain M candidate target cells, M is greater than 1 positive integer;

The second processing module, for for each candidate target cells, carry out respectively following processing:

According to the each historical quality of handoff assessment result of this recorded candidate target cells, determine the averaged historical quality of handoff assessment result of this candidate target cells; According to the level intensity of this candidate target cells getting, this quality of handoff of determining this candidate target cells predicts the outcome; Predict the outcome according to the averaged historical quality of handoff assessment result of this candidate target cells and this quality of handoff, determine the final assessment result of this candidate target cells;

The order descending according to the value of final assessment result sorts to each candidate target cells, will after sequence, be defined as Target cell in primary candidate target cells, and carries out switching flow.

In base station controller, also can further comprise: the 3rd processing module, switch corresponding quality of handoff assessment result for generating with this, the line item of going forward side by side, a historical quality of handoff assessment result while being next time defined as candidate target cells by base station controller as Target cell.

Particularly, the 3rd processing module determines that terminal need to carry out community switching, generates the quality of handoff instruction of a 5bit, and wherein, bit4 is congested indicating bit, and bit3 is that call drop indicating bit, bit2 and bit1 are the poor indicating bit of matter, and bit0 is handoff failure indicating bit; Initially, the value of each indicating bit is all set to 0;

Determine whether Target cell resource congestion occurs, if so, the value of congested indicating bit is set to 1, and the binary numeral of 5bit is converted to 10 system numerical value, with the 16 10 system numerical value that deduct after conversion, obtain this and switch corresponding quality of handoff assessment result;

Otherwise the value of congested indicating bit is set to 0;

Determine whether this switches successful, and if so, the value of handoff failure indicating bit is set to 0, otherwise the value of handoff failure indicating bit is set to 1;

Determine the affiliated span of level intensity of Target cell, if belong to the first span >-A,, the value of the poor indicating bit of matter is set to 00, if belong to the second span (B ,-A], the value of the poor indicating bit of matter is set to 01, if belong to the 3rd span (C,-B], the value of the poor indicating bit of matter is set to 10, if belong to the 4th span (D,-C], the value of the poor indicating bit of matter is set to 11; Wherein, A, B, C and D are positive integer, and D>C>B>A;

Determine whether to occur one of following situation: call drop after call drop, handover success in handoff procedure, handover delay are overtime, if, the value of call drop indicating bit is set to 1, otherwise, the value of call drop indicating bit is set to 0, and the binary numeral of 5bit is converted to 10 system numerical value, with the 16 10 system numerical value that deduct after conversion, obtain this and switch corresponding quality of handoff assessment result.

In the second processing module, can specifically comprise again:

The first processing unit, for for each candidate target cells, respectively according to the each historical quality of handoff assessment result of this recorded candidate target cells, determines the averaged historical quality of handoff assessment result of this candidate target cells;

The second processing unit, for for each candidate target cells, according to the level intensity of this candidate target cells getting, this quality of handoff of determining this candidate target cells predicts the outcome respectively;

The 3rd processing unit, for for each candidate target cells, predicts the outcome according to the averaged historical quality of handoff assessment result of this candidate target cells and this quality of handoff respectively, determines the final assessment result of this candidate target cells;

Fourth processing unit, for according to the descending order of the value of final assessment result, being sorted in each candidate target cells, will be defined as Target cell in primary candidate target cells after sequence, and carry out switching flow.

Wherein,

The first processing unit, for each candidate target cells, carries out respectively following processing:

Whether to the number of T-Tmax this time period be greater than N, N is greater than 1 positive integer if determining in the each historical quality of handoff assessment result of this candidate target cells of recording that the rise time is positioned at T, T represents current time;

If so, utilize rise time N the historical quality of handoff assessment result nearest apart from current time to calculate the averaged historical quality of handoff assessment result of this candidate target cells otherwise, utilize the rise time to be positioned at T and calculate to the each historical quality of handoff assessment result of this time period of T-Tmax

Wherein, for arbitrary historical quality of handoff assessment result, far away apart from current time, less on the impact of the averaged historical quality of handoff assessment result calculating.

${\stackrel{\‾}{H}}_{1-N^{\′}}=H_1.e^{-\frac{a}{T_{\max }}\·{\mathrm{\Δt}}_1}+...+H_{N^{\′}}\·e^{-\frac{a}{T_{\max }}\·{\mathrm{\Δt}}_{N^{\′}}}=\underset{i=1}{\overset{N^{\′}}{\mathrm{\Σ}}}{H}_i\·e^{-\frac{a}{T_{\max }}\·{\mathrm{\Δt}}_i};$

Wherein, N' represents to calculate time historical quality of handoff assessment result used number, Δ t _irepresent the duration at interval between rise time of i historical quality of handoff assessment result and current time, represent N' historical quality of handoff assessment result, a represents the positive integer of predetermined value.

The second processing unit, for each candidate target cells, carries out respectively following processing:

Determine the affiliated span of level intensity of this candidate target cells;

If belong to the first span >-A,, this quality of handoff that calculates this candidate target cells H that predicts the outcome ₀: H ₀=16-0*2;

If belong to the second span (B ,-A], this quality of handoff that calculates this candidate target cells H that predicts the outcome ₀: H ₀=16-1*2;

If belong to the 3rd span (C ,-B], this quality of handoff that calculates this candidate target cells H that predicts the outcome ₀: H ₀=16-2*2;

If belong to the 4th span (D ,-C], this quality of handoff that calculates this candidate target cells H that predicts the outcome ₀: H ₀=16-3*2;

Wherein, A, B, C and D are positive integer, and D>C>B>A.

The 3rd processing unit, for each candidate target cells, carries out respectively following processing:

Calculate the final assessment result of this candidate target cells

${\stackrel{\‾}{H}}_{0-N^{\′}}=K\·(H_0+\underset{i=1}{\overset{N^{\′}}{\mathrm{\Σ}}}{H}_i\·e^{-\frac{a}{T_{\max }}\·{\mathrm{\Δt}}_i});$ Wherein, $K=1/\underset{i=0}{\overset{N^{\′}}{\mathrm{\Σ}}}{e}^{-\frac{a}{T_{\max }}\·{\mathrm{\Δt}}_i}.$

The specific works flow process of said apparatus embodiment please refer to the respective description in preceding method embodiment, repeats no more herein.

The foregoing is only preferred embodiment of the present invention, in order to limit the present invention, within the spirit and principles in the present invention not all, any amendment of making, be equal to replacement, improvement etc., within all should being included in the scope of protection of the invention.

Claims (15)

1. a cell switching method, is characterized in that, comprising:

In the time that a definite terminal need to be carried out community switching, base station controller obtains M candidate target cells, and M is greater than 1 positive integer;

For each candidate target cells, described base station controller carries out respectively following processing:

According to the each historical quality of handoff assessment result of this recorded candidate target cells, determine the averaged historical quality of handoff assessment result of this candidate target cells;

According to the level intensity of this candidate target cells getting, this quality of handoff of determining this candidate target cells predicts the outcome;

Predict the outcome according to the averaged historical quality of handoff assessment result of this candidate target cells and this quality of handoff, determine the final assessment result of this candidate target cells;

Described base station controller sorts to each candidate target cells according to the descending order of the value of final assessment result, will after sequence, be defined as Target cell in primary candidate target cells, and carries out switching flow.

2. method according to claim 1, is characterized in that,

The method further comprises: generate and switch corresponding quality of handoff assessment result with this, the line item of going forward side by side, a historical quality of handoff assessment result while being next time defined as candidate target cells by described base station controller as described Target cell.

3. method according to claim 2, is characterized in that, described generation is switched corresponding quality of handoff assessment result with this and comprised:

In the time that definite described terminal need to be carried out community switching, generate the quality of handoff instruction of a 5bit, wherein, bit4 is congested indicating bit, and bit3 is that call drop indicating bit, bit2 and bit1 are the poor indicating bit of matter, and bit0 is handoff failure indicating bit; Initially, the value of each indicating bit is all set to 0;

Determine whether described Target cell resource congestion occurs, if so, the value of described congested indicating bit is set to 1, and the binary numeral of 5bit is converted to 10 system numerical value, with the 16 10 system numerical value that deduct after conversion, obtain this and switch corresponding quality of handoff assessment result;

Otherwise the value of described congested indicating bit is set to 0;

Determine whether this switches successful, and if so, the value of described handoff failure indicating bit is set to 0, otherwise the value of described handoff failure indicating bit is set to 1;

Determine the affiliated span of level intensity of described Target cell, if belong to the first span >-A,, the value of the poor indicating bit of described matter is set to 00, if belong to the second span (B,-A], the value of the poor indicating bit of described matter is set to 01, if belong to the 3rd span (C,-B], the value of the poor indicating bit of described matter is set to 10, if belong to the 4th span (D,-C], the value of the poor indicating bit of described matter is set to 11; Wherein, A, B, C and D are positive integer, and D>C>B>A;

Determine whether to occur one of following situation: call drop after call drop, handover success in handoff procedure, handover delay are overtime, and if so, the value of described call drop indicating bit is set to 1, otherwise the value of described call drop indicating bit is set to 0; And the binary numeral of 5bit is converted to 10 system numerical value, with the 16 10 system numerical value that deduct after conversion, obtain this and switch corresponding quality of handoff assessment result.

4. according to the method in claim 2 or 3, it is characterized in that, described in determine this candidate target cells averaged historical quality of handoff assessment result comprise:

Whether to the number of T-Tmax this time period be greater than N, N is greater than 1 positive integer if determining in the each historical quality of handoff assessment result of this candidate target cells of recording that the rise time is positioned at T, T represents current time;

If so, utilize rise time N the historical quality of handoff assessment result nearest apart from current time to calculate the averaged historical quality of handoff assessment result of this candidate target cells otherwise, utilize the rise time to be positioned at T and calculate to the each historical quality of handoff assessment result of this time period of T-Tmax

Wherein, for arbitrary historical quality of handoff assessment result, far away apart from current time, less on the impact of the averaged historical quality of handoff assessment result calculating.

5. method according to claim 4, is characterized in that,

${\stackrel{\‾}{H}}_{1-N^{\′}}=H_1.e^{-\frac{a}{T_{\max }}\·{\mathrm{\Δt}}_1}+...+H_{N^{\′}}\·e^{-\frac{a}{T_{\max }}\·{\mathrm{\Δt}}_{N^{\′}}}=\underset{i=1}{\overset{N^{\′}}{\mathrm{\Σ}}}{H}_i\·e^{-\frac{a}{T_{\max }}\·{\mathrm{\Δt}}_i};$

Wherein, N' represents to calculate time historical quality of handoff assessment result used number, Δ t _irepresent the duration at interval between rise time of i historical quality of handoff assessment result and current time, represent N' historical quality of handoff assessment result, a represents the positive integer of predetermined value.

6. method according to claim 5, is characterized in that, described in determine this candidate target cells this quality of handoff predict the outcome and comprise:

Determine the affiliated span of level intensity of this candidate target cells;

If belong to the first span >-A,, this quality of handoff that calculates this candidate target cells H that predicts the outcome ₀: H ₀=16-0*2;

If belong to the second span (B ,-A], this quality of handoff that calculates this candidate target cells H that predicts the outcome ₀: H ₀=16-1*2;

If belong to the 3rd span (C ,-B], this quality of handoff that calculates this candidate target cells H that predicts the outcome ₀: H ₀=16-2*2;

If belong to the 4th span (D ,-C], this quality of handoff that calculates this candidate target cells H that predicts the outcome ₀: H ₀=16-3*2;

Wherein, A, B, C and D are positive integer, and D>C>B>A.

7. method according to claim 6, is characterized in that, described in determine this candidate target cells final assessment result comprise:

Calculate the final assessment result of this candidate target cells

${\stackrel{\‾}{H}}_{0-N^{\′}}=K\·(H_0+\underset{i=1}{\overset{N^{\′}}{\mathrm{\Σ}}}{H}_i\·e^{-\frac{a}{T_{\max }}\·{\mathrm{\Δt}}_i});$ Wherein, $K=1/\underset{i=0}{\overset{N^{\′}}{\mathrm{\Σ}}}{e}^{-\frac{a}{T_{\max }}\·{\mathrm{\Δt}}_i}.$

8. a base station controller, is characterized in that, comprising:

The first processing module, for need to carry out when a definite terminal community switch time, obtain M candidate target cells, M is greater than 1 positive integer;

The second processing module, for for each candidate target cells, carry out respectively following processing:

According to the each historical quality of handoff assessment result of this recorded candidate target cells, determine the averaged historical quality of handoff assessment result of this candidate target cells; According to the level intensity of this candidate target cells getting, this quality of handoff of determining this candidate target cells predicts the outcome; Predict the outcome according to the averaged historical quality of handoff assessment result of this candidate target cells and this quality of handoff, determine the final assessment result of this candidate target cells;

The order descending according to the value of final assessment result sorts to each candidate target cells, will after sequence, be defined as Target cell in primary candidate target cells, and carries out switching flow.

9. base station controller according to claim 8, is characterized in that,

Described base station controller further comprises: the 3rd processing module, switch corresponding quality of handoff assessment result for generating with this, the line item of going forward side by side, a historical quality of handoff assessment result while being next time defined as candidate target cells by described base station controller as described Target cell.

10. base station controller according to claim 9, is characterized in that,

Described the 3rd processing module determines that described terminal need to carry out community switching, generates the quality of handoff instruction of a 5bit, and wherein, bit4 is congested indicating bit, and bit3 is that call drop indicating bit, bit2 and bit1 are the poor indicating bit of matter, and bit0 is handoff failure indicating bit; Initially, the value of each indicating bit is all set to 0;

Determine whether described Target cell resource congestion occurs, if so, the value of described congested indicating bit is set to 1, and the binary numeral of 5bit is converted to 10 system numerical value, with the 16 10 system numerical value that deduct after conversion, obtain this and switch corresponding quality of handoff assessment result;

Otherwise the value of described congested indicating bit is set to 0;

Determine whether this switches successful, and if so, the value of described handoff failure indicating bit is set to 0, otherwise the value of described handoff failure indicating bit is set to 1;

Determine the affiliated span of level intensity of described Target cell, if belong to the first span >-A,, the value of the poor indicating bit of described matter is set to 00, if belong to the second span (B,-A], the value of the poor indicating bit of described matter is set to 01, if belong to the 3rd span (C,-B], the value of the poor indicating bit of described matter is set to 10, if belong to the 4th span (D,-C], the value of the poor indicating bit of described matter is set to 11; Wherein, A, B, C and D are positive integer, and D>C>B>A;

Determine whether to occur one of following situation: call drop after call drop, handover success in handoff procedure, handover delay are overtime, and if so, the value of described call drop indicating bit is set to 1, otherwise the value of described call drop indicating bit is set to 0; And the binary numeral of 5bit is converted to 10 system numerical value, with the 16 10 system numerical value that deduct after conversion, obtain this and switch corresponding quality of handoff assessment result.

11. according to the base station controller described in claim 9 or 10, it is characterized in that, described the second processing module comprises:

The first processing unit, for for each candidate target cells, respectively according to the each historical quality of handoff assessment result of this recorded candidate target cells, determines the averaged historical quality of handoff assessment result of this candidate target cells;

The second processing unit, for for each candidate target cells, according to the level intensity of this candidate target cells getting, this quality of handoff of determining this candidate target cells predicts the outcome respectively;

The 3rd processing unit, for for each candidate target cells, predicts the outcome according to the averaged historical quality of handoff assessment result of this candidate target cells and this quality of handoff respectively, determines the final assessment result of this candidate target cells;

Fourth processing unit, for according to the descending order of the value of final assessment result, being sorted in each candidate target cells, will be defined as Target cell in primary candidate target cells after sequence, and carry out switching flow.

12. base station controllers according to claim 11, is characterized in that,

Described the first processing unit, for each candidate target cells, carries out respectively following processing:

Whether to the number of T-Tmax this time period be greater than N, N is greater than 1 positive integer if determining in the each historical quality of handoff assessment result of this candidate target cells of recording that the rise time is positioned at T, T represents current time;

If so, utilize rise time N the historical quality of handoff assessment result nearest apart from current time to calculate the averaged historical quality of handoff assessment result of this candidate target cells otherwise, utilize the rise time to be positioned at T and calculate to the each historical quality of handoff assessment result of this time period of T-Tmax

Wherein, for arbitrary historical quality of handoff assessment result, far away apart from current time, less on the impact of the averaged historical quality of handoff assessment result calculating.

13. base station controllers according to claim 12, is characterized in that,

${\stackrel{\‾}{H}}_{1-N^{\′}}=H_1.e^{-\frac{a}{T_{\max }}\·{\mathrm{\Δt}}_1}+...+H_{N^{\′}}\·e^{-\frac{a}{T_{\max }}\·{\mathrm{\Δt}}_{N^{\′}}}=\underset{i=1}{\overset{N^{\′}}{\mathrm{\Σ}}}{H}_i\·e^{-\frac{a}{T_{\max }}\·{\mathrm{\Δt}}_i};$

Wherein, N' represents to calculate time historical quality of handoff assessment result used number, Δ t _irepresent the duration at interval between rise time of i historical quality of handoff assessment result and current time, represent N' historical quality of handoff assessment result, a represents the positive integer of predetermined value.

14. base station controllers according to claim 13, is characterized in that,

Described the second processing unit, for each candidate target cells, carries out respectively following processing:

Determine the affiliated span of level intensity of this candidate target cells;

If belong to the first span >-A,, this quality of handoff that calculates this candidate target cells H that predicts the outcome ₀: H ₀=16-0*2;

If belong to the second span (B ,-A], this quality of handoff that calculates this candidate target cells H that predicts the outcome ₀: H ₀=16-1*2;

If belong to the 3rd span (C ,-B], this quality of handoff that calculates this candidate target cells H that predicts the outcome ₀: H ₀=16-2*2;

If belong to the 4th span (D ,-C], this quality of handoff that calculates this candidate target cells H that predicts the outcome ₀: H ₀=16-3*2;

Wherein, A, B, C and D are positive integer, and D>C>B>A.

15. base station controllers according to claim 14, is characterized in that,

Described the 3rd processing unit, for each candidate target cells, carries out respectively following processing:

Calculate the final assessment result of this candidate target cells

${\stackrel{\‾}{H}}_{0-N^{\′}}=K\·(H_0+\underset{i=1}{\overset{N^{\′}}{\mathrm{\Σ}}}{H}_i\·e^{-\frac{a}{T_{\max }}\·{\mathrm{\Δt}}_i});$ Wherein, $K=1/\underset{i=0}{\overset{N^{\′}}{\mathrm{\Σ}}}{e}^{-\frac{a}{T_{\max }}\·{\mathrm{\Δt}}_i}.$