CN102905317A - Mobile load balancing method used for multiple cells - Google Patents

Abstract

The invention discloses a mobile load balancing method used for multiple cells. The problems of the existing load balancing method, such as ping-pong load transfer and low load balancing convergence speed are solved. The method comprises the following implementation steps of: determining a cell cluster and triggering load balance; generating a source cell collection and a target cell collection in the cell cluster; carrying out priority ranking on the source cell collection and calculating load transfer step length; carrying out priority ranking on the target cell collection; sequentially selecting target cells by the priority from the source cell with the highest priority to carry out load transfer; after the load transfer of the source cell with the highest priority, selecting the target cell with the lower priority from the source cell collection to carry out load transfer; and finishing the load transfer process until load transfer is carried out on all the source cells in the cell cluster. The ping-pong load transfer problem is effectively solved, and meanwhile the load balancing convergence speed is raised, so that the system performance is improved.

Description

A kind of mobility load-balancing method that is applied to many residential quarters

Technical field

The present invention relates to wireless communication technology field, particularly a kind of mobility load-balancing method can be used for the mobility load balancing of a plurality of minizones among the advanced international mobile communication system IMT-Advanced.

Background technology

Advanced international mobile communication system IMT-Advanced is different from conventional cellular network, adopt the network configuration of flattening to replace traditional centralized control structure, as shown in Figure 1, pass through X2 interface direct interaction information between the base station, and mode is through consultation carried out corresponding allocation of radio resources and switching.

The new feature of IMT-Advanced system and technical need are so that legacy network management and optimization method are no longer efficient, and self-organizing network SON technology can improve the self organization ability of network, realize self-configuring, self-optimizing and the certainly healing of network, simplify design and the O﹠M of wireless network, significantly reduce the maintenance of network cost, can well satisfy new feature and the technical need of IMT-Advanced system.

The resource that wireless cellular network in the IMT-Advanced system has is limited, but because the inhomogeneities of user's location distribution and the professional randomness of initiating, load meeting in the network presents unbalanced distribution, causes limited resource not to be fully utilized.For addressing the above problem, mobility load balancing MLB technology as the important use-case of SON is introduced into, this technology is when reducing network management and optimizing labor workload, also so that in two networks or two systems heavier side of load fractional load transferred among the opposing party gone, thereby the load Distribution between equalizing network or system, improve wireless resource utility efficiency, improve systematic function.

Existing MLB technology mainly is in homogeneous network, the equilibrium of Hot Spot and its adjacent target minizone load, concrete grammar is: information interaction is carried out by the base station of X2 interface and its adjacent cell in the base station of Hot Spot, obtain the load condition of its adjacent cell, therefrom selecting the lightest adjacent cell of load to carry out load as Target cell shifts, until the load condition of Hot Spot is when being lower than the load balancing thresholding, load balancing finishes.This method is owing to only consider to select the lightest residential quarter of load as the Target cell of load transfer, thereby several Hot Spot may select same residential quarter as Target cell, Target cell self may become Hot Spot and then need outside transferring load after load balancing finishes, thereby produce the table tennis transfer process of load, cause the convergence rate of load balancing slack-off; In addition, after single Hot Spot load balancing finishes, because other Hot Spot are not alleviated high load condition, thus easily cause the zone under burst service to block, thus the overall performance of system affected.

Summary of the invention

The object of the invention is to the deficiency for above-mentioned existing MLB technology, a kind of mobility load-balancing method that is applied to many residential quarters is provided, to realize reposefully load balancing, avoids the table tennis of load to shift, accelerate the convergence rate of load balancing, and then the performance of elevator system.

A kind of mobility load-balancing method that is applied to many residential quarters provided by the invention comprises the steps:

(1) in load balancing in the execution cycle, the load condition of each cell detection in the system self, and with its adjacent cell interacting load information, simultaneously with self load capacity l and load balancing thresholding l _ThCompare, by l 〉=l _ThResidential quarter and its adjacent cell form the cell cluster that size is N, and in cell cluster internal trigger load balancing process;

(2) residential quarter of the N in the cell cluster is divided into θ cell-of-origin and a N-θ Target cell, i.e. load capacity l 〉=l _ThThe residential quarter of-ε is the cell-of-origin, otherwise is Target cell, and wherein ε is cell load protection surplus, and its value is less than load balancing thresholding l _ThA positive number, and form cell-of-origin set θ by θ cell-of-origin _s, form Target cell set θ by a N-θ Target cell _t

(3) to cell-of-origin set θ _sSize according to load capacity is carried out prioritization, carry out at first load by the highest cell-of-origin i of priority and shift, and computational load shifts step-length: Δ l wherein _i=l _i-(l _Th-the load capacity that ε) need to unload for the highest cell-of-origin i of priority, l _iBe the load capacity of the highest cell-of-origin i of priority, m is the maximum load transfer number, and value is positive integer;

(4) to Target cell set θ _tAccording to the Target cell label

Size carry out prioritization, this label

According to the receivable load capacity Δ of Target cell j l _j=l _j-(l _Th-ε) scope at place obtains, l wherein _jLoad capacity for Target cell j:

$\hat{j}=\left\{\begin{array}{cc}0,& \mathrm{\&Delta;}{l}_j<{\mathrm{\&pi;}}_i\\ 1,& {\mathrm{\&pi;}}_i\&le;\mathrm{\&Delta;}{l}_j<2{\mathrm{\&pi;}}_i\\ .& \\ .& \\ .& \\ m-1,& (m-1){\mathrm{\&pi;}}_i\&le;\mathrm{\&Delta;}{l}_j<m{\mathrm{\&pi;}}_i\\ m,& m{\mathrm{\&pi;}}_i\&le;\mathrm{\&Delta;}{l}_j\end{array}\right.;$

(5) the cell-of-origin i that priority is the highest carries out load according to priority successively select target residential quarter to be shifted;

(6) the cell-of-origin i that priority is the highest returns step (3) after finishing the load transfer, from cell-of-origin set θ _sIn according to priority select next cell-of-origin to proceed load to shift, until the load transfer has all been carried out in all cell-of-origins in the cell cluster, then a load balancing process finishes.

The present invention compared with prior art has following advantage:

(1) by the setting of cell load protection surplus ε, makes Hot Spot carry out in advance load and shift, thereby can avoid the regional obstructing problem that caused by burst service; Simultaneously, cell load protection surplus ε also makes Target cell leave certain load surplus, even after the load that receives a plurality of Hot Spot transfers, also can avoid self becoming the possibility of Hot Spot, thereby the load of effectively avoiding rattling is shifted;

(2) shift the setting of step-length π by load, realized reposefully mobility load balancing MLB, and load transfer number in the single load transfer process and the load transfer number of whole system can be controlled, accelerated mobility load balancing MLB convergence rate.

Description of drawings

Fig. 1 is the configuration diagram of IMT-Advanced of the prior art system;

Fig. 2 is the overview flow chart of mobility load balancing of the present invention;

Fig. 3 is the sub-process figure that load is shifted among the present invention.

Embodiment

With reference to Fig. 2, a kind of mobility load-balancing method that is applied to many residential quarters that the present invention proposes, concrete steps are as follows:

Step 1 is determined cell cluster, and triggers load balancing.

1a) in load balancing in the execution cycle, the base station of each residential quarter obtains the current load condition in residential quarter in the system, and carries out load information interaction by the base station of the X2 interface between the base station and its adjacent cell;

1b) each residential quarter is with self load capacity l and load balancing thresholding l _ThCompare, wherein load balancing thresholding l _ThFor normalized value, by default, and 0＜l _Th＜1, if the load capacity l of residential quarter 〉=l _Th, then by this residential quarter and its adjacent cell cell cluster that to form a size be N, and in cell cluster internal trigger load balancing process, otherwise, wait for the next load balancing execution cycle.

Step 2 generates cell-of-origin set θ _sWith Target cell set θ _t

2a) residential quarter of the N in the cell cluster is carried out respectively as acting: if the load capacity l of residential quarter 〉=l _Th-ε, then this residential quarter is the cell-of-origin, otherwise is Target cell, and wherein ε is cell load protection surplus, and its value is less than l _ThA positive number;

2b) residential quarter of the N in the cell cluster is divided into θ cell-of-origin and a N-θ Target cell after judging process finishes;

2c) form cell-of-origin set θ by θ cell-of-origin _s, form Target cell set θ by a N-θ Target cell _t

Step 3 is to cell-of-origin set θ _sCarry out prioritization, and computational load shifts step-length.

3a) to cell-of-origin set θ _sCarry out from big to small prioritization according to load, obtain limit priority with the cell-of-origin of proof load maximum, carry out at first the load transfer operation;

3b) shift step-length π by the highest cell-of-origin i computational load of priority _i:

At first, calculate the load capacity Δ l that needs unloading by the highest cell-of-origin i of priority _i=l _i-(l _Th-ε), l wherein _iLoad capacity for the highest cell-of-origin i of priority;

Secondly, computational load shifts step-length:

Wherein m is the maximum load transfer number, and value is positive integer.

Step 4 is to Target cell set θ _tCarry out prioritization.

4a) calculate the receivable load capacity Δ of Target cell j l _j=l _j-(l _Th-ε), l wherein _jLoad capacity for Target cell j;

4b) according to Δ l _jThe scope at place is obtained the label of Target cell j

$\hat{j}=\left\{\begin{array}{cc}0,& \mathrm{\&Delta;}{l}_j<{\mathrm{\&pi;}}_i\\ 1,& {\mathrm{\&pi;}}_i\&le;\mathrm{\&Delta;}{l}_j<2{\mathrm{\&pi;}}_i\\ .& \\ .& \\ .& \\ m-1,& (m-1){\mathrm{\&pi;}}_i\&le;\mathrm{\&Delta;}{l}_j<m{\mathrm{\&pi;}}_i\\ m,& m{\mathrm{\&pi;}}_i\&le;\mathrm{\&Delta;}{l}_j\end{array}\right.;$

4c) Target cell set θ _tAccording to the Target cell label

Size carry out prioritization, the Target cell the strongest with the proof load receiving ability receives load at first, realizes the reasonable utilization of resource.

Step 5 is carried out load by the highest cell-of-origin i of priority and is shifted.

With reference to Fig. 3, being implemented as follows of this step:

The cell-of-origin i that 5a) priority is the highest gathers θ from Target cell _tIn press label

Select target residential quarter j carries out the load transfer from big to small, and the load capacity that once shifts is

M π wherein _iThe load capacity that need to shift for the highest cell-of-origin i of priority, Be Target cell j maximum receivable load capacity once;

5b) Target cell j is according to the value of utility formula, and current value of utility and the residential quarter reception size of calculation plot is Δ respectively _jLoad capacity after corresponding value of utility, and two values are compared if the residential quarter receives value of utility after the load greater than current value of utility, execution in step 5d then), otherwise execution in step 5c);

Wherein, being expressed as follows of value of utility formula:

$\tilde{U}=U-C=\left\{\begin{array}{c}a\&CenterDot;{\log }_2(1+l),l<l_{\mathrm{th}}-\mathrm{\&epsiv;}\\ a\&CenterDot;{\log }_2(1+l)-\frac{b}{\mathrm{\&epsiv;}}(l-(l_{\mathrm{th}}-\mathrm{\&epsiv;})),l_{\mathrm{th}}-\mathrm{\&epsiv;}\&le;l<l_{\mathrm{th}}\\ a\&CenterDot;{\log }_2(1+l)+{(l-(l_{\mathrm{th}}+\mathrm{\&epsiv;}))}^2-(b+{\mathrm{\&epsiv;}}^2),l_{\mathrm{th}}\&le;l\end{array}\right.$

Wherein, The value of utility of expression residential quarter, U represents the gross earnings of residential quarter, and C represents the cost of residential quarter, and a is the parameter relevant with the gross earnings U of residential quarter, and value is 0 to 1, b to be the parameter relevant with the cost C of residential quarter, value is 0 to 1;

The cell-of-origin i that 5c) priority is the highest gathers θ from Target cell _tSelect next Target cell to proceed load and shift, if Target cell set θ _tIn do not have next Target cell, the load transfer process of the cell-of-origin i that then priority is the highest finishes; Otherwise, return step 5a);

The cell-of-origin i that 5d) priority is the highest is according to the value of utility formula, and current value of utility and the residential quarter transfer size of calculation plot is Δ respectively _jLoad capacity after corresponding value of utility, and two values are compared, if the value of utility after the transferring load of residential quarter greater than current value of utility, it is Δ that the cell-of-origin i that then priority is the highest shifts size to Target cell j _jLoad capacity, value of utility formula wherein and step 5b) in the value of utility formula identical;

The cell-of-origin i that 5e) priority is the highest carries out as acting: if

Then upgrade m π _iValue be Return step 5c); Otherwise the load transfer process of the cell-of-origin i that priority is the highest finishes.

Step 6 is carried out load balancing and is finished judgement.

If the load transfer has all been carried out in all cell-of-origins in the cell cluster, then a load balancing process finishes, otherwise returns step 3, from cell-of-origin set θ _sIn according to priority select next cell-of-origin to proceed load to shift.

More than be instantiation of the present invention, do not consist of any limitation of the invention, obviously, under thought of the present invention, can carry out different changes, but these changes all belong to the row of protection scope of the present invention.

Claims (4)

1. a mobility load-balancing method that is applied to many residential quarters comprises the steps:

(1) in load balancing in the execution cycle, the load condition of each cell detection in the system self, and with its adjacent cell interacting load information, simultaneously with self load capacity l and load balancing thresholding l _ThCompare, by l 〉=l _ThResidential quarter and its adjacent cell form the cell cluster that size is N, and in cell cluster internal trigger load balancing process;

(2) residential quarter of the N in the cell cluster is divided into θ cell-of-origin and a N-θ Target cell, i.e. load capacity l 〉=l _ThThe residential quarter of-ε is the cell-of-origin, otherwise is Target cell, and wherein ε is cell load protection surplus, and its value is less than load balancing thresholding l _ThA positive number, and form cell-of-origin set θ by θ cell-of-origin _s, form Target cell set θ by a N-θ Target cell _t

(3) to cell-of-origin set θ _sSize according to load capacity is carried out prioritization, carry out at first load by the highest cell-of-origin i of priority and shift, and computational load shifts step-length:

Δ l wherein _i=l _i-(l _Th-the load capacity that ε) need to unload for the highest cell-of-origin i of priority, l _iBe the load capacity of the highest cell-of-origin i of priority, m is the maximum load transfer number, and value is positive integer;

(4) to Target cell set θ _tAccording to the Target cell label

Size carry out prioritization, this label

According to the receivable load capacity Δ of Target cell j l _j=l _j-(l _Th-ε) scope at place obtains, l wherein _jLoad capacity for Target cell j:

$\hat{j}=\left\{\begin{array}{cc}0,& \mathrm{\&Delta;}{l}_j<{\mathrm{\&pi;}}_i\\ 1,& {\mathrm{\&pi;}}_i\&le;\mathrm{\&Delta;}{l}_j<2{\mathrm{\&pi;}}_i\\ .& \\ .& \\ .& \\ m-1,& (m-1){\mathrm{\&pi;}}_i\&le;\mathrm{\&Delta;}{l}_j<m{\mathrm{\&pi;}}_i\\ m,& m{\mathrm{\&pi;}}_i\&le;\mathrm{\&Delta;}{l}_j\end{array}\right.;$

(5) the cell-of-origin i that priority is the highest carries out load according to priority successively select target residential quarter to be shifted;

(6) the cell-of-origin i that priority is the highest returns step (3) after finishing the load transfer, from cell-of-origin set θ _sIn according to priority select next cell-of-origin to proceed load to shift, until the load transfer has all been carried out in all cell-of-origins in the cell cluster, then a load balancing process finishes.

2. a kind of mobility load-balancing method that is applied to many residential quarters according to claim 1, the load condition of each cell detection in the system described in the step 1) self wherein, and with its adjacent cell interacting load information, be that base station by each residential quarter obtains the current load condition in residential quarter, and carry out load information interaction by the base station of the X2 interface between the base station and its adjacent cell.

3. a kind of mobility load-balancing method that is applied to many residential quarters according to claim 1, the cell-of-origin i that wherein priority described in the step 5) is the highest carry out load according to priority successively select target residential quarter to be shifted, and carries out as follows:

The cell-of-origin i that 5a) priority is the highest gathers θ from Target cell _tIn press label Select target residential quarter j carries out the load transfer from big to small, and the load capacity that once shifts is

M π wherein _iThe load capacity that need to shift for the highest cell-of-origin i of priority,

Be Target cell j maximum receivable load capacity once;

5b) Target cell j is according to the value of utility formula, respectively the current value of utility of calculation plot and residential quarter receive the value of utility of correspondence after the load capacity that size is Δ j, and two values are compared, if the value of utility after the reception load of residential quarter is greater than current value of utility, execution in step 5d then), otherwise execution in step 5c);

The cell-of-origin i that 5c) priority is the highest gathers θ from Target cell _tSelect next Target cell to proceed load and shift, if Target cell set θ _tIn do not have next Target cell, the load transfer process of the cell-of-origin i that then priority is the highest finishes; Otherwise, return step 5a);

The cell-of-origin i that 5d) priority is the highest is according to the value of utility formula, and current value of utility and the residential quarter transfer size of calculation plot is Δ respectively _jLoad capacity after corresponding value of utility, and two values are compared, if the value of utility after the transferring load of residential quarter greater than current value of utility, it is Δ that the cell-of-origin i that then priority is the highest shifts size to Target cell j _jLoad capacity;

The cell-of-origin i that 5e) priority is the highest carries out as acting: if

Then upgrade m π _iValue be Return step 5c); Otherwise the load transfer process of the cell-of-origin i that priority is the highest finishes.

4. a kind of mobility load-balancing method that is applied to many residential quarters according to claim 3, wherein step 5b) and step 5d) described in the value of utility formula, be expressed as follows:

$\tilde{U}=U-C=\left\{\begin{array}{cc}a\&CenterDot;{\log }_2(1+l),& l<l_{\mathrm{th}}-\mathrm{\&epsiv;}\\ a\&CenterDot;{\log }_2(1+l)-\frac{b}{\mathrm{\&epsiv;}}(l-(l_{\mathrm{th}}-\mathrm{\&epsiv;})),& l_{\mathrm{th}}-\mathrm{\&epsiv;}\&le;l<l_{\mathrm{th}}\\ a\&CenterDot;{\log }_2(1+l)+{(l-(l_{\mathrm{th}}+\mathrm{\&epsiv;}))}^2-(b+{\mathrm{\&epsiv;}}^2),& l_{\mathrm{th}}\&le;l\end{array}\right.$

Wherein,

The value of utility of expression residential quarter, U represents the gross earnings of residential quarter, and C represents the cost of residential quarter, and a is the parameter relevant with the gross earnings U of residential quarter, and value is 0 to 1, b to be the parameter relevant with the cost C of residential quarter, value is 0 to 1.