CN102256307A - Method and system for balancing distributed load in LTE (Long Term Evolution) access network - Google Patents

Abstract

The invention discloses a method and system for balancing a distributed load in an LTE (Long Term Evolution) access network, belonging to the technical field of wireless communication. The method comprises the following steps of: (S1) acquiring load information of a cell and an adjacent cell of the cell; (S2) judging loads of the cell and the adjacent cell, if the loads are judged to be normal loads, continuing to execute the step (S1), if the loads are judged to be overloads, executing the step (S3), and if the loads are judged to be high loads, executing the step (S4), wherein the overload state is that the loads are greater than or equal to a second threshold value; the high load state is that the loads are greater than or equal to a third threshold value and small than or equal to the second threshold value; and the normal load state is that the loads are smaller than the first threshold value; (S3) executing the load balancing process; and (S4) executing the load balancing preparation process. According to the method and the system, the load unbalance phenomenon in the network can be found in real time, and automatic distributed load balance can be realized.

Description

LTE Access Network distributed load equalizing method and system

Technical field

The present invention relates to wireless communication technology field, particularly a kind of LTE Access Network distributed load equalizing method and system.

Background technology

Fast development along with the network and the communication technology, the development of Radio Access Network presents on a large scale, opening, isomery, dynamic trend, not only be provided with and dispose consuming time, the fallibility of the Radio Access Network with These characteristics, and high-rise business goal, external environment condition and the user's request etc. disposed in the system of back all may constantly change, the ability that system dynamics is adapted to these variations has higher requirement, as the dynamic calibration of dynamically synthetic, the system parameters of the dynamic-configuration of resource, service etc.Only rely at present network manager system to be configured, to diagnose, to repair and reshuffle etc., not only need expend very high administrative expenses according to system mode and high-rise management strategy, and, along with network further develops, will be more and more heavy in hand also.Through long term studies and practice, people recognize that gradually traditional network management can't solve the whole issue that network management faces, and need to seek new network management architecture and method.

Autonomous management has from perception, self-configuring, self-optimizing, self-healing, self-shield five big base attributes; can hide system complexity by the means of " technical management technology "; the system that makes can oneself manage oneself under the guidance of the management strategy that network manager is formulated; thereby realize the reduction of operation funds by reducing human intervention to network operation; peak optimizating network benefit and service quality effectively improve network operation usefulness simultaneously.

But the research at autonomous management still rests on notion, demand or framework stage at present, still lacks the specific aim research to the concrete autonomous management function of particular type of network.The load balancing self-optimizing is an important content in the autonomous management, for understanding the state of development of prior art, existing patent is retrieved, and compares, analyzes, and filters out the higher patent information of following degree related to the present invention:

1, the autonomous management system and method for autonomous system (application number/patent No.: 200410058894.6), this disclosure of the Invention a kind of autonomous management system and method for autonomous system.The autonomous management of autonomous system can comprise supervision by management system with method, and the course of action that will carry out in by management system of suggestion.Can judge whether the keeper has carried out the course of action of suggestion.Respond described judgement, can judge also whether the output of described course of action is consistent with the output of prediction.If, respond the output of course of action and the consistent judgement of output of prediction so, can change the branch counting number.On the contrary, the output of response course of action and the inconsistent judgement of output of prediction can oppositely change the branch counting number.In a word, when a minute counting number is crossed threshold value, can be switched to self-adaptive component by the management of management system.

2, a kind of load-balancing method (application number/patent No.: 200510132568.X) of WLAN (wireless local area network).This disclosure of the Invention a kind of load-balancing method of WLAN (wireless local area network), WAP (wireless access point) by the mutual discovery load minimum between the WAP (wireless access point), it is that capacity is born in load that the little WAP (wireless access point) of load is distributed the switching planned number to the big WAP (wireless access point) of load, switch to the little WAP (wireless access point) of load by its terminal of wireless access point control that load is big, if it is low once to be adjusted to power, illustrate to fall into two terminal quantities in the overlapping region between the WAP (wireless access point) very little.Then change switching target, restart the load balancing adjustment process, so circulation is to reach the balance of the concentrated load of whole expansion service.

3, the parameter selection optimization of Qie Huaning (application number/patent No.: 200410060081.6), a kind of method and apparatus that is used in cellular network, selecting handoff parameter of this invention design, its method is the delay of at first measuring handover process, and the result based on affiliated measuring process is provided with described handoff parameter then.Can be according to system load and the dynamic maximized system capacity of physical configuration, thus being optimized of the parameter of making and capacity is possible.

4, based on (application number/the patent No.: 200910023243.6) of the user selection switching method under the moving load equilibrating mechanism.This disclosure of the Invention a kind of based on the user selection switching method under the moving load equilibrating mechanism, mainly solve communication disruption and table tennis switching problem that signal quality that existing method is prone to descends rapidly and caused under the situation of user's high-speed motion.

5, area load control method, system and equipment (application number/patent No.: 200710162709.1), this invention relates to wireless communication field, a kind of area load control method, system and equipment are disclosed, make that the resident load of each sub-district of whole network can be more balanced, reduced and inserted congested possibility.In this invention, add up the number of non-occupied terminal in each zone, non-occupied terminal is carried out load balancing, also can duplicate equilibrium to non-occupied terminal by the base station according to the number of add up non-occupied terminal in each zone that obtains.

The defective of background technology

The defective of above-mentioned first piece of patent is: this invention is narrated is a kind of management method at the network that has the autonomous management ability, promptly, when network and when possessing self ability of autonomous management, how to determine to manage, but do not illustrate how network possesses the autonomous management ability by the network autonomous management or by the keeper.

The defective of above-mentioned second piece of patent is: this invention narration be the characteristic that a kind of load-balancing method of WLAN (wireless local area network) can not adapt to the LTE wireless network.In addition, this scheme is to distribute the switching planned number to realize load balancing by the little WAP (wireless access point) of load to the big WAP (wireless access point) of load, rather than switches according to the heavy sub-district actual demand of load, can not satisfy the demand of heavy duty sub-district conscientiously.

The defective of above-mentioned the 3rd piece of patent is: this invention is by adjusting handoff parameter the time of delay of measuring terminals handover process, and does not consider the loading condition of this sub-district and neighbor cell.

The defective of above-mentioned the 4th piece of patent is: this invention is that the handoff parameter of adjusting two neighbor cells (heavy duty, a underload) is realized load balancing, how not to select which user to switch but describe in detail on the one hand; This on the other hand method is not accurately to switch according to the load capacity of overloaded cells.

The defective of above-mentioned the 5th piece of patent is: the access that this invention only too much may form at non-occupied terminal is congested carries out load balancing, and not have consideration to be in the formed traffic overload of terminal of connection status.

Summary of the invention

(1) technical problem that will solve

The technical problem to be solved in the present invention is: for realizing long evolving system (Long Tem Evolution, LTE) autonomous load balancing of wireless access network, promptly under the condition of no human administrator intervention, find the overload sub-district timely and accurately, and based on current offered load state, the autonomous handoff parameter of revising independently generates handover scheme, to realize load balancing.

(2) technical scheme

For solving the problems of the technologies described above, the invention provides a kind of LTE Access Network distributed load equalizing method, may further comprise the steps:

S1: obtain this sub-district and with the load of described this sub-district neighbor cell, the quantization formula of cell load is:

$\mathrm{LOAD}=\frac{{\mathrm{\Σ}}_u\frac{D_u}{R\left({\mathrm{SINR}}_u\right)}}{{\mathrm{PRB}}_{\mathrm{tot}}}---\left(1\right)$

Wherein, LOAD represents cell load, PRB _TotThe sum of the Physical Resource Block of expression sub-district, D _uThe business demand speed of expression user u, SINR _uThe Signal to Interference plus Noise Ratio of a Physical Resource Block of expression, R (SINR _u) represent that a Physical Resource Block is dry than following the service rate that can reach at current letter,

Speed D is satisfied in expression _uThe number of required Physical Resource Block, described cell load is: needed Physical Resource Block PRB amount sum of all customer services and the total PRB in sub-district in the sub-district _TotBetween ratio;

S2: judge the load of this sub-district and neighbor cell,, then continue to carry out the S1 step if be judged as normal load; If be judged as overload, then execution in step S3; If be judged as high capacity, then execution in step S4;

Overload: load＞=second threshold value;

High load condition: first threshold value=＜load＜second threshold value;

Normal load state: load＜first threshold value;

S3: carry out the load balancing process, make overloaded cells and its neighbor cell reach load balancing;

S4: carry out the load balancing set-up procedure, and forward step S1 to.

Wherein, described step S3 specifically comprises:

S3.1: locking overloaded cells and neighbor cell thereof;

S3.2: determine that being fit to carry out the user of switching in the overloaded cells collects U;

S3.3: determine that according to following formula needs carry out the number of users N that load balancing is switched:

$N=\max (0,\mathrm{num}\×(1-\frac{1}{\mathrm{LOAD}}))---\left(2\right)$

Wherein, num represents number of users total in the overloaded cells,

The number of users of initiating the service request failure in the expression overloaded cells, N has reflected will reach the cell load equilibrium, the number of users that need switch;

S3.4: according to utility function U (u, i j) collect the U from the user and select a less terminal use of utility function value to carry out the load balancing switching, being expressed as of utility function:

U(u，i，j)＝ω ₁×ΔHM _ij+ω ₂×LOAD _j；

Wherein, parameter L OAD _jThe load of expression Target cell j, parameter Δ HM _IjExpression for trigger user u switch to Target cell j from overloaded cells i need be to handoff threshold HM _IjThe index word of carrying out, ω ₁And ω ₂Be the coefficient of two parameters, ω ₁And ω ₂Be nonnegative number, and ω ₁+ ω ₂=1;

S3.5: according to Δ HM _IjRevise handoff threshold HM _IjTrigger switching, with amended HM to selected terminal use _IjBe standard, triggering terminal user u switches to Target cell j from cell-of-origin i;

S3.6: the load and the handoff threshold HM that upgrade this sub-district and neighbor cell _Ij

S3.7: N subtracts 1 with number of users, and the user collects among the U deletion user u, judges N ≠ 0, and the user collects U for empty, then goes to execution in step S3.4, otherwise goes to execution in step S3.8;

S3.8: the lock-out state of removing overloaded cells and neighbor cell.

Wherein, described step S4 specifically comprises:

S4.1: will have normally loaded neighbor cell according to the load LOAD of neighbor cell and put into the tabulation of target switching cell;

S4.2: judge whether described target switching cell tabulation is empty, if empty, represents no switchable Target cell, carries out S4.3; Otherwise expression has switchable Target cell, carries out S4.4;

S4.3: adjust RRM parameter in this sub-district, to improve the load capacity of this sub-district;

S4.4: continue the load of monitoring objective switching cell.

Wherein, among the described step S4.1, neighbor cell height according to load in the tabulation of target switching cell carries out priority arrangement, and load low priority more is high more.

The present invention also provides a kind of LTE Access Network distributed load equalizing system, comprising:

The load acquiring unit, be used to obtain this sub-district and with the load of described this sub-district neighbor cell; The quantization formula of cell load is:

$\mathrm{LOAD}=\frac{{\mathrm{\Σ}}_u\frac{D_u}{R\left({\mathrm{SINR}}_u\right)}}{{\mathrm{PRB}}_{\mathrm{tot}}}---\left(1\right)$

Wherein, LOAD represents cell load, PRB _TotThe sum of the Physical Resource Block of expression sub-district, D _uThe business demand speed of expression user u, SINR _uThe Signal to Interference plus Noise Ratio of a Physical Resource Block of expression, R (SINR _u) represent that a Physical Resource Block is dry than following the service rate that can reach at current letter,

Speed D is satisfied in expression _uThe number of required Physical Resource Block, therefore described cell load is: needed Physical Resource Block PRB amount sum of all customer services and the total PRB in sub-district in the sub-district _TotBetween ratio;

The load judgment unit is used to judge the load of this sub-district and neighbor cell, if be judged as normal load, then continues to carry out the load acquiring unit; If be judged as overload, then carry out Load Balance Unit; If be judged as high capacity, then carry out the load balancing preparatory unit,

Overload: load＞=second threshold value;

High load condition: first threshold value=＜load＜second threshold value;

Normal load state: load＜first threshold value;

Load Balance Unit is used to carry out the load balancing process, makes overloaded cells and its neighbor cell reach load balancing;

The load balancing preparatory unit is used to carry out the load balancing set-up procedure, and forwards execution load acquiring unit to.

(3) beneficial effect

Can find load unbalanced phenomena in the network in real time by method of the present invention, and realized autonomous distributed load equalizing, make that the service-user number reduces in the overloaded cells, and the number of service subscribers of adjacent underload sub-district increases, the whole resource utilization of network improves, and has improved the network operation quality effectively.

Description of drawings

Fig. 1 is a kind of LTE Access Network distributed load equalizing method flow chart of the embodiment of the invention;

Fig. 2 is the particular flow sheet of step S103 among Fig. 1;

Fig. 3 is the particular flow sheet of step S104 among Fig. 1.

Embodiment

Below in conjunction with drawings and Examples, the specific embodiment of the present invention is described in further detail.Following examples are used to illustrate the present invention, but are not used for limiting the scope of the invention.

As shown in Figure 1, LTE Access Network distributed load equalizing method of the present invention comprises:

Step S101, obtain this sub-district and with the load of described this sub-district neighbor cell.The quantization formula of cell load is:

$\mathrm{LOAD}=\frac{{\mathrm{\Σ}}_u\frac{D_u}{R\left({\mathrm{SINR}}_u\right)}}{{\mathrm{PRB}}_{\mathrm{tot}}}---\left(1\right)$

Wherein, LOAD represents cell load, PRB _TotThe sum of the Physical Resource Block of expression sub-district, D _uThe business demand speed of expression user u, SINR _uThe Signal to Interference plus Noise Ratio of a Physical Resource Block of expression, R (SINR _u) represent that a Physical Resource Block is dry than following the service rate that can reach at current letter,

Speed D is satisfied in expression _uThe number of required Physical Resource Block, therefore described cell load is: needed PRB amount sum of all customer services and the total PRB in sub-district in the sub-district _TotBetween ratio.The load of this sub-district can (be above-mentioned PRB according to this sub-district relevant information directly _Tot, D _uDeng) calculate, the load of neighbor cell can obtain by the X2 interface between the evolved Node B (eNB) calculating after the relevant information.

Step S102 judges the load of this sub-district and neighbor cell, if be judged as normal load, then continues to carry out the S101 step; If be judged as overload, then execution in step S103; If be judged as high capacity, then execution in step S104.

Overload: load＞=second threshold value;

High load condition: first threshold value=＜load＜second threshold value;

Normal load state: load＜first threshold value;

Two thresholdings can be made amendment according to the actual requirements, represent just can meet consumers' demand as LOAD=1, if LOAD=2 represents to have the user's request of half to satisfy.Therefore, second threshold value can be set for greater than 1 value, as: 1.5 or 2 etc., first threshold value is 0.8.

Step S103 carries out the load balancing process, makes overloaded cells and its neighbor cell reach load balancing, specifically as shown in Figure 2, comprising:

Step S201, locking overloaded cells and neighbor cell thereof.Locking is for fear of concurrent load balancing process takes place, because in the process of carrying out load balancing, this cell load and neighbor cell load are always in monitoring, also may judge it is overload, but should not initiate the load balancing process once more this moment, so will lock to avoid the triggering load balancing process once more in the load balancing process.

Step S202 determines that being fit to carry out the user of switching in the overloaded cells collects U.Can determine according to conventional switch triggering method, if that is: the measured value RSRP of the source base station i of reporting of user and certain adjacent base station j (Reference Signal Receiving Power: Reference Signal Received Power) and RSRQ (Reference Signal Receiving Quality: parameters such as absolute value Reference Signal Received Quality) and difference approach the handoff threshold HM of current setting _IjThe time, then this user is added into the user and collects among the U.

Step S203, determine to carry out the number of users N that load balancing is switched:

Formula (1) has clearly been indicated the loading condition of sub-district.If all users are met in LOAD≤1 expression sub-district, if LOAD=2 represents to have only in the sub-district 50% user to be met.Then the number of users of business demand satisfied (expression is if the user initiates service request, but network does not have resource can distribute to the user, and request is failed, and the user can't use business) is expressed as follows in this sub-district:

$N=\max (0,\mathrm{num}\×(1-\frac{1}{\mathrm{LOAD}}))---\left(2\right)$

Wherein, num represents number of users in the sub-district,

The unsatisfied number of users of business demand in the expression sub-district, N has reflected will reach load balancing, the number of users that need switch.

Step S204, according to utility function U (u, i j) collect the U from the user and select a less terminal use of utility function value to carry out the load balancing switching, being expressed as of utility function:

U(u，i，j)＝ω ₁×ΔHM _ij+ω ₂×LOAD _j；

Wherein, parameter L OAD _jThe load of expression Target cell j, parameter Δ HM _IjExpression for trigger user u switch to Target cell j from overloaded cells i need be to handoff threshold HM _IjThe index word of carrying out, ω ₁And ω ₂Be the coefficient of two parameters, ω ₁And ω ₂Be nonnegative number, and ω ₁+ ω ₂=1, value is according to concrete actual conditions and difference, as: its value respectively is 0.5.

Step S205 is according to Δ HM _IjRevise handoff threshold HM _IjTrigger the switching to selected terminal use, promptly current handoff threshold is HM _Ij, index word is Δ HM _Ij, with amended HM _IjBe standard, triggering terminal user u switches to Target cell j from cell-of-origin i.

Step S206 upgrades the load information and the handoff threshold HM of this sub-district and neighbor cell _JjWherein, load calculates according to formula (1), and handoff threshold is the handoff threshold of revising in the S205 step.

Step S207, N subtracts 1 with number of users, and the user collects among the U deletion user u, judges N ≠ 0, and the user collects U for empty, then forwards step S204 step to and carries out, otherwise go to step S208.

Step S208, the lock-out state of releasing overloaded cells and neighbor cell.

Step S104 carries out the load balancing set-up procedure, and idiographic flow comprises as shown in Figure 3:

Step S301, to have normally loaded neighbor cell according to the load LOAD of neighbor cell and put into the tabulation of target switching cell, for the user with overloaded cells switches to the lower neighbor cell of load, preferably, neighbor cell height according to load in the tabulation of target switching cell carries out priority arrangement, load low priority more is high more, in table, arrange forward, with easy-to-look-up.

Step S302 judges that whether described target switching cell tabulation is empty, if empty, represents no switchable Target cell, then execution in step S303; Otherwise expression has switchable Target cell, execution in step S304.

Step S303 adjusts RRM parameter in this sub-district, as base station transmitting power, antenna tilt etc., with the load capacity of this sub-district of further raising, to reduce load.

Step S304, execution in step S101 continues monitoring objective switching cell information, safeguards the tabulation of target switching cell, after this cell load of box lunch overload, can carry out the load balancing process timely and effectively, can switch in the high target switching cell of priority.

Method of the present invention is tested, and experimental result is as follows:

Sub-district ID in the following table be 24 sub-district as observing the sub-district, this cell initial mobile phone terminal (being the user) number is 30 (supposing to be in overload), is 6dB with the initial handoff threshold of other adjacent sub-district; After carrying out the load balancing process, this sub-district mobile phone terminal quantity reduces to 17, and variation has also all taken place in the handoff threshold between each neighbor cell, and has reduced the size of its service area thus, makes the user who is in the border be switched respectively to neighbor cell 2,3,4,5,6.Following table is depicted as the effect comparison of carrying out the load-balancing method front and back.

The present invention also provides a kind of LTE Access Network distributed load equalizing system, comprising:

The load acquiring unit, be used to obtain this sub-district and with the load of described this sub-district neighbor cell; The quantization formula of cell load is:

$\mathrm{LOAD}=\frac{{\mathrm{\Σ}}_u\frac{D_u}{R\left({\mathrm{SINR}}_u\right)}}{{\mathrm{PRB}}_{\mathrm{tot}}}---\left(1\right)$

Wherein, LOAD represents cell load, PRB _TotThe sum of the Physical Resource Block of expression sub-district, D _uThe business demand speed of expression user u, SINR _uThe Signal to Interference plus Noise Ratio of a Physical Resource Block of expression, R (SINR _u) represent that a Physical Resource Block is dry than following the service rate that can reach at current letter,

Speed D is satisfied in expression _uThe number of required Physical Resource Block, therefore described cell load is: needed Physical Resource Block PRB amount sum of all customer services and the total PRB in sub-district in the sub-district _TotBetween ratio.

The load judgment unit is used to judge the load of this sub-district and neighbor cell, if be judged as normal load, then continues to carry out the load acquiring unit; If be judged as overload, then carry out Load Balance Unit; If be judged as high capacity, then carry out the load balancing preparatory unit.

Overload: load＞=second threshold value;

High load condition: first threshold value=＜load＜second threshold value;

Normal load state: load＜first threshold value.

Load Balance Unit is used to carry out the load balancing process, makes overloaded cells and its neighbor cell reach load balancing.

The load balancing preparatory unit is used to carry out the load balancing set-up procedure, and forwards execution load acquiring unit to.

Above execution mode only is used to illustrate the present invention; and be not limitation of the present invention; the those of ordinary skill in relevant technologies field; under the situation that does not break away from the spirit and scope of the present invention; can also make various variations and modification; therefore all technical schemes that are equal to also belong to category of the present invention, and scope of patent protection of the present invention should be defined by the claims.

Claims (5)

1. a LTE Access Network distributed load equalizing method is characterized in that, may further comprise the steps:

S1: obtain this sub-district and with the load of described this sub-district neighbor cell, the quantization formula of cell load is:

$\mathrm{LOAD}=\frac{{\mathrm{\Σ}}_u\frac{D_u}{R\left({\mathrm{SINR}}_u\right)}}{{\mathrm{PRB}}_{\mathrm{tot}}}---\left(1\right)$

Wherein, LOAD represents cell load, PRB _TotThe sum of the Physical Resource Block of expression sub-district, D _uThe business demand speed of expression user u, SINR _uThe Signal to Interference plus Noise Ratio of a Physical Resource Block of expression, R (SINR _u) represent that a Physical Resource Block is dry than following the service rate that can reach at current letter,

Speed D is satisfied in expression _uThe number of required Physical Resource Block, described cell load is: needed Physical Resource Block PRB amount sum of all customer services and the total PRB in sub-district in the sub-district _TotBetween ratio;

S2: judge the load of this sub-district and neighbor cell,, then continue to carry out the S1 step if be judged as normal load; If be judged as overload, then execution in step S3; If be judged as high capacity, then execution in step S4;

Overload: load＞=second threshold value;

High load condition: first threshold value=＜load＜second threshold value;

Normal load state: load＜first threshold value;

S3: carry out the load balancing process, make overloaded cells and its neighbor cell reach load balancing;

S4: carry out the load balancing set-up procedure, and forward step S1 to.

2. LTE Access Network distributed load equalizing method as claimed in claim 1 is characterized in that described step S3 specifically comprises:

S3.1: locking overloaded cells and neighbor cell thereof;

S3.2: determine that being fit to carry out the user of switching in the overloaded cells collects U;

S3.3: determine that according to following formula needs carry out the number of users N that load balancing is switched:

$N=\max (0,\mathrm{num}\×(1-\frac{1}{\mathrm{LOAD}}))---\left(2\right)$

Wherein, num represents number of users total in the overloaded cells,

The number of users of initiating the service request failure in the expression overloaded cells, N has reflected will reach the cell load equilibrium, the number of users that need switch;

S3.4: according to utility function U (u, i j) collect the U from the user and select a less terminal use of utility function value to carry out the load balancing switching, being expressed as of utility function:

U(u，i，j)＝ω ₁×ΔHM _ij+ω ₂×LOAD _j；

Wherein, parameter L OADj represents the load of Target cell j, parameter Δ HM _IjExpression for trigger user u switch to Target cell j from overloaded cells i need be to handoff threshold HM _IjThe index word of carrying out, ω ₁And ω ₂Be the coefficient of two parameters, ω ₁And ω ₂Be nonnegative number, and ω ₁+ ω ₂=1;

S3.5: according to Δ HM _IjRevise handoff threshold HM _IjTrigger switching, with amended HM to selected terminal use _IjBe standard, triggering terminal user u switches to Target cell j from cell-of-origin i;

S3.6: the load and the handoff threshold HM that upgrade this sub-district and neighbor cell _Ij

S3.7: N subtracts 1 with number of users, and the user collects among the U deletion user u, judges N ≠ 0, and the user collects U for empty, then goes to execution in step S3.4, otherwise goes to execution in step S3.8;

S3.8: the lock-out state of removing overloaded cells and neighbor cell.

3. LTE Access Network distributed load equalizing method as claimed in claim 1 is characterized in that described step S4 specifically comprises:

S4.1: will have normally loaded neighbor cell according to the load LOAD of neighbor cell and put into the tabulation of target switching cell;

S4.2: judge whether described target switching cell tabulation is empty, if empty, represents no switchable Target cell, carries out S4.3; Otherwise expression has switchable Target cell, carries out S4.4;

S4.3: adjust RRM parameter in this sub-district, to improve the load capacity of this sub-district;

S4.4: continue the load of monitoring objective switching cell.

4. LTE Access Network distributed load equalizing method as claimed in claim 3 is characterized in that, among the described step S4.1, neighbor cell height according to load in the tabulation of target switching cell carries out priority arrangement, and load low priority more is high more.

5. a LTE Access Network distributed load equalizing system is characterized in that, comprising:

The load acquiring unit, be used to obtain this sub-district and with the load of described this sub-district neighbor cell; The quantization formula of cell load is:

$\mathrm{LOAD}=\frac{{\mathrm{\Σ}}_u\frac{D_u}{R\left({\mathrm{SINR}}_u\right)}}{{\mathrm{PRB}}_{\mathrm{tot}}}---\left(1\right)$

Wherein, LOAD represents cell load, PRB _TotThe sum of the Physical Resource Block of expression sub-district, D _uThe business demand speed of expression user u, SINR _uThe Signal to Interference plus Noise Ratio of a Physical Resource Block of expression, R (SINR _u) represent that a Physical Resource Block is dry than following the service rate that can reach at current letter,

Speed D is satisfied in expression _uThe number of required Physical Resource Block, therefore described cell load is: needed Physical Resource Block PRB amount sum of all customer services and the total PRB in sub-district in the sub-district _TotBetween ratio;

The load judgment unit is used to judge the load of this sub-district and neighbor cell, if be judged as normal load, then continues to carry out the load acquiring unit; If be judged as overload, then carry out Load Balance Unit; If be judged as high capacity, then carry out the load balancing preparatory unit,

Overload: load＞=second threshold value;

High load condition: first threshold value=＜load＜second threshold value;

Normal load state: load＜first threshold value;

Load Balance Unit is used to carry out the load balancing process, makes overloaded cells and its neighbor cell reach load balancing;

The load balancing preparatory unit is used to carry out the load balancing set-up procedure, and forwards execution load acquiring unit to.

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