CN102625369B

CN102625369B - Load balancing optimization method for guaranteeing quality of service requirements of users of different levels in classified manner

Info

Publication number: CN102625369B
Application number: CN201210069725.7A
Authority: CN
Inventors: 尤肖虎; 王浩; 潘志文
Original assignee: Southeast University
Current assignee: Southeast University
Priority date: 2012-03-16
Filing date: 2012-03-16
Publication date: 2014-07-09
Anticipated expiration: 2032-03-16
Also published as: CN102625369A

Abstract

本发明是一种移动通信系统中分类保证不同等级用户服务质量要求的负载均衡优化方法，由于考虑到不同业务等级的用户，在进行负载均衡切换时，可以优先保证高等级GBR用户的保障比特率要求，其次提高低等级non-GBR用户实际可得速率，并且分别优先选择占用系统资源数最多的用户来进行负载均衡的切换，因此，大大降低了切换次数，从而降低了系统的信令开销，并降低了GBR用户接入阻塞率，提高了系统资源利用率和系统总吞吐量。The present invention is a load balancing optimization method for classifying and guaranteeing service quality requirements of users of different grades in a mobile communication system. Due to consideration of users of different service grades, when performing load balancing switching, the guaranteed bit rate of high-grade GBR users can be guaranteed preferentially Second, increase the actual available rate of low-level non-GBR users, and give priority to users who occupy the most system resources to perform load balancing switching. Therefore, the number of switching times is greatly reduced, thereby reducing the signaling overhead of the system. And it reduces the GBR user access blocking rate, improves system resource utilization and system total throughput.

Description

Load balancing optimization method for classifying and guaranteeing the quality of service requirements of different levels of users

技术领域 technical field

本发明是一种移动通信系统中分类保证不同等级用户服务质量要求的负载均衡优化方法，属于移动通信中的网络技术领域。The invention relates to a load balancing optimization method for classifying and guaranteeing service quality requirements of users of different levels in a mobile communication system, and belongs to the network technical field in mobile communication.

背景技术 Background technique

在蜂窝移动通信系统中，各小区间的负载往往是不均衡的，有的小区负载比较高，有的小区负载比较低，从而导致高负载小区无线资源紧张而不能满足用户的服务质量(QoS，Quality of Service)要求，而在低负载小区，出现了浪费无线资源的情况。为了提高无线资源的利用率，人们提出了负载均衡算法，即通过将高负载小区中的边缘用户切换到低负载小区中，实现小区间负载的近似均衡。对于不同业务类型的用户，负载均衡达到的效果是不同的。对于有保障比特率(GBR)要求的高优先级用户，应首先满足其保障比特率要求，则负载均衡可以降低该类业务用户的接入阻塞率；对于没有保障比特率(non-GBR)要求的低优先级用户，应在满足所有GBR用户的保障比特率要求后，为所有non-GBR用户按速率公平的原则分配剩余资源，使他们得到相同的实际可得速率，则负载均衡可以提高繁忙小区中non-GBR用户实际可得速率。现有的负载均衡算法在进行负载均衡时没有考虑不同优先级的业务，因此不能保证不同业务相应的QoS要求，从而导致较低的系统资源利用率和高负载小区中较差的用户服务质量。本发明提出了一种优先保证高等级GBR用户的保障比特率要求，其次提高低等级non-GBR用户实际可得速率的负载均衡优化方法。In a cellular mobile communication system, the loads among the cells are often unbalanced, some cells have relatively high loads, and some cells have relatively low loads, resulting in tight wireless resources in high-load cells and unable to meet user quality of service (QoS, Quality of Service) requirements, while in low-load cells, wireless resources are wasted. In order to improve the utilization rate of wireless resources, people have proposed a load balancing algorithm, that is, by switching the edge users in the high-load cell to the low-load cell, the approximate load balance among the cells is realized. For users of different business types, the effect of load balancing is different. For high-priority users with guaranteed bit rate (GBR) requirements, their guaranteed bit rate requirements should be met first, then load balancing can reduce the access blocking rate of such service users; for those without guaranteed bit rate (non-GBR) requirements The low-priority users should allocate the remaining resources to all non-GBR users according to the principle of rate fairness after meeting the guaranteed bit rate requirements of all GBR users, so that they can get the same actual available rate, then load balancing can improve the busy rate. Actual available rate of non-GBR users in the cell. Existing load balancing algorithms do not consider services with different priorities when performing load balancing, so they cannot guarantee the corresponding QoS requirements of different services, resulting in low system resource utilization and poor user service quality in high-load cells. The invention proposes a load balancing optimization method that first guarantees the guaranteed bit rate requirements of high-level GBR users, and secondly improves the actual available rate of low-level non-GBR users.

发明内容 Contents of the invention

技术问题：本发明的目的是提出一种移动通信系统中分类保证不同等级用户服务质量要求的负载均衡优化方法，从而在达到负载均衡的同时，降低了GBR用户接入阻塞率，提高了系统资源利用率和系统总吞吐量。Technical problem: the purpose of the present invention is to propose a load balancing optimization method that classifies and guarantees the quality of service requirements of users of different levels in a mobile communication system, thereby reducing the GBR user access blocking rate and improving system resources while achieving load balancing. Utilization and total system throughput.

技术方案：本发明的目的是提出一种移动通信系统中分类保证不同等级用户服务质量要求的负载均衡优化方法，包括如下步骤：Technical solution: the purpose of the present invention is to propose a load balancing optimization method that classifies and guarantees the quality of service requirements of different levels of users in a mobile communication system, including the following steps:

第一步，在一个负载均衡周期内，每一个小区对于本小区内不同等级的用户，按照其相应的保障比特率及最大需求速率要求分配系统资源；In the first step, within a load balancing period, each cell allocates system resources according to its corresponding guaranteed bit rate and maximum demand rate requirements for users of different levels in the cell;

第二步，各基站与其相邻基站交换各自的负载信息，负载信息包括小区内所有有保障比特率GBR(Guaranteed Bit Rate)用户占用的资源数ρ^GBR及所有没有保障比特率non-GBR(non Guaranteed Bit Rate)用户占用的资源数ρ^non-GBR；In the second step, each base station exchanges its load information with its adjacent base stations. The load information includes the number of resources ρ ^GBR occupied by all GBR (Guaranteed Bit Rate) users in the cell and all non-GBR (non-GBR) users without a guaranteed bit rate. Guaranteed Bit Rate) the number of resources occupied by users ρ ^non-GBR ;

第三步，对任一小区i，若其内所有GBR用户占用的资源数ρ_i ^GBR超过给定的由运行商根据自己的要求设定的对于GBR用户的负载均衡切换门限ψ^GBR，则需进行GBR用户负载均衡切换。对于所有处于小区i边缘而且可以切换到相邻小区中的GBR用户，根据以下公式选择在本小区内占用资源数最多的用户k^·为首选切换用户In the third step, for any cell i, if the number of resources ρ _i ^GBR occupied by all GBR users in it exceeds the given load balancing switching threshold ψ ^GBR for GBR users set by the operator according to its own requirements, then need Perform GBR user load balancing switching. For all GBR users who are at the edge of cell i and can be handed over to adjacent cells, select the user k that occupies the most resources in this cell according to the following formula ^as the preferred handover user

k^·＝arg maxρ_i，k ^GBR ^k ＝arg maxρ _i,k ^GBR

其中ρ_i，k ^GBR是小区i分配给GBR用户k的资源数，对于首选切换用户k^·，选择所有满足如下两个条件的相邻小区为备选小区：Among them, ρ _{i, k} ^GBR is the number of resources allocated by cell i to GBR user k ^. For the preferred handover user k , select all adjacent cells that meet the following two conditions as candidate cells:

条件一： ${SINR}_{{j, k}^{\cdot}} &GreaterEqual; AC_threshold$ Condition one: ${SINR}_{{j, k}^{&Center Dot;}} &Greater Equal; AC_threshold$

条件二： ${ρ_{j}}^{GBR} + {ρ_{{j, k}^{\cdot}}}^{GBR} \leq ψ^{GBR}$ Condition two: ${ρ_{j}}^{GBR} + {ρ_{{j, k}^{&Center Dot;}}}^{GBR} \leq ψ^{GBR}$

其中Ac_threshold是由运行商根据自己要求设定的用户接入门限，是首选切换用户k^·在备选小区j中的信干噪比。条件一即用户k^·在备选小区中的信干噪比不低于由运行商根据自己要求设定的用户接入门限Ac_threshold；ρ_j ^GBR是备选小区j内所有GBR用户占用的资源数，

是首选切换用户k^·在备选小区j中达到其保障比特率要求所需占用的资源数，条件二即用户k^·切换到任一备选小区后在该小区中占用的资源数与该小区内原有的所有GBR用户占用的资源数之和不高于该小区GBR用户负载均衡切换门限ψ^GBR。Among them, Ac_threshold is the user access threshold set by the operator according to its own requirements. is the preferred switching user k ^· The SINR in the candidate cell j. Condition 1 is user ^k The SINR in the candidate cell is not lower than the user access threshold Ac_threshold set by the operator according to its own requirements; ρ _j ^GBR is the number of resources occupied by all GBR users in the candidate cell j ,

is the preferred switching user k ^. The number of resources occupied by the candidate cell j to meet its guaranteed bit rate requirements. The second condition is user k ^. After switching to any candidate cell, the number of resources occupied in this cell The sum of resources occupied by all original GBR users in the cell is not higher than the GBR user load balancing switching threshold ψ ^GBR in this cell.

在所有满足上述条件的备选小区中，根据以下公式选择切换完成后所有GBR用户占用的资源数最低的小区j^·为目标小区Among all the candidate cells that meet the above conditions, select the cell j with the lowest number of resources occupied by all GBR users after the handover is completed according to the following formula ^as the target cell

${j j}^{\cdot &Center Dot;} = = arg arg min min (({ρ ρ}_{j j}^{GBR GBR} + + {ρ ρ}_{{j j . . k k}^{\cdot &Center Dot;}}^{GBR GBR}))$

则将用户k^·由源小区i切换至目标小区j^·；Then user ^k is handed over from source cell i to target cell j ^;

第四步，在当前的负载均衡周期内，重复第三步，直到小区i内所有GBR用户占用的资源数ρ_i ^GBR低于GBR用户负载均衡切换门限ψ^GBR或没有满足切换条件的边缘用户(即所有剩余的边缘GBR用户不能同时满足条件一和条件二)，则小区i停止GBR用户负载均衡切换；The fourth step is to repeat the third step in the current load balancing period until the number of resources ρ _i ^GBR occupied by all GBR users in the cell i is lower than the GBR user load balancing switching threshold ψ ^GBR or there are no edge users that meet the switching conditions ( That is, all remaining edge GBR users cannot simultaneously satisfy condition 1 and condition 2), then cell i stops GBR user load balancing switching;

第五步，在当前负载均衡周期内，对于所有小区完成第三，四两步，停止全网内GBR用户负载均衡切换；The fifth step is to complete the third and fourth steps for all cells in the current load balancing period, and stop the load balancing switching of GBR users in the entire network;

第六步，对于任一小区i，若其中non-GBR用户实际可得速率没有达到用户需求的最大速率，则需进行non-GBR用户负载均衡切换。对于所有处于小区i边缘可以切换到相邻小区中的non-GBR用户k，根据以下公式选择在本小区内占用资源数最多的non-GBR用户k^·为首选切换用户Step 6: For any cell i, if the actual available rate of the non-GBR user does not reach the maximum rate required by the user, load balancing switching of the non-GBR user is required. For all non-GBR users k at the edge of cell i that can be handed over to adjacent cells, select the non-GBR user k that occupies the most resources in this cell according to the following formula ^as the preferred handover user

k^·＝arg max ρ_i，k ^non-GBR ^k ＝arg max ρ _i,k ^non-GBR

其中ρ_i，k ^non-GBR是小区i分配给non-GBR用户k的资源数，对于首选切换用户k^·，选择所有满足如下两个条件的相邻小区为备选小区：Among them, ρ _{i, k} ^non-GBR is the number of resources allocated by cell i to non-GBR user k. For the preferred handover user ^k , select all adjacent cells that meet the following two conditions as candidate cells:

条件三： ${SINR}_{{j, k}^{\cdot}} &GreaterEqual; Ac_threshold$ Condition three: ${SINR}_{{j, k}^{&Center Dot;}} &Greater Equal; Ac_threshold$

条件四： $V_{{i, k}^{\cdot}}^{non - GBR} < V_{{j, k}^{\cdot}}^{non - GBR}$ Condition four: $V_{{i, k}^{\cdot}}^{non - GBR} < V_{{j, k}^{&Center Dot;}}^{non - GBR}$

条件三即首选切换用户k^·在备选小区中的信干噪比不低于运行商根据自己要求设定的用户接入门限Ac_threshold；

是用户k^·在源小区中实际可得速率，

是用户k^·在备选小区j中实际可得速率，条件四即用户k^·在备选小区中的实际可得速率要大于在源小区中的实际可得速率。The third condition is the preferred handover user k ^. The signal-to-interference-noise ratio in the candidate cell is not lower than the user access threshold Ac_threshold set by the operator according to its own requirements;

is user ^k The actual available rate in the source cell,

is the actual available rate of user ^k in the candidate cell j, and the fourth condition is that the actual available rate of user ^k in the candidate cell is greater than the actual available rate in the source cell.

在所有满足上述条件的备选小区中，根据以下公式选择切换完成后总负载最低的小区j^·为目标小区Among all the candidate cells that meet the above conditions, select the cell j with the lowest total load after the handover is completed according to the following formula ^as the target cell

${j j}^{\cdot &Center Dot;} = = arg arg min min (({ρ ρ}_{j j}^{GBR GBR} + + {ρ ρ}_{j j}^{non non - - GBR GBR} + + {ρ ρ}_{{j j,, k k}^{\cdot &Center Dot;}}^{non non - - GBR GBR}))$

其中ρ_j ^GBR是备选小区j内已有的所有GBR用户占用的资源数，ρ_j ^non-GBR是备选小区j内已有的所有non-GBR用户占用的资源数，

是non-GBR用户k^·在备选小区j中占用的资源数。Where ρ _j ^GBR is the number of resources occupied by all existing GBR users in candidate cell j, ρ _j ^non-GBR is the number of resources occupied by all existing non-GBR users in candidate cell j,

is non-GBR user k ^• The number of resources occupied in candidate cell j.

第七步，在当前的负载均衡周期内，重复第六步，直到小区i内所有non-GBR用户达到他们的最大需求速率要求或没有满足切换条件的边缘用户(即所有剩余的边缘non-GBR用户不能同时满足条件一和条件二)，则小区i停止non-GBR用户负载均衡切换；The seventh step, in the current load balancing period, repeat the sixth step until all non-GBR users in cell i reach their maximum demand rate requirements or there are no edge users that meet the switching conditions (that is, all remaining edge non-GBR users The user cannot satisfy condition 1 and condition 2) at the same time, then cell i stops non-GBR user load balancing switching;

第八步，在当前负载均衡周期内，对于所有小区完成第六，七两步，停止全网non-GBR用户负载均衡切换，算法结束。The eighth step, in the current load balancing period, complete the sixth and seventh steps for all cells, stop the non-GBR user load balancing switching in the whole network, and the algorithm ends.

对于GBR用户负载均衡切换时首选切换用户k^·及相应目标小区j^·的选择：For the selection of the preferred handover user k ^and the corresponding target cell ^j when GBR user load balancing handover:

k^·＝arg max ρ_i，k ^GBR ^k ＝arg max ρ _i,k ^GBR

${j j}^{\cdot &Center Dot;} = = arg arg min min (({ρ ρ}_{j j}^{GBR GBR} + + {ρ ρ}_{{j j,, k k}^{\cdot &Center Dot;}}^{GBR GBR}))$

对于non-GBR用户负载均衡切换时首选切换用户k^·及相应目标小区j^·的选择：For non-GBR user load balancing handover, the choice of the preferred handover user k ^and the corresponding target cell ^j :

k^·＝arg max ρ_i，k ^non-GBR ^k ＝arg max ρ _i,k ^non-GBR

的方法为：首先定义以下变量：The method is: first define the following variables:

GBR用户k在某一小区i中所占资源数Number of resources occupied by GBR user k in a certain cell i

${ρ ρ}_{i i,, k k}^{GBR GBR} = = \frac{{θ θ}_{k k}}{B B * * {log log}_{22} ((11 + + {SINR SINR}_{i i,, k k}))} - - - - - - [[11]]$

其中θ_k为GBR用户k的保障比特率要求，B为一个最小资源单位的等价带宽，SINR_i，k为用户k在小区i中的信干噪比。Where θ _k is the guaranteed bit rate requirement of GBR user k, B is the equivalent bandwidth of a minimum resource unit, and SINR _{i, k} is the signal-to-interference-noise ratio of user k in cell i.

对于网络中任一小区i，定义其内所有GBR用户占用的资源数：For any cell i in the network, define the number of resources occupied by all GBR users in it:

${ρ ρ}_{i i}^{GBR GBR} = = {Σ Σ}_{k k = = 11}^{{G G}_{i i}} {ρ ρ}_{i i,, k k}^{GBR GBR} - - - - - - [[22]]$

即小区i分配给其内所有GBR用户的总资源数。其中G_i是小区i中所有的GBR用户；

为小区i给GBR用户k分配的资源数。That is, the total number of resources allocated to all GBR users in cell i. Where G _i is all GBR users in cell i;

Number of resources allocated to GBR user k by cell i.

non-GBR用户k在某一小区i中所占资源数Number of resources occupied by non-GBR user k in a certain cell i

${ρ ρ}_{i i,, k k}^{non non - - GBR GBR} = = \frac{{V V}_{i i,, k k}^{non non - - GBR GBR}}{B B * * {log log}_{22} ((11 - - {SINR SINR}_{i i,, k k}))}$

[3][3]

其中B为一个最小资源单位的等价带宽，SINR_i，k为用户k在小区i中的信干噪比，

为小区i中所有non-GBR用户的实际可得速率，可按下述方法得到：where B is the equivalent bandwidth of a minimum resource unit, SINR _{i, k} is the signal-to-interference-noise ratio of user k in cell i,

is the actual available rate of all non-GBR users in cell i, which can be obtained as follows:

对小区i中的每个non-GBR用户k，可测得其在小区i中收到的信干噪比SINR_i，k，从而可求得其在一个最小资源单位上的实际可得速率For each non-GBR user k in cell i, the signal-to-interference and noise ratio SINR _i,k received in cell i can be measured, so that its actual available rate in a minimum resource unit can be obtained

${T T}_{i i,, k k}^{non non - - GBR GBR} = = B B * * {log log}_{22} ((11 + + {SINR SINR}_{i i,, k k}))$

[4][4]

求出小区i内所有non-GBR用户在一个最小资源单位上的实际可得速率

的最小公倍数lcm，则由于小区i中所有non-GBR用户要得到相同实际可得速率，可知任一non-GBR用户k分得的虚拟资源数Find the actual available rate of all non-GBR users in cell i on a minimum resource unit

The least common multiple of lcm, since all non-GBR users in cell i want to get the same actual available rate, it can be known that the number of virtual resources allocated to any non-GBR user k

${ρ ρ}_{i i,, k k} = = \frac{lcm lcm}{{T T}_{i i,, k k}^{non non - - GBR GBR}}$

[5][5]

则non-GBR用户k实际可以分得的资源数为Then the number of resources that non-GBR user k can actually get is

${ρ ρ}_{i i,, k k}^{non non - - GBR GBR} = = \frac{Virtual virtual__{ρ ρ}_{i i,, k k}}{{Σ Σ}_{k k = = 11}^{{N N}_{i i}} Virtual virtual__{ρ ρ}_{i i,, k k}} * * ((S S - - {ρ ρ}_{i i}^{GBR GBR}))$

[6][6]

其中N_i是小区i中所有的non-GBR用户，S是小区总资源。Where N _i is all non-GBR users in cell i, and S is the total resource of the cell.

则小区i所有non-GBR用户的实际可得速率可由其任一用户k按下式得到Then the actual available rate of all non-GBR users in cell i can be obtained by any user k in the cell i as follows

${V V}_{i i}^{non non - - GBR GBR} = = {ρ ρ}_{i i,, k k}^{non non - - GBR GBR} * * {T T}_{i i,, k k}^{non non - - GBR GBR}$

[7][7]

若小区i内所有non-GBR用户的实际可得速率超过其最大需求速率，则将小区i内所有non-GBR用户的实际可得速率设置为其最大需求速率。If the actual available rates of all non-GBR users in cell i exceed their maximum required rates, set the actual available rates of all non-GBR users in cell i to their maximum required rates.

对于网络中任一小区i，定义其所有non-GBR用户占用的资源数：For any cell i in the network, define the number of resources occupied by all its non-GBR users:

${ρ ρ}_{i i}^{non non - - GBR GBR} = = {Σ Σ}_{k k = = 11}^{{N N}_{i i}} {ρ ρ}_{i i,, k k}^{non non - - GBR GBR} - - - - - - [[88]]$

即小区i分给其内所有non-GBR用户的总资源数。That is, the total number of resources allocated by cell i to all non-GBR users in it.

假设小区i中的GBR用户k^·因为负载均衡而切换到目标小区j，为了保证负载均衡切换的有效性，应满足以下条件：Assuming that GBR user ^k in cell i is handed over to target cell j due to load balancing, in order to ensure the effectiveness of load balancing handover, the following conditions should be met:

条件一即用户k^·接收到的备选小区的信干噪比不低于由运行商根据自己要求设定的用户接入门限Ac_threshold。条件二即用户k^·切换到任一备选小区后在该小区中占用的资源数加上该小区内原有的所有GBR用户占用的资源数之和不高于该小区的GBR用户负载均衡切换门限ψ^GBR。The first condition is that user k ^· The SINR of the candidate cell received is not lower than the user access threshold Ac_threshold set by the operator according to its own requirements. The second condition is user ^k After switching to any candidate cell, the sum of the number of resources occupied by the cell plus the number of resources occupied by all original GBR users in the cell is not higher than the GBR user load balancing switching threshold of the cell ψ ^GBR .

仅当上述条件均满足时，该用户才能进行负载均衡的切换。Only when the above conditions are met, the user can switch the load balancing.

假设小区i中的non-GBR用户k^·因为负载均衡而切换到目标小区j，为了保证负载均衡切换的有效性，应满足以下条件：Assuming that non-GBR user ^k in cell i is handed over to target cell j due to load balancing, in order to ensure the effectiveness of load balancing handover, the following conditions should be met:

条件三： ${SINR}_{{j, k}^{\cdot}} &GreaterEqual; Ac_threshold$ Condition three: ${SINR}_{{j, k}^{\cdot}} &Greater Equal; Ac_threshold$

条件四： $V_{{i, k}^{\cdot}}^{non - GBR} < V_{{j, k}^{\cdot}}^{non - GBR}$ Condition four: $V_{{i, k}^{&Center Dot;}}^{non - GBR} < V_{{j, k}^{&Center Dot;}}^{non - GBR}$

条件三即用户k^·到备选小区的信干噪比不低于由运行商根据自己要求设定的用户接入门限Ac_threshold。条件四即用户k^·在备选小区中的实际可得速率要大于在源小区中的实际可得速率，且用户k^·在备选小区中获得的实际可得速率应由备选小区的剩余资源计算得出，即备选小区内已有的non-GBR用户自身实际可得速率不下降。The third condition is that user k ^· The signal to interference and noise ratio to the candidate cell is not lower than the user access threshold Ac_threshold set by the operator according to its own requirements. The fourth condition is that the user ^k 's actual available rate in the candidate cell is greater than the actual available rate in the source cell, and user k ^'s actual available rate in the candidate cell should be determined by the remaining rate of the candidate cell. The resources are calculated, that is, the actual available rate of the existing non-GBR users in the candidate cell does not decrease.

其中用户在源小区的实际可得速率

可由[1]～[7]得到。The actual available rate of the user in the source cell

It can be obtained from [1]～[7].

用户k^·在目标小区j中的实际可得速率

可按下述方式求得：User k ^· Actual available rate in target cell j

It can be obtained as follows:

${V V}_{j j {,, k k}^{\cdot &Center Dot;}}^{non non - - GBR GBR} = = B B * * {log log}_{22} ((11 + + {SINR SINR}_{j j {,, k k}^{\cdot &Center Dot;}})) * * ((S S - - {ρ ρ}_{j j}^{GBR GBR} - - {ρ ρ}_{j j}^{non non - - GBR GBR}))$

[9][9]

若小区j内所有non-GBR用户的实际可得速率超过其最大需求速率，则将小区j内所有non-GBR用户的实际可得速率设置为其最大需求速率。注意切换用户k^·在目标小区j内的实际可得速率只取决于目标小区j中的剩余资源数，从而目标小区j内已有的non-GBR用户自身实际可得速率不下降。If the actual available rates of all non-GBR users in cell j exceed their maximum required rates, then set the actual available rates of all non-GBR users in cell j to their maximum required rates. Pay attention to switching user k ^· The actual available rate in the target cell j only depends on the remaining resources in the target cell j, so the actual available rate of the existing non-GBR users in the target cell j does not decrease.

有益效果：由于考虑到不同业务等级的用户，在进行负载均衡切换时，可以优先保证高等级GBR用户的保障比特率要求，其次提高低等级non-GBR用户实际可得速率，并且分别优先选择占用系统资源数最多的用户来进行负载均衡的切换，因此，大大降低了切换次数，从而降低了系统的信令开销，并降低了GBR用户接入阻塞率，提高了系统资源利用率和系统总吞吐量。Beneficial effects: Considering users of different service levels, when performing load balancing switching, the guaranteed bit rate requirements of high-level GBR users can be guaranteed first, and secondly, the actual available rate of low-level non-GBR users can be increased, and priority is given to occupying The user with the largest number of system resources performs load balancing switching, thus greatly reducing the number of switching times, thereby reducing the signaling overhead of the system, reducing the access blocking rate of GBR users, and improving the utilization rate of system resources and the total throughput of the system quantity.

具体实施方式 Detailed ways

本发明提出了一种移动通信系统中分类保证不同等级用户服务质量要求的负载均衡优化方法。The invention proposes a load balancing optimization method for classifying and guaranteeing service quality requirements of users of different levels in a mobile communication system.

以LTE系统为例来给出一种实施例：Taking the LTE system as an example to give an embodiment:

首先定义以下变量：First define the following variables:

${ρ ρ}_{i i,, k k}^{GBR GBR} = = \frac{{θ θ}_{k k}}{B B * * {log log}_{22} ((11 - - {SINR SINR}_{i i,, k k}))} - - - - - - [[11]]$

Number of resources allocated to GBR user k by cell i.

[3][3]

${T T}_{i i,, k k}^{non non - - GBR GBR} = = B B * * {lon the lon}_{22} ((11 + + {SINR SINR}_{i i,, k k}))$

[4][4]

${Virtual virtual__ρ ρ}_{i i,, k k} = = \frac{lcm lcm}{{T T}_{i i,, k k}^{non non - - GBR GBR}}$

[5][5]

[6][6]

[7][7]

若小区i内所有non-GBR用户的实际可得速率超过其最大需求速率，则将小区i内所有non-GBR用户的实际可得速率设置为其最大需求速率。If the actual available rates of all non-GBR users in cell i exceed their maximum required rates, then set the actual available rates of all non-GBR users in cell i to their maximum required rates.

其中用户在源小区的实际可得速率可由[1]～[7]得到。The actual available rate of the user in the source cell It can be obtained from [1]～[7].

用户k^·在目标小区j中的实际可得速率

可按下述方式求得：User k ^· Actual available rate in target cell j

It can be obtained as follows:

[9][9]

第一步，在一个负载均衡周期内，每个小区对于本小区内所有GBR用户，按照最大化最小(max-min)公平的方式分配系统资源，严格保证所有该类用户的保障比特率要求；对于所有最大需求速率要求的non-GBR用户，以速率公平的方式分配剩余的系统资源；In the first step, within a load balancing period, each cell allocates system resources in a max-min fair way to all GBR users in the cell, and strictly guarantees the guaranteed bit rate requirements of all such users; For all non-GBR users with maximum demand rate requirements, allocate the remaining system resources in a rate-fair manner;

第二步，各eNB(E-UTRAN NodeB)通过X2接口，交换各自小区的由公式[2]定义的所有GBR用户占用的资源数和由公式[4]定义的所有non-GBR用户占用的资源数信息；In the second step, each eNB (E-UTRAN NodeB) exchanges the number of resources occupied by all GBR users defined by formula [2] and the resources occupied by all non-GBR users defined by formula [4] in their respective cells through the X2 interface number information;

第三步，对任一小区i，根据公式[2]计算其内所有GBR用户占用的资源数ρ_i ^GBR。若其内所有GBR用户占用的资源数ρ_i ^GBR超过给定的由运行商根据自己的要求设定的对于GBR用户的负载均衡的切换门限ψ^GBR，则需进行GBR用户负载均衡切换，后转入第四步。若其内所有GBR用户占用的资源数ρ_i ^GBR小于门限ψ^GBR，则直接转入第五步；In the third step, for any cell i, calculate the number of resources ρ _i ^GBR occupied by all GBR users in it according to the formula [2]. If the number of resources ρ _i ^GBR occupied by all GBR users in it exceeds the given switching threshold ψ ^GBR for GBR user load balancing set by the operator according to its own requirements, it is necessary to perform GBR user load balancing switching, and then turn to Go to the fourth step. If the number of resources ρ _i ^GBR occupied by all GBR users is less than the threshold ψ ^GBR , then go directly to the fifth step;

第四步，在当前的负载均衡周期内，重复第三步，直到小区i内所有GBR用户占用的资源数低于GBR用户负载均衡切换门限ψ^GBR或没有满足切换条件的边缘用户，则小区i停止GBR用户负载均衡切换；The fourth step is to repeat the third step in the current load balancing period until the number of resources occupied by all GBR users in cell i is lower than the GBR user load balancing switching threshold ^ψGBR or there are no edge users that meet the switching conditions, then cell i Stop GBR user load balancing switching;

第六步，对任一小区i内所有non-GBR用户根据公式[1]～[7]计算其实际可得速率

。若其实际可得速率

没有达到用户需求的最大速率，则需进行non-GBR用户负载均衡切换，后转入第七步。若其实际可得速率达到用户需求的最大速率，则直接转入第八步；The sixth step is to calculate the actual available rate of all non-GBR users in any cell i according to the formulas [1]~[7]

. if its actual attainable rate

If the maximum rate required by the user is not reached, non-GBR user load balancing switching is required, and then turn to the seventh step. if its actual attainable rate When the maximum rate required by the user is reached, go directly to the eighth step;

第七步，在当前的负载均衡周期内，重复第六步，直到小区i中所有non-GBR用户均达到他们的最大需求速率或没有满足切换条件的边缘用户，则小区i停止non-GBR用户负载均衡切换；The seventh step, in the current load balancing period, repeat the sixth step until all non-GBR users in cell i reach their maximum demand rate or there are no edge users that meet the switching conditions, then cell i stops non-GBR users load balancing switching;

第八步，在当前负载均衡周期内，对于所有小区完成第六，七两步，停止全网内non-GBR用户负载均衡切换，算法结束。The eighth step, in the current load balancing cycle, complete the sixth and seventh steps for all cells, stop the non-GBR user load balancing switching in the whole network, and the algorithm ends.

Claims

1. a kind of load balancing optimization method that classification guarantees the quality of service requirements of users of different grades, it is characterized in that the method comprises the steps:

In the first step, within a load balancing cycle, each cell allocates system resources according to its corresponding guaranteed bit rate and maximum demand rate requirements for users of different levels in the cell;

In the second step, each base station exchanges its load information with its adjacent base stations. The load information includes the number of resources ρ ^GBR occupied by all GBR users with guaranteed bit rate in the cell and the number of resources ρ ^non occupied by non-GBR users without guaranteed bit rate. ^-GBR ;

In the third step, for any cell i, if the number of resources ρ _i ^GBR occupied by all GBR users in it exceeds the given load balancing switching threshold ψ ^GBR for GBR users set by the operator according to its own requirements, then need Perform load-balancing handover of GBR users; for all GBR users who are at the edge of cell i and can be handed over to adjacent cells, select the user ^k that occupies the most resources in this cell according to the following formula as the preferred handover user

^k ＝arg maxρ _i,k ^GBR

Among them, ρ _i,k ^GBR is the number of resources allocated by cell i to GBR user k ^. For the preferred handover user k , select all adjacent cells that meet the following two conditions as candidate cells:

Condition one:

Condition two:

Among them, Ac_threshold is the user access threshold set by the operator according to its own requirements.

It is the preferred switching user ^k The SINR in the candidate cell j; condition one is user ^k The SINR in the candidate cell is not lower than the user access threshold set by the operator according to its own requirements Ac_threshold; ρ _j ^GBR is the number of resources occupied by all GBR users in the candidate cell j, is the preferred switching user k ^. The number of resources occupied by the candidate cell j to meet its guaranteed bit rate requirements; the second condition is user k ^. After switching to any candidate cell, the number of resources occupied in this cell is the same as The sum of the number of resources occupied by all the original GBR users in the cell is not higher than the GBR user load balancing switching threshold ^ψGBR in this cell;

Among all the candidate cells that meet the above conditions, select the cell j with the lowest number of resources occupied by all GBR users after the handover is completed according to the following formula ^as the target cell

Then user ^k is handed over from source cell i to target cell j ^;

The fourth step is to repeat the third step in the current load balancing period until the number of resources ρ _i ^GBR occupied by all GBR users in the cell i is lower than the GBR user load balancing switching threshold ψ ^GBR or there are no edge users that meet the switching conditions; That is, if all the remaining edge GBR users cannot satisfy condition 1 and condition 2 at the same time, cell i stops GBR user load balancing switching;

The fifth step is to complete the third and fourth steps for all cells in the current load balancing period, and stop the load balancing switching of GBR users in the entire network;

Step 6: For any cell i, if the actual available rate of the non-GBR user does not reach the maximum rate required by the user, load balancing switching of the non-GBR user is required; For the non-GBR user k in the cell, select the non-GBR user k that occupies the most resources in the cell according to the following formula ^as the preferred handover user

^k ＝arg maxρ _i,k ^non-GBR

Among them, ρ _i,k ^non-GBR is the number of resources allocated by cell i to non-GBR user k. For the preferred handover user ^k , select all adjacent cells that meet the following two conditions as candidate cells:

Condition three:

Condition four:

The third condition is the preferred handover user k ^. The signal-to-interference-noise ratio in the candidate cell is not lower than the user access threshold Ac_threshold set by the operator according to its own requirements;

is user ^k The actual available rate in the source cell, User ^k is the actual available rate in the candidate cell j, and the fourth condition is that the user ^k 's actual available rate in the candidate cell is greater than the actual available rate in the source cell;

Among all the candidate cells that meet the above conditions, select the cell j with the lowest total load after the handover is completed according to the following formula ^as the target cell

Where ρ _j ^GBR is the number of resources occupied by all existing GBR users in candidate cell j, ρ _j ^non-GBR is the number of resources occupied by all existing non-GBR users in candidate cell j,

is the number of resources occupied by non-GBR user ^k in candidate cell j;

Then user ^k is handed over from source cell i to target cell j ^;

The seventh step, in the current load balancing period, repeat the sixth step until all non-GBR users in cell i reach their maximum demand rate requirements or there are no edge users that meet the switching conditions, that is, all remaining edge non-GBR users If the user cannot satisfy the conditions 3 and 4 at the same time, the cell i stops the non-GBR user load balancing switching;

The eighth step, in the current load balancing cycle, complete the sixth and seventh steps for all cells, stop the non-GBR user load balancing switching in the whole network, and end. the

2. classification according to claim 1 guarantees the load balancing optimization method that different grades of user service quality require, it is characterized in that described preferred switching user k ^and corresponding target community j ^, preferred switching when GBR user load balancing switches Selection of user k ^and corresponding target cell ^j :

^k ＝arg maxρ _i,k ^GBR

For non-GBR user load balancing handover, the choice of the preferred handover user k ^and the corresponding target cell ^j :

^k ＝arg maxρ _i,k ^non-GBR

The method is: first define the following variables:

Number of resources occupied by GBR user k in a certain cell i

Where θ _k is the guaranteed bit rate requirement of GBR user k, B is the equivalent bandwidth of a minimum resource unit, and SINR _i,k is the signal-to-interference-noise ratio of user k in cell i;

For any cell i in the network, define the number of resources occupied by all GBR users in it:

That is, the total number of resources allocated to all GBR users in cell i; where G _i is all GBR users in cell i;

The number of resources allocated to GBR user k for cell i;

The number of resources occupied by non-GBR user k in a certain cell i

Where B is the equivalent bandwidth of a minimum resource unit, SINR _i,k is the signal-to-interference-noise ratio of user k in cell i,

For each non-GBR user k in cell i, the signal-to-interference-noise ratio SINR _i,k received in cell i can be measured, so that its actual available rate in a minimum resource unit can be obtained

Find the actual available rate of all non-GBR users in cell i on a minimum resource unit

Then the number of resources that non-GBR user k can actually share is

Where N _i is all non-GBR users in cell i, S is the total resource of the cell;

Then the actual available rate of all non-GBR users in cell i can be obtained by any user k in the cell i as follows

If the actual available rate of all non-GBR users in cell i exceeds its maximum required rate, set the actual available rate of all non-GBR users in cell i to its maximum required rate;

For any cell i in the network, define the number of resources occupied by all its non-GBR users:

That is, the total number of resources allocated by cell i to all non-GBR users in it;

Assuming that GBR user ^k in cell i is handed over to target cell j due to load balancing, in order to ensure the effectiveness of load balancing handover, the following conditions should be met:

Condition one:

Condition two:

The first condition is user k ^. The signal-to-interference and noise ratio received by the candidate cell is not lower than the user access threshold Ac_threshold set by the operator according to its own requirements; the second condition is user k ^. After switching to any candidate cell The resource number occupied in this cell plus the resource number occupied by all original GBR users in this cell is not higher than the GBR user load balancing switching threshold ^ψGBR in this cell;

Only when the above conditions are met, the user can switch the load balancing;

Assuming that non-GBR user ^k in cell i is handed over to target cell j due to load balancing, in order to ensure the effectiveness of load balancing handover, the following conditions should be met:

Condition three:

Condition four:

The third condition is user k ^. The signal-to-interference and noise ratio to the candidate cell is not lower than the user access threshold Ac_threshold set by the operator according to its own requirements. The fourth condition is user k ^. The actual available rate in the candidate cell must be is greater than the actual available rate in the source cell, and user ^k The actual available rate in the candidate cell should be calculated from the remaining resources of the candidate cell, that is, the existing non-GBR users in the candidate cell The actual attainable rate does not decrease,

The actual available rate of the user in the source cell It can be obtained from [1]～[7],

User k ^· Actual available rate in target cell j It can be obtained as follows:

If the actual available rate of all non-GBR users in cell j exceeds their maximum required rate, set the actual available rate of all non-GBR users in cell j to their maximum required rate; pay attention to switching user ^k in the target cell The actual available rate in j only depends on the number of remaining resources in the target cell j, so the actual available rate of the existing non-GBR users in the target cell j does not decrease;

Only when the above conditions are met, the user can switch the load balancing. the