CN102244904B - A channel reservation switching control method based on service priority - Google Patents

Abstract

The invention relates to a channel reservation switching control method based on service priority. The method comprises the following steps: a current cell acquires the position information of users regularly; when the users move to the border of the current cell, the current cell notifies a neighboring cell to be switched to; the neighboring cell sets different reserved channels for different users on the basis of service priority according to the occupation condition of channels of the neighboring cell; and when the reserved channels are not enough, urgent users occupy channels reserved for users with low priority in a complete occupation way, and the users with low priority enter a queuing line and wait for scheduling. By utilizing the method disclosed by the invention, the switching failure rate of the users can be reduced obviously, the switching performance of the urgent users can be guaranteed, and the requirements of urgent communication tasks can be met.

Description

A channel reservation switching control method based on service priority

technical field

The invention relates to a service priority-based channel reservation switching control method in an air-space network, which dynamically reserves different channel numbers for different priority services and allows high priority services to preempt low priority service channels. The invention is mainly used to reduce the switching failure rate, ensure the connection rate of new call users, and ensure the switching performance of emergency users, and belongs to the technical field of wireless networks.

Background technique

The aerospace information network is an intelligent system organically composed of various types of satellite systems in different orbits, near-space platforms, aircraft and ground-level equipment in accordance with the principle of maximum and effective comprehensive utilization of information resources. , Tian's integrated network system. Handover control method is one of the key technologies of aerospace network resource management. In handover control, the first thing to decide is whether to handover and when it should be handed over; secondly, which base station should be handed over to and how the handover process should be carried out. How to reduce the failure rate of handover and ensure the connection rate of new call users and the handover performance of emergency users is the focus of handover control method research.

Typical control strategies for air-space network handover mainly include: no priority strategy, handover queuing strategy and channel reservation strategy.

1. In the non-priority strategy, when the handover call and the original call apply for an idle channel at the same time, they have the same possibility of obtaining channel service. When all the channels of the cell are in a busy state, neither the original call nor the handover call can obtain the channel, and the handover failure rate of this strategy is relatively high.

2. Queuing handover requests is an optimization method to effectively reduce the failure rate of handover calls. The core idea of switching queuing strategy is to treat new users and switching users separately. For a new user, if the base station does not have enough idle channels, the access is rejected; for a handover user, if the channel resource of the base station can meet its QoS requirements, the request is accepted immediately, otherwise the request is sent to the buffer area to wait in line, and Scheduled on a first-come, first-served basis. If the queue buffer area is full, the access of the switching user is rejected. The handover queuing strategy effectively reduces the handover call failure rate, but when the cell is busy and there are many handover requests, the handover call failure rate will become relatively high.

3. The channel reservation strategy is to reserve a part of channels for switching calls, even when the arrival rate of new calls is very high, the channels are reserved for switching calls. When a user enters an adjacent cell, the reserved channel is allocated to the user, and the channels reserved by other cells are released at the same time, and the channel is reserved for the next possible switch of the user in the new adjacent cell. This strategy can reduce the handover failure rate to a certain extent, but it also increases the blocking rate of new calls.

Contents of the invention

The object of the present invention is to propose a handover control method for an aerospace network, which can reduce the handover failure rate of users, ensure the connection rate of new calling users, and ensure the handover performance of emergency users at the same time. the

The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a method for controlling channel reservation switching based on service priority, comprising the following steps:

Step 1. According to the special situation, divide the priority of users and services. Users are divided into emergency users and ordinary users; services are divided into data services, video streaming services and call voice services. Data services have the highest priority and video streaming services have priority The call voice service has the lowest priority;

Step 2, for users in the network, regularly obtain information such as their speed and coordinates, and calculate the time when they arrive at the cell boundary;

Step 3, for a user who is about to move to an adjacent cell, notify the base station controller of the adjacent cell of the user information, and prepare for handover;

Step 4, each cell base station sets a busy/idle state and shares the state information. According to the busy and idle status of adjacent cells, set different numbers of reserved channels for emergency and ordinary users;

Step 5: Adjacent cells inquire about channel usage and assign channels to users or preempt channels for low-priority users according to user service levels;

Step 6: After the user handover is completed, the channel resources of the original cell are released.

On the basis of the above technical solutions, the present invention can also be improved as follows.

In step 4, different bandwidths are dynamically reserved for different users. The bandwidth reserved for common users is part of the bandwidth reserved for emergency users.

According to the priorities of users and services and the usage of cell channels, the processing methods of adjacent cells for the received handover requests are as follows:

If the free channel of the cell can meet the channel needs of the handover user, the channel is directly allocated to the handover user in a first-come-first-served manner;

If the cell is in a busy state and the idle channel cannot meet the channel requirements of the switching user, different responses will be made according to the level of the user and the service. If it is an emergency user, the reserved channel will be assigned to it. When the reserved channel still cannot meet the needs of switching users, the low-priority services of other users will be preempted in a completely preemptive manner; if it is an ordinary user, the reserved channel will be reserved When the channel is greater than a certain value, a reserved channel is allocated for it, otherwise, it negotiates with other users, and uses a partial preemption method to preempt the channels of other users' low-priority services.

The method of the invention proposes an air-space network switching control method based on service classification, channel reservation and preemption. By using the method proposed by the present invention, different channels can be reserved for different users according to the busy conditions of the cell, and high-priority services are allowed to preempt low-priority service channels, which can reduce the handover failure rate of users while ensuring new The call completion rate ensures the switching performance of emergency users.

Description of drawings

Fig. 1 is the process of a traditional control method for channel reservation switching in an air-space network.

Fig. 2 is an improved air-space network handover control method.

Fig. 3 is the relationship between channels of the improved air-space network handover control method.

Fig. 4 is a schematic flow chart of the present invention.

Detailed ways

The principles and features of the present invention are described below in conjunction with the accompanying drawings, and the examples given are only used to explain the present invention, and are not intended to limit the scope of the present invention.

Figure 1 shows the process of the traditional air-space network channel reservation handover control method. After receiving the handover request, the base station controller of the cell first judges whether it has enough free channels. If there are enough channels, it is allocated to the handover user. Success; if not, check whether there are enough reserved channels, if there is, the switch is successful, otherwise wait in line. Fig. 2 is to use the improved method that the present invention proposes. Comparing the two, it can be found that in Figure 2, the functions of setting reserved channels, judging user services, and selecting switching modes are mainly added.

The specific description of several new functions is given below.

和

分别为： Set reserved channels: according to the busy status of the cell, set different reserved channels for emergency and ordinary users. The number of new channels reserved by the cell for emergency users and ordinary users

and

They are:

                                      (1)

(1)

                              (2)

(2)

分别表示符合

的紧急用户数和普通用户数，

和

分别为该小区原来为紧急用户和普通用户预留的信道数，

为除去预留信道以外的空闲信道数，

为小区总的信道数。 in, and

Respectively indicate conformity

The number of emergency users and the number of ordinary users,

and

Respectively, the number of channels originally reserved for emergency users and ordinary users in the cell,

is the number of free channels excluding reserved channels,

is the total number of channels in the cell.

User service identification: Users are divided into emergency users and ordinary users according to needs, and services are divided into data services, video streaming services, and voice streaming services.

，用户请求的信道数为

，为普通用户预留的信道中的空闲信道为

，为紧急用户预留的信道中的空闲信道为

。 Select the switching mode: make different switching responses according to the types of users and services and the usage of channels. As shown in Figure 3, assume that the number of channels currently available in the cell is C, and the number of occupied channels in the system is

, the number of channels requested by the user is

, the idle channel among the channels reserved for ordinary users is

, the idle channel among the channels reserved for emergency users is

.

，则呼叫可以被接纳，否则呼叫被阻塞。 For newly generated calls, they are connected sequentially according to the priorities of emergency services and ordinary services. If the number of channels requested by the call

, the call can be admitted, otherwise the call is blocked.

时，切换呼叫可以被接纳，并先占用信道

，若其信道不够则再占用部分

的信道；否则小区通过对当前正在服务业务的协商，通过降低切换请求申请的带宽资源以及正在服务业务的带宽资源的方式进行切换；如果协商失败，则该切换请求将排队等待；在等待一定时间后若还未能获得信道，则该呼叫被中断。 For ordinary users to switch calls, when switching the number of channels requested by the call

When , the handover call can be accepted and the channel will be occupied first

, if the channel is not enough, then occupy part of

Otherwise, the cell will switch over by reducing the bandwidth resources applied for by the handover request and the bandwidth resources of the service being served through negotiation on the currently serving business; if the negotiation fails, the handover request will wait in line; waiting for a certain period of time Afterwards, if the channel cannot be obtained, the call is interrupted.

时，呼叫可以被正常接纳，信道占用规则同普通业务切换呼叫；否则采用完全抢占方式抢占低优先级业务信道,被抢占的业务进入排队队列等待。 For emergency user handover calls, all channel resources in neighboring cells can be used ,when

, the call can be accepted normally, and the channel occupancy rule is the same as that of ordinary services to switch calls; otherwise, the low-priority service channel is preempted by the full preemption method, and the preempted service enters the queuing queue to wait.

The method of the present invention utilizes the above-mentioned functional modules to dynamically reserve unused channel numbers for different users, and at the same time responds by allocating idle channels, allocating reserved channels, and preempting channels according to the levels of users and services and the busy or idle conditions of channels in the cell. As shown in Fig. 4, the concrete flow process that the inventive method comprises is:

1 The user accesses a cell, and the cell regularly obtains the user's location information;

2. When the user moves to the edge of the cell, the base station controller of the cell sends a handover request to the adjacent cell to which the user will switch;

3 Neighboring cells update the switching channels reserved for ordinary users and emergency users according to the busyness and idleness of their own channels;

4 If the adjacent cell has enough free channels, it will be allocated to the handover user, and the user parameters will be matched, and the handover will be successful;

5. If there are not enough free channels in the adjacent cell, the corresponding reserved channel will be allocated to the user;

6 If the reserved channel cannot meet the user's needs, if it is an emergency user switching, then the user can preempt other users' low-priority services; if it is an ordinary user switching, then the user negotiates with other low-priority services, and applies If the negotiation fails, the switching request will be queued; if the channel cannot be obtained after waiting for a certain period of time, the call will be interrupted;

7 The whole process is over.

The following is a specific embodiment of the present invention. A user starts to access cell A, and according to the user's movement, it will be handed over to the neighboring cell B. Referring to Figure 4, the working engineering is as follows:

，小区A的基站控制器定时获取A的位置信息； 1. When a user accesses cell A, the number of occupied channels is

, the base station controller of cell A regularly acquires the location information of A;

时，小区A的基站控制器向相邻小区B的基站控制器发送切换请求，小区B做好切换准备； 2. The base station controller of cell A calculates the time to reach the cell boundary according to the user's location information, and when it is less than a certain threshold

, the base station controller of cell A sends a handover request to the base station controller of adjacent cell B, and cell B is ready for handover;

； 3. After receiving the handover request, the base station controller of cell B calculates the channels reserved for emergency users and ordinary users according to the formulas (1) and (2) according to the busy and idle conditions of the channels in the cell and

;

，则为用户分配信道，匹配用户参数，切换成功；否则可能出现5、6、7三种情况，以下进行逐一判断； 4. If the channel available in cell B

, the channel is allocated to the user, the user parameters are matched, and the handover is successful; otherwise, three situations 5, 6, and 7 may occur, and the following judgments are made one by one;

时，新呼叫不能再获得信道，小区B为用户分配预留信道，切换成功； 5. when

When , the new call can no longer obtain the channel, cell B allocates a reserved channel for the user, and the handover is successful;

6. When , if the user is an emergency user, a reserved channel is assigned to the user, and the handover is successful; and the bandwidth resources of the serving business are switched; if the negotiation fails, the switching request will be queued; if the channel cannot be obtained after waiting for a certain period of time, the call will be interrupted;

且

时，若用户为紧急用户，则为用户分配信道并抢占其他低优先级业务的信道资源，匹配用户参数，切换成功，被抢占的低优先级业务进入排队队列等候调度；若用户为普通用户，则切换规则同6； 7. When

and

, if the user is an emergency user, a channel is assigned to the user and channel resources of other low-priority services are preempted, user parameters are matched, the handover is successful, and the preempted low-priority services enter the queuing queue for scheduling; if the user is an ordinary user, The switching rules are the same as 6;

8. The whole process is over.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims (2)

1. A channel reservation switching control method based on service priority is characterized by comprising the following steps:

the method comprises the following steps that firstly, according to special situations, priority division is carried out on users and services, and the users are divided into emergency users and ordinary users; the service is divided into data service, video stream service and calling voice service, the data service has the highest priority, the video stream service has the second priority and the calling voice service has the lowest priority;

and step two, for the users in the network, acquiring information such as speed, coordinates and the like of the users at regular time, and calculating the time t for the users to reach the boundary of the current cell according to the following formula.

Wherein,

in order to arrive at the boundary point coordinates,

is the position coordinate of the user, and v is the moving speed of the user;

step three, for the user moving to the adjacent cell, informing the adjacent cell base station controller of the user information, and making a switching preparation;

step four, each cell base station sets busy-idle state and shares state information, sets different reserved channel numbers for emergency and common users according to the busy-idle state of adjacent cells, and reserves new channel numbers for emergency and common users in the adjacent cells

And

respectively as follows:

wherein,and

respectively indicate current intra-cell coincidence

The number of emergency users and the number of general users,

andrespectively representing the number of channels originally reserved by the adjacent cell for emergency users and normal users,

the number of free channels for the neighboring cell except for the reserved channel,

the total number of channels for the neighboring cells;

step five, the adjacent cell inquires the channel use condition and allocates channels for users or seizes the channels of low priority users according to the grade of user service, different switching strategies are adopted for different users according to the channel use condition of the adjacent cell, and when the current available resource quantity of the adjacent cell is larger than the preset threshold value, the adjacent cell can be switched to the new modeWhen the user is switched, the user acquires a channel in a first-arrival first-service mode; when in use

When the new call can not obtain the channel, the switching user obtains the channel in a first-arrival first-service mode; when in use

Only the emergency user can switch the callObtaining a channel, matching user terminal parameters, registering user information and prompting successful switching;

step six, releasing the channel resources of the original cell after the user switching is finished.

2. The handover control method according to claim 1, wherein the handover control is performed when the handover control is performed

And the common user negotiates with other users in the cell, and occupies channels of low-priority services of other users in a partial occupation mode.

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