KR101007740B1 - Method for call admission control and device thereof - Google Patents

Abstract

The present invention relates to a call admission control method and apparatus thereof.

According to the present invention, the call admission control method is to determine whether to allow a fast uplink packet access call in consideration of the total traffic usage. According to the call admission control method, if a high speed uplink packet access call cannot be accepted, a fallback of the high speed uplink packet access call to date, wherein the fallback is a procedure for rejecting an incoming call and inducing a reflow of a new call. The fallback type is determined based on the statistics. And performing a fallback procedure of the fast uplink packet access call corresponding to the determined fallback type.

In this way, by identifying the fallback pattern that can utilize the available resources through the rate of fallback to determine the optimal fallback procedure, it is possible to simplify the overload avoidance and fallback procedure in the network to ensure the fallback success rate and the subscriber QoS.

Fallback, Call Admission Control (CAC), High Speed Uplink Packet Access (HSUPA), High Speed Downlink Packet Access (HSDPA), Dedicated Channel (DCH)

Description

Method for call admission control and device

The present invention relates to a call admission control method and apparatus thereof. More specifically, the present invention relates to a call admission control method and apparatus for determining whether to allow a fast uplink packet access call in consideration of total traffic usage in a WCDMA (Wideband Code Division Multiple Access) network.

Since radio resources are limited, in order to guarantee the quality of service to the mobile terminal, the number of calls to be connected must be limited. That is, it is necessary to determine whether to allow a new incoming call in consideration of the current resource use situation, and this decision process is called call admission control (hereinafter referred to as 'CAC'). According to this call admission control scheme, the radio capacity threshold is fixed and the call is accepted if the threshold is not exceeded in consideration of the capacity that the requested call will occupy.

For example, in the WPC network, when there is a shortage of High Speed Uplink Packet Access (hereinafter referred to as HSUPA) resources, the CAC operates when a specific threshold set by the operator is reached. Then, the network does not allow any further high speed uplink packet access call setup, so a dedicated channel (hereinafter referred to as 'DCH') or a high speed downlink packet access for an incoming call may be used. (Hereinafter referred to as 'HSDPA') to fall back.

In this case, the mobile terminal attempting the first HSUPA call needs to fallback, which can increase the congestion of wired and wireless resources. In addition, there is a high probability of guaranteeing and disconnecting a quality of service (hereinafter referred to as 'QoS') during the fallback procedure.

On the other hand, there are five cases of falling back when the HSUPA call is attempted as follows.

1) Establish or release a Radio Access Bear (RAB) assignment

2) IU RELEASE

3) Primary Cell Change

4) Inter-RNC UE with Hard Handover

5) Hard Handover Alarm

Above, 1) and 2) are related to RabAssignment and 3), 4) and 5) are related to mobility of the mobile terminal.

In addition, there are two types of fallbacks, one of which is a mono type (MonoStep), in which a HSUPA call falls back to a DCH call. The other type is a multi-step (MultiStep), in which the HSUPA call first falls back to the HSDPA call, and then falls back to the DCH call if the HSDPA call fallback fails.

In this case, in the related art, the operator sets the fallback type in advance and operates it fixedly. Therefore, when the multi-type is defined, even if the HSDPA resources are overloaded, the procedure to fall back to HSUPA → HSDPA → DCH must be followed, thus preventing the system from excessively occupying resources and falling back. .

An object of the present invention is to provide a call admission control method and apparatus for optimizing a fallback procedure of a fast uplink packet access call.

The call admission control method according to another feature of the present invention to achieve the problem as described above,

A call admission control method for determining whether to allow a fast uplink packet access call in consideration of total traffic usage, the method comprising: (a) if the fast uplink packet access call cannot be accepted, Fallback, where the fallback is a procedure for rejecting an incoming call and inducing a reflow of a new call—determining the fallback type based on statistics; And (b) performing a fallback procedure of the fast uplink packet access call corresponding to the fallback type determined in step (a).

In addition, the call admission control device according to another feature of the present invention,

A call admission control device for determining whether to allow a fast uplink packet access call in consideration of the total traffic usage, wherein the fast uplink packet access up to now is not available when a fast uplink packet access call received from a mobile terminal cannot be accepted. Fallback of a call, wherein the fallback is a procedure for rejecting an incoming call and inducing a reflow of a new call-a call admission controller for determining a fallback type based on statistics; And a setting unit configured to perform a fallback procedure of a fast uplink packet access call corresponding to the fallback type with the mobile terminal.

According to the present invention, an optimal fallback procedure can be automatically performed by determining an optimal fallback procedure according to traffic conditions through calculation of a fallback ratio per unit time. In addition, by controlling the fallback procedure according to the fallback ratio of the unit time statistics, omitting the fallback procedure from the HSDPA to the DCH can reduce the system load and fallback time, and increase the subscriber QoS and fallback success rate.

In addition, by determining the fallback pattern by identifying the fallback pattern that can utilize the available resources through the ratio of fallback, it is possible to guarantee the fallback success rate and subscriber QoS as much as possible by simplifying the overload avoidance and fallback procedure in the network.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise. In addition, the term "… unit" described in the specification means a unit for processing at least one function or operation, which may be implemented in hardware or software or a combination of hardware and software.

Now, a call admission control method and apparatus thereof according to an embodiment of the present invention will be described in detail with reference to the drawings.

Prior to the description with reference to the drawings, in this specification, High Speed Uplink Packet Access (hereinafter referred to as 'HSUPA') is a 3GPP Release 6 technology that was first approved in June 2004 and up to 5.76 in uplink. Provide Mbps. In addition, High Speed Downlink Packet Access (hereinafter referred to as 'HSDPA') is a 3GPP Release 5 technology that was first approved in March 2002 and dramatically improved wireless network performance through high speed scheduling. Provides up to 14.4 Mbps on the link. Also, a dedicated channel (hereinafter referred to as 'DCH') is an uplink dedicated channel. Next-generation wireless communication systems provide these HSUPAs and HSDPAs to provide improved data rates across the air interface, supporting Internet access and multimedia type applications.

1 is a block diagram showing the configuration of a call admission control device according to an embodiment of the present invention.

As shown in FIG. 1, the call admission control apparatus 200 includes a receiver 220, a call admission controller 240, and a setup unit 260.

The receiver 220 receives a High Speed Uplink Packet Access (hereinafter referred to as "HSUPA") call from the mobile terminal 100. The receiver 220 determines whether the call admission controller 240 is driven by monitoring whether the current radio resource usage, that is, the total traffic usage reaches a preset threshold. When the total traffic usage reaches a preset threshold, the receiver 220 rejects the received HSUPA call setup and drives the call admission controller 240. On the other hand, when the total traffic usage does not reach the preset threshold, the receiver 220 transmits the received HSUPA call to the setter 260 to instruct the call setup.

The call acceptance controller 240 operates when the receiver 220 rejects the HSUPA call setup. The call admission controller 240 determines a fallback type based on the fallback statistics of the HSUPA call. Here, the fallback is a procedure for rejecting an incoming call and inducing a reflow of a new call. In other words, if the current radio resource is not enough to support the incoming call is switched to another type of call.

The call admission control unit 240 includes a calculation module 242, a fallback type information DB 244, and a determination module 246.

The calculation module 242 calculates a first ratio A falling back from the HSUPA call to the HSDPA call per preset unit time and a second ratio B falling back from the HSDPA call to the DCH call, respectively. The calculation method uses the following equations (1) and (2).

A = first ratio (rate to fall back from HSUPA to HSDPA)

a = number of successful HSUPA Rab establishment among all Rabtypes

b = number of successes when falling back from HSUPA to HSDPA

c = number of failures when falling back from HSUPA to HSDPA

B = second ratio (ratio to fall back from HSUPA to DCH)

d = Number of successful HSUPA Rab establishments in GrantedRab type

e = number of successes when falling back from HSUPA to DCH

f = Failure when falling back from HSUPA → DCH

Here, the calculation module 242 may generate statistics on the fallback call for a preset unit time. That is, the elements (a, b, c, d, e, f) of Equations 1 and 2, which are output for each preset unit time, are collected, and the fallback ratios are substituted by substituting them into Equations 1 and 2. , B). At this time, the preset unit time is adjusted by the operator according to the situation. For example, it can be adjusted in minutes and set to '5 minutes' as the default value.

The fallback type information DB 244 stores fallback type information defined based on the relationship between the first ratio and the second ratio calculated by the calculation module 242. Here, the fallback type information is configured as shown in Table 1 below.

Item type A> B and B≤50% First type (MonoStep) A = B Second type (MultiStep) A <B Second type (MultiStep) A≥90% First type (MonoStep)

As shown in Table 1, the 'item' field defines a relationship between A and B, and the type indicates a fallback type corresponding to each item.

The determination module 246 analyzes the relationship between the first ratio A and the second ratio B calculated by the calculation module 242 with reference to Table 1 to determine the corresponding fallback type. The determining module 246 determines the fallback type for the HSUPA call received from the receiving unit 220 based on the determined fallback type and provides the setting unit 260 to the fallback type.

The setting unit 260 performs a fallback procedure of the HSUPA call corresponding to the fallback type determined by the determination module 246 with the mobile terminal 100. That is, when the fallback type is the first type (MonoStep), the HSUPA call is directly fallback to the DCH call. In addition, when the fallback type is a second type (MultiStep), the HSUPA call is first fallen back to the HSDPA call. Then, if this fallback fails, the HSDPA call falls back to the DCH call.

Then, the sequential operation of the call admission control device having such a configuration will be described.

2 is a flowchart illustrating a series of processes of a call admission control method according to an embodiment of the present invention. At this time, the process will be described through linkage between the components of FIG. 1.

As shown in FIG. 2, the receiver 220 receives a HSUPA radio bearer establishment request from the mobile terminal 100 (S101).

The reception unit 220 determines whether the total traffic usage exceeds a preset threshold (S103) and checks whether there is a capacity for call setup received in step S101.

In this case, when the reception unit 220 determines that the total traffic usage does not exceed the preset threshold in step S103, the setting unit 260 performs the HSUPA radio bearer establishment procedure requested by the mobile terminal 100 in step S101. (S105).

On the other hand, if the reception unit 220 determines that the total traffic usage exceeds the preset threshold in step S103, the call admission control mode according to the driving of the call admission control unit 240 is started (S107).

The determination module 246 determines a fallback type suitable for the fallback pattern of the current HSUPA, which the calculation module 242 has grasped through the calculation referring to Equations 1 and 2 mentioned in the description of FIG. 1 (S109) (S111). . That is, the determination module 246 determines the HSUPA up to the present time determined based on the first ratio A and the second ratio B calculated by the calculation module 242 based on the fallback type information stored in the fallback type information DB 244. Determines the fallback type to which the fallback rate belongs.

The setting unit 260 determines whether the fallback type determined in step S111 is a first type, that is, a monotype or a second type, that is, a multistep (S113).

If the fallback type determined in step S113 is the first type, the setting unit 260 immediately falls back the HSUPA call to the DCH call and proceeds with a radio bearer establishment procedure with the mobile terminal 100 (S115).

If the fallback type determined in step S113 is the second type, the setting unit 260 first falls back the HSUPA call to the HSDPA call and proceeds to establish a radio bearer with the mobile terminal 100 (S117).

The setting unit 260 determines whether the process in step S117 is successful (S119). If successful, terminate all procedures.

If it is not successful, the setting unit 260 performs a radio bearer establishment procedure with the mobile terminal 100 by falling back the HSDPA call to the DCH call (S121).

3 is a flowchart illustrating a fallback type determination process according to an exemplary embodiment of the present invention. In particular, FIG. 2 is a flowchart illustrating steps S109 and S111 of FIG. 2 in detail.

As shown in FIG. 3, the calculation module 242 of FIG. 1 calculates a first ratio A falling back from the HSUPA call to the HSDPA call (S201) when the predetermined unit time arrives (S201). At this time, the calculation is performed using Equation 1. The calculation module 242 calculates a second ratio B falling back from the HSDPA call to the DCH call (S205).

The determination module 246 of FIG. 1 grasps the relationship between the first ratio A and the second ratio B calculated in steps S203 and S205 (S207).

The determination module 246 determines that the fallback type is the first type (mono type) when the A value is greater than B and B is 50% or less or A value is 90% or more (S209).

In addition, when the A value is equal to the B value or the A value is smaller than the B value, the determination module 246 determines the fallback type as the second type (multi-type) (S211).

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

1 is a block diagram showing the configuration of a call admission control device according to an embodiment of the present invention.

2 is a flowchart illustrating a series of processes of a call admission control method according to an embodiment of the present invention.

3 is a flowchart illustrating a fallback type determination process according to an embodiment of the present invention.

Claims (8)

A call admission control method for determining whether to allow a fast uplink packet access call in consideration of overall traffic usage, (a) If the high speed uplink packet access call is unacceptable, fallback of the high speed uplink packet access call to date, wherein the fallback is a procedure for rejecting an incoming call and inducing a reflow of new calls. Determining a fallback type; And (b) performing a fallback procedure of the fast uplink packet access call corresponding to the fallback type determined in step (a); Call admission control method comprising a. The method of claim 1, In step (b), If the fallback type is a first type, falling back the fast uplink packet access call to a dedicated channel access call; And If the fallback type is the second type, the fast uplink packet access call falls back to the fast downlink packet access call, and if the fallback of the fast downlink packet access call fails, the fast uplink packet access call is transferred to the dedicated channel access call. Fallback Step Call admission control method comprising a. The method according to claim 1 or 2, In step (a), (Iii) calculating a fallback ratio of the fast uplink packet access call per preset unit time; And (Ii) determining the fallback type corresponding to the calculated fallback ratio by checking the fallback type information predefined for each fallback ratio; Call admission control method comprising a. The method of claim 3, In the step (iii), When a preset unit time arrives, a first ratio of falling back from a high speed uplink packet access call to a high speed downlink packet access call and a second ratio of falling back to a dedicated channel call from the high speed downlink packet access call are respectively calculated. Call admission control method. The method of claim 4, wherein Step (ii), And selecting a fallback type to which the fallback ratio calculated in step (iii) belongs with reference to the fallback type information defined based on the relationship between the first ratio and the second ratio. A call admission control device for determining whether to allow a fast uplink packet access call in consideration of total traffic usage, If a fast uplink packet access call received from a mobile terminal cannot be accepted, the fallback of a high speed uplink packet access call to date, where a fallback is a procedure for rejecting an incoming call and inducing a reflow of new calls-statistics A call admission controller to determine a fallback type based on the call admission control unit; And A setting unit for performing a fallback procedure of a fast uplink packet access call corresponding to the fallback type with the mobile terminal; Call admission control device comprising a. The method of claim 6, The setting unit, If the fallback type is the first type, the received high speed uplink packet access call falls back to the dedicated channel access call; and if the fallback type is the second type, the received high speed uplink packet access call is connected to the high speed downlink packet connection. And returning the high speed uplink packet access call to the dedicated channel access call when falling back to the call and failing to fall back to the high speed downlink packet access call. The method according to claim 6 or 7, The call acceptance control unit, A calculation module for calculating a first rate of falling back from a high speed uplink packet access call to a high speed downlink packet access call and a second rate of falling back to a dedicated channel call per preset unit time; A fallback type information DB for storing fallback type information defined based on a relationship between the first ratio and the second ratio; And Determination module for determining the fallback type corresponding to the first ratio and the second ratio calculated by the calculation module with reference to the fallback type information DB Call admission control device comprising a.

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