WO2005011319A1

WO2005011319A1 - Call reception control method and call reception control system

Info

Publication number: WO2005011319A1
Application number: PCT/JP2004/009527
Authority: WO
Inventors: Masahiro Ono; Morihisa Momona
Original assignee: Nec Corporation
Priority date: 2003-07-25
Filing date: 2004-07-05
Publication date: 2005-02-03
Also published as: JPWO2005011319A1

Abstract

When receiving a call, it is judged whether a terminal call can be contained in a network resource held by the system (step A01). When it is judged that it can be contained, a terminal having a preferable radio link quality is received at random with a higher priority by using a weight function depending on the radio link quality or the like (step A2). Thus, it is possible to provide a call reception control method and a call reception control system capable of improving the network use efficiency and reducing the block drop ratio.

Description

Specification

Call admission control method and call admission control system

Technical field

[0001] The present invention relates to a call admission control method and a call admission control system for a multi-service in a network, and more particularly to a call for making a call admission judgment based on various conditions based on various conditions in a multi-service in a mobile network. The present invention relates to an admission control method and a call admission control system.

Background art

[0002] Call admission control (CAC) technology considers the network 'operator's current network' resource usage, near-future call probability, and in the case of a mobile network, handover occurrence probability In addition, it determines whether the calling user can use the managed network.

[0003] In recent years, technology for applying this call admission control technology under multi-services in a mobile network has been actively performed. Here, the multi-service means a service of a plurality of QoS (Quality of Service) classes. The superiority of the CAC algorithm is generally determined by the network usage rate and the block rate / drop rate, which is the probability of rejecting a call. In other words, the higher the network usage rate, the better, and the lower the block rate / drop rate, the better.

[0004] Hereinafter, a conventional example of a technique for setting the block rate / drop rate low will be described below.

[0005] For example, the target is a call of two QoS classes, and the state of the network is determined by the network usage rate, し Priority Access, and conditional

Access and Equal Access. Then, the reception process is changed based on the combination of the QoS class and the network state of the generated call, and a new call is processed as follows for each network usage rate at the time of the new call generation.

1 In the Equal Access state, all traffic is accepted unconditionally regardless of the QoS class.

2 In the Conditional Access state, low priority class calls are accepted conditionally, The first class call is accepted unconditionally.

3 In the Priority Access state, only calls in the high priority class are accepted.

[0006] The above processing enables call admission control to set a low blocking ratio for a call with a high QoS class for multi-service (for example, Non-Patent Documents 1 and 2).

[0007] Non-Patent Document 1: Jay R. Moorman, John W. Lockwood, "Wireless Call Admission

OntrolUsing Threshold Access sharing

Non-Patent Document 2: Proceedingsof IEEE GLOBECOM '01, Volume 6, pp. 3698-3703, Nov. 2001

Disclosure of the invention

Problems to be solved by the invention

[0008] However, the conventional technique has the following two problems.

[0009] In the conventional CAC algorithm, admission control was performed without particularly considering calls in the near future in the order in which calls are generated. For this reason, the call acceptance is determined from the required resource amount of the new call and the remaining resource amount, and if the call can be accepted, it is accepted unconditionally.

[0010] However, in a mobile network, for example, after accepting a call from a user (terminal) having a large required resource amount and a poor radio link quality, a radio link quality having a small required resource amount is not acceptable. When there are many calls by good users (terminals), there is a problem that inefficient admission control is performed from the viewpoint of a block rate and a network usage rate.

[0011] Further, in the conventional technology, since the CAC algorithm does not consider the calling user's contracted ISP, it is provided between the operator of the mopile network and the ISP using indices such as the number of accommodated users, a block rate, and a resource amount. When contracted for services, there was a problem that it was impossible to maintain such a contract.

[0012] An object of the present invention has been made in view of the above-described problems, and it is possible to improve the network usage rate and reduce the block drop rate by accepting a call stochastically using a weight function at the time of admission judgment. An object of the present invention is to provide a call admission control method and a call admission control system that can be implemented.

[0013] Further, an object of the present invention is to provide an allocated resource amount contracted with an ISP to which a calling user belongs, The amount of resources allocated to the ISP at that time is measured, the call acceptance is determined so as to satisfy the contract contents (number of accommodated users, block rate, resource amount), and the service as contracted can be provided to the ISP. A call admission control method and a call admission control system are provided.

Means for solving the problem

[0014] In order to achieve the above object, the call admission control method according to the present invention is configured such that when a call from a terminal is received, the call from the terminal can be accommodated in a network resource held by the system. Whether accommodation is possible or not,

A call admission judgment step of judging whether or not the terminal can accept a call based on an admission probability changed by a weighting function when it is judged that the terminal can be accommodated in the accommodating judgment step. Is what you do.

[0015] The weight function may be a weight function depending on radio link quality, a weight function depending on a call quality level required by a terminal, a function depending on an unused resource amount of a network, or two or more functions. It is desirable to use a weighting function according to the requirements.

[0016] In the call admission determining step, a value obtained from a function depending on the radio link quality may be compared with a random number to stochastically determine whether the terminal has accepted a call. Things. Further, in the call admission determining step, a value obtained from a weighting function depending on a quality level of a call requested by the terminal is compared with a random number, so that the terminal accepts a call stochastically. It may be.

[0017] In the call admission determining step, a weight function power depending on the amount of unused resources of the network is compared with the obtained value and a random number to stochastically determine whether the terminal has accepted a call. This may be done. Further, in the call admission determining step, the random number according to a different distribution depending on the radio link quality is compared with a predetermined threshold value, so that the call reception of the terminal is stochastically determined. It is acceptable.

[0018] Further, in the call admission determining step, a random number that follows a different distribution depending on the quality level of the call is compared with a predetermined threshold value, thereby stochastically determining whether the terminal has accepted a call. This may be done. Also, in the above-mentioned call admission determination step In addition, a random number according to a different distribution depending on the amount of unused resources of the network may be compared with a predetermined threshold to stochastically determine whether the terminal has accepted a call. Good thing. Further, in the call admission judgment step, two or more judgments of accepting a call from the terminal may be made based on the reception probabilities by different weighting functions.

[0019] Further, in the call admission determining step, the network 'resource usage is managed for each call quality level, and the admission probability is set using the resource usage threshold set for each call quality level as a boundary. It is also possible to switch the weight function to be determined so as to judge the calling of the terminal.

[0020] The apparatus further comprises a disconnection step. When the disconnection step determines that the new call cannot be accommodated in the network resource, the accommodating / non-accommodation determination step determines whether the new call can be accommodated in the network. Calculate the disconnection priority based on the call quality level and the radio link quality for the call of the terminal, and disconnect the call with the highest disconnection priority to accommodate a new call. Is also good.

[0021] The method further includes a disconnection step. In the disconnection step, when the network resource usage is equal to or more than a threshold, a call quality level and a radio link quality for a call of a terminal accommodated in the network. And the call having the highest disconnection priority may be disconnected to maintain the other calls that are accommodated.

[0022] Further, in the call admission judging step, when performing the judging process, an amount of resources allocated to the terminal by an Internet service provider to which the calling terminal belongs, and an amount of resources allocated to the terminal at the time of calling. The terminal may determine whether to accept a call based on the above.

[0023] Further, the call admission control method according to the present invention is characterized in that, when a call from a mobile terminal is received, an accommodation availability determination step of determining whether or not it can be accommodated in a network resource held by the system. If it is determined in the accommodating availability determination step that the call cannot be accepted, disconnection priority is given to the call of the mobile terminal accommodated in the network by a weight function depending on the call quality level or the radio link quality. Call and the call with the highest disconnect priority is disconnected. , And an accommodation processing step for accommodating a new call.

[0024] Further, the call admission control method according to the present invention is characterized in that, when a call from a mobile terminal is received, it is determined whether or not it can be accommodated in a network resource held by the system. Has,

In the accommodating availability determination step, based on the amount of resources allocated to a plurality of terminals by the Internet service provider to which the calling terminal belongs and the amount of resources allocated to the terminal at the time of calling, A configuration for determining whether to accept a call may be adopted.

The call admission control method according to the present invention can be applied to call admission control at a destination at the time of a handover of a terminal movement.

[0026] A call admission control system for implementing the call admission control method according to the present invention, in response to a call from a terminal, determines whether or not the call from the terminal can be accommodated in a network resource held by the system. Means for determining whether accommodation is possible,

A call acceptance determining means for determining whether to accept a call from the terminal based on a reception probability changed by a weighting function when the accommodation possibility determination means determines that accommodation is possible.

[0027] It is preferable that the call admission judging means judges the admission of the call from the terminal based on an admission probability that changes according to a weight function depending on a radio link quality. Further, the call admission judgment means may judge the admission of the call from the terminal based on an admission probability changed by a weight function depending on a call quality level requested by the terminal. Further, the call admission determining means may judge the reception of the call from the terminal based on an admission probability changed by a weight function depending on an unused resource amount of the network. Further, the call admission judgment means may judge the reception of the call from the terminal based on an admission probability changed by a weight function having two or more factors as factors.

[0028] Further, the call admission determining means may stochastically determine whether the terminal has accepted a call by comparing a value obtained from a weight function dependent on radio link quality with a random number. Weight function power depending on the call quality level required by the user Compares the obtained value with a random number By doing so, the reception of the call by the terminal may be determined stochastically. Further, the call admission determining means is configured to stochastically determine whether the terminal has accepted a call by comparing the obtained weight function power obtained based on the amount of unused resources in the network with a random number. Is also good.

[0029] Further, the call admission judgment means may stochastically judge the admission of the call from the terminal by comparing a random number according to a different distribution depending on the radio link quality with a predetermined threshold value. It may be. Further, the call admission determining means compares the random number according to a different distribution depending on the call quality level with a predetermined threshold value to stochastically determine whether the terminal has accepted the call. Is also good. Further, the call admission determining means probabilistically determines whether the terminal has accepted a call by comparing a random number that follows a different distribution depending on the amount of unused resources in the network with a predetermined threshold. This may be done. Further, the call admission judgment means may judge whether or not the terminal has accepted the call based on the reception probabilities by different weight functions. Further, the call admission determining means manages network 'resource usage for each call quality level, and sets a weight for determining a reception probability with a threshold of resource usage set for each call quality level as a boundary. The function may be switched.

[0030] The apparatus further includes disconnection processing means, and when it is determined that the new call cannot be accommodated in the network 'resource, the disconnection processing means can add a call to another terminal accommodated in the network. On the other hand, a new call may be accommodated by calculating the disconnection priority based on the call quality level and the radio link quality, and disconnecting the call having the highest disconnection priority.

[0031] The communication apparatus further includes a disconnection processing unit, and the disconnection processing unit, when the resource usage of the network becomes equal to or more than a threshold value, provides a call quality level and radio By calculating the disconnection priority based on the link quality and disconnecting the call with the highest disconnection priority, it is possible to retain the other calls and maintain other calls. .

[0032] Further, there is provided second disconnection processing means, wherein the second disconnection processing means is configured to allocate resources of the terminal by an Internet service provider to which the calling terminal belongs, The reception of a call by the terminal may be determined based on the amount of resources allocated to the terminal.

[0033] Further, the call admission control system according to the present invention, when receiving a call from a mobile terminal, determines whether or not accommodation is possible in a network resource held by the system; ,

If it is determined by the accommodating availability judging means that the call cannot be accepted, the disconnection priority is calculated for the call of the mobile terminal accommodated in the network by a weight function depending on the call quality level or the radio link quality. And a means for disconnecting the call having the highest disconnection priority and accommodating a new call.

[0034] Further, the call admission control system according to the present invention, when receiving a call from a mobile terminal, includes an accommodating / non-acceptable judging means for judging whether or not the call can be accommodated in a network resource held by the system. Have

The accommodating / non-accommodating determination means is configured to make a call to the terminal based on the resource amount allocated to the terminal by the Internet service provider to which the caller belongs and the resource amount allocated to the terminal at the time of the call. May be determined.

[0035] The call admission control system according to the present invention can be applied to a call admission control system at a movement destination at the time of handover of terminal movement.

The invention's effect

According to the present invention, at the time of accepting a call, it is determined whether or not a call from a terminal can be accommodated within a network resource held by the system. Since a terminal having good wireless link quality or the like is accepted with a stochastic priority using a weighting function that depends on, the network utilization rate can be improved and the block drop rate can be reduced.

[0037] Further, the present invention provides a method for accommodating a network even if the resource usage of the network is equal to or more than a threshold value or if it is determined that a new call cannot be accommodated in the network resource. Calculates the disconnection priority based on the call quality level and the radio link quality for the call of the other terminal that is disconnecting, and disconnects the call with the highest disconnection priority so that the existing call or new call Because it is designed to accommodate calls, it is possible to make effective use of the network. it can.

Further, the present invention measures the amount of resources allocated to the ISP to which the calling user belongs and the amount of resources allocated to the ISP at that time, and determines the contents of the contract (number of accommodated users, block rate, resource The system is configured to judge the call acceptance so as to satisfy the service amount, etc., so that ISPs can be provided with the services as contracted.

Brief Description of Drawings

FIG. 1 is a diagram showing an example of an access network to which the present invention is applied.

FIG. 2 is a block diagram showing an example of a wireless network control station.

[FIG. 3] FIG. 3 is a diagram for explaining operations from transmission of a call request message to transmission of a reception permission / prohibition notification message.

FIG. 4 is an operation flowchart of a call admission control process.

FIG. 5 is an operation flowchart of a common process.

FIG. 6 is an operation flowchart of a radio link quality dependent process.

[FIG. 7] FIG. 7 is a flowchart in a case where a function is changed according to a condition as to whether or not a resource usage amount predetermined for each QoS class has been exceeded.

FIG. 8 is a diagram showing a table of Max QoS Nos for the number of QoS classes.

FIG. 9 is an operation flowchart of Embodiment 2.

FIG. 10 is a flowchart of ISP-dependent processing.

[FIG. 11] FIG. 11 is a diagram showing a ISP Info table having Max Isp No elements, which is the number of ISPs.

FIG. 12 is a flowchart of another embodiment of the second embodiment.

FIG. 13 is a flowchart of a first disconnected call selection process.

FIG. 14 is a flowchart of a second call disconnection process.

FIG. 15 is an operation flowchart of the fourth embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

According to the present invention, at the time of accepting a call, it is determined whether or not a call from a terminal can be accommodated in a network resource held by the system. Stochastically prioritize terminals with good wireless link quality using weighting functions that depend on quality, etc. And accept it. As a result, it is possible to improve the network usage rate and reduce the block drop rate.

[0041] Further, even when it is determined that a new call cannot be accommodated in the network resource, the present invention provides a call quality of another terminal accommodated in the network. It is characterized by calculating the disconnection priority based on the level and the radio link quality, and accommodating a new call by disconnecting the call having the highest disconnection priority. Further, when the network 'resource usage becomes equal to or larger than the threshold, the disconnection priority based on the call quality level and the radio link quality is calculated for the call of the terminal accommodated in the network, Disconnect Disconnects the call with the highest priority so that other calls can be accommodated and maintained. As a result, the network can be effectively used.

Further, the present invention measures the amount of resources allocated to the ISP (Internet Service Provider) to which the calling user belongs and the amount of resources allocated to the ISP at that time, and determines the contents of the contract (the number of accommodated users). , Block rate, resource amount, etc.). As a result, the service according to the contract can be provided to the ISP.

Hereinafter, specific examples of the present invention will be described.

Example 1

Example 1 of the present invention will be described.

FIG. 1 is a diagram showing an example of an access network to which the present invention is applied. As shown in FIG. 1, an access network to which the present invention is applied is configured by a network including a radio access network 121, a core network 122, and an external network 123.

The radio access network 121 also has an arbitrary number of terminals 101 and 102, a radio base station 103, and a radio network control station 104. The terminals 101 and 102 in the senor 124 are connected to the radio base station 103 by a radio link.

The wireless base station 103 is controlled by the wireless network control station 104, and performs processing such as establishment and disconnection of a wireless link and data transfer processing.

The radio network controller 104 performs call admission control, radio link establishment / disconnection signaling, data transfer processing, and instructions for calls from the terminals 101 and 102. Further, the wireless network control station 104 is connected to the core network 122. [0049] Core network 122 is a network that transfers packets.

Note that the radio access network 121 may take the form of a single node, which need not necessarily be separated into the radio base station 103 and the radio network control station 104. The wireless network control station 104 may be directly connected to the external network 123 without providing the core network 122. In this case, the functions of the core network are covered on the wireless access network side.

[0051] The external network 123 includes the Izumi Access Network 121 and a plurality of ISPs 111-113. These ISPs 111 have contracts with the operators of the core network 122.

Next, an operation example of the present embodiment and an operation relating to call admission control of the radio network control station 104 at that time will be described.

FIG. 2 is a block diagram showing an example of the wireless network control station 104.

The wireless network control station 104 includes input / output terminals 201 and 202 connected to the wireless base station 103 as shown in FIG. 2, a transfer unit 211, a message creation unit 212, and an acceptability determination unit 213. , A storage unit 214, and a network use status monitor unit 215.

The network usage monitoring unit 215 periodically monitors the network usage, and records information obtained by the monitoring in the storage unit 214. The information stored in storage section 214 includes a report on the used resources from radio base station 103, a report on the used resources from terminals 101 and 102, and the like.

Next, the operation from the transmission of the call request message of the terminals 101 and 102 to the transmission of the acceptance permission / prohibition notification message of the radio network controller 104 will be described. FIG. 3 is a diagram for explaining an operation from transmission of a call request message to transmission of a reception permission / prohibition notification message.

First, the terminals 101 and 102 transmit a call request message 301 to the wireless base station 103 by a user operation. At this time, the terminals 101 and 102 include information on the call such as the required resource amount and the required QoS class of the generated call and the identifiable terminal ID in the message 301 and transmit these to the radio base station 103. The radio base station 103 outputs the received call request message 301 to the radio network controller 104.

[0058] However, depending on the system, the wireless network control station 104 may further include the core network 12 In some cases, the call request message 301 may be transferred to the nodes in 2 and the call request message 301 may be output to the radio network control station 104 after processing in the core network 122.

The present invention relates to a call admission control process in the radio network controller 104, regardless of the route of the call request message up to the radio network controller 104. However, the present invention is applicable to a system in which the radio network control station 104 generates a call admission control process.

[0060] Further, the information including the call request message 301 need not necessarily be included at the time when the terminals 101 and 102 make a call, and may be converted or converted at a node of the core network 122 through which the information is transmitted. Specifically, the terminals 101 and 102 include the received CIR (Carrier power to Interference power Ratio) data of the pilot channel in the description information, and the radio network control station 104 transmits the information from the terminals 101 and 102 to the information. It is conceivable to calculate the required resource amount based on this. The unit of the required resource amount may be arbitrary, but when using the conventional call admission control method, the required power / maximum base station power in the downlink direction, and the noise in the uplink direction.

It is common to handle resource amounts using units such as Rise.

When the call request message 301 is input to the input terminal 202 of the wireless network control station 104, the wireless network control station 104 starts a call admission control process 302 shown in FIG. The call admission control process 302 is a process for controlling whether or not to accept calls from the terminals 101 and 102.

[0062] More specifically, when a call request message 301 is input from the input terminal 202 to the acceptability determination unit 213, the acceptability determination unit 213 starts the call acceptance control process 302.

[0063] In the call admission control process, the admissibility judging unit 213 judges whether or not the terminal can accept the call from the network usage status recorded in the storage unit 214 and the information included in the call request message. , And outputs the result to message creation section 212.

[0064] Message creating section 212 shapes the message into a format that terminals 101 and 102 can understand, and outputs the shaped message data to transfer section 211.

[0065] The transfer unit 211 outputs the input message as an acceptability notification message 303 at the output terminal. It transmits to terminals 101 and 102 through child 201.

Next, the call admission control process 302 in the operation of the first embodiment will be described.

The call admission control process 302 in the first embodiment sequentially executes a common process (step A01) and a radio link quality dependent process (step A02) as shown in FIG.

[0068] The common process (step AO1) is a process for responding to a call from a terminal to determine whether or not the call from the terminal can be accommodated in a network resource held by the system. Then, in the radio link quality dependent processing (step A02), after it is determined in the common processing (step A01) that the call can be accepted, the call is stochastically determined based on a function depending on the radio link quality of the calling terminal. Is performed again.

First, the common processing will be described.

FIG. 5 is an operation flowchart of the common process.

[0071] The outgoing call request message 301 is an index value indicating the required resource amount of the call.

Contains Index. The New Call Index includes the received power of pilot channels received by terminals 101 and 102 and the CIR (Carrier

to Interference Radio (ratio of desired wave to interference wave power).

[0072] The radio network controller 104 transmits a New Call from the received call request message 301.

Extract Index (Step B01).

[0073] Subsequently, an index value indicating the amount of resources currently consumed in the same cell as the New Call Index

Tsh which is an index value indicating the sum of the Total Used Index and the upper limit of the usable resources

Compare with Index (Step B02).

As a result of the comparison, the sum is Tsh

If it is smaller than Index, it is determined that the network can accommodate terminal calls, so calls from terminals are accepted (Accept, ACCEPT). If the sum is Tsh

If it is larger than the Index, it will exceed the upper limit set when a call from the terminal is accepted, so the call from the terminal will be rejected (Reject, REJECT).

The above is the outline of the common processing.

Next, the radio link quality dependent processing will be described.

[0077] The radio link quality dependent process determines that it is possible to accept a call from a terminal in the common process described above. After the disconnection, the process is characterized by re-determining the acceptability of a call from the terminal based on a function depending on the radio link quality of the calling terminal.

Hereinafter, a specific operation of the radio link quality dependent processing will be described. FIG. 6 is an operation flowchart of the wireless link quality dependent processing.

First, an acceptance probability value is calculated using an arbitrary P_Weight () function (weight function), and this acceptance probability value is compared with a random number rand () generated in the range of 0 to 1 (step). C01). If the random number rand () is smaller than the acceptance probability value, the terminal accepts the call from the terminal (accept, ACCEPT), and if it is larger, rejects the call from the terminal (reject, REJECT).

Here, the P_Weight () function (weight function) may be arbitrary, but some specific examples will be shown below.

The first specific example is represented by the following (Equation 1).

P.Weight () = (Tsh Index-Total Used Index- New Call Index) I Tsh

Index * (Normalized QoL) (Equation 1)

In this (Equation 1), ((Tsh Index-Total Used Index-New Call Index) I Tsh Index) indicates the remaining resource index value, and (Normalized

QoL) indicates the radio link quality. Equation 1 represents (remaining resource amount index value) * (wireless link quality). However, each section is standardized. As a result, the probability that a call with a lower radio link quality is accepted is lower, so that it is possible to accept more calls with a better radio link quality than before. That is, it is possible to improve the network usage rate and reduce the call loss rate.

[0082] A second specific example is represented by the following (Equation 2).

P.Weight () = (Tsh Index-Total Used Index- New Call Index) I Tsh

Index * (Normalized QoS Class) * (Normalized QoL) (Equation 2)

In this (Equation 2), ((Tsh Index-Total Used Index-New Call Index) I Tsh Index) indicates the remaining resource index value, and (Normalized

(QoS Class) indicates the QoS class, and (Normalized QoL) indicates the radio link quality. Equation 2 represents (remaining resource amount index value) * (QoS class) * (radio link quality). However, each section is standardized. As a result, the effect of the first specific example is In addition to the results, it becomes possible to change the reception probability for each QoS class, which is the call quality level, according to the operator's policy.

[0083] Finally, the third specific example is to change the function according to the condition of whether or not the amount of resource usage determined for each QoS class has been exceeded. FIG. 7 shows a flowchart in the case where the function is changed according to the condition of whether or not the resource usage exceeds a predetermined or predetermined resource usage for each QoS class.

First, as shown in FIG. 8, Max Qos No tables for the number of QoS classes are prepared, and the used index, which is the amount of resources monitored for each QoS class, is used.

It holds information on Tsh Index QoS, which is the upper limit of resource usage set for each QoS class. Set the QoS class of the new call as New Call QoS No.

Determine Tsh Index QoS of Call QoS No)-(Used Index QoS of New Call QoS No)> 0. Then, the function is changed according to the condition of whether or not the resource usage amount predetermined for each QoS class has been exceeded (step D01).

[0085] As a result of the determination, if it is 0 or more, that is, if the resource usage exceeds the resource usage predetermined for each QoS class, the following (formula 3) is used as P_Weight (step D02).

P—Weight () = {(New Call QoS No Tsh Index QoS) — (New Call QoS No Used Index QoS) —New Call Index} I (New Call QoS No Tsh Index QoS) *

(NormalizedQoL) (Equation 3)

In this (Equation 3), {(Tsh Index QoS of New Call QoS No) — (Used Index QoS of New Call QoS No) —New

Call Index} I (Tsh Index QoS of New Call QoS No) indicates the remaining resource amount index value assigned to the QoS class.

QoL) indicates the radio link quality.

(Equation 3) represents (remaining resource amount index value assigned to the QoS class) * (radio link quality). However, each section is standardized.

[0086] On the other hand, if the result of the determination is 0 or less, that is, if the resource usage exceeds the predetermined resource usage for each QoS class, the following (Equation 4) is used as P_Weight () (step D03).

P.Weight () = (Tsh Index (Tsh Index QoS of QoS # 0) (QoS # Max QoS No Tsh

Index QoS)-New Call Index} I Tsh Index * (NormalizedQoL) (Equation 4)

In this (Equation 4), (Tsh Index (Tsh Index QoS of QoS # 0) (QoS # Max QoS

No Tsh Index

QoS)-New Call Index} I Tsh Index indicates the remaining resource amount index value of the resources that are not allocated to the QoS class among all available resources. (Normalized

QoL) indicates the radio link quality.

(Equation 4) represents (remaining resource amount index value among resources that are not allocated to the QoS class among all available resources) * (radio link quality). However, both sections are standardized.

[0087] Finally, the reception probability value is calculated using the P_Weight () function, and the reception probability value is calculated from 0

Compare with the random number rand () generated in the range of 1 (step D04). If the random number is smaller than the acceptance probability value, the call from the terminal is accepted (accept, ACCEPT), and if the random number is larger, the call from the terminal is rejected (reject, REJECT).

As a result, a fixed amount of resources are allocated to each QoS class, and call admission control in a form in which the surplus resources are shared by all QoS classes becomes possible.

In the above call admission control, a threshold value that changes depending on the radio link quality and the QoS is set, random numbers with a uniform distribution are generated, and comparison is made to determine whether or not the call can be admitted.

As an example of another embodiment, a predetermined threshold value is determined in advance, random numbers according to different parameters are generated depending on the radio link quality and QoS, and comparison is performed to determine whether or not the reception is possible. It may be configured as follows.

[0091] For example, an arbitrary threshold is set to 0.5. When generating random numbers according to different parameters, for terminals with wireless link quality q, N (q) whose average is normalized by the maximum value of the observed wireless link quality, and random numbers that follow a normal distribution with a variance of 0.2 Generate. However, these values are optional. In this case, similarly to the above-described embodiment, the wireless link quality q is excellent, and the higher the wireless link quality, the higher the reception probability can be expected.

[0092] As described above, according to the present invention, it is possible to improve the network usage rate of the operator and to reduce the block rate and the drop rate. Example 2

[0093] Example 2 of the present invention will be described.

In the second embodiment, as the call admission control process, instead of the radio link quality dependence process in the first embodiment, the contract contents with the ISP as shown in FIG. 9 (number of accommodated users, block rate, resource amount) ISP dependent processing (step A03) that depends on

[0095] The operation of the ISP-dependent processing (step A03) will be described below.

FIG. 10 is a flowchart of ISP-dependent processing.

First, as shown in FIG. 11, an ISP having Max Isp No elements, which is the number of contracted ISPs

A table called Info is prepared in the storage unit, and service is provided to the core network 122 for each ISP.

Index and information of Used Index, which is an index value of the resource amount used by the terminal group to which the terminal currently belongs, is held.

First, a New Call ISP No designating the ISP to which the terminal belongs is extracted from the call request message 301 (step E01).

[0099] Next, from the storage unit 214, the Contract Index and Used Index of the ISP and the index of the required resource amount of the user (New

From the Call Index), calculate the amount of Over Index in which the used resource index value when a new call is accepted exceeds the contracted resource index value (step E02). This can be expressed as the following (Equation 5).

Over Index = (Used Index of New Call ISP No) + New Call Index-(Contract Index of New Call ISP No) (Equation 5)

However, the service provision contract resource amount index value may be a value converted from another index used in the contract, such as the bandwidth or the number of accommodated users.

[0100] Next, the sign of Over Index is determined (step E03). If it is negative, it means that the contract index value is not exceeded, so the call is accepted (Accept, ACCEPT). If it is positive, the difference between the upper limit value of the usable resource amount and the index value of the total used resource amount is obtained, and it is checked whether or not there is a surplus resource amount in all the resources (step E04). Margm Index represents the overall margin. This can be expressed as the following (Equation 6).

Total Used Index + New and all Index— Tsh Index Margin Index (Equation 6)

If the inequality of (Equation 6) holds, the call from the terminal is accepted (accept,

ACCEPT), rejects the call from the terminal if it does not work (REJECT).

[0101] In the above processing, call admission control can be performed for each ISP based on a contract. Also,

In the resources of each ISP, the above-described processing in consideration of the QoS class may be performed.

[0102] In the second embodiment, the ISP-dependent process may be used alone as the call admission control process in which the ISP-dependent process is performed after the common process, except for the common process.

[0103] The ISP-dependent processing described above may be used in combination with the common processing and the radio link quality-dependent processing described in the first embodiment as shown in FIG.

[0104] In the ISP-dependent processing described above, a threshold value that changes depending on the ISP contract contents (the number of accommodated users, the block rate, the amount of resources, and the like) is set, and a random number with a uniform distribution is generated. Go

However, a decision was made on whether or not to accept, but a fixed threshold value was determined in advance in the same way as the above-mentioned radio link quality and QoS, and it depends on the ISP contract contents (number of accommodated users, block rate, amount of resources, etc.). May be configured to generate random numbers according to different parameters, and make a comparison to determine whether or not to accept.

According to the present invention as described above, call admission control can be performed based on a contract with an ISP to which a user belongs.

Example 3

[0106] Embodiment 3 of the present invention will be described.

The third embodiment relates to a process of disconnecting a call from a terminal. The call disconnection selection process is performed in the following two cases.

[0108] In the first case, the radio link quality of the terminal that has already accepted the call deteriorates, the amount of resources required to maintain the call increases, and it is impossible to keep all the calls. In this case, the call is disconnected and the other calls are kept.

[0109] The second case is a case where a call from a new terminal cannot be accepted from the viewpoint of system resources, but it is necessary to accept a call from that terminal due to an operator policy. [0110] In the first case, the call is independently performed separately from a new call, but the same effect as the call admission control can be expected. Therefore, first, the cutting process performed alone will be described.

FIG. 13 is a flowchart of the first disconnected call selection process.

First, the ordering is performed by the cutting priority function Cost () (step F01).

[0113] The disconnection priority function Cost () may be arbitrarily set. For example, the following equation (7) is considered.

uost () = Normalized yob Class * Normalized QoL equation (7)

This equation (7) represents (QoS class) * (wireless link quality). However, each section is standardized. According to this formula, the disconnection priority is calculated for all the accommodated calls (step F01). Then, the call having the higher disconnection priority is disconnected, and the other call is continued (step F02).

Next, a description will be given of a disconnected call selection process in the second case described above.

FIG. 14 is a flowchart of the second call disconnection process.

[0116] First, it is determined whether or not the existing call is to be disconnected (step F10). This determination may be made dynamically using parameters such as the New Call Index, or may be set statically according to the operator's policy. If it is determined that a new call will be accepted even after the existing call is disconnected, then the ordering is performed using the disconnect priority function Cost () (step F11).

The disconnection priority function Cost () may be arbitrarily set, but an example of the above equation (7) can be considered. Ost; = Normalized QoS Class * Normalized QoL equation (7)

This equation represents (QoS class) * (radio link quality). However, each section is standardized. According to this formula (7), the disconnection priority is calculated for all the accommodated calls.

[0118] The call having the highest disconnection priority among all the calls is stored in accordance with the calculated disconnection priority (step F12). This processing is stopped here and the result of the disconnected call selection processing is returned.

Move to the next process as ACCEPT. Then, the call with the highest disconnection priority selected at the end of the call admission control after performing all the set processing is disconnected to accept a new call. become.

Example 4

[0119] Embodiment 4 of the present invention will be described.

Example 4 is a combination of Example 1, Example 2, and Example 3 described above.

[0121] Fig. 15 shows an example of the overall processing combining the common processing, the ISP-dependent processing, the wireless link quality-dependent processing, and the disconnection processing.

In FIG. 15, common processing (step G01), ISP-dependent processing (step G02), and wireless link quality-dependent processing (step G03) are performed in this order.

[0123] However, if the result of step G01 is rejection (REJECT), the processing shifts to the disconnected call selection processing (step G04). If the new call is accepted even if the existing call is disconnected, the ISP-dependent processing ( Step G05), radio link quality dependent processing (step G06), and then the call with the highest disconnection priority stored last is disconnected (step G07), and a new call is accepted.

Industrial applicability

The present invention is a technology capable of improving the network usage rate of an operator and lowering the block rate and drop rate, and is suitable for a call admission control technique in an access network.

Further, the present invention is a technology capable of performing call admission control based on a contract with an ISP to which a user belongs, and is suitable for a technology of call admission control in an access network.

Further, the call admission control of the present invention can apply the same mechanism to a handover call when a terminal moves between cells in a mobile communication network.

Claims

The scope of the claims

[1] an accommodation acceptability determining step of, when receiving a call from a terminal, determining whether or not the call from the terminal can be accommodated in a network resource held by the system;

A call admission determining step for judging whether the terminal can accept a call based on an admission probability changed by a weighting function when it is judged that the terminal can be accommodated in the accommodating judgment step. Call admission control method to be performed.

[2] The call admission control method according to claim 1, wherein a function dependent on radio link quality is used as the weight function.

3. The call admission control method according to claim 1, wherein a function dependent on a call quality level requested by a terminal is used as the weight function.

4. The call admission control method according to claim 1, wherein a function depending on an unused resource amount of a network is used as the weight function.

[5] The call admission control method according to claim 1, wherein a function having two or more requirements as factors is used as the weight function.

[6] In the call admission determining step, a value obtained from a weighting function depending on a radio link quality is compared with a random number to stochastically determine whether the terminal has accepted a call. The call admission control method according to claim 1, wherein

[7] In the call admission determining step, a weight function depending on the quality level of the call requested by the terminal is compared with the obtained value and a random number, so that the reception of the call from the terminal is efficiently performed. 2. The call admission control method according to claim 1, wherein the determination is made.

[8] In the call admission judging step, a weight function power dependent on the amount of unused resources in the network is compared with the obtained value and a random number, thereby stochastically judging the call reception of the terminal. 2. The call admission control method according to claim 1, wherein:

[9] In the call admission determining step, a random number that follows a different distribution depending on the radio link quality is compared with a predetermined threshold value, thereby stochastically determining whether the terminal has accepted a call. 2. The call admission control method according to claim 1, wherein:

[10] In the call admission determining step, by comparing a random number that follows a different distribution depending on the call quality level with a predetermined threshold value, it is possible to confirm that the terminal has accepted the call. 2. The call admission control method according to claim 1, wherein the judgment is made at a regular rate.

[11] In the call admission determining step, by comparing a random number according to a different distribution depending on the amount of unused resources of the network with a predetermined threshold value, the terminal can stably accept the call. 2. The call admission control method according to claim 1, wherein the determination is made.

12. The call admission control method according to claim 1, wherein in the call admission judgment step, two or more judgments of admission of a call from a terminal are made based on admission probabilities by different weight functions.

[13] In the call admission determining step, a weight function for managing a network's resource usage for each call quality level and determining an admission probability using a resource usage threshold value set for each call quality level as a boundary 2. The call admission control method according to claim 1, wherein the call reception is switched to determine the reception of a call from the terminal.

[14] The method further includes a cutting processing step,

In the disconnection processing step, when it is determined in the accommodability determination step that the new call cannot be accommodated in the network resource, the call is transmitted to another terminal accommodated in the network. 2. The call reception according to claim 1, wherein a call priority is calculated based on the quality level and the radio link quality, and a call having the highest disconnection priority is disconnected to accommodate a new call. Control method.

[15] The method further includes a cutting step.

In the disconnection processing step, if the network resource usage is equal to or greater than a threshold, a disconnection priority is calculated based on the call quality level and the radio link quality for a call of a terminal accommodated in the network. 2. The call admission control method according to claim 1, further comprising disconnecting the call having the highest disconnection priority so as to maintain the other accommodated calls.

[16] In the call admission determining step, when performing the determining process, the amount of resources allocated to the terminal by the Internet service provider to which the calling terminal belongs and the amount of resources allocated to the terminal at the time of calling are further reduced. 2. The call admission control method according to claim 1, wherein the call reception of the terminal is determined based on the received call.

[17] An accommodation determination step for determining whether or not it can be accommodated in the network 'resources held by the system when receiving a call from the mobile terminal;

If it is determined in the accommodating availability judgment step that the call cannot be accepted, the disconnection priority is calculated for the call of the mobile terminal accommodated in the network by a call quality level or a weight function depending on the radio link quality. A call receiving control step of disconnecting a call having the highest disconnection priority and accommodating a new call.

[18] An accommodation availability determination step for determining whether or not the system can be accommodated in the network's resources held by the system when receiving a call from the mobile terminal,

In the accommodating availability determination step, based on the amount of resources allocated to a plurality of terminals by the Internet service provider to which the calling terminal belongs and the amount of resources allocated to the terminal at the time of calling, A call admission control method characterized by determining whether an incoming call has been received.

[19] A handover reception method, wherein the call admission control method according to claim 1 is applied to call admission control in a destination network at the time of handover of terminal movement.

[20] A handover reception method characterized by applying the call admission control method according to claim 17 to call admission control in a destination network at the time of handover of terminal movement.

[21] A handover reception method, wherein the call admission control method according to claim 18 is applied to call admission control in a destination network at the time of handover of terminal movement.

[22] accommodation availability determining means for determining whether or not the call from the terminal can be accommodated in the network 'resources held by the system in response to the call from the terminal;

A call admission judgment unit for judging whether or not the terminal can accept a call based on an admission probability changed by a weighting function when the admission judgment unit judges that the call can be accommodated. Reception control system.

23. The call according to claim 22, wherein the call admission judgment means judges the admission of the call from the terminal based on an admission probability changed by a weight function depending on radio link quality. Reception control system.

[24] The call admission determining means judges reception of a call from the terminal based on an admission probability changed by a weight function depending on a quality level of a call requested by the terminal. 23. The call admission control system according to claim 22, wherein:

25. The terminal according to claim 22, wherein the call admission judgment unit judges the call reception of the terminal based on an admission probability that changes according to a weight function that depends on an unused resource amount of the network. 2. The call admission control system according to 1.

26. The terminal according to claim 22, wherein the call admission judgment means judges the call reception of the terminal based on an admission probability changed by a weight function having two or more requirements as factors. Call admission control system.

[27] The call admission determining means stochastically determines whether the terminal has accepted a call by comparing a value obtained from a weight function dependent on radio link quality with a random number. 23. The call admission control system according to claim 22, wherein:

[28] The call admission judging means compares the value obtained from the weight function depending on the quality level of the call requested by the terminal with a random number, thereby stochastically judging the admission of the call from the terminal. 23. The call admission control system according to claim 22, wherein the call reception is terminated.

[29] The call admission determining means probabilistically determines whether the terminal has accepted a call by comparing a random number with a value obtained from a weight function depending on an unused resource amount of the network. 23. The call admission control system according to claim 22, wherein:

[30] The call admission determination means may stochastically determine whether the terminal has accepted a call by comparing a random number that follows a different distribution depending on the radio link quality with a predetermined threshold. 23. The call admission control system according to claim 22, wherein:

[31] The call admission determining means probabilistically determines whether the terminal has accepted a call by comparing a random number that follows a different distribution depending on the call quality level with a predetermined threshold value. 23. The call admission control system according to claim 22, wherein:

[32] The call admission determining means compares the random number according to a different distribution depending on the amount of unused resources of the network with a predetermined threshold, thereby stochastically determining whether the terminal has accepted the call. 23. The call admission control system according to claim 22, wherein:

33. The call admission control system according to claim 22, wherein said call admission judgment means judges two or more call acceptances of the terminal based on reception probabilities by different weight functions.

[34] The call admission determination unit manages the network resource usage for each call quality level. 23. The call admission control system according to claim 22, wherein a weight function for determining an admission probability is switched with a threshold of a resource usage amount set for each call quality level as a boundary.

[35] It further has a cutting processing means,

The disconnection processing means, when it is determined that the new call cannot be accommodated in the network resource, determines the call quality level and the radio link quality for the call of another terminal accommodated in the network. 23. The call admission control system according to claim 22, wherein a disconnection priority is calculated based on the call, and a call having the highest disconnection priority is disconnected to accommodate a new call.

[36] It further has a cutting processing means,

The disconnection processing means, when the network resource usage is equal to or greater than a threshold, determines a disconnection priority based on the call quality level and the radio link quality for a call of a terminal accommodated in the network. 23. The call admission control system according to claim 22, wherein the call that has the highest priority of disconnection is calculated, and the call other than the call that has the highest priority is maintained.

[37] Further, a second call acceptance determining means is provided,

The second call acceptance determining means determines whether or not the terminal has been allocated to the terminal based on the amount of resources allocated to the terminal by the Internet service provider to which the calling terminal belongs and the amount of resources allocated to the terminal at the time of calling. 23. The call admission control system according to claim 22, wherein the call admission is determined.

[38] An accommodation availability determination unit that determines whether or not it can be accommodated in the network's resources held by the system when receiving a call from the mobile terminal;

If it is determined by the accommodating availability judging means that the call cannot be accepted, the disconnection priority is calculated for the call of the mobile terminal accommodated in the network by a weight function depending on the call quality level or the radio link quality. A call admission control system comprising: a call processing unit that disconnects a call having the highest disconnection priority and accommodates a new call.

[39] When a call from the mobile terminal is received, the system has a accommodation availability determination unit that determines whether or not the system can be accommodated in the network's resources held by the system, The accommodating / non-accommodating determination means is configured to make a call to the terminal based on an amount of resources allocated to the plurality of terminals by the Internet service provider to which the calling terminal belongs, and an amount of resources allocated to the terminal at the time of calling. A call admission control system characterized by having a function of judging reception of a call.

[40] A handover reception system characterized in that the call admission control system according to claim 22 is applied to call admission control in a destination network at the time of handover of terminal movement.

[41] A handover reception system characterized in that the call admission control system according to claim 38 is applied to call admission control in a destination network at the time of handover of terminal movement.

[42] A handover reception system characterized in that the call admission control system according to claim 39 is applied to call admission control in a destination network at the time of handover of terminal movement.