JP2008124560A - Resource managing device, radio base station, radio communication system, resource managing method, and resource managing program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio communication system capable of determining the amount of resources to be secured for a radio base station while taking continuation of communication and efficient use of resources into consideration. <P>SOLUTION: The radio communication system comprises radio terminal device (STA1 to STAn, where n is an arbitrary integer), radio base stations (AP1 and AP2) which perform radio communication with the radio terminal devices (STA1 to STAn) using resources needed for the radio communication, and a resource managing device (2) which manages the resources, and the resource managing device (2) determines the amount of resources to be secured for the radio base station (AP2) according to movement possibilities (p1, p2, ..., pn) that the radio terminal devices move to the radio base station (AP2). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a resource management device, a radio base station, a radio communication system, a resource management method, and a resource management program for managing resources required when radio communication is performed between a radio terminal device and a radio base station. Is.

  In general, in wireless communication, there is a limit to the distance at which wireless communication can be performed between a wireless base station and a wireless terminal device.

  For this reason, each wireless base station forms a “cell” and performs wireless communication with a wireless terminal device existing in the formed “cell”. The “cell” is a range in which wireless communication is possible between the wireless base station and the wireless terminal device.

  As shown in FIG. 13, when the wireless terminal device (STA) moves from the first cell (cell 1) to the second cell (cell 2), the first cell (cell 1) before the movement is moved. ) Forming the second cell (cell 2) after movement from the wireless connection between the first wireless base station (AP1) forming the wireless terminal device (STA1) and the wireless terminal device (STA) Communication is performed by switching to a wireless connection between (AP2) and the wireless terminal device (STA). This operation is known as “handover” and is known to the world.

  In order to continue the communication performed in the first cell (cell 1) before the movement in the second cell (cell 2) after the movement during the “handover” operation, it is used for the communication. In addition, it is necessary to secure resources in the first radio base station (AP1) also in the second radio base station (AP2).

  For this reason, in order to continue communication even in a cell in which the wireless terminal device (STA) may move, the wireless terminal device (STA) may move before the handover of the wireless terminal device (STA). There is a method in which resources used in the radio base station (AP) before movement are reserved in advance in all of the radio base stations (AP).

  However, if resources are reserved in advance in all the radio base stations (AP) to which the radio terminal apparatus (STA) may move as in the method described above, the radio terminal apparatus (STA) does not move. In the radio base station (AP), the resources reserved in advance are wasted, and in the radio base station (AP) where the radio terminal apparatus (STA) has not moved, other radio terminal apparatuses (AP) STA) will not be able to communicate.

  In addition, when resources for a plurality of wireless terminal apparatuses (STAs) are secured in advance using the above-described method, securing useless resources increases.

  For this reason, a method that considers continuation of communication and efficient operation of resources is considered necessary.

  For this reason, as a technical document filed prior to the present invention, the location information of a terminal is obtained, and when a terminal exists in a handover spare area in the vicinity of the periphery of a cell in communication, There is a document disclosing a method for securing resources (hereinafter referred to as a first method) in a base station (see, for example, Patent Document 1).

  Note that the above-mentioned Patent Literature 1 predicts a destination cell of a terminal from the current location information and past location information of the terminal, reserves resources only in the base station of the predicted destination cell, A method (hereinafter, referred to as a second method) for improving usage efficiency and preventing interruption during communication is also disclosed.

  Further, in Patent Document 1, when the number of terminals existing in the handover spare area exceeds a predetermined number, the range of the handover spare area is narrowed, and the resources to be secured for the base station of the adjacent cell are reduced. Also disclosed is a method for preventing a decrease in the number of terminals that can communicate in adjacent cells (hereinafter referred to as a third method).

  However, in the first method disclosed in Patent Document 1, the number of terminals that can perform communication in adjacent cells is reduced.

  In other words, if there is only a terminal in the handover spare area, it is not possible to make a complete judgment as to whether to move to an adjacent cell or to which cell. If secured, there will be a shortage of resources for newly starting communication in the adjacent cell. For this reason, the number of terminals that can perform communication in adjacent cells decreases.

  In the second method disclosed in Patent Document 1, communication may be interrupted in the middle.

  That is, if the cell where the terminal actually moves is different from the destination cell, communication resources are not secured. For this reason, communication is interrupted on the way.

  In the third method disclosed in Patent Document 1, communication may be interrupted in the middle.

  That is, by narrowing the range of the handover spare area, there may be a case where resources are not secured for terminals that originally need to secure resources. For this reason, communication is interrupted on the way.

  Therefore, in order to solve the above-described problems, it is necessary to determine the amount of resources to be secured in the radio base station while considering continuation of communication and efficient operation of resources.

  In addition, as a technical document filed prior to the present invention, there is a document that discloses a technique for preventing waste of network resources when establishing a plurality of backup connections in a mobile network system (for example, Patent Document 2).

In addition, there is a document that discloses a technique for avoiding invalid connection processing when connection cannot be made due to a shortage of base station resources and improving connection efficiency (see, for example, Patent Document 3).
Japanese Patent Application Laid-Open No. 11-187452 JP 2000-78633 A JP 2003-299131 A

  However, in Patent Documents 2 and 3 described above, it is necessary to describe anything about determining the amount of resources to be secured in the radio base station in consideration of continuation of communication and efficient operation of resources (resources). There is no suggestion about sex.

  The present invention has been made in view of the above circumstances, and is a resource management apparatus capable of determining the amount of resources to be secured in a radio base station while considering continuation of communication and efficient operation of resources. It is an object of the present invention to provide a radio base station, a radio communication system, a resource management method, and a resource management program.

  In order to achieve this object, the present invention has the following features.

  The resource management apparatus according to the present invention is a resource management apparatus that manages resources required when wireless communication is performed between a wireless terminal apparatus and a wireless base station, and the wireless terminal apparatus can move to the wireless base station. It is characterized by having a resource determining means for determining the amount of resources to be secured in the radio base station in accordance with a certain movement probability.

  In the resource management apparatus according to the present invention, the resource determining means determines the amount of resources according to the call loss rate of the radio terminal apparatus in the radio base station.

  In the resource management device according to the present invention, the resource determining means determines the amount of resources so that the call loss rate is a predetermined value or less.

  In the resource management device according to the present invention, the amount of resources is at least one of the amount of resources for handover calls of the wireless terminal device and the amount of resources for new calls of the wireless terminal device. It is a feature.

  In addition, the resource management apparatus according to the present invention is characterized in that it has first adjusting means for adjusting the distribution of the amount of resources for handover calls and the amount of resources for new calls.

  In addition, the resource management apparatus according to the present invention includes a second adjustment unit that adjusts the distribution of the amount of resources for handover calls and the amount of resources that can be shared for handover calls and new calls. It is characterized by.

  In the resource management apparatus according to the present invention, the adjusting means adjusts the distribution according to the call loss rate.

  In the resource management device according to the present invention, the call loss rate is at least one of a call loss rate at the time of handover of the wireless terminal device and a call loss rate at the time of a new call of the wireless terminal device.

  In the resource management device according to the present invention, the adjustment means weights at least one of the call loss rate at the time of handover of the wireless terminal device and the call loss rate at the time of a new call of the wireless terminal device. , The distribution is adjusted.

  In the resource management apparatus according to the present invention, the resource determining means determines the amount of the resource at an arbitrary time interval.

  In addition, the resource management apparatus according to the present invention is characterized by determining whether or not to permit connection of a handover call based on the amount of resources.

  In addition, the resource management apparatus according to the present invention is characterized by determining whether or not to permit connection of a new call based on the amount of resources.

  The radio base station according to the present invention is a radio base station that performs radio communication with a radio terminal device using resources necessary for radio communication, and the radio terminal device moves to the radio base station. It is characterized by having resource determining means for determining the amount of resources to be secured in the radio base station according to the movement probability that may occur.

  In addition, a wireless communication system according to the present invention includes a wireless base station that performs wireless communication with the wireless terminal device using resources necessary for wireless communication, and resource management that manages resources. The resource management device should be secured in the radio base station according to the probability of movement of the radio terminal device to the radio base station. It has a resource determining means for determining the amount of resources.

  A wireless communication system according to the present invention includes a wireless terminal device and a wireless base station that performs wireless communication with the wireless terminal device using resources necessary for wireless communication. A radio base station, wherein the radio base station determines a resource amount to be secured in the radio base station according to a movement probability that the radio terminal apparatus may move to the radio base station It is characterized by having.

  A resource management method according to the present invention is a resource management method performed by a resource management device that manages resources required when wireless communication is performed between a wireless terminal device and a wireless base station. The resource management apparatus performs a resource determination step of determining an amount of resources to be secured in the radio base station according to a movement probability that may move to the radio base station.

  A resource management method according to the present invention is a resource management method performed in a wireless base station that performs wireless communication with a wireless terminal device using resources necessary for wireless communication. The radio base station performs a resource determination step of determining an amount of resources to be secured in the radio base station according to a movement probability that may move to the radio base station.

  A resource management program according to the present invention is a resource management program that is executed by a resource management device that manages resources required when wireless communication is performed between a wireless terminal device and a wireless base station. The resource management apparatus is configured to execute resource determination processing for determining the amount of resources to be secured in the radio base station according to a movement probability that may move to the radio base station. .

  A resource management program according to the present invention is a resource management program to be executed in a radio base station that performs radio communication with a radio terminal apparatus using resources necessary for radio communication. The radio base station is caused to execute a resource determination process for determining an amount of resources to be secured in the radio base station according to a movement probability that the radio base station may move to. .

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to determine the quantity of the resource which should be ensured in a wireless base station, considering the continuation of communication and the efficient operation of resources.

(Features of this embodiment)
First, the features of the wireless communication system in the present embodiment will be described with reference to FIG.

  The wireless communication system in this embodiment is between a wireless terminal device (STA1 to n: n is an arbitrary integer) and a wireless terminal device (STA1 to n) using resources necessary for wireless communication. The wireless communication system includes a wireless base station (AP1, 2) that performs wireless communication and a resource management device (2) that manages resources.

  Then, the resource management device (2) determines whether the wireless terminal devices (STA1 to STAn) move to the wireless base station (AP2) according to the movement probability (p1, p2,... Pn). It is characterized in that the amount of resources to be secured in the base station (AP2) is determined.

  As a result, the resource management device (2) can determine the amount of resources to be secured in the radio base station (AP2) in consideration of continuation of communication and efficient operation of resources. Hereinafter, the wireless communication system according to the present embodiment will be described in detail with reference to the accompanying drawings.

<System configuration of wireless communication system>
First, the system configuration of the wireless communication system in the present embodiment will be described with reference to FIG.

  The radio communication system according to the present embodiment includes radio base stations (AP1, 2), radio terminal apparatuses (STA1 to n), and a resource management apparatus (2).

  In the radio communication system according to the present embodiment, the first radio base station (AP1) forms a first cell (cell 1), and the radio that exists in the formed first cell (cell 1). Wireless communication is performed with a terminal device (STA). Similarly to the first radio base station (AP1), the second radio base station (AP2) forms a second cell (cell 2), and the second cell (cell 2) is formed in the second cell (cell 2). Wireless communication is performed with an existing wireless terminal device (STA).

  The radio base stations (AP1, AP2) are configured to be connected to the resource management device (2) via a network (NW). The network (NW) is not particularly limited, and any network can be applied as long as information can be transmitted and received between the radio base stations (AP1, AP2) and the resource management device (2). .

  The wireless terminal devices (STA1 to n) are wirelessly connected to the wireless base stations (AP1, AP2) and communicate via the wireless base stations (AP1, AP2). Examples of the wireless terminal device (STA) include wireless devices such as a mobile phone, a PDA (Personal Digital Assistance), and a PC (Personal Computer).

  In the wireless communication system according to the present embodiment, as shown in FIG. 1, the wireless terminal device (STA) may move from the first cell (cell 1) to the second cell (cell 2). The movement probabilities are p1 to pn.

  For example, the movement probability that the first wireless terminal apparatus (STA1) may move from the first cell (cell 1) to the second cell (cell 2) is p1, and the second wireless terminal apparatus (STA2) ) Is assumed to be p2 as a probability of movement from the first cell (cell 1) to the second cell (cell 2), and the nth (n is an arbitrary integer) wireless terminal device (STAn) The probability of movement that may move from the first cell (cell 1) to the second cell (cell 2) is pn.

  In addition, as shown in FIG. 1, the wireless communication system in the present embodiment newly establishes a wireless connection to the second wireless base station (AP2) other than the handover call, and the second wireless base station (AP2 )) (Hereinafter referred to as “new call”).

  The resource management device (2) manages resources (resources) to be secured in each radio base station (AP1, AP2) existing under the management of the resource management device (2). The resource management device (2) includes a server device for managing the resources of each wireless base station (AP), a centralized control device that centrally controls each wireless base station (AP), a wireless base station, A station (AP) or the like is applicable.

  As resources managed by the resource management device (2), any information can be managed as long as the information is necessary when the wireless base stations (AP1, AP2) perform wireless communication with the wireless terminal device (STA). For example, resources allocated to a handover call, resources allocated to a new call, and the like can be given.

<Internal configuration of resource management device 2>
Next, the internal configuration of the resource management device (2) will be described with reference to FIG.

  The resource management device (2) in the present embodiment includes a call control information collection unit (20), a call admission control unit (21), a resource information management unit (22), a terminal location information collection unit (23), The terminal movement speed information collection unit (24), the cell movement probability calculation unit (25), and the free resource allocation determination unit (26) are configured.

  The call control information collection unit (20) collects call control information transmitted when the wireless terminal device (STA) starts or ends communication. The call control information collection unit (20) acquires call control information from the wireless terminal device (STA) via the wireless base station (AP).

  When the call admission control unit (21) accepts a call connection request from the radio terminal apparatus (STA), the call admission control unit (21) determines the radio base station (AP) based on the information managed by the resource information management unit (22). Check the resource usage status, determine whether to permit call connection of the wireless terminal device (STA) that has accepted the call connection request, and determine the determination result as a wireless base station (AP) or wireless terminal device (STA). ).

  The call connection request includes a handover call connection request requested as a handover call and a new call connection request requested as a new call.

  The resource information management unit (22) is a resource for handover call and a resource for a new call that are used by a call of a wireless terminal device (STA) during a call, a free resource determined by a free resource allocation determination unit (26) It manages resource allocation with resources.

  Further, the resource information management unit (22), when a call connection request is received from the wireless terminal device (STA), indicates whether or not a resource necessary for the call connection request is available. Notify

  If the call connection request is a handover call connection request, the resource usage status for the handover call is referred to. If the necessary resources for the handover call connection request are available, the call connection is permitted. Call connection is prohibited.

  If the call connection request is a new call connection request, the resource usage status for the new call is referred to. If the necessary resources for the new call connection request are available, call connection is permitted. Call connection is prohibited.

  The terminal location information collection unit (23) collects the location information of each wireless terminal device (STA) during a call from the wireless base station (AP) or the wireless terminal device (STA).

  The terminal movement speed information collection unit (24) collects movement speed information of each wireless terminal device (STA) in a call from the wireless base station (AP) or the wireless terminal device (STA). The moving speed information includes not only the moving speed amount but also vector information indicating the moving direction.

  The cell movement probability calculation unit (25) wirelessly communicates based on the position information collected by the terminal position information collection unit (23) and the movement speed information collected by the terminal movement speed information collection unit (24). The terminal apparatus (STA) calculates a movement probability that may move from a cell that currently exists to another cell.

  Based on the movement probability calculated by the cell movement probability calculation unit (25), the free resource allocation determination unit (26) determines the free resources of the current radio base station (AP) obtained from the resource information management unit (22), The resource allocation to be allocated to the handover call resource and the new call resource is determined.

  The free resource allocation determination unit (26) allocates resources allocated to the handover call resource and the new call resource so that the sum of the handover call loss rate and the new call loss rate is minimized. decide.

<Method for determining resource allocation>
Next, a method for determining the resource allocation to be allocated to the handover call and the new call will be described with reference to FIG. In the following description, the allocation determination operation of resources to be allocated to the second radio base station (AP2) will be described as an example. The allocation determination operation described below is performed under the management of the resource management device (2). This is performed for all radio base stations (AP) existing in the network.

  First, the resource management device (2) confirms a wireless terminal device (STA) that is in a call via the first wireless base station (AP1) (step S1).

  The resource management device (2) performs a process for determining whether to permit or prohibit call connection for a call connection request by a handover call or a call connection request by a new call with the call control information collection unit (20). The call admission control unit (21) and the resource information management unit (22) are used. Then, since the call for which the resource management device (2) has decided to permit the call connection is in a call, the resource management device (2) confirms the wireless terminal device (STA) that is making the call. It becomes possible to do.

  Also, the resource management device (2) can confirm the call termination through the call control information collection unit (20), as in the case of the above-described call origination.

  Also, in the first radio base station (AP1), it is possible to confirm the radio terminal apparatus (STA) that is in a call.

  Next, the resource management device (2) collects the location information of the radio terminal device (STA) that is in a call via the first radio base station (AP1) in the terminal location information collection unit (23). Further, the resource management device (2) collects the moving speed information of the wireless terminal device (STA) that is in a call via the first wireless base station (AP1) in the terminal moving speed information collection unit (24).

  Then, the resource management device (2) uses the position information collected by the terminal position information collection unit (23) and the movement speed information collected by the terminal movement speed collection unit (24) to A cell movement probability calculation unit calculates a movement probability that a wireless terminal device (STA) that is talking through the station (AP1) may move from the first cell (cell 1) to the second cell (cell 2). Calculation is performed in (25) (step S2).

  When calculating the movement probability, the second radio base station (STA) is calculated from the current position of the radio terminal apparatus (STA) existing in the first cell (cell 1) of the first radio base station (AP1). When the shortest distance of AP2) to the second cell (cell 2) is short, the movement probability is increased, and when the movement speed in the shortest distance direction is large, the movement probability is increased. It is preferable to do.

  In addition to the method of calculating the movement probability using the position information and the moving speed information, a method using an open angle into a certain cell as viewed from the wireless terminal device (STA), the number of adjacent cells, etc. is also applied. Is possible.

  For example, as shown in FIG. 4, two straight lines (a, b) passing through the center (O) of the wireless terminal device (STA) and in contact with the outer periphery of the cell (cell 2) can be considered. ) Is an angle (θ) formed by the two straight lines (a, b). If the angle (θ) is large, it is preferable to calculate so as to increase the movement probability.

  In addition, the number of adjacent cells is the number of cells adjacent to the cell where the wireless terminal device (STA) is currently present. If the number of adjacent cells is large, calculation is performed so that the movement probability per cell is small. Is preferred. That is, if there are many neighboring cells, the number of cells that the wireless terminal apparatus (STA) may move increases, and the movement probability per cell decreases.

  In addition, the calculation method of a movement probability can apply various methods according to the request | requirement of a system, It is not limited to the method mentioned above, It is constructed so that a movement probability may be calculated in consideration of all conditions. It is possible.

  Next, the resource management device (2) confirms the used resources used by the wireless terminal device (STA) that is in a call via the second wireless base station (AP2) (step S3). Further, the resource management device (2) confirms the free resources of the second radio base station (AP2) (step S4).

  The method for confirming the wireless terminal device (STA) that is in a call via the second wireless base station (AP2) is performed using the same method as that for the first wireless base station (AP1) described above. It will be. Then, the resource management device (2) manages the resources used by the wireless terminal device (STA) that is in a call via the second wireless base station (AP2) in the resource information management unit (22). It will be. At this time, free resources of the second radio base station (AP2) are also managed by the resource information management unit (22).

  Next, the resource management device (2) determines allocation of free resources of the second radio base station (AP2) (step S5).

  Note that a resource for handover call requesting a call connection to the second radio base station (AP2) and a new call connection request to the second radio base station (AP2) other than the handover call are provided. The resource allocation determination for the call resource is performed by the free resource allocation determination unit (26).

  In the present embodiment, the resources for handover calls are used only for handover calls, and the resources for new calls are used only for new calls. The resource allocation is preferably determined such that the sum of the call loss rate of the handover call and the call loss rate of the new call is minimized.

  When obtaining the minimum value of the sum of the call loss rates, for example, the handover call loss rate is weighted so that priority is given to the allocation of resources for handover calls, and then the handover call for which weighting is performed. It is also possible to determine such that the sum of the call loss rate of the new call and the call loss rate of the new call is minimized. In addition, the weight of the call loss rate of the new call is weighted so that priority is given to the allocation of resources for the new call, and the sum of the call loss rate of the handover call and the call loss rate of the weighted new call is minimized. It is also possible to determine as follows. It is also possible to weight both call loss rates.

  Further, instead of determining the sum of the call loss rates to be minimum, it is also possible to determine the sum of the call loss rates to be a predetermined value or less. In this case, it is preferable to construct so that the predetermined value can be arbitrarily changed.

  Next, the processing from step S1 to step S5 described above is executed at an information update time: Δt interval (step S6). As a result, the distribution determination operation is performed at intervals of information update time: Δt.

  The information update time: Δt can be arbitrarily changed. For example, the information update time: Δt is arbitrarily determined for each system according to the movement change amount of the wireless terminal device (STA), the amount of traffic, and the like. Will do.

<Detailed Algorithm for Allocation Determination in Step S5 of FIG. 3>
Next, a detailed algorithm for determining the distribution in step S5 shown in FIG. 3 will be described with reference to FIG.

For example, it is assumed that the sum of call loss rates: f (M, p ₁ , p ₂ ,..., P _n ) is expressed by the following equation (1).

Formula (1)
f (M, p ₁ , p ₂ ,..., p _n ) = w1 · B1 (M, p ₁ , p ₂ , ..., p _n ) + (1-w1) · B2 (M), w1 = 0 to 1

Where w1 is a weight for determining the priority of resource allocation, B1 (M, p ₁ , p ₂ ,..., P _n ) is a handover call loss rate, B2 (M) is a new call loss rate, and M is for handover call. Free resource allocation

The call loss rate is a function of M and the movement probability p. In the following description, f (M, p ₁ , p ₂ ,..., P _n ) = f (M, P), B1 (M, p ₁ , p ₂ , ..., p _n ) = B ₁ (M, P P).

  First, the value of w1 is determined based on the wireless communication service policy (step S10).

  Next, an initial value is substituted (step S11). In this embodiment, M = 0 and g = 10000 are substituted as initial values.

  The granularity of M is the number of calls. G is a variable to which the sum of call loss rates is substituted, and a large value is arbitrarily substituted as an initial value.

  Next, using the probability of movement from the first cell (cell 1) to the second cell (cell 2), the call loss rate B1 (M, P) of the handover call when the allocation amount for handover calls is M Calculate (step S12).

  Next, a call loss rate B2 (M) of a new call is calculated (step S13). In this embodiment, the new call occurrence distribution is assumed to be a Poisson distribution.

  Next, in consideration of the value of w1 determined in step S10, the total call loss rate: f (M, P) = w1 · B1 (M, P) + (1−w1) · B2 (M) is calculated ( Step S14).

  Next, f (M, P) and g are compared (step S15). If f (M, P) <g (step S15 / Yes), f (M, P) is substituted for g, and h “G = f (M, P), h = M” is substituted for M (step S16).

  Note that h is a variable to which M is substituted when f (M, P) is substituted for g. Finally, when the sum of the call loss rate of the handover call and the call loss rate of the new call is minimum, This is the value of the resource allocation amount for handover calls.

  If f (M, P) ≧ g (step S15 / No), no processing is performed.

  Next, it is determined whether or not M = L (step S17). Note that L is the amount of free resources of the second radio base station (AP2).

  According to the above determination, if M = L (step S17 / Yes), h assigned in step S16 is the resource allocation amount for the handover call for minimizing the sum of the call loss rate of the handover call and the call loss rate of the new call. (Step S18).

  If M ≠ L (step S17 / No), M = M + 1 is set (step S19), the process proceeds to S12, and the above-described processing is repeated.

  Note that the above-described algorithm is an example, and is not limited to the above processing, and any algorithm can be applied as long as the allocation determination in step S5 can be performed.

  FIG. 6 shows the resource allocation amount determined by the above-described method of the present embodiment and the resource allocation amount determined by the conventional method.

  Note that FIG. 6 shows a case where the resource allocation amount of the handover call resource and the new call resource is determined by the above-described method of the present embodiment (a) and the conventional method (Patent Document 1, etc.). The comparison with the case (b) determined by the above method) is shown.

  The resource allocation amount determined by the method of the present embodiment shown in FIG. 6A is such that the resource allocation M for handover calls and the new call are such that the sum of the call loss rate for handover calls and the call loss rate for new calls is minimized. This is a result of determining the resource allocation LM.

  Note that, as shown in FIG. 6B, the resource allocation amount determined by the conventional method (the method of Patent Document 1 or the like) secures resources for all calls that may be handed over. There is a possibility that the call loss rate of calls will be significantly increased, and if there are terminals that do not actually perform handover, resources for handover calls will be wasted. As a result, it is assumed that the sum of the call loss rate of the handover call and the call loss rate of the new call is not the minimum.

  FIG. 7 also shows that the resource management device (2) re-acquires location information and movement speed information of the wireless terminal device (STA), recalculates the movement probability between cells, The timing for re-determining resource allocation of free resources other than used resources by STA) is shown.

  As shown in FIG. 7, resource allocation redetermination processing is performed at Δt intervals, and thereafter, call admission control for handover calls and new calls is performed based on the determined resource allocation.

  In addition, when the call accepted in the resource management device (2) is terminated between, for example, Δt and 2Δt, the reflection of the free resource by the termination call is performed in 2Δt. It is also possible to apply a method in which redistribution is determined by reflecting it as a free resource at the timing when the resource management device (2) detects a call termination.

  Further, when the resource management device (2) detects the end call, it is reflected as a free resource, and a resource for performing call connection when a handover call or a new call newly requests a call connection. A method of connecting a connection request call using a free resource due to an end call when the call is insufficient is also applicable.

  As described above, the resource management device (2) in the present embodiment enables the wireless terminal device (STA) to start a call via the wireless base station (AP) existing under the management of the resource management device (2). When the call control information collection unit (20) receives the transmitted call connection request signal, the call admission control unit (21) can secure resources necessary for the call connection request call to start a call. The resource information management unit (22) confirms whether or not the resource can be secured, and the call admission control unit (21) notifies the wireless terminal device (STA) of call connection permission. Thereby, a telephone call is started.

  In addition, when the call control information collection unit (20) receives a call termination signal for the wireless terminal device (STA) that is talking to finish the call, the call that terminates the call through the call admission control unit (21). The resource reserved for the purpose is released in the resource information management unit (22).

  For this reason, the resource management device (2) in the present embodiment collects information on the start and end of calls of the wireless terminal device (STA) and manages the resources of the wireless base station (AP) based on the collected information. Therefore, the resource management device (2) determines the presence of a wireless terminal device (STA) that is in a call via the wireless base station (AP) that exists under the management of the resource management device (2). It becomes possible to confirm.

  Further, the resource management device (2) collects the location information of the wireless terminal device (STA) that is in a call via the wireless base station (AP) existing under the management of the resource management device (2), The moving speed information of the wireless terminal device (STA) that is collecting in the unit (23) is collected in the terminal moving speed information collecting unit (24), and based on the collected position information and moving speed information. In addition, a cell movement probability calculation unit (25) calculates a movement probability that the wireless terminal apparatus (STA) may move from a cell that currently exists to another cell.

  Then, the resource management device (2) is based on the movement probability calculated by the cell movement probability calculation unit (25) and the free resources of the radio base station (AP) managed by the resource information management unit (22). The free resource allocation determining unit (26) determines the resource allocation between the resources allocated for the handover call and the resources allocated for the new call in each radio base station (AP), and the determined resource allocation is The resource information management unit (22) manages it.

  When a call connection request for a handover call is made, it is determined whether or not resources for the call connection request call can be secured by referring to the resource allocation allocated for the handover call.

  Further, when a call connection request for a new call is made, it is determined whether or not resources for the call connection request call can be secured by referring to the resource allocation allocated for the new call.

  For this reason, according to the resource management apparatus (2) of the present embodiment, in the radio base station (AP) of the cell having a high movement probability, a large number of resources are secured and the radio base station (AP) of the cell having a low movement probability. In this case, it is possible to secure a small number of resources. Therefore, it is possible to increase the probability of communication continuity of the wireless terminal device (STA) and reduce the amount of unnecessary resources secured.

  Further, according to the resource management device (2) of the present embodiment, in the radio base station (AP) according to the movement probability that the radio terminal device (STA) may move to the radio base station (AP). Since the amount of resources to be secured is determined, the amount of resources to be secured does not become 0 unless the movement probability is 0. Therefore, the probability of communication continuity of the wireless terminal apparatus (STA) can be increased. . Therefore, it is possible to increase the probability of communication continuity of the wireless terminal device (STA) at the time of handover regardless of where the wireless terminal device (STA) is in the cell.

  In addition, according to the resource management device (2) of the present embodiment, the weighting for determining the priority between the call loss rate (disconnection rate) of the handover call and the call loss rate of the new call is performed, and then for the handover call and the new call. Therefore, it is possible to adjust the call loss rate of the handover call and the call loss rate of the new call.

(Second Embodiment)
Next, a second embodiment will be described.

  The resource management device (2) of the first embodiment secures in the radio base station (AP) according to the movement probability that the radio terminal device (STA) may move to the radio base station (AP). The amount of resources to be determined is determined and allocated to a handover call resource and a new call resource. The handover call resource is used only for the handover call, and the new call resource is used only for the new call. Decided to use.

  The resource management device (2) of the second embodiment secures in the radio base station (AP) according to the movement probability that the radio terminal device (STA) may move to the radio base station (AP). The amount of resources to be determined, and allocated to resources for handover calls and competing resources that can be used for both handover calls and new calls, and resources for handover calls are used for handover calls, The contention resource is used for a handover call and a new call.

  This makes it possible to use the contention resource for the handover call when the resources for the handover call are insufficient, thereby further reducing the call loss rate for the handover call, that is, the call disconnection during the call. It becomes possible. Hereinafter, the resource management device (2) of the second embodiment will be described with reference to FIG.

  For example, as shown in FIG. 8, the resource management device (2) in the second embodiment includes a resource allocation M for handover calls in which free resources of a radio base station (AP) are allocated only to handover calls, and handover It is distributed to a competing resource allocation LM that can be used for both calls and new calls.

  Also in this case, as in the first embodiment, the total call loss rate of the handover call and the new call is minimized by the free resource allocation determination unit (26) of the resource management device (2). In addition, it is preferable to determine resource allocation.

  In the determination method shown in FIG. 8, when there is a call connection request for a handover call and there are insufficient free resources for the handover call, it is used for both the handover call and the new call. If there is an available contention resource, it becomes possible to permit call connection of a handover call using the available resource. As a result, the call loss rate for the handover call, that is, the call disconnection during a call can be further reduced.

  Next, examples of the above-described wireless communication system of the present embodiment will be described.

(First embodiment)
First, the first embodiment will be described with reference to FIGS.

  In the first embodiment, as shown in FIG. 9, the wireless terminal device (30) performs call connection for a new call with the opposite wireless terminal device (31) via the second wireless base station (AP2). The processing operation in this case will be described.

  First, the resource management device (2) collects the position information and the moving speed information of the wireless terminal device (STA) that is talking over the first wireless base station (AP1) (step S20). The movement probability of moving from the cell (cell 1) of the radio base station (AP1) to the cell (cell 2) of the second radio base station (AP2) is calculated (step S21).

  Next, the resource management device (2) confirms an available resource in the second radio base station (AP2) (step S22).

  Next, the resource management device (2) uses the probability of movement of the second radio base station (AP2) to the cell (cell 2) to perform handover for the free resources in the second radio base station (AP2). The allocation of the resources allocated for calls and the resources allocated for new calls is determined (step S23).

  In addition, a series of processes from step S21 to step S23 described above are periodically performed.

  Next, since the wireless terminal device (30) starts a call with the opposite wireless terminal device (31), as shown in FIG. 9, the SIP (Session Initiation Protocol) server is passed through the second wireless base station (AP2). In response to (3), an INVITE message is transmitted (step S24).

  The SIP server (3) that has received the INVITE message transmits a new call connection request signal to the resource management device (2) (step S25).

  The resource management device (2) that has received the new call connection request signal makes a call connection determination with reference to the resource allocation for the new call of the free resource of the second radio base station (AP2) (step S26). . Then, if resources can be secured in the second radio base station (AP2), the resource management device (2) transmits a new call connection response signal permitting call connection to the SIP server (3) (step S27). .

  The SIP server (3) that has received the new call connection response signal permitting connection transfers the INVITE message to the opposite wireless terminal device (31) (step S28).

  As described above, a call between the wireless terminal device (30) and the opposite wireless terminal device (31) is started (step S29).

  As described above, the wireless terminal device (30) can perform call connection of a new call with the opposing wireless terminal device (31) via the second wireless base station (AP2).

(Second embodiment)
Next, a second embodiment will be described with reference to FIGS.

  In the second embodiment, as shown in FIG. 11, the wireless terminal device (32) in communication with the opposite wireless terminal device (31) is connected to the first wireless base station (AP1) via the first wireless base station (AP1). Move from the cell (cell 1) of the base station (AP1) to the cell (cell 2) of the second radio base station (AP2) and continue the call via the second radio base station (AP2) The processing operation will be described.

  First, the wireless terminal device (32) makes a call with the opposite wireless terminal device (31) via the first wireless base station (AP1) (step S40).

  The resource management device (2) collects the position information and the moving speed information of the wireless terminal device (STA) that is talking through the first wireless base station (AP1) (step S41), and the first wireless base station The movement probability of moving from the cell (cell 1) of the station (AP1) to the cell (cell 2) of the second radio base station (AP2) is calculated (step S42).

  Next, the resource management device (2) confirms a free resource in the second radio base station (AP2) (step S43).

  Next, the resource management device (2) uses the probability of movement of the second radio base station (AP2) to the cell (cell 2) to perform handover for the free resources in the second radio base station (AP2). The allocation of the resources allocated for calls and the resources allocated for new calls is determined (step S44).

  In addition, a series of processes from step S41 to step S44 described above are periodically performed.

  Next, as shown in FIG. 11, the wireless terminal device (32) moves to the cell (cell 2) of the second wireless base station (AP2), and passes through the second wireless base station (AP2). A handover call connection request signal is transmitted to the resource management device (2) (step S45).

  The resource management device (2) that has received the handover call connection request signal refers to the resource allocation for the handover call of the free resource of the second radio base station (AP2) and performs call connection determination (step S46). . Then, if resources can be secured in the second radio base station (AP2), the resource management device (2) transmits a handover call connection response signal permitting call connection to the radio terminal device (32) (step S47). ).

  The wireless terminal device (32) that has received the handover call connection response signal that permits connection continues the call with the opposite wireless terminal device (31) via the second wireless base station (AP2) (step S48). .

  In this way, the wireless terminal device (32) is connected to the cell (cell 1) of the first wireless base station (AP1) during a call with the opposite wireless terminal device (31) via the first wireless base station (AP1). ), It is possible to continue the call via the second radio base station (AP2) even when the cell moves to the cell (cell 2) of the second radio base station (AP2).

  The above-described embodiment is a preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiment alone, and various modifications are made without departing from the gist of the present invention. Implementation is possible.

  For example, in the first embodiment described above, the resource management device (2) determines that the radio base station (STA) corresponds to the radio base station (STA) according to the movement probability that the radio terminal device (STA) may move to the radio base station (AP). AP) determines the amount of resources to be secured and allocates resources for handover calls and for new calls. The resources for handover calls are used only for handover calls, and the resources for new calls are However, if there is a shortage of resources for a new call when there is a shortage of resources for a new call, the free resource for the new call is used for the handover call. It is also possible to make it. In addition, when there is a shortage of resources for a new call and there is a free resource for a handover call, the free resource for the handover call can be used for a new call.

  Further, the control operation performed by the resource management device (2) constituting the wireless communication system of the above-described embodiment can be configured to be performed by the wireless base station (AP). The system configuration shown in FIG. 13 is constructed.

  In addition, the control operation in the control devices such as the radio base station (AP), the radio terminal device (STA), and the resource management device (2) that configure the radio communication system of the above-described embodiment is not a hardware configuration, but a computer program or the like The above-mentioned program is recorded on a recording medium such as an optical recording medium, a magnetic recording medium, a magneto-optical recording medium, or a semiconductor, and the above-described program is recorded from the recording medium. It is also possible to cause each control device to execute the control operation described above by causing each control device to read it. Further, the control operation described above can be executed in each control device by causing the control device described above to read the program from an external device connected via a predetermined network.

  The resource management apparatus, the radio base station, the radio communication system, the resource management method, and the resource management program according to the present invention can be applied to a radio communication system that considers movement of a radio terminal apparatus indoors and outdoors.

It is a figure which shows the system configuration | structure of the radio | wireless communications system in this embodiment. It is a figure which shows the internal structure of the resource management apparatus (2) which comprises the radio | wireless communications system of this embodiment. It is a flowchart which shows a series of processing operation | movement until it determines free resource allocation. It is a figure which shows the open angle ((theta)) in the certain cell (cell 2) seen from the radio | wireless terminal apparatus (STA). It is a flowchart which shows the example of allocation determination algorithm of the free resource of step S5 shown in FIG. It is a figure which shows the comparative example of the example of free resource allocation by the method of this embodiment, and the example of allocation by the conventional method. It is a figure which shows the example which performs redetermination processing of free resource allocation at information update time: (DELTA) t interval. It is a figure which shows the example of the free resource allocation in 2nd Embodiment, and when the resource allocation for a handover call is insufficient, the example of the free resource allocation in the case where it configures to use the resource allocation for a new call FIG. It is a figure which shows the system configuration example for demonstrating one Example in the case of connecting a new call in the radio | wireless communications system of this embodiment. 10 is a sequence chart showing a processing operation when a new call is connected in the system configuration shown in FIG. 9. It is a figure which shows the system configuration example for demonstrating an Example at the time of connecting a handover call in the radio | wireless communications system of this embodiment. 12 is a sequence chart showing processing operations when a handover call is connected in the system configuration shown in FIG. FIG. 6 is a diagram for explaining a handover operation.

Explanation of symbols

AP radio base station STA radio terminal device NW network 2 resource management device 20 call control information collection unit 21 call admission control unit 22 resource information management unit 23 terminal location information collection unit 24 terminal movement speed information collection unit 25 cell movement probability calculation unit 26 Free resource allocation determination unit 3 SIP server 30, 32 Wireless terminal device 31 Opposite wireless terminal device

Claims (19)

A resource management device that manages resources required when performing wireless communication between a wireless terminal device and a wireless base station,
A resource management apparatus comprising resource determining means for determining an amount of the resource to be secured in the radio base station according to a movement probability that the radio terminal apparatus may move to the radio base station. The resource determination means includes
The resource management apparatus according to claim 1, wherein the resource amount is determined according to a call loss rate of the wireless terminal apparatus in the wireless base station. The resource determination means includes
The resource management apparatus according to claim 2, wherein the resource amount is determined so that the call loss rate is equal to or less than a predetermined value.   The amount of the resource is at least one of an amount of a resource for handover call of the wireless terminal device and an amount of a resource for new call of the wireless terminal device. The resource management device according to any one of the above.   5. The resource management apparatus according to claim 4, further comprising first adjusting means for adjusting distribution of the amount of resources for the handover call and the amount of resources for the new call.   5. The apparatus according to claim 4, further comprising second adjusting means for adjusting distribution of the amount of resources for the handover call and the amount of resources that can be shared for the handover call and the new call. 5. The resource management device according to 5. The adjusting means includes
The resource management apparatus according to claim 5 or 6, wherein the distribution is adjusted according to the call loss rate.   8. The call loss rate according to claim 2, wherein the call loss rate is at least one of a call loss rate at the time of handover of the wireless terminal device and a call loss rate at the time of a new call of the wireless terminal device. The resource management device described in 1. The adjusting means includes
The distribution is adjusted after weighting at least one of a call loss rate at the time of handover of the wireless terminal device and a call loss rate at the time of a new call of the wireless terminal device. 8. The resource management device according to 8. The resource determination means includes
The resource management apparatus according to claim 1, wherein the resource amount is determined at an arbitrary time interval.   The resource management apparatus according to any one of claims 1 to 10, wherein whether or not to permit a handover call connection is determined based on the amount of the resource.   12. The resource management apparatus according to claim 1, wherein whether or not to permit connection of a new call is determined based on the amount of the resource. A wireless base station that performs wireless communication with a wireless terminal device using resources necessary for wireless communication,
A radio base station comprising resource determining means for determining an amount of the resource to be secured in the radio base station according to a movement probability that the radio terminal apparatus may move to the radio base station. A wireless base station, a wireless base station that performs wireless communication with the wireless terminal device using resources necessary for wireless communication, and a resource management device that manages the resource. A wireless communication system,
The resource management device
A wireless communication system, comprising resource determining means for determining an amount of the resource to be secured in the wireless base station according to a movement probability that the wireless terminal device may move to the wireless base station. A wireless communication system comprising: a wireless terminal device; and a wireless base station that performs wireless communication with the wireless terminal device using resources necessary for wireless communication,
The radio base station is
A wireless communication system, comprising resource determining means for determining an amount of the resource to be secured in the wireless base station according to a movement probability that the wireless terminal device may move to the wireless base station. A resource management method performed by a resource management device that manages resources required when wireless communication is performed between a wireless terminal device and a wireless base station,
The resource management apparatus performs a resource determination step of determining an amount of the resource to be secured in the radio base station according to a movement probability that the radio terminal apparatus may move to the radio base station. To manage resources. A resource management method performed by a wireless base station that performs wireless communication with a wireless terminal device using resources necessary for wireless communication,
The radio base station performs a resource determination step of determining an amount of the resource to be secured in the radio base station according to a movement probability that the radio terminal device may move to the radio base station. To manage resources. A resource management program to be executed in a resource management device that manages resources required when performing wireless communication between a wireless terminal device and a wireless base station,
The resource management apparatus is caused to execute a resource determination process for determining an amount of the resource to be secured in the radio base station according to a movement probability that the radio terminal apparatus may move to the radio base station. Resource management program. A resource management program to be executed in a wireless base station that performs wireless communication with a wireless terminal device using resources necessary for wireless communication,
According to a movement probability that a wireless terminal device may move to a wireless base station, the wireless base station is caused to execute a resource determination process for determining an amount of the resource to be secured in the wireless base station. Resource management program.

Images